Slide 1

SUPER-3HC at ELETTRA Update
G.Penco, M.Svandrlik
• Operation
• Uptime
• Maintenance
• Performance vs filling

• Conclusions

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

1

Operation/Uptime/Maintenance/Performance vs Filling
• 3HC is routinely in operation during user’s shifts.
• Lifetime depends on ultimate vacuum conditioning and
filling pattern, highest value we can obtain is 27 hrs
(320 mA; 2.0 GeV)
• Filling pattern set to 96%
• During refill and energy ramping 3HC set at +94 kHz
(from 3rd harmonic) - Transverse Feedbacks ON
• Once beam is at 2.0 Gev 3HC is activated by tuning it at
+64 kHz

• Longitudinal Coupled Bunch Instabilities are cured by 3HC,
Transverse Instabilities are cured by Feedbacks.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

2

Operation/Uptime/Maintenance/Performance vs Filling
• The increase in Beam Lifetime obtained when 3HC is
active, allows us to refill ELETTRA every 36 hrs instead
of 24 hrs, as it used to be in the past.

3HC tuned:only 3 refills
in 5 days operation

How it was
before 3HC

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

3

Operation/Uptime/Maintenance/Performance vs Filling
• General uptime of the system is good. Since September
2003 only one event caused significant User’s downtime,
on Saturday, 31/01/2004.
Users' downtime caused by 3HC, in hours
30
25
20
15,8
15
10
5
0

0,0

0,0

0,0

0,0

0,6

0,0

RUN 85
RUN 86
RUN 87
RUN 88
RUN 89
RUN 90
RUN 91
AUG - SEP 03 SEP - OCT 03 NOV - DEC 03 JAN - FEB 04 MAR - APR 04 APR - MAG 04 JUN - JUL 04

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

4

Operation/Uptime/Maintenance/Performance vs Filling
• The event on 31/01/04 was related to a failure of a rough
pumping unit of the valve-box insulation vacuum. This was a
temporary installation, replaced during the next shutdown
with a fail-safe one.
• The uptime statistics does not include systems stops due to
electrical
power
interruptions,
mostly
caused
by
thunderstorms in the surroundings. In this case most
machine systems are stopped and the restart time of the
cryogenic plant is hidden in the general restart of the
systems. For this reason the idea of connecting 3HC to a new
UPS has not yet been implemented (also financial reasons).

• We still do not have a He recovery system, the experience
made so far shows that we can survive without it, not
affecting the uptime of the system.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

5

Operation/Uptime/Maintenance/Performance vs Filling
• Several important maintenance interventions have been
successfully performed in the last 12 months.
• In November 2003 the leaky gate valve between 3HC
and the superconducting wiggler was substituted.
This required to break
the cavity vacuum. A
clean area was therefore
created inside the
storage ring tunnel. The
replacement followed
clean room procedures
and was done by CEA
and Elettra staff.
The field performance of
the cavity has not been
affected by this
intervention.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

6

Operation/Uptime/Maintenance/Performance vs Filling
• In December 2003 the tuning system of cell 1 failed for
the 2nd time (1st time in March). In January 2004 the tuning
system was replaced with an upgraded version.
• The tuning system is under vacuum, at cold. The gear box
was found to be blocked.
• Tests at Saclay showed that the reason could be a heating
problem (from the motor).
• Even if the number of cycles
after which this shows up is
huge, we are limiting the
movements of the system.
• No problem since January 04
• CEA is studying a solution to
move the motor outside the
cryomodule.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

7

Operation/Uptime/Maintenance/Performance vs Filling

• During the January shutdown the cryogenic plant annual
maintenance was performed.
• After this maintenance the nominal performance is back to
the original, i.e. about 30-35 litres/hour at 13 bar of HP.
• In August 2004 the cryomodule has been warmed-up again
in order to replace a coaxial cable which takes out the
voltage signal of cell 2.
• In this occasion also the fundamental mode rejection of the
dipolar HOM couplers has been improved. In fact on one of
them some over-heating effects were observed when tuning
the cell.

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

8

Operation/Uptime/Maintenance/Performance vs Filling
• ELETTRA used to operate with a partial filling of the bunch
train: typically a 10% empty gap was present.

• As well known, with such a gap the passive third harmonic
cavity induces a phase modulation over the bunch train.
• Several STREAK CAMERA experiments were performed for
various fillings, measuring the effect on:
– Phase Shift
– Bunch lengthening
– Landau Damping

– Beam Lifetime

• As a result, a new optimum filling was set for operations.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

9

80% Filling: Phase Shift/Bunch Length/Landau/Lifetime
Phase Shift along the train for different tuning
60

Ibeam=315mA,
Filling at 80%

Relative Phase (Deg)

50
40
1499,070 MHz
1499,060 MHz

30

1499,050 MHz
1499,025 MHz

20

Bunch length along the train for different tuning
1499,070 MHz

1499,020 MHz
1499,015 MHz

10
1499,060 MHz
600
700
800

RMS Bunch Length (ps)

90

1499,050 MHz

80

900

1000

1100

1200

1300

1400

Bunch position in the train (ps)

1499,025 MHz

70

1499,020 MHz

60

1499,015 MHz

50
40
30
700

900
1100
1300
Bunch position in the train (ps)

1500

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

10

1500

100% Filling: Phase Shift/Bunch Length/Landau/Lifetime

Relative Phase (Deg)

Ibeam=315mA,
Uniform Filling

Bunch length along the train for different tuning
1499,050 MHz
1499,025 MHz

RMS Bunch Length (ps)

200
180

1499,040 MHz
1499,020 MHz

1499,030 MHz
1499,015 MHz

Phase Shift along the train for different tuning

50
45
40
35
30
25
20
15
10

1499,040 MHz

1499,030 MHz
1499,020 MHz

1499,025 MHz
1499,015 MHz

1499,014 MHz
0

1499,014 MHz

160

1499,050 MHz

200

400

600

800

Bunch position in the train (ps)

Bunch overstretching

140
120
100
80
60
40
20
0

200

400

600

Bunch position in the train (ps)

800

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

11

100% Filling: Phase Shift/Bunch Length/Landau/Lifetime
The Bunch Profile Averaged on the bunch train in the case of Uniform
Filling is shown below for different tuning positions of 3HC. The “nominal
tuning” of 3HC would be around +75 kHz. Beyond this postion the Bunch

begins to show an overstreched profile. Beam Lifetime increases until the
position of +62 kHz, which is the operating position. A few kHz beyond that,
lifetime starts to decay to a few hours; further the beam is lost.
Df= +92 kHz

Df= +82 kHz

Df= +72 kHz

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

Df= +62 kHz

12

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime

Deg

Phase Shift along the bunch train

45

Uniform Filling
Filling at 98%
Filling at 96%
Filling at 90%
Filling at 80%
Filling at 70%

40
35
30
25
20
15
10
5
0

1499.010 1499.015 1499.020 1499.025 1499.030 1499.035 1499.040 1499.045 1499.050 1499.055 1499.060 1499.065 1499.070

3HC Frequency (MHz)

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

13

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime

Bunch length along the train

<> (ps)
140

Filling at 70%
Filling at 80%
Filling at 90%
Filling at 96%
Filling at 98%
Uniform Filling

130
120
110
100
90
80
70
60
50
40
30
1499.010

1499.015

1499.020

1499.025

1499.030

1499.035

1499.040

1499.045

1499.050

1499.055

1499.060

1499.065

1499.070

3HC Frequency (MHz)

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

14

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
The Landau damping seems to be influenced by the different contribution of the
increasing gap width and of the average bunch length, which is reduced as the
gap increases.

Scale is
different!

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

15

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
These strak camera images show the different effect of 3HC on the beam
between 90% filling (on the left) and uniform filling (on the right). The Landau
damping effect is similar in both cases, the 90% filling shows the expected effect
of the phase modulation along th ebunch train.
Phase
Modulation
present.
Stronger
Phase
Modulation
Bunches are
longer in the
train centre.

Df= +112 kHz

Longitudinal
UNSTABLE
Beam

Df= +92 kHz

Longitudinal
STABLE
Beam
Bunch
Length is
Uniform

Df= +62 kHz

90% Filling

Uniform Filling

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

16

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
The best performance in terms of lifetime is obtained with a fractional filling of 96%. By
further increasing the filling, the maximum obtained lifetime is lower, suggesting that the
optimum setting for ELETTRA requires a small amount of “empty gap”.
The 96% filling is now taken as the new standard filling pattern for User’s Operation
Mode (320mA, 2.0GeV). In this condition 3HC is usually tuned from 1499.050 MHz
(Df=92kHz) to 1499.020MHz (Df=62kHz).

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

17

Machine Upgrades and Ultimate Lifetime Value
During 2003 and 2004 several new vacuum
chamber installations were performed. In June
2003 a new Aluminum-NEG coated chamber
was installed in section ID10. In pre-3HC
conditions the nominal lifetime was recovered at
a dynamic pressure of about 10-11 mbar/mA. In
the example of the ID10 chamber this took
about 70 Ah, i.e. about 2,5 weeks operation.

In fact the ultimate lifetime with 3HC
active, i.e. about 27 hours at 2.0
GeV 320 mA, was reached mid of
September 2003, that is about 6
weeks of operation after the ID10
installation (there were 2 weeks
shutdown in August).
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

18

Conclusions
• 3HC routinely in operation at Elettra
• Stable Beam, refill every 36 hours
• Operability and Reliability good
• Careful maintenance to prevent
faults, recovery time can be long!
• Experiments at different fillings
confirm expected effects (phase
modulation, bunch lengthening)
• New standard filling set to 96%
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

19


Slide 2

SUPER-3HC at ELETTRA Update
G.Penco, M.Svandrlik
• Operation
• Uptime
• Maintenance
• Performance vs filling

• Conclusions

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

1

Operation/Uptime/Maintenance/Performance vs Filling
• 3HC is routinely in operation during user’s shifts.
• Lifetime depends on ultimate vacuum conditioning and
filling pattern, highest value we can obtain is 27 hrs
(320 mA; 2.0 GeV)
• Filling pattern set to 96%
• During refill and energy ramping 3HC set at +94 kHz
(from 3rd harmonic) - Transverse Feedbacks ON
• Once beam is at 2.0 Gev 3HC is activated by tuning it at
+64 kHz

• Longitudinal Coupled Bunch Instabilities are cured by 3HC,
Transverse Instabilities are cured by Feedbacks.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

2

Operation/Uptime/Maintenance/Performance vs Filling
• The increase in Beam Lifetime obtained when 3HC is
active, allows us to refill ELETTRA every 36 hrs instead
of 24 hrs, as it used to be in the past.

3HC tuned:only 3 refills
in 5 days operation

How it was
before 3HC

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

3

Operation/Uptime/Maintenance/Performance vs Filling
• General uptime of the system is good. Since September
2003 only one event caused significant User’s downtime,
on Saturday, 31/01/2004.
Users' downtime caused by 3HC, in hours
30
25
20
15,8
15
10
5
0

0,0

0,0

0,0

0,0

0,6

0,0

RUN 85
RUN 86
RUN 87
RUN 88
RUN 89
RUN 90
RUN 91
AUG - SEP 03 SEP - OCT 03 NOV - DEC 03 JAN - FEB 04 MAR - APR 04 APR - MAG 04 JUN - JUL 04

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

4

Operation/Uptime/Maintenance/Performance vs Filling
• The event on 31/01/04 was related to a failure of a rough
pumping unit of the valve-box insulation vacuum. This was a
temporary installation, replaced during the next shutdown
with a fail-safe one.
• The uptime statistics does not include systems stops due to
electrical
power
interruptions,
mostly
caused
by
thunderstorms in the surroundings. In this case most
machine systems are stopped and the restart time of the
cryogenic plant is hidden in the general restart of the
systems. For this reason the idea of connecting 3HC to a new
UPS has not yet been implemented (also financial reasons).

• We still do not have a He recovery system, the experience
made so far shows that we can survive without it, not
affecting the uptime of the system.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

5

Operation/Uptime/Maintenance/Performance vs Filling
• Several important maintenance interventions have been
successfully performed in the last 12 months.
• In November 2003 the leaky gate valve between 3HC
and the superconducting wiggler was substituted.
This required to break
the cavity vacuum. A
clean area was therefore
created inside the
storage ring tunnel. The
replacement followed
clean room procedures
and was done by CEA
and Elettra staff.
The field performance of
the cavity has not been
affected by this
intervention.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

6

Operation/Uptime/Maintenance/Performance vs Filling
• In December 2003 the tuning system of cell 1 failed for
the 2nd time (1st time in March). In January 2004 the tuning
system was replaced with an upgraded version.
• The tuning system is under vacuum, at cold. The gear box
was found to be blocked.
• Tests at Saclay showed that the reason could be a heating
problem (from the motor).
• Even if the number of cycles
after which this shows up is
huge, we are limiting the
movements of the system.
• No problem since January 04
• CEA is studying a solution to
move the motor outside the
cryomodule.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

7

Operation/Uptime/Maintenance/Performance vs Filling

• During the January shutdown the cryogenic plant annual
maintenance was performed.
• After this maintenance the nominal performance is back to
the original, i.e. about 30-35 litres/hour at 13 bar of HP.
• In August 2004 the cryomodule has been warmed-up again
in order to replace a coaxial cable which takes out the
voltage signal of cell 2.
• In this occasion also the fundamental mode rejection of the
dipolar HOM couplers has been improved. In fact on one of
them some over-heating effects were observed when tuning
the cell.

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

8

Operation/Uptime/Maintenance/Performance vs Filling
• ELETTRA used to operate with a partial filling of the bunch
train: typically a 10% empty gap was present.

• As well known, with such a gap the passive third harmonic
cavity induces a phase modulation over the bunch train.
• Several STREAK CAMERA experiments were performed for
various fillings, measuring the effect on:
– Phase Shift
– Bunch lengthening
– Landau Damping

– Beam Lifetime

• As a result, a new optimum filling was set for operations.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

9

80% Filling: Phase Shift/Bunch Length/Landau/Lifetime
Phase Shift along the train for different tuning
60

Ibeam=315mA,
Filling at 80%

Relative Phase (Deg)

50
40
1499,070 MHz
1499,060 MHz

30

1499,050 MHz
1499,025 MHz

20

Bunch length along the train for different tuning
1499,070 MHz

1499,020 MHz
1499,015 MHz

10
1499,060 MHz
600
700
800

RMS Bunch Length (ps)

90

1499,050 MHz

80

900

1000

1100

1200

1300

1400

Bunch position in the train (ps)

1499,025 MHz

70

1499,020 MHz

60

1499,015 MHz

50
40
30
700

900
1100
1300
Bunch position in the train (ps)

1500

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

10

1500

100% Filling: Phase Shift/Bunch Length/Landau/Lifetime

Relative Phase (Deg)

Ibeam=315mA,
Uniform Filling

Bunch length along the train for different tuning
1499,050 MHz
1499,025 MHz

RMS Bunch Length (ps)

200
180

1499,040 MHz
1499,020 MHz

1499,030 MHz
1499,015 MHz

Phase Shift along the train for different tuning

50
45
40
35
30
25
20
15
10

1499,040 MHz

1499,030 MHz
1499,020 MHz

1499,025 MHz
1499,015 MHz

1499,014 MHz
0

1499,014 MHz

160

1499,050 MHz

200

400

600

800

Bunch position in the train (ps)

Bunch overstretching

140
120
100
80
60
40
20
0

200

400

600

Bunch position in the train (ps)

800

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

11

100% Filling: Phase Shift/Bunch Length/Landau/Lifetime
The Bunch Profile Averaged on the bunch train in the case of Uniform
Filling is shown below for different tuning positions of 3HC. The “nominal
tuning” of 3HC would be around +75 kHz. Beyond this postion the Bunch

begins to show an overstreched profile. Beam Lifetime increases until the
position of +62 kHz, which is the operating position. A few kHz beyond that,
lifetime starts to decay to a few hours; further the beam is lost.
Df= +92 kHz

Df= +82 kHz

Df= +72 kHz

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

Df= +62 kHz

12

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime

Deg

Phase Shift along the bunch train

45

Uniform Filling
Filling at 98%
Filling at 96%
Filling at 90%
Filling at 80%
Filling at 70%

40
35
30
25
20
15
10
5
0

1499.010 1499.015 1499.020 1499.025 1499.030 1499.035 1499.040 1499.045 1499.050 1499.055 1499.060 1499.065 1499.070

3HC Frequency (MHz)

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

13

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime

Bunch length along the train

<> (ps)
140

Filling at 70%
Filling at 80%
Filling at 90%
Filling at 96%
Filling at 98%
Uniform Filling

130
120
110
100
90
80
70
60
50
40
30
1499.010

1499.015

1499.020

1499.025

1499.030

1499.035

1499.040

1499.045

1499.050

1499.055

1499.060

1499.065

1499.070

3HC Frequency (MHz)

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

14

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
The Landau damping seems to be influenced by the different contribution of the
increasing gap width and of the average bunch length, which is reduced as the
gap increases.

Scale is
different!

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

15

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
These strak camera images show the different effect of 3HC on the beam
between 90% filling (on the left) and uniform filling (on the right). The Landau
damping effect is similar in both cases, the 90% filling shows the expected effect
of the phase modulation along th ebunch train.
Phase
Modulation
present.
Stronger
Phase
Modulation
Bunches are
longer in the
train centre.

Df= +112 kHz

Longitudinal
UNSTABLE
Beam

Df= +92 kHz

Longitudinal
STABLE
Beam
Bunch
Length is
Uniform

Df= +62 kHz

90% Filling

Uniform Filling

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

16

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
The best performance in terms of lifetime is obtained with a fractional filling of 96%. By
further increasing the filling, the maximum obtained lifetime is lower, suggesting that the
optimum setting for ELETTRA requires a small amount of “empty gap”.
The 96% filling is now taken as the new standard filling pattern for User’s Operation
Mode (320mA, 2.0GeV). In this condition 3HC is usually tuned from 1499.050 MHz
(Df=92kHz) to 1499.020MHz (Df=62kHz).

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

17

Machine Upgrades and Ultimate Lifetime Value
During 2003 and 2004 several new vacuum
chamber installations were performed. In June
2003 a new Aluminum-NEG coated chamber
was installed in section ID10. In pre-3HC
conditions the nominal lifetime was recovered at
a dynamic pressure of about 10-11 mbar/mA. In
the example of the ID10 chamber this took
about 70 Ah, i.e. about 2,5 weeks operation.

In fact the ultimate lifetime with 3HC
active, i.e. about 27 hours at 2.0
GeV 320 mA, was reached mid of
September 2003, that is about 6
weeks of operation after the ID10
installation (there were 2 weeks
shutdown in August).
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

18

Conclusions
• 3HC routinely in operation at Elettra
• Stable Beam, refill every 36 hours
• Operability and Reliability good
• Careful maintenance to prevent
faults, recovery time can be long!
• Experiments at different fillings
confirm expected effects (phase
modulation, bunch lengthening)
• New standard filling set to 96%
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

19


Slide 3

SUPER-3HC at ELETTRA Update
G.Penco, M.Svandrlik
• Operation
• Uptime
• Maintenance
• Performance vs filling

• Conclusions

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

1

Operation/Uptime/Maintenance/Performance vs Filling
• 3HC is routinely in operation during user’s shifts.
• Lifetime depends on ultimate vacuum conditioning and
filling pattern, highest value we can obtain is 27 hrs
(320 mA; 2.0 GeV)
• Filling pattern set to 96%
• During refill and energy ramping 3HC set at +94 kHz
(from 3rd harmonic) - Transverse Feedbacks ON
• Once beam is at 2.0 Gev 3HC is activated by tuning it at
+64 kHz

• Longitudinal Coupled Bunch Instabilities are cured by 3HC,
Transverse Instabilities are cured by Feedbacks.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

2

Operation/Uptime/Maintenance/Performance vs Filling
• The increase in Beam Lifetime obtained when 3HC is
active, allows us to refill ELETTRA every 36 hrs instead
of 24 hrs, as it used to be in the past.

3HC tuned:only 3 refills
in 5 days operation

How it was
before 3HC

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

3

Operation/Uptime/Maintenance/Performance vs Filling
• General uptime of the system is good. Since September
2003 only one event caused significant User’s downtime,
on Saturday, 31/01/2004.
Users' downtime caused by 3HC, in hours
30
25
20
15,8
15
10
5
0

0,0

0,0

0,0

0,0

0,6

0,0

RUN 85
RUN 86
RUN 87
RUN 88
RUN 89
RUN 90
RUN 91
AUG - SEP 03 SEP - OCT 03 NOV - DEC 03 JAN - FEB 04 MAR - APR 04 APR - MAG 04 JUN - JUL 04

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

4

Operation/Uptime/Maintenance/Performance vs Filling
• The event on 31/01/04 was related to a failure of a rough
pumping unit of the valve-box insulation vacuum. This was a
temporary installation, replaced during the next shutdown
with a fail-safe one.
• The uptime statistics does not include systems stops due to
electrical
power
interruptions,
mostly
caused
by
thunderstorms in the surroundings. In this case most
machine systems are stopped and the restart time of the
cryogenic plant is hidden in the general restart of the
systems. For this reason the idea of connecting 3HC to a new
UPS has not yet been implemented (also financial reasons).

• We still do not have a He recovery system, the experience
made so far shows that we can survive without it, not
affecting the uptime of the system.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

5

Operation/Uptime/Maintenance/Performance vs Filling
• Several important maintenance interventions have been
successfully performed in the last 12 months.
• In November 2003 the leaky gate valve between 3HC
and the superconducting wiggler was substituted.
This required to break
the cavity vacuum. A
clean area was therefore
created inside the
storage ring tunnel. The
replacement followed
clean room procedures
and was done by CEA
and Elettra staff.
The field performance of
the cavity has not been
affected by this
intervention.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

6

Operation/Uptime/Maintenance/Performance vs Filling
• In December 2003 the tuning system of cell 1 failed for
the 2nd time (1st time in March). In January 2004 the tuning
system was replaced with an upgraded version.
• The tuning system is under vacuum, at cold. The gear box
was found to be blocked.
• Tests at Saclay showed that the reason could be a heating
problem (from the motor).
• Even if the number of cycles
after which this shows up is
huge, we are limiting the
movements of the system.
• No problem since January 04
• CEA is studying a solution to
move the motor outside the
cryomodule.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

7

Operation/Uptime/Maintenance/Performance vs Filling

• During the January shutdown the cryogenic plant annual
maintenance was performed.
• After this maintenance the nominal performance is back to
the original, i.e. about 30-35 litres/hour at 13 bar of HP.
• In August 2004 the cryomodule has been warmed-up again
in order to replace a coaxial cable which takes out the
voltage signal of cell 2.
• In this occasion also the fundamental mode rejection of the
dipolar HOM couplers has been improved. In fact on one of
them some over-heating effects were observed when tuning
the cell.

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

8

Operation/Uptime/Maintenance/Performance vs Filling
• ELETTRA used to operate with a partial filling of the bunch
train: typically a 10% empty gap was present.

• As well known, with such a gap the passive third harmonic
cavity induces a phase modulation over the bunch train.
• Several STREAK CAMERA experiments were performed for
various fillings, measuring the effect on:
– Phase Shift
– Bunch lengthening
– Landau Damping

– Beam Lifetime

• As a result, a new optimum filling was set for operations.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

9

80% Filling: Phase Shift/Bunch Length/Landau/Lifetime
Phase Shift along the train for different tuning
60

Ibeam=315mA,
Filling at 80%

Relative Phase (Deg)

50
40
1499,070 MHz
1499,060 MHz

30

1499,050 MHz
1499,025 MHz

20

Bunch length along the train for different tuning
1499,070 MHz

1499,020 MHz
1499,015 MHz

10
1499,060 MHz
600
700
800

RMS Bunch Length (ps)

90

1499,050 MHz

80

900

1000

1100

1200

1300

1400

Bunch position in the train (ps)

1499,025 MHz

70

1499,020 MHz

60

1499,015 MHz

50
40
30
700

900
1100
1300
Bunch position in the train (ps)

1500

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

10

1500

100% Filling: Phase Shift/Bunch Length/Landau/Lifetime

Relative Phase (Deg)

Ibeam=315mA,
Uniform Filling

Bunch length along the train for different tuning
1499,050 MHz
1499,025 MHz

RMS Bunch Length (ps)

200
180

1499,040 MHz
1499,020 MHz

1499,030 MHz
1499,015 MHz

Phase Shift along the train for different tuning

50
45
40
35
30
25
20
15
10

1499,040 MHz

1499,030 MHz
1499,020 MHz

1499,025 MHz
1499,015 MHz

1499,014 MHz
0

1499,014 MHz

160

1499,050 MHz

200

400

600

800

Bunch position in the train (ps)

Bunch overstretching

140
120
100
80
60
40
20
0

200

400

600

Bunch position in the train (ps)

800

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

11

100% Filling: Phase Shift/Bunch Length/Landau/Lifetime
The Bunch Profile Averaged on the bunch train in the case of Uniform
Filling is shown below for different tuning positions of 3HC. The “nominal
tuning” of 3HC would be around +75 kHz. Beyond this postion the Bunch

begins to show an overstreched profile. Beam Lifetime increases until the
position of +62 kHz, which is the operating position. A few kHz beyond that,
lifetime starts to decay to a few hours; further the beam is lost.
Df= +92 kHz

Df= +82 kHz

Df= +72 kHz

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

Df= +62 kHz

12

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime

Deg

Phase Shift along the bunch train

45

Uniform Filling
Filling at 98%
Filling at 96%
Filling at 90%
Filling at 80%
Filling at 70%

40
35
30
25
20
15
10
5
0

1499.010 1499.015 1499.020 1499.025 1499.030 1499.035 1499.040 1499.045 1499.050 1499.055 1499.060 1499.065 1499.070

3HC Frequency (MHz)

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

13

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime

Bunch length along the train

<> (ps)
140

Filling at 70%
Filling at 80%
Filling at 90%
Filling at 96%
Filling at 98%
Uniform Filling

130
120
110
100
90
80
70
60
50
40
30
1499.010

1499.015

1499.020

1499.025

1499.030

1499.035

1499.040

1499.045

1499.050

1499.055

1499.060

1499.065

1499.070

3HC Frequency (MHz)

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

14

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
The Landau damping seems to be influenced by the different contribution of the
increasing gap width and of the average bunch length, which is reduced as the
gap increases.

Scale is
different!

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

15

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
These strak camera images show the different effect of 3HC on the beam
between 90% filling (on the left) and uniform filling (on the right). The Landau
damping effect is similar in both cases, the 90% filling shows the expected effect
of the phase modulation along th ebunch train.
Phase
Modulation
present.
Stronger
Phase
Modulation
Bunches are
longer in the
train centre.

Df= +112 kHz

Longitudinal
UNSTABLE
Beam

Df= +92 kHz

Longitudinal
STABLE
Beam
Bunch
Length is
Uniform

Df= +62 kHz

90% Filling

Uniform Filling

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

16

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
The best performance in terms of lifetime is obtained with a fractional filling of 96%. By
further increasing the filling, the maximum obtained lifetime is lower, suggesting that the
optimum setting for ELETTRA requires a small amount of “empty gap”.
The 96% filling is now taken as the new standard filling pattern for User’s Operation
Mode (320mA, 2.0GeV). In this condition 3HC is usually tuned from 1499.050 MHz
(Df=92kHz) to 1499.020MHz (Df=62kHz).

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

17

Machine Upgrades and Ultimate Lifetime Value
During 2003 and 2004 several new vacuum
chamber installations were performed. In June
2003 a new Aluminum-NEG coated chamber
was installed in section ID10. In pre-3HC
conditions the nominal lifetime was recovered at
a dynamic pressure of about 10-11 mbar/mA. In
the example of the ID10 chamber this took
about 70 Ah, i.e. about 2,5 weeks operation.

In fact the ultimate lifetime with 3HC
active, i.e. about 27 hours at 2.0
GeV 320 mA, was reached mid of
September 2003, that is about 6
weeks of operation after the ID10
installation (there were 2 weeks
shutdown in August).
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

18

Conclusions
• 3HC routinely in operation at Elettra
• Stable Beam, refill every 36 hours
• Operability and Reliability good
• Careful maintenance to prevent
faults, recovery time can be long!
• Experiments at different fillings
confirm expected effects (phase
modulation, bunch lengthening)
• New standard filling set to 96%
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

19


Slide 4

SUPER-3HC at ELETTRA Update
G.Penco, M.Svandrlik
• Operation
• Uptime
• Maintenance
• Performance vs filling

• Conclusions

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

1

Operation/Uptime/Maintenance/Performance vs Filling
• 3HC is routinely in operation during user’s shifts.
• Lifetime depends on ultimate vacuum conditioning and
filling pattern, highest value we can obtain is 27 hrs
(320 mA; 2.0 GeV)
• Filling pattern set to 96%
• During refill and energy ramping 3HC set at +94 kHz
(from 3rd harmonic) - Transverse Feedbacks ON
• Once beam is at 2.0 Gev 3HC is activated by tuning it at
+64 kHz

• Longitudinal Coupled Bunch Instabilities are cured by 3HC,
Transverse Instabilities are cured by Feedbacks.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

2

Operation/Uptime/Maintenance/Performance vs Filling
• The increase in Beam Lifetime obtained when 3HC is
active, allows us to refill ELETTRA every 36 hrs instead
of 24 hrs, as it used to be in the past.

3HC tuned:only 3 refills
in 5 days operation

How it was
before 3HC

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

3

Operation/Uptime/Maintenance/Performance vs Filling
• General uptime of the system is good. Since September
2003 only one event caused significant User’s downtime,
on Saturday, 31/01/2004.
Users' downtime caused by 3HC, in hours
30
25
20
15,8
15
10
5
0

0,0

0,0

0,0

0,0

0,6

0,0

RUN 85
RUN 86
RUN 87
RUN 88
RUN 89
RUN 90
RUN 91
AUG - SEP 03 SEP - OCT 03 NOV - DEC 03 JAN - FEB 04 MAR - APR 04 APR - MAG 04 JUN - JUL 04

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

4

Operation/Uptime/Maintenance/Performance vs Filling
• The event on 31/01/04 was related to a failure of a rough
pumping unit of the valve-box insulation vacuum. This was a
temporary installation, replaced during the next shutdown
with a fail-safe one.
• The uptime statistics does not include systems stops due to
electrical
power
interruptions,
mostly
caused
by
thunderstorms in the surroundings. In this case most
machine systems are stopped and the restart time of the
cryogenic plant is hidden in the general restart of the
systems. For this reason the idea of connecting 3HC to a new
UPS has not yet been implemented (also financial reasons).

• We still do not have a He recovery system, the experience
made so far shows that we can survive without it, not
affecting the uptime of the system.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

5

Operation/Uptime/Maintenance/Performance vs Filling
• Several important maintenance interventions have been
successfully performed in the last 12 months.
• In November 2003 the leaky gate valve between 3HC
and the superconducting wiggler was substituted.
This required to break
the cavity vacuum. A
clean area was therefore
created inside the
storage ring tunnel. The
replacement followed
clean room procedures
and was done by CEA
and Elettra staff.
The field performance of
the cavity has not been
affected by this
intervention.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

6

Operation/Uptime/Maintenance/Performance vs Filling
• In December 2003 the tuning system of cell 1 failed for
the 2nd time (1st time in March). In January 2004 the tuning
system was replaced with an upgraded version.
• The tuning system is under vacuum, at cold. The gear box
was found to be blocked.
• Tests at Saclay showed that the reason could be a heating
problem (from the motor).
• Even if the number of cycles
after which this shows up is
huge, we are limiting the
movements of the system.
• No problem since January 04
• CEA is studying a solution to
move the motor outside the
cryomodule.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

7

Operation/Uptime/Maintenance/Performance vs Filling

• During the January shutdown the cryogenic plant annual
maintenance was performed.
• After this maintenance the nominal performance is back to
the original, i.e. about 30-35 litres/hour at 13 bar of HP.
• In August 2004 the cryomodule has been warmed-up again
in order to replace a coaxial cable which takes out the
voltage signal of cell 2.
• In this occasion also the fundamental mode rejection of the
dipolar HOM couplers has been improved. In fact on one of
them some over-heating effects were observed when tuning
the cell.

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

8

Operation/Uptime/Maintenance/Performance vs Filling
• ELETTRA used to operate with a partial filling of the bunch
train: typically a 10% empty gap was present.

• As well known, with such a gap the passive third harmonic
cavity induces a phase modulation over the bunch train.
• Several STREAK CAMERA experiments were performed for
various fillings, measuring the effect on:
– Phase Shift
– Bunch lengthening
– Landau Damping

– Beam Lifetime

• As a result, a new optimum filling was set for operations.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

9

80% Filling: Phase Shift/Bunch Length/Landau/Lifetime
Phase Shift along the train for different tuning
60

Ibeam=315mA,
Filling at 80%

Relative Phase (Deg)

50
40
1499,070 MHz
1499,060 MHz

30

1499,050 MHz
1499,025 MHz

20

Bunch length along the train for different tuning
1499,070 MHz

1499,020 MHz
1499,015 MHz

10
1499,060 MHz
600
700
800

RMS Bunch Length (ps)

90

1499,050 MHz

80

900

1000

1100

1200

1300

1400

Bunch position in the train (ps)

1499,025 MHz

70

1499,020 MHz

60

1499,015 MHz

50
40
30
700

900
1100
1300
Bunch position in the train (ps)

1500

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

10

1500

100% Filling: Phase Shift/Bunch Length/Landau/Lifetime

Relative Phase (Deg)

Ibeam=315mA,
Uniform Filling

Bunch length along the train for different tuning
1499,050 MHz
1499,025 MHz

RMS Bunch Length (ps)

200
180

1499,040 MHz
1499,020 MHz

1499,030 MHz
1499,015 MHz

Phase Shift along the train for different tuning

50
45
40
35
30
25
20
15
10

1499,040 MHz

1499,030 MHz
1499,020 MHz

1499,025 MHz
1499,015 MHz

1499,014 MHz
0

1499,014 MHz

160

1499,050 MHz

200

400

600

800

Bunch position in the train (ps)

Bunch overstretching

140
120
100
80
60
40
20
0

200

400

600

Bunch position in the train (ps)

800

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

11

100% Filling: Phase Shift/Bunch Length/Landau/Lifetime
The Bunch Profile Averaged on the bunch train in the case of Uniform
Filling is shown below for different tuning positions of 3HC. The “nominal
tuning” of 3HC would be around +75 kHz. Beyond this postion the Bunch

begins to show an overstreched profile. Beam Lifetime increases until the
position of +62 kHz, which is the operating position. A few kHz beyond that,
lifetime starts to decay to a few hours; further the beam is lost.
Df= +92 kHz

Df= +82 kHz

Df= +72 kHz

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

Df= +62 kHz

12

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime

Deg

Phase Shift along the bunch train

45

Uniform Filling
Filling at 98%
Filling at 96%
Filling at 90%
Filling at 80%
Filling at 70%

40
35
30
25
20
15
10
5
0

1499.010 1499.015 1499.020 1499.025 1499.030 1499.035 1499.040 1499.045 1499.050 1499.055 1499.060 1499.065 1499.070

3HC Frequency (MHz)

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

13

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime

Bunch length along the train

<> (ps)
140

Filling at 70%
Filling at 80%
Filling at 90%
Filling at 96%
Filling at 98%
Uniform Filling

130
120
110
100
90
80
70
60
50
40
30
1499.010

1499.015

1499.020

1499.025

1499.030

1499.035

1499.040

1499.045

1499.050

1499.055

1499.060

1499.065

1499.070

3HC Frequency (MHz)

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

14

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
The Landau damping seems to be influenced by the different contribution of the
increasing gap width and of the average bunch length, which is reduced as the
gap increases.

Scale is
different!

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

15

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
These strak camera images show the different effect of 3HC on the beam
between 90% filling (on the left) and uniform filling (on the right). The Landau
damping effect is similar in both cases, the 90% filling shows the expected effect
of the phase modulation along th ebunch train.
Phase
Modulation
present.
Stronger
Phase
Modulation
Bunches are
longer in the
train centre.

Df= +112 kHz

Longitudinal
UNSTABLE
Beam

Df= +92 kHz

Longitudinal
STABLE
Beam
Bunch
Length is
Uniform

Df= +62 kHz

90% Filling

Uniform Filling

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

16

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
The best performance in terms of lifetime is obtained with a fractional filling of 96%. By
further increasing the filling, the maximum obtained lifetime is lower, suggesting that the
optimum setting for ELETTRA requires a small amount of “empty gap”.
The 96% filling is now taken as the new standard filling pattern for User’s Operation
Mode (320mA, 2.0GeV). In this condition 3HC is usually tuned from 1499.050 MHz
(Df=92kHz) to 1499.020MHz (Df=62kHz).

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

17

Machine Upgrades and Ultimate Lifetime Value
During 2003 and 2004 several new vacuum
chamber installations were performed. In June
2003 a new Aluminum-NEG coated chamber
was installed in section ID10. In pre-3HC
conditions the nominal lifetime was recovered at
a dynamic pressure of about 10-11 mbar/mA. In
the example of the ID10 chamber this took
about 70 Ah, i.e. about 2,5 weeks operation.

In fact the ultimate lifetime with 3HC
active, i.e. about 27 hours at 2.0
GeV 320 mA, was reached mid of
September 2003, that is about 6
weeks of operation after the ID10
installation (there were 2 weeks
shutdown in August).
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

18

Conclusions
• 3HC routinely in operation at Elettra
• Stable Beam, refill every 36 hours
• Operability and Reliability good
• Careful maintenance to prevent
faults, recovery time can be long!
• Experiments at different fillings
confirm expected effects (phase
modulation, bunch lengthening)
• New standard filling set to 96%
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

19


Slide 5

SUPER-3HC at ELETTRA Update
G.Penco, M.Svandrlik
• Operation
• Uptime
• Maintenance
• Performance vs filling

• Conclusions

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

1

Operation/Uptime/Maintenance/Performance vs Filling
• 3HC is routinely in operation during user’s shifts.
• Lifetime depends on ultimate vacuum conditioning and
filling pattern, highest value we can obtain is 27 hrs
(320 mA; 2.0 GeV)
• Filling pattern set to 96%
• During refill and energy ramping 3HC set at +94 kHz
(from 3rd harmonic) - Transverse Feedbacks ON
• Once beam is at 2.0 Gev 3HC is activated by tuning it at
+64 kHz

• Longitudinal Coupled Bunch Instabilities are cured by 3HC,
Transverse Instabilities are cured by Feedbacks.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

2

Operation/Uptime/Maintenance/Performance vs Filling
• The increase in Beam Lifetime obtained when 3HC is
active, allows us to refill ELETTRA every 36 hrs instead
of 24 hrs, as it used to be in the past.

3HC tuned:only 3 refills
in 5 days operation

How it was
before 3HC

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

3

Operation/Uptime/Maintenance/Performance vs Filling
• General uptime of the system is good. Since September
2003 only one event caused significant User’s downtime,
on Saturday, 31/01/2004.
Users' downtime caused by 3HC, in hours
30
25
20
15,8
15
10
5
0

0,0

0,0

0,0

0,0

0,6

0,0

RUN 85
RUN 86
RUN 87
RUN 88
RUN 89
RUN 90
RUN 91
AUG - SEP 03 SEP - OCT 03 NOV - DEC 03 JAN - FEB 04 MAR - APR 04 APR - MAG 04 JUN - JUL 04

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

4

Operation/Uptime/Maintenance/Performance vs Filling
• The event on 31/01/04 was related to a failure of a rough
pumping unit of the valve-box insulation vacuum. This was a
temporary installation, replaced during the next shutdown
with a fail-safe one.
• The uptime statistics does not include systems stops due to
electrical
power
interruptions,
mostly
caused
by
thunderstorms in the surroundings. In this case most
machine systems are stopped and the restart time of the
cryogenic plant is hidden in the general restart of the
systems. For this reason the idea of connecting 3HC to a new
UPS has not yet been implemented (also financial reasons).

• We still do not have a He recovery system, the experience
made so far shows that we can survive without it, not
affecting the uptime of the system.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

5

Operation/Uptime/Maintenance/Performance vs Filling
• Several important maintenance interventions have been
successfully performed in the last 12 months.
• In November 2003 the leaky gate valve between 3HC
and the superconducting wiggler was substituted.
This required to break
the cavity vacuum. A
clean area was therefore
created inside the
storage ring tunnel. The
replacement followed
clean room procedures
and was done by CEA
and Elettra staff.
The field performance of
the cavity has not been
affected by this
intervention.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

6

Operation/Uptime/Maintenance/Performance vs Filling
• In December 2003 the tuning system of cell 1 failed for
the 2nd time (1st time in March). In January 2004 the tuning
system was replaced with an upgraded version.
• The tuning system is under vacuum, at cold. The gear box
was found to be blocked.
• Tests at Saclay showed that the reason could be a heating
problem (from the motor).
• Even if the number of cycles
after which this shows up is
huge, we are limiting the
movements of the system.
• No problem since January 04
• CEA is studying a solution to
move the motor outside the
cryomodule.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

7

Operation/Uptime/Maintenance/Performance vs Filling

• During the January shutdown the cryogenic plant annual
maintenance was performed.
• After this maintenance the nominal performance is back to
the original, i.e. about 30-35 litres/hour at 13 bar of HP.
• In August 2004 the cryomodule has been warmed-up again
in order to replace a coaxial cable which takes out the
voltage signal of cell 2.
• In this occasion also the fundamental mode rejection of the
dipolar HOM couplers has been improved. In fact on one of
them some over-heating effects were observed when tuning
the cell.

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

8

Operation/Uptime/Maintenance/Performance vs Filling
• ELETTRA used to operate with a partial filling of the bunch
train: typically a 10% empty gap was present.

• As well known, with such a gap the passive third harmonic
cavity induces a phase modulation over the bunch train.
• Several STREAK CAMERA experiments were performed for
various fillings, measuring the effect on:
– Phase Shift
– Bunch lengthening
– Landau Damping

– Beam Lifetime

• As a result, a new optimum filling was set for operations.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

9

80% Filling: Phase Shift/Bunch Length/Landau/Lifetime
Phase Shift along the train for different tuning
60

Ibeam=315mA,
Filling at 80%

Relative Phase (Deg)

50
40
1499,070 MHz
1499,060 MHz

30

1499,050 MHz
1499,025 MHz

20

Bunch length along the train for different tuning
1499,070 MHz

1499,020 MHz
1499,015 MHz

10
1499,060 MHz
600
700
800

RMS Bunch Length (ps)

90

1499,050 MHz

80

900

1000

1100

1200

1300

1400

Bunch position in the train (ps)

1499,025 MHz

70

1499,020 MHz

60

1499,015 MHz

50
40
30
700

900
1100
1300
Bunch position in the train (ps)

1500

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

10

1500

100% Filling: Phase Shift/Bunch Length/Landau/Lifetime

Relative Phase (Deg)

Ibeam=315mA,
Uniform Filling

Bunch length along the train for different tuning
1499,050 MHz
1499,025 MHz

RMS Bunch Length (ps)

200
180

1499,040 MHz
1499,020 MHz

1499,030 MHz
1499,015 MHz

Phase Shift along the train for different tuning

50
45
40
35
30
25
20
15
10

1499,040 MHz

1499,030 MHz
1499,020 MHz

1499,025 MHz
1499,015 MHz

1499,014 MHz
0

1499,014 MHz

160

1499,050 MHz

200

400

600

800

Bunch position in the train (ps)

Bunch overstretching

140
120
100
80
60
40
20
0

200

400

600

Bunch position in the train (ps)

800

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

11

100% Filling: Phase Shift/Bunch Length/Landau/Lifetime
The Bunch Profile Averaged on the bunch train in the case of Uniform
Filling is shown below for different tuning positions of 3HC. The “nominal
tuning” of 3HC would be around +75 kHz. Beyond this postion the Bunch

begins to show an overstreched profile. Beam Lifetime increases until the
position of +62 kHz, which is the operating position. A few kHz beyond that,
lifetime starts to decay to a few hours; further the beam is lost.
Df= +92 kHz

Df= +82 kHz

Df= +72 kHz

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

Df= +62 kHz

12

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime

Deg

Phase Shift along the bunch train

45

Uniform Filling
Filling at 98%
Filling at 96%
Filling at 90%
Filling at 80%
Filling at 70%

40
35
30
25
20
15
10
5
0

1499.010 1499.015 1499.020 1499.025 1499.030 1499.035 1499.040 1499.045 1499.050 1499.055 1499.060 1499.065 1499.070

3HC Frequency (MHz)

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

13

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime

Bunch length along the train

<> (ps)
140

Filling at 70%
Filling at 80%
Filling at 90%
Filling at 96%
Filling at 98%
Uniform Filling

130
120
110
100
90
80
70
60
50
40
30
1499.010

1499.015

1499.020

1499.025

1499.030

1499.035

1499.040

1499.045

1499.050

1499.055

1499.060

1499.065

1499.070

3HC Frequency (MHz)

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

14

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
The Landau damping seems to be influenced by the different contribution of the
increasing gap width and of the average bunch length, which is reduced as the
gap increases.

Scale is
different!

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

15

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
These strak camera images show the different effect of 3HC on the beam
between 90% filling (on the left) and uniform filling (on the right). The Landau
damping effect is similar in both cases, the 90% filling shows the expected effect
of the phase modulation along th ebunch train.
Phase
Modulation
present.
Stronger
Phase
Modulation
Bunches are
longer in the
train centre.

Df= +112 kHz

Longitudinal
UNSTABLE
Beam

Df= +92 kHz

Longitudinal
STABLE
Beam
Bunch
Length is
Uniform

Df= +62 kHz

90% Filling

Uniform Filling

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

16

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
The best performance in terms of lifetime is obtained with a fractional filling of 96%. By
further increasing the filling, the maximum obtained lifetime is lower, suggesting that the
optimum setting for ELETTRA requires a small amount of “empty gap”.
The 96% filling is now taken as the new standard filling pattern for User’s Operation
Mode (320mA, 2.0GeV). In this condition 3HC is usually tuned from 1499.050 MHz
(Df=92kHz) to 1499.020MHz (Df=62kHz).

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

17

Machine Upgrades and Ultimate Lifetime Value
During 2003 and 2004 several new vacuum
chamber installations were performed. In June
2003 a new Aluminum-NEG coated chamber
was installed in section ID10. In pre-3HC
conditions the nominal lifetime was recovered at
a dynamic pressure of about 10-11 mbar/mA. In
the example of the ID10 chamber this took
about 70 Ah, i.e. about 2,5 weeks operation.

In fact the ultimate lifetime with 3HC
active, i.e. about 27 hours at 2.0
GeV 320 mA, was reached mid of
September 2003, that is about 6
weeks of operation after the ID10
installation (there were 2 weeks
shutdown in August).
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

18

Conclusions
• 3HC routinely in operation at Elettra
• Stable Beam, refill every 36 hours
• Operability and Reliability good
• Careful maintenance to prevent
faults, recovery time can be long!
• Experiments at different fillings
confirm expected effects (phase
modulation, bunch lengthening)
• New standard filling set to 96%
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

19


Slide 6

SUPER-3HC at ELETTRA Update
G.Penco, M.Svandrlik
• Operation
• Uptime
• Maintenance
• Performance vs filling

• Conclusions

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

1

Operation/Uptime/Maintenance/Performance vs Filling
• 3HC is routinely in operation during user’s shifts.
• Lifetime depends on ultimate vacuum conditioning and
filling pattern, highest value we can obtain is 27 hrs
(320 mA; 2.0 GeV)
• Filling pattern set to 96%
• During refill and energy ramping 3HC set at +94 kHz
(from 3rd harmonic) - Transverse Feedbacks ON
• Once beam is at 2.0 Gev 3HC is activated by tuning it at
+64 kHz

• Longitudinal Coupled Bunch Instabilities are cured by 3HC,
Transverse Instabilities are cured by Feedbacks.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

2

Operation/Uptime/Maintenance/Performance vs Filling
• The increase in Beam Lifetime obtained when 3HC is
active, allows us to refill ELETTRA every 36 hrs instead
of 24 hrs, as it used to be in the past.

3HC tuned:only 3 refills
in 5 days operation

How it was
before 3HC

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

3

Operation/Uptime/Maintenance/Performance vs Filling
• General uptime of the system is good. Since September
2003 only one event caused significant User’s downtime,
on Saturday, 31/01/2004.
Users' downtime caused by 3HC, in hours
30
25
20
15,8
15
10
5
0

0,0

0,0

0,0

0,0

0,6

0,0

RUN 85
RUN 86
RUN 87
RUN 88
RUN 89
RUN 90
RUN 91
AUG - SEP 03 SEP - OCT 03 NOV - DEC 03 JAN - FEB 04 MAR - APR 04 APR - MAG 04 JUN - JUL 04

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

4

Operation/Uptime/Maintenance/Performance vs Filling
• The event on 31/01/04 was related to a failure of a rough
pumping unit of the valve-box insulation vacuum. This was a
temporary installation, replaced during the next shutdown
with a fail-safe one.
• The uptime statistics does not include systems stops due to
electrical
power
interruptions,
mostly
caused
by
thunderstorms in the surroundings. In this case most
machine systems are stopped and the restart time of the
cryogenic plant is hidden in the general restart of the
systems. For this reason the idea of connecting 3HC to a new
UPS has not yet been implemented (also financial reasons).

• We still do not have a He recovery system, the experience
made so far shows that we can survive without it, not
affecting the uptime of the system.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

5

Operation/Uptime/Maintenance/Performance vs Filling
• Several important maintenance interventions have been
successfully performed in the last 12 months.
• In November 2003 the leaky gate valve between 3HC
and the superconducting wiggler was substituted.
This required to break
the cavity vacuum. A
clean area was therefore
created inside the
storage ring tunnel. The
replacement followed
clean room procedures
and was done by CEA
and Elettra staff.
The field performance of
the cavity has not been
affected by this
intervention.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

6

Operation/Uptime/Maintenance/Performance vs Filling
• In December 2003 the tuning system of cell 1 failed for
the 2nd time (1st time in March). In January 2004 the tuning
system was replaced with an upgraded version.
• The tuning system is under vacuum, at cold. The gear box
was found to be blocked.
• Tests at Saclay showed that the reason could be a heating
problem (from the motor).
• Even if the number of cycles
after which this shows up is
huge, we are limiting the
movements of the system.
• No problem since January 04
• CEA is studying a solution to
move the motor outside the
cryomodule.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

7

Operation/Uptime/Maintenance/Performance vs Filling

• During the January shutdown the cryogenic plant annual
maintenance was performed.
• After this maintenance the nominal performance is back to
the original, i.e. about 30-35 litres/hour at 13 bar of HP.
• In August 2004 the cryomodule has been warmed-up again
in order to replace a coaxial cable which takes out the
voltage signal of cell 2.
• In this occasion also the fundamental mode rejection of the
dipolar HOM couplers has been improved. In fact on one of
them some over-heating effects were observed when tuning
the cell.

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

8

Operation/Uptime/Maintenance/Performance vs Filling
• ELETTRA used to operate with a partial filling of the bunch
train: typically a 10% empty gap was present.

• As well known, with such a gap the passive third harmonic
cavity induces a phase modulation over the bunch train.
• Several STREAK CAMERA experiments were performed for
various fillings, measuring the effect on:
– Phase Shift
– Bunch lengthening
– Landau Damping

– Beam Lifetime

• As a result, a new optimum filling was set for operations.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

9

80% Filling: Phase Shift/Bunch Length/Landau/Lifetime
Phase Shift along the train for different tuning
60

Ibeam=315mA,
Filling at 80%

Relative Phase (Deg)

50
40
1499,070 MHz
1499,060 MHz

30

1499,050 MHz
1499,025 MHz

20

Bunch length along the train for different tuning
1499,070 MHz

1499,020 MHz
1499,015 MHz

10
1499,060 MHz
600
700
800

RMS Bunch Length (ps)

90

1499,050 MHz

80

900

1000

1100

1200

1300

1400

Bunch position in the train (ps)

1499,025 MHz

70

1499,020 MHz

60

1499,015 MHz

50
40
30
700

900
1100
1300
Bunch position in the train (ps)

1500

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

10

1500

100% Filling: Phase Shift/Bunch Length/Landau/Lifetime

Relative Phase (Deg)

Ibeam=315mA,
Uniform Filling

Bunch length along the train for different tuning
1499,050 MHz
1499,025 MHz

RMS Bunch Length (ps)

200
180

1499,040 MHz
1499,020 MHz

1499,030 MHz
1499,015 MHz

Phase Shift along the train for different tuning

50
45
40
35
30
25
20
15
10

1499,040 MHz

1499,030 MHz
1499,020 MHz

1499,025 MHz
1499,015 MHz

1499,014 MHz
0

1499,014 MHz

160

1499,050 MHz

200

400

600

800

Bunch position in the train (ps)

Bunch overstretching

140
120
100
80
60
40
20
0

200

400

600

Bunch position in the train (ps)

800

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

11

100% Filling: Phase Shift/Bunch Length/Landau/Lifetime
The Bunch Profile Averaged on the bunch train in the case of Uniform
Filling is shown below for different tuning positions of 3HC. The “nominal
tuning” of 3HC would be around +75 kHz. Beyond this postion the Bunch

begins to show an overstreched profile. Beam Lifetime increases until the
position of +62 kHz, which is the operating position. A few kHz beyond that,
lifetime starts to decay to a few hours; further the beam is lost.
Df= +92 kHz

Df= +82 kHz

Df= +72 kHz

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

Df= +62 kHz

12

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime

Deg

Phase Shift along the bunch train

45

Uniform Filling
Filling at 98%
Filling at 96%
Filling at 90%
Filling at 80%
Filling at 70%

40
35
30
25
20
15
10
5
0

1499.010 1499.015 1499.020 1499.025 1499.030 1499.035 1499.040 1499.045 1499.050 1499.055 1499.060 1499.065 1499.070

3HC Frequency (MHz)

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

13

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime

Bunch length along the train

<> (ps)
140

Filling at 70%
Filling at 80%
Filling at 90%
Filling at 96%
Filling at 98%
Uniform Filling

130
120
110
100
90
80
70
60
50
40
30
1499.010

1499.015

1499.020

1499.025

1499.030

1499.035

1499.040

1499.045

1499.050

1499.055

1499.060

1499.065

1499.070

3HC Frequency (MHz)

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

14

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
The Landau damping seems to be influenced by the different contribution of the
increasing gap width and of the average bunch length, which is reduced as the
gap increases.

Scale is
different!

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

15

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
These strak camera images show the different effect of 3HC on the beam
between 90% filling (on the left) and uniform filling (on the right). The Landau
damping effect is similar in both cases, the 90% filling shows the expected effect
of the phase modulation along th ebunch train.
Phase
Modulation
present.
Stronger
Phase
Modulation
Bunches are
longer in the
train centre.

Df= +112 kHz

Longitudinal
UNSTABLE
Beam

Df= +92 kHz

Longitudinal
STABLE
Beam
Bunch
Length is
Uniform

Df= +62 kHz

90% Filling

Uniform Filling

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

16

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
The best performance in terms of lifetime is obtained with a fractional filling of 96%. By
further increasing the filling, the maximum obtained lifetime is lower, suggesting that the
optimum setting for ELETTRA requires a small amount of “empty gap”.
The 96% filling is now taken as the new standard filling pattern for User’s Operation
Mode (320mA, 2.0GeV). In this condition 3HC is usually tuned from 1499.050 MHz
(Df=92kHz) to 1499.020MHz (Df=62kHz).

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

17

Machine Upgrades and Ultimate Lifetime Value
During 2003 and 2004 several new vacuum
chamber installations were performed. In June
2003 a new Aluminum-NEG coated chamber
was installed in section ID10. In pre-3HC
conditions the nominal lifetime was recovered at
a dynamic pressure of about 10-11 mbar/mA. In
the example of the ID10 chamber this took
about 70 Ah, i.e. about 2,5 weeks operation.

In fact the ultimate lifetime with 3HC
active, i.e. about 27 hours at 2.0
GeV 320 mA, was reached mid of
September 2003, that is about 6
weeks of operation after the ID10
installation (there were 2 weeks
shutdown in August).
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

18

Conclusions
• 3HC routinely in operation at Elettra
• Stable Beam, refill every 36 hours
• Operability and Reliability good
• Careful maintenance to prevent
faults, recovery time can be long!
• Experiments at different fillings
confirm expected effects (phase
modulation, bunch lengthening)
• New standard filling set to 96%
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

19


Slide 7

SUPER-3HC at ELETTRA Update
G.Penco, M.Svandrlik
• Operation
• Uptime
• Maintenance
• Performance vs filling

• Conclusions

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

1

Operation/Uptime/Maintenance/Performance vs Filling
• 3HC is routinely in operation during user’s shifts.
• Lifetime depends on ultimate vacuum conditioning and
filling pattern, highest value we can obtain is 27 hrs
(320 mA; 2.0 GeV)
• Filling pattern set to 96%
• During refill and energy ramping 3HC set at +94 kHz
(from 3rd harmonic) - Transverse Feedbacks ON
• Once beam is at 2.0 Gev 3HC is activated by tuning it at
+64 kHz

• Longitudinal Coupled Bunch Instabilities are cured by 3HC,
Transverse Instabilities are cured by Feedbacks.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

2

Operation/Uptime/Maintenance/Performance vs Filling
• The increase in Beam Lifetime obtained when 3HC is
active, allows us to refill ELETTRA every 36 hrs instead
of 24 hrs, as it used to be in the past.

3HC tuned:only 3 refills
in 5 days operation

How it was
before 3HC

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

3

Operation/Uptime/Maintenance/Performance vs Filling
• General uptime of the system is good. Since September
2003 only one event caused significant User’s downtime,
on Saturday, 31/01/2004.
Users' downtime caused by 3HC, in hours
30
25
20
15,8
15
10
5
0

0,0

0,0

0,0

0,0

0,6

0,0

RUN 85
RUN 86
RUN 87
RUN 88
RUN 89
RUN 90
RUN 91
AUG - SEP 03 SEP - OCT 03 NOV - DEC 03 JAN - FEB 04 MAR - APR 04 APR - MAG 04 JUN - JUL 04

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

4

Operation/Uptime/Maintenance/Performance vs Filling
• The event on 31/01/04 was related to a failure of a rough
pumping unit of the valve-box insulation vacuum. This was a
temporary installation, replaced during the next shutdown
with a fail-safe one.
• The uptime statistics does not include systems stops due to
electrical
power
interruptions,
mostly
caused
by
thunderstorms in the surroundings. In this case most
machine systems are stopped and the restart time of the
cryogenic plant is hidden in the general restart of the
systems. For this reason the idea of connecting 3HC to a new
UPS has not yet been implemented (also financial reasons).

• We still do not have a He recovery system, the experience
made so far shows that we can survive without it, not
affecting the uptime of the system.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

5

Operation/Uptime/Maintenance/Performance vs Filling
• Several important maintenance interventions have been
successfully performed in the last 12 months.
• In November 2003 the leaky gate valve between 3HC
and the superconducting wiggler was substituted.
This required to break
the cavity vacuum. A
clean area was therefore
created inside the
storage ring tunnel. The
replacement followed
clean room procedures
and was done by CEA
and Elettra staff.
The field performance of
the cavity has not been
affected by this
intervention.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

6

Operation/Uptime/Maintenance/Performance vs Filling
• In December 2003 the tuning system of cell 1 failed for
the 2nd time (1st time in March). In January 2004 the tuning
system was replaced with an upgraded version.
• The tuning system is under vacuum, at cold. The gear box
was found to be blocked.
• Tests at Saclay showed that the reason could be a heating
problem (from the motor).
• Even if the number of cycles
after which this shows up is
huge, we are limiting the
movements of the system.
• No problem since January 04
• CEA is studying a solution to
move the motor outside the
cryomodule.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

7

Operation/Uptime/Maintenance/Performance vs Filling

• During the January shutdown the cryogenic plant annual
maintenance was performed.
• After this maintenance the nominal performance is back to
the original, i.e. about 30-35 litres/hour at 13 bar of HP.
• In August 2004 the cryomodule has been warmed-up again
in order to replace a coaxial cable which takes out the
voltage signal of cell 2.
• In this occasion also the fundamental mode rejection of the
dipolar HOM couplers has been improved. In fact on one of
them some over-heating effects were observed when tuning
the cell.

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

8

Operation/Uptime/Maintenance/Performance vs Filling
• ELETTRA used to operate with a partial filling of the bunch
train: typically a 10% empty gap was present.

• As well known, with such a gap the passive third harmonic
cavity induces a phase modulation over the bunch train.
• Several STREAK CAMERA experiments were performed for
various fillings, measuring the effect on:
– Phase Shift
– Bunch lengthening
– Landau Damping

– Beam Lifetime

• As a result, a new optimum filling was set for operations.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

9

80% Filling: Phase Shift/Bunch Length/Landau/Lifetime
Phase Shift along the train for different tuning
60

Ibeam=315mA,
Filling at 80%

Relative Phase (Deg)

50
40
1499,070 MHz
1499,060 MHz

30

1499,050 MHz
1499,025 MHz

20

Bunch length along the train for different tuning
1499,070 MHz

1499,020 MHz
1499,015 MHz

10
1499,060 MHz
600
700
800

RMS Bunch Length (ps)

90

1499,050 MHz

80

900

1000

1100

1200

1300

1400

Bunch position in the train (ps)

1499,025 MHz

70

1499,020 MHz

60

1499,015 MHz

50
40
30
700

900
1100
1300
Bunch position in the train (ps)

1500

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

10

1500

100% Filling: Phase Shift/Bunch Length/Landau/Lifetime

Relative Phase (Deg)

Ibeam=315mA,
Uniform Filling

Bunch length along the train for different tuning
1499,050 MHz
1499,025 MHz

RMS Bunch Length (ps)

200
180

1499,040 MHz
1499,020 MHz

1499,030 MHz
1499,015 MHz

Phase Shift along the train for different tuning

50
45
40
35
30
25
20
15
10

1499,040 MHz

1499,030 MHz
1499,020 MHz

1499,025 MHz
1499,015 MHz

1499,014 MHz
0

1499,014 MHz

160

1499,050 MHz

200

400

600

800

Bunch position in the train (ps)

Bunch overstretching

140
120
100
80
60
40
20
0

200

400

600

Bunch position in the train (ps)

800

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

11

100% Filling: Phase Shift/Bunch Length/Landau/Lifetime
The Bunch Profile Averaged on the bunch train in the case of Uniform
Filling is shown below for different tuning positions of 3HC. The “nominal
tuning” of 3HC would be around +75 kHz. Beyond this postion the Bunch

begins to show an overstreched profile. Beam Lifetime increases until the
position of +62 kHz, which is the operating position. A few kHz beyond that,
lifetime starts to decay to a few hours; further the beam is lost.
Df= +92 kHz

Df= +82 kHz

Df= +72 kHz

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

Df= +62 kHz

12

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime

Deg

Phase Shift along the bunch train

45

Uniform Filling
Filling at 98%
Filling at 96%
Filling at 90%
Filling at 80%
Filling at 70%

40
35
30
25
20
15
10
5
0

1499.010 1499.015 1499.020 1499.025 1499.030 1499.035 1499.040 1499.045 1499.050 1499.055 1499.060 1499.065 1499.070

3HC Frequency (MHz)

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

13

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime

Bunch length along the train

<> (ps)
140

Filling at 70%
Filling at 80%
Filling at 90%
Filling at 96%
Filling at 98%
Uniform Filling

130
120
110
100
90
80
70
60
50
40
30
1499.010

1499.015

1499.020

1499.025

1499.030

1499.035

1499.040

1499.045

1499.050

1499.055

1499.060

1499.065

1499.070

3HC Frequency (MHz)

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

14

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
The Landau damping seems to be influenced by the different contribution of the
increasing gap width and of the average bunch length, which is reduced as the
gap increases.

Scale is
different!

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

15

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
These strak camera images show the different effect of 3HC on the beam
between 90% filling (on the left) and uniform filling (on the right). The Landau
damping effect is similar in both cases, the 90% filling shows the expected effect
of the phase modulation along th ebunch train.
Phase
Modulation
present.
Stronger
Phase
Modulation
Bunches are
longer in the
train centre.

Df= +112 kHz

Longitudinal
UNSTABLE
Beam

Df= +92 kHz

Longitudinal
STABLE
Beam
Bunch
Length is
Uniform

Df= +62 kHz

90% Filling

Uniform Filling

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

16

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
The best performance in terms of lifetime is obtained with a fractional filling of 96%. By
further increasing the filling, the maximum obtained lifetime is lower, suggesting that the
optimum setting for ELETTRA requires a small amount of “empty gap”.
The 96% filling is now taken as the new standard filling pattern for User’s Operation
Mode (320mA, 2.0GeV). In this condition 3HC is usually tuned from 1499.050 MHz
(Df=92kHz) to 1499.020MHz (Df=62kHz).

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

17

Machine Upgrades and Ultimate Lifetime Value
During 2003 and 2004 several new vacuum
chamber installations were performed. In June
2003 a new Aluminum-NEG coated chamber
was installed in section ID10. In pre-3HC
conditions the nominal lifetime was recovered at
a dynamic pressure of about 10-11 mbar/mA. In
the example of the ID10 chamber this took
about 70 Ah, i.e. about 2,5 weeks operation.

In fact the ultimate lifetime with 3HC
active, i.e. about 27 hours at 2.0
GeV 320 mA, was reached mid of
September 2003, that is about 6
weeks of operation after the ID10
installation (there were 2 weeks
shutdown in August).
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

18

Conclusions
• 3HC routinely in operation at Elettra
• Stable Beam, refill every 36 hours
• Operability and Reliability good
• Careful maintenance to prevent
faults, recovery time can be long!
• Experiments at different fillings
confirm expected effects (phase
modulation, bunch lengthening)
• New standard filling set to 96%
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

19


Slide 8

SUPER-3HC at ELETTRA Update
G.Penco, M.Svandrlik
• Operation
• Uptime
• Maintenance
• Performance vs filling

• Conclusions

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

1

Operation/Uptime/Maintenance/Performance vs Filling
• 3HC is routinely in operation during user’s shifts.
• Lifetime depends on ultimate vacuum conditioning and
filling pattern, highest value we can obtain is 27 hrs
(320 mA; 2.0 GeV)
• Filling pattern set to 96%
• During refill and energy ramping 3HC set at +94 kHz
(from 3rd harmonic) - Transverse Feedbacks ON
• Once beam is at 2.0 Gev 3HC is activated by tuning it at
+64 kHz

• Longitudinal Coupled Bunch Instabilities are cured by 3HC,
Transverse Instabilities are cured by Feedbacks.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

2

Operation/Uptime/Maintenance/Performance vs Filling
• The increase in Beam Lifetime obtained when 3HC is
active, allows us to refill ELETTRA every 36 hrs instead
of 24 hrs, as it used to be in the past.

3HC tuned:only 3 refills
in 5 days operation

How it was
before 3HC

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

3

Operation/Uptime/Maintenance/Performance vs Filling
• General uptime of the system is good. Since September
2003 only one event caused significant User’s downtime,
on Saturday, 31/01/2004.
Users' downtime caused by 3HC, in hours
30
25
20
15,8
15
10
5
0

0,0

0,0

0,0

0,0

0,6

0,0

RUN 85
RUN 86
RUN 87
RUN 88
RUN 89
RUN 90
RUN 91
AUG - SEP 03 SEP - OCT 03 NOV - DEC 03 JAN - FEB 04 MAR - APR 04 APR - MAG 04 JUN - JUL 04

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

4

Operation/Uptime/Maintenance/Performance vs Filling
• The event on 31/01/04 was related to a failure of a rough
pumping unit of the valve-box insulation vacuum. This was a
temporary installation, replaced during the next shutdown
with a fail-safe one.
• The uptime statistics does not include systems stops due to
electrical
power
interruptions,
mostly
caused
by
thunderstorms in the surroundings. In this case most
machine systems are stopped and the restart time of the
cryogenic plant is hidden in the general restart of the
systems. For this reason the idea of connecting 3HC to a new
UPS has not yet been implemented (also financial reasons).

• We still do not have a He recovery system, the experience
made so far shows that we can survive without it, not
affecting the uptime of the system.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

5

Operation/Uptime/Maintenance/Performance vs Filling
• Several important maintenance interventions have been
successfully performed in the last 12 months.
• In November 2003 the leaky gate valve between 3HC
and the superconducting wiggler was substituted.
This required to break
the cavity vacuum. A
clean area was therefore
created inside the
storage ring tunnel. The
replacement followed
clean room procedures
and was done by CEA
and Elettra staff.
The field performance of
the cavity has not been
affected by this
intervention.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

6

Operation/Uptime/Maintenance/Performance vs Filling
• In December 2003 the tuning system of cell 1 failed for
the 2nd time (1st time in March). In January 2004 the tuning
system was replaced with an upgraded version.
• The tuning system is under vacuum, at cold. The gear box
was found to be blocked.
• Tests at Saclay showed that the reason could be a heating
problem (from the motor).
• Even if the number of cycles
after which this shows up is
huge, we are limiting the
movements of the system.
• No problem since January 04
• CEA is studying a solution to
move the motor outside the
cryomodule.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

7

Operation/Uptime/Maintenance/Performance vs Filling

• During the January shutdown the cryogenic plant annual
maintenance was performed.
• After this maintenance the nominal performance is back to
the original, i.e. about 30-35 litres/hour at 13 bar of HP.
• In August 2004 the cryomodule has been warmed-up again
in order to replace a coaxial cable which takes out the
voltage signal of cell 2.
• In this occasion also the fundamental mode rejection of the
dipolar HOM couplers has been improved. In fact on one of
them some over-heating effects were observed when tuning
the cell.

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

8

Operation/Uptime/Maintenance/Performance vs Filling
• ELETTRA used to operate with a partial filling of the bunch
train: typically a 10% empty gap was present.

• As well known, with such a gap the passive third harmonic
cavity induces a phase modulation over the bunch train.
• Several STREAK CAMERA experiments were performed for
various fillings, measuring the effect on:
– Phase Shift
– Bunch lengthening
– Landau Damping

– Beam Lifetime

• As a result, a new optimum filling was set for operations.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

9

80% Filling: Phase Shift/Bunch Length/Landau/Lifetime
Phase Shift along the train for different tuning
60

Ibeam=315mA,
Filling at 80%

Relative Phase (Deg)

50
40
1499,070 MHz
1499,060 MHz

30

1499,050 MHz
1499,025 MHz

20

Bunch length along the train for different tuning
1499,070 MHz

1499,020 MHz
1499,015 MHz

10
1499,060 MHz
600
700
800

RMS Bunch Length (ps)

90

1499,050 MHz

80

900

1000

1100

1200

1300

1400

Bunch position in the train (ps)

1499,025 MHz

70

1499,020 MHz

60

1499,015 MHz

50
40
30
700

900
1100
1300
Bunch position in the train (ps)

1500

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

10

1500

100% Filling: Phase Shift/Bunch Length/Landau/Lifetime

Relative Phase (Deg)

Ibeam=315mA,
Uniform Filling

Bunch length along the train for different tuning
1499,050 MHz
1499,025 MHz

RMS Bunch Length (ps)

200
180

1499,040 MHz
1499,020 MHz

1499,030 MHz
1499,015 MHz

Phase Shift along the train for different tuning

50
45
40
35
30
25
20
15
10

1499,040 MHz

1499,030 MHz
1499,020 MHz

1499,025 MHz
1499,015 MHz

1499,014 MHz
0

1499,014 MHz

160

1499,050 MHz

200

400

600

800

Bunch position in the train (ps)

Bunch overstretching

140
120
100
80
60
40
20
0

200

400

600

Bunch position in the train (ps)

800

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

11

100% Filling: Phase Shift/Bunch Length/Landau/Lifetime
The Bunch Profile Averaged on the bunch train in the case of Uniform
Filling is shown below for different tuning positions of 3HC. The “nominal
tuning” of 3HC would be around +75 kHz. Beyond this postion the Bunch

begins to show an overstreched profile. Beam Lifetime increases until the
position of +62 kHz, which is the operating position. A few kHz beyond that,
lifetime starts to decay to a few hours; further the beam is lost.
Df= +92 kHz

Df= +82 kHz

Df= +72 kHz

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

Df= +62 kHz

12

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime

Deg

Phase Shift along the bunch train

45

Uniform Filling
Filling at 98%
Filling at 96%
Filling at 90%
Filling at 80%
Filling at 70%

40
35
30
25
20
15
10
5
0

1499.010 1499.015 1499.020 1499.025 1499.030 1499.035 1499.040 1499.045 1499.050 1499.055 1499.060 1499.065 1499.070

3HC Frequency (MHz)

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

13

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime

Bunch length along the train

<> (ps)
140

Filling at 70%
Filling at 80%
Filling at 90%
Filling at 96%
Filling at 98%
Uniform Filling

130
120
110
100
90
80
70
60
50
40
30
1499.010

1499.015

1499.020

1499.025

1499.030

1499.035

1499.040

1499.045

1499.050

1499.055

1499.060

1499.065

1499.070

3HC Frequency (MHz)

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

14

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
The Landau damping seems to be influenced by the different contribution of the
increasing gap width and of the average bunch length, which is reduced as the
gap increases.

Scale is
different!

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

15

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
These strak camera images show the different effect of 3HC on the beam
between 90% filling (on the left) and uniform filling (on the right). The Landau
damping effect is similar in both cases, the 90% filling shows the expected effect
of the phase modulation along th ebunch train.
Phase
Modulation
present.
Stronger
Phase
Modulation
Bunches are
longer in the
train centre.

Df= +112 kHz

Longitudinal
UNSTABLE
Beam

Df= +92 kHz

Longitudinal
STABLE
Beam
Bunch
Length is
Uniform

Df= +62 kHz

90% Filling

Uniform Filling

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

16

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
The best performance in terms of lifetime is obtained with a fractional filling of 96%. By
further increasing the filling, the maximum obtained lifetime is lower, suggesting that the
optimum setting for ELETTRA requires a small amount of “empty gap”.
The 96% filling is now taken as the new standard filling pattern for User’s Operation
Mode (320mA, 2.0GeV). In this condition 3HC is usually tuned from 1499.050 MHz
(Df=92kHz) to 1499.020MHz (Df=62kHz).

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

17

Machine Upgrades and Ultimate Lifetime Value
During 2003 and 2004 several new vacuum
chamber installations were performed. In June
2003 a new Aluminum-NEG coated chamber
was installed in section ID10. In pre-3HC
conditions the nominal lifetime was recovered at
a dynamic pressure of about 10-11 mbar/mA. In
the example of the ID10 chamber this took
about 70 Ah, i.e. about 2,5 weeks operation.

In fact the ultimate lifetime with 3HC
active, i.e. about 27 hours at 2.0
GeV 320 mA, was reached mid of
September 2003, that is about 6
weeks of operation after the ID10
installation (there were 2 weeks
shutdown in August).
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

18

Conclusions
• 3HC routinely in operation at Elettra
• Stable Beam, refill every 36 hours
• Operability and Reliability good
• Careful maintenance to prevent
faults, recovery time can be long!
• Experiments at different fillings
confirm expected effects (phase
modulation, bunch lengthening)
• New standard filling set to 96%
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

19


Slide 9

SUPER-3HC at ELETTRA Update
G.Penco, M.Svandrlik
• Operation
• Uptime
• Maintenance
• Performance vs filling

• Conclusions

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

1

Operation/Uptime/Maintenance/Performance vs Filling
• 3HC is routinely in operation during user’s shifts.
• Lifetime depends on ultimate vacuum conditioning and
filling pattern, highest value we can obtain is 27 hrs
(320 mA; 2.0 GeV)
• Filling pattern set to 96%
• During refill and energy ramping 3HC set at +94 kHz
(from 3rd harmonic) - Transverse Feedbacks ON
• Once beam is at 2.0 Gev 3HC is activated by tuning it at
+64 kHz

• Longitudinal Coupled Bunch Instabilities are cured by 3HC,
Transverse Instabilities are cured by Feedbacks.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

2

Operation/Uptime/Maintenance/Performance vs Filling
• The increase in Beam Lifetime obtained when 3HC is
active, allows us to refill ELETTRA every 36 hrs instead
of 24 hrs, as it used to be in the past.

3HC tuned:only 3 refills
in 5 days operation

How it was
before 3HC

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

3

Operation/Uptime/Maintenance/Performance vs Filling
• General uptime of the system is good. Since September
2003 only one event caused significant User’s downtime,
on Saturday, 31/01/2004.
Users' downtime caused by 3HC, in hours
30
25
20
15,8
15
10
5
0

0,0

0,0

0,0

0,0

0,6

0,0

RUN 85
RUN 86
RUN 87
RUN 88
RUN 89
RUN 90
RUN 91
AUG - SEP 03 SEP - OCT 03 NOV - DEC 03 JAN - FEB 04 MAR - APR 04 APR - MAG 04 JUN - JUL 04

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

4

Operation/Uptime/Maintenance/Performance vs Filling
• The event on 31/01/04 was related to a failure of a rough
pumping unit of the valve-box insulation vacuum. This was a
temporary installation, replaced during the next shutdown
with a fail-safe one.
• The uptime statistics does not include systems stops due to
electrical
power
interruptions,
mostly
caused
by
thunderstorms in the surroundings. In this case most
machine systems are stopped and the restart time of the
cryogenic plant is hidden in the general restart of the
systems. For this reason the idea of connecting 3HC to a new
UPS has not yet been implemented (also financial reasons).

• We still do not have a He recovery system, the experience
made so far shows that we can survive without it, not
affecting the uptime of the system.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

5

Operation/Uptime/Maintenance/Performance vs Filling
• Several important maintenance interventions have been
successfully performed in the last 12 months.
• In November 2003 the leaky gate valve between 3HC
and the superconducting wiggler was substituted.
This required to break
the cavity vacuum. A
clean area was therefore
created inside the
storage ring tunnel. The
replacement followed
clean room procedures
and was done by CEA
and Elettra staff.
The field performance of
the cavity has not been
affected by this
intervention.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

6

Operation/Uptime/Maintenance/Performance vs Filling
• In December 2003 the tuning system of cell 1 failed for
the 2nd time (1st time in March). In January 2004 the tuning
system was replaced with an upgraded version.
• The tuning system is under vacuum, at cold. The gear box
was found to be blocked.
• Tests at Saclay showed that the reason could be a heating
problem (from the motor).
• Even if the number of cycles
after which this shows up is
huge, we are limiting the
movements of the system.
• No problem since January 04
• CEA is studying a solution to
move the motor outside the
cryomodule.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

7

Operation/Uptime/Maintenance/Performance vs Filling

• During the January shutdown the cryogenic plant annual
maintenance was performed.
• After this maintenance the nominal performance is back to
the original, i.e. about 30-35 litres/hour at 13 bar of HP.
• In August 2004 the cryomodule has been warmed-up again
in order to replace a coaxial cable which takes out the
voltage signal of cell 2.
• In this occasion also the fundamental mode rejection of the
dipolar HOM couplers has been improved. In fact on one of
them some over-heating effects were observed when tuning
the cell.

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

8

Operation/Uptime/Maintenance/Performance vs Filling
• ELETTRA used to operate with a partial filling of the bunch
train: typically a 10% empty gap was present.

• As well known, with such a gap the passive third harmonic
cavity induces a phase modulation over the bunch train.
• Several STREAK CAMERA experiments were performed for
various fillings, measuring the effect on:
– Phase Shift
– Bunch lengthening
– Landau Damping

– Beam Lifetime

• As a result, a new optimum filling was set for operations.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

9

80% Filling: Phase Shift/Bunch Length/Landau/Lifetime
Phase Shift along the train for different tuning
60

Ibeam=315mA,
Filling at 80%

Relative Phase (Deg)

50
40
1499,070 MHz
1499,060 MHz

30

1499,050 MHz
1499,025 MHz

20

Bunch length along the train for different tuning
1499,070 MHz

1499,020 MHz
1499,015 MHz

10
1499,060 MHz
600
700
800

RMS Bunch Length (ps)

90

1499,050 MHz

80

900

1000

1100

1200

1300

1400

Bunch position in the train (ps)

1499,025 MHz

70

1499,020 MHz

60

1499,015 MHz

50
40
30
700

900
1100
1300
Bunch position in the train (ps)

1500

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

10

1500

100% Filling: Phase Shift/Bunch Length/Landau/Lifetime

Relative Phase (Deg)

Ibeam=315mA,
Uniform Filling

Bunch length along the train for different tuning
1499,050 MHz
1499,025 MHz

RMS Bunch Length (ps)

200
180

1499,040 MHz
1499,020 MHz

1499,030 MHz
1499,015 MHz

Phase Shift along the train for different tuning

50
45
40
35
30
25
20
15
10

1499,040 MHz

1499,030 MHz
1499,020 MHz

1499,025 MHz
1499,015 MHz

1499,014 MHz
0

1499,014 MHz

160

1499,050 MHz

200

400

600

800

Bunch position in the train (ps)

Bunch overstretching

140
120
100
80
60
40
20
0

200

400

600

Bunch position in the train (ps)

800

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

11

100% Filling: Phase Shift/Bunch Length/Landau/Lifetime
The Bunch Profile Averaged on the bunch train in the case of Uniform
Filling is shown below for different tuning positions of 3HC. The “nominal
tuning” of 3HC would be around +75 kHz. Beyond this postion the Bunch

begins to show an overstreched profile. Beam Lifetime increases until the
position of +62 kHz, which is the operating position. A few kHz beyond that,
lifetime starts to decay to a few hours; further the beam is lost.
Df= +92 kHz

Df= +82 kHz

Df= +72 kHz

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

Df= +62 kHz

12

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime

Deg

Phase Shift along the bunch train

45

Uniform Filling
Filling at 98%
Filling at 96%
Filling at 90%
Filling at 80%
Filling at 70%

40
35
30
25
20
15
10
5
0

1499.010 1499.015 1499.020 1499.025 1499.030 1499.035 1499.040 1499.045 1499.050 1499.055 1499.060 1499.065 1499.070

3HC Frequency (MHz)

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

13

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime

Bunch length along the train

<> (ps)
140

Filling at 70%
Filling at 80%
Filling at 90%
Filling at 96%
Filling at 98%
Uniform Filling

130
120
110
100
90
80
70
60
50
40
30
1499.010

1499.015

1499.020

1499.025

1499.030

1499.035

1499.040

1499.045

1499.050

1499.055

1499.060

1499.065

1499.070

3HC Frequency (MHz)

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

14

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
The Landau damping seems to be influenced by the different contribution of the
increasing gap width and of the average bunch length, which is reduced as the
gap increases.

Scale is
different!

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

15

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
These strak camera images show the different effect of 3HC on the beam
between 90% filling (on the left) and uniform filling (on the right). The Landau
damping effect is similar in both cases, the 90% filling shows the expected effect
of the phase modulation along th ebunch train.
Phase
Modulation
present.
Stronger
Phase
Modulation
Bunches are
longer in the
train centre.

Df= +112 kHz

Longitudinal
UNSTABLE
Beam

Df= +92 kHz

Longitudinal
STABLE
Beam
Bunch
Length is
Uniform

Df= +62 kHz

90% Filling

Uniform Filling

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

16

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
The best performance in terms of lifetime is obtained with a fractional filling of 96%. By
further increasing the filling, the maximum obtained lifetime is lower, suggesting that the
optimum setting for ELETTRA requires a small amount of “empty gap”.
The 96% filling is now taken as the new standard filling pattern for User’s Operation
Mode (320mA, 2.0GeV). In this condition 3HC is usually tuned from 1499.050 MHz
(Df=92kHz) to 1499.020MHz (Df=62kHz).

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

17

Machine Upgrades and Ultimate Lifetime Value
During 2003 and 2004 several new vacuum
chamber installations were performed. In June
2003 a new Aluminum-NEG coated chamber
was installed in section ID10. In pre-3HC
conditions the nominal lifetime was recovered at
a dynamic pressure of about 10-11 mbar/mA. In
the example of the ID10 chamber this took
about 70 Ah, i.e. about 2,5 weeks operation.

In fact the ultimate lifetime with 3HC
active, i.e. about 27 hours at 2.0
GeV 320 mA, was reached mid of
September 2003, that is about 6
weeks of operation after the ID10
installation (there were 2 weeks
shutdown in August).
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

18

Conclusions
• 3HC routinely in operation at Elettra
• Stable Beam, refill every 36 hours
• Operability and Reliability good
• Careful maintenance to prevent
faults, recovery time can be long!
• Experiments at different fillings
confirm expected effects (phase
modulation, bunch lengthening)
• New standard filling set to 96%
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

19


Slide 10

SUPER-3HC at ELETTRA Update
G.Penco, M.Svandrlik
• Operation
• Uptime
• Maintenance
• Performance vs filling

• Conclusions

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

1

Operation/Uptime/Maintenance/Performance vs Filling
• 3HC is routinely in operation during user’s shifts.
• Lifetime depends on ultimate vacuum conditioning and
filling pattern, highest value we can obtain is 27 hrs
(320 mA; 2.0 GeV)
• Filling pattern set to 96%
• During refill and energy ramping 3HC set at +94 kHz
(from 3rd harmonic) - Transverse Feedbacks ON
• Once beam is at 2.0 Gev 3HC is activated by tuning it at
+64 kHz

• Longitudinal Coupled Bunch Instabilities are cured by 3HC,
Transverse Instabilities are cured by Feedbacks.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

2

Operation/Uptime/Maintenance/Performance vs Filling
• The increase in Beam Lifetime obtained when 3HC is
active, allows us to refill ELETTRA every 36 hrs instead
of 24 hrs, as it used to be in the past.

3HC tuned:only 3 refills
in 5 days operation

How it was
before 3HC

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

3

Operation/Uptime/Maintenance/Performance vs Filling
• General uptime of the system is good. Since September
2003 only one event caused significant User’s downtime,
on Saturday, 31/01/2004.
Users' downtime caused by 3HC, in hours
30
25
20
15,8
15
10
5
0

0,0

0,0

0,0

0,0

0,6

0,0

RUN 85
RUN 86
RUN 87
RUN 88
RUN 89
RUN 90
RUN 91
AUG - SEP 03 SEP - OCT 03 NOV - DEC 03 JAN - FEB 04 MAR - APR 04 APR - MAG 04 JUN - JUL 04

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

4

Operation/Uptime/Maintenance/Performance vs Filling
• The event on 31/01/04 was related to a failure of a rough
pumping unit of the valve-box insulation vacuum. This was a
temporary installation, replaced during the next shutdown
with a fail-safe one.
• The uptime statistics does not include systems stops due to
electrical
power
interruptions,
mostly
caused
by
thunderstorms in the surroundings. In this case most
machine systems are stopped and the restart time of the
cryogenic plant is hidden in the general restart of the
systems. For this reason the idea of connecting 3HC to a new
UPS has not yet been implemented (also financial reasons).

• We still do not have a He recovery system, the experience
made so far shows that we can survive without it, not
affecting the uptime of the system.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

5

Operation/Uptime/Maintenance/Performance vs Filling
• Several important maintenance interventions have been
successfully performed in the last 12 months.
• In November 2003 the leaky gate valve between 3HC
and the superconducting wiggler was substituted.
This required to break
the cavity vacuum. A
clean area was therefore
created inside the
storage ring tunnel. The
replacement followed
clean room procedures
and was done by CEA
and Elettra staff.
The field performance of
the cavity has not been
affected by this
intervention.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

6

Operation/Uptime/Maintenance/Performance vs Filling
• In December 2003 the tuning system of cell 1 failed for
the 2nd time (1st time in March). In January 2004 the tuning
system was replaced with an upgraded version.
• The tuning system is under vacuum, at cold. The gear box
was found to be blocked.
• Tests at Saclay showed that the reason could be a heating
problem (from the motor).
• Even if the number of cycles
after which this shows up is
huge, we are limiting the
movements of the system.
• No problem since January 04
• CEA is studying a solution to
move the motor outside the
cryomodule.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

7

Operation/Uptime/Maintenance/Performance vs Filling

• During the January shutdown the cryogenic plant annual
maintenance was performed.
• After this maintenance the nominal performance is back to
the original, i.e. about 30-35 litres/hour at 13 bar of HP.
• In August 2004 the cryomodule has been warmed-up again
in order to replace a coaxial cable which takes out the
voltage signal of cell 2.
• In this occasion also the fundamental mode rejection of the
dipolar HOM couplers has been improved. In fact on one of
them some over-heating effects were observed when tuning
the cell.

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

8

Operation/Uptime/Maintenance/Performance vs Filling
• ELETTRA used to operate with a partial filling of the bunch
train: typically a 10% empty gap was present.

• As well known, with such a gap the passive third harmonic
cavity induces a phase modulation over the bunch train.
• Several STREAK CAMERA experiments were performed for
various fillings, measuring the effect on:
– Phase Shift
– Bunch lengthening
– Landau Damping

– Beam Lifetime

• As a result, a new optimum filling was set for operations.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

9

80% Filling: Phase Shift/Bunch Length/Landau/Lifetime
Phase Shift along the train for different tuning
60

Ibeam=315mA,
Filling at 80%

Relative Phase (Deg)

50
40
1499,070 MHz
1499,060 MHz

30

1499,050 MHz
1499,025 MHz

20

Bunch length along the train for different tuning
1499,070 MHz

1499,020 MHz
1499,015 MHz

10
1499,060 MHz
600
700
800

RMS Bunch Length (ps)

90

1499,050 MHz

80

900

1000

1100

1200

1300

1400

Bunch position in the train (ps)

1499,025 MHz

70

1499,020 MHz

60

1499,015 MHz

50
40
30
700

900
1100
1300
Bunch position in the train (ps)

1500

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

10

1500

100% Filling: Phase Shift/Bunch Length/Landau/Lifetime

Relative Phase (Deg)

Ibeam=315mA,
Uniform Filling

Bunch length along the train for different tuning
1499,050 MHz
1499,025 MHz

RMS Bunch Length (ps)

200
180

1499,040 MHz
1499,020 MHz

1499,030 MHz
1499,015 MHz

Phase Shift along the train for different tuning

50
45
40
35
30
25
20
15
10

1499,040 MHz

1499,030 MHz
1499,020 MHz

1499,025 MHz
1499,015 MHz

1499,014 MHz
0

1499,014 MHz

160

1499,050 MHz

200

400

600

800

Bunch position in the train (ps)

Bunch overstretching

140
120
100
80
60
40
20
0

200

400

600

Bunch position in the train (ps)

800

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

11

100% Filling: Phase Shift/Bunch Length/Landau/Lifetime
The Bunch Profile Averaged on the bunch train in the case of Uniform
Filling is shown below for different tuning positions of 3HC. The “nominal
tuning” of 3HC would be around +75 kHz. Beyond this postion the Bunch

begins to show an overstreched profile. Beam Lifetime increases until the
position of +62 kHz, which is the operating position. A few kHz beyond that,
lifetime starts to decay to a few hours; further the beam is lost.
Df= +92 kHz

Df= +82 kHz

Df= +72 kHz

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

Df= +62 kHz

12

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime

Deg

Phase Shift along the bunch train

45

Uniform Filling
Filling at 98%
Filling at 96%
Filling at 90%
Filling at 80%
Filling at 70%

40
35
30
25
20
15
10
5
0

1499.010 1499.015 1499.020 1499.025 1499.030 1499.035 1499.040 1499.045 1499.050 1499.055 1499.060 1499.065 1499.070

3HC Frequency (MHz)

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

13

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime

Bunch length along the train

<> (ps)
140

Filling at 70%
Filling at 80%
Filling at 90%
Filling at 96%
Filling at 98%
Uniform Filling

130
120
110
100
90
80
70
60
50
40
30
1499.010

1499.015

1499.020

1499.025

1499.030

1499.035

1499.040

1499.045

1499.050

1499.055

1499.060

1499.065

1499.070

3HC Frequency (MHz)

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

14

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
The Landau damping seems to be influenced by the different contribution of the
increasing gap width and of the average bunch length, which is reduced as the
gap increases.

Scale is
different!

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

15

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
These strak camera images show the different effect of 3HC on the beam
between 90% filling (on the left) and uniform filling (on the right). The Landau
damping effect is similar in both cases, the 90% filling shows the expected effect
of the phase modulation along th ebunch train.
Phase
Modulation
present.
Stronger
Phase
Modulation
Bunches are
longer in the
train centre.

Df= +112 kHz

Longitudinal
UNSTABLE
Beam

Df= +92 kHz

Longitudinal
STABLE
Beam
Bunch
Length is
Uniform

Df= +62 kHz

90% Filling

Uniform Filling

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

16

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
The best performance in terms of lifetime is obtained with a fractional filling of 96%. By
further increasing the filling, the maximum obtained lifetime is lower, suggesting that the
optimum setting for ELETTRA requires a small amount of “empty gap”.
The 96% filling is now taken as the new standard filling pattern for User’s Operation
Mode (320mA, 2.0GeV). In this condition 3HC is usually tuned from 1499.050 MHz
(Df=92kHz) to 1499.020MHz (Df=62kHz).

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

17

Machine Upgrades and Ultimate Lifetime Value
During 2003 and 2004 several new vacuum
chamber installations were performed. In June
2003 a new Aluminum-NEG coated chamber
was installed in section ID10. In pre-3HC
conditions the nominal lifetime was recovered at
a dynamic pressure of about 10-11 mbar/mA. In
the example of the ID10 chamber this took
about 70 Ah, i.e. about 2,5 weeks operation.

In fact the ultimate lifetime with 3HC
active, i.e. about 27 hours at 2.0
GeV 320 mA, was reached mid of
September 2003, that is about 6
weeks of operation after the ID10
installation (there were 2 weeks
shutdown in August).
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

18

Conclusions
• 3HC routinely in operation at Elettra
• Stable Beam, refill every 36 hours
• Operability and Reliability good
• Careful maintenance to prevent
faults, recovery time can be long!
• Experiments at different fillings
confirm expected effects (phase
modulation, bunch lengthening)
• New standard filling set to 96%
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

19


Slide 11

SUPER-3HC at ELETTRA Update
G.Penco, M.Svandrlik
• Operation
• Uptime
• Maintenance
• Performance vs filling

• Conclusions

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

1

Operation/Uptime/Maintenance/Performance vs Filling
• 3HC is routinely in operation during user’s shifts.
• Lifetime depends on ultimate vacuum conditioning and
filling pattern, highest value we can obtain is 27 hrs
(320 mA; 2.0 GeV)
• Filling pattern set to 96%
• During refill and energy ramping 3HC set at +94 kHz
(from 3rd harmonic) - Transverse Feedbacks ON
• Once beam is at 2.0 Gev 3HC is activated by tuning it at
+64 kHz

• Longitudinal Coupled Bunch Instabilities are cured by 3HC,
Transverse Instabilities are cured by Feedbacks.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

2

Operation/Uptime/Maintenance/Performance vs Filling
• The increase in Beam Lifetime obtained when 3HC is
active, allows us to refill ELETTRA every 36 hrs instead
of 24 hrs, as it used to be in the past.

3HC tuned:only 3 refills
in 5 days operation

How it was
before 3HC

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

3

Operation/Uptime/Maintenance/Performance vs Filling
• General uptime of the system is good. Since September
2003 only one event caused significant User’s downtime,
on Saturday, 31/01/2004.
Users' downtime caused by 3HC, in hours
30
25
20
15,8
15
10
5
0

0,0

0,0

0,0

0,0

0,6

0,0

RUN 85
RUN 86
RUN 87
RUN 88
RUN 89
RUN 90
RUN 91
AUG - SEP 03 SEP - OCT 03 NOV - DEC 03 JAN - FEB 04 MAR - APR 04 APR - MAG 04 JUN - JUL 04

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

4

Operation/Uptime/Maintenance/Performance vs Filling
• The event on 31/01/04 was related to a failure of a rough
pumping unit of the valve-box insulation vacuum. This was a
temporary installation, replaced during the next shutdown
with a fail-safe one.
• The uptime statistics does not include systems stops due to
electrical
power
interruptions,
mostly
caused
by
thunderstorms in the surroundings. In this case most
machine systems are stopped and the restart time of the
cryogenic plant is hidden in the general restart of the
systems. For this reason the idea of connecting 3HC to a new
UPS has not yet been implemented (also financial reasons).

• We still do not have a He recovery system, the experience
made so far shows that we can survive without it, not
affecting the uptime of the system.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

5

Operation/Uptime/Maintenance/Performance vs Filling
• Several important maintenance interventions have been
successfully performed in the last 12 months.
• In November 2003 the leaky gate valve between 3HC
and the superconducting wiggler was substituted.
This required to break
the cavity vacuum. A
clean area was therefore
created inside the
storage ring tunnel. The
replacement followed
clean room procedures
and was done by CEA
and Elettra staff.
The field performance of
the cavity has not been
affected by this
intervention.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

6

Operation/Uptime/Maintenance/Performance vs Filling
• In December 2003 the tuning system of cell 1 failed for
the 2nd time (1st time in March). In January 2004 the tuning
system was replaced with an upgraded version.
• The tuning system is under vacuum, at cold. The gear box
was found to be blocked.
• Tests at Saclay showed that the reason could be a heating
problem (from the motor).
• Even if the number of cycles
after which this shows up is
huge, we are limiting the
movements of the system.
• No problem since January 04
• CEA is studying a solution to
move the motor outside the
cryomodule.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

7

Operation/Uptime/Maintenance/Performance vs Filling

• During the January shutdown the cryogenic plant annual
maintenance was performed.
• After this maintenance the nominal performance is back to
the original, i.e. about 30-35 litres/hour at 13 bar of HP.
• In August 2004 the cryomodule has been warmed-up again
in order to replace a coaxial cable which takes out the
voltage signal of cell 2.
• In this occasion also the fundamental mode rejection of the
dipolar HOM couplers has been improved. In fact on one of
them some over-heating effects were observed when tuning
the cell.

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

8

Operation/Uptime/Maintenance/Performance vs Filling
• ELETTRA used to operate with a partial filling of the bunch
train: typically a 10% empty gap was present.

• As well known, with such a gap the passive third harmonic
cavity induces a phase modulation over the bunch train.
• Several STREAK CAMERA experiments were performed for
various fillings, measuring the effect on:
– Phase Shift
– Bunch lengthening
– Landau Damping

– Beam Lifetime

• As a result, a new optimum filling was set for operations.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

9

80% Filling: Phase Shift/Bunch Length/Landau/Lifetime
Phase Shift along the train for different tuning
60

Ibeam=315mA,
Filling at 80%

Relative Phase (Deg)

50
40
1499,070 MHz
1499,060 MHz

30

1499,050 MHz
1499,025 MHz

20

Bunch length along the train for different tuning
1499,070 MHz

1499,020 MHz
1499,015 MHz

10
1499,060 MHz
600
700
800

RMS Bunch Length (ps)

90

1499,050 MHz

80

900

1000

1100

1200

1300

1400

Bunch position in the train (ps)

1499,025 MHz

70

1499,020 MHz

60

1499,015 MHz

50
40
30
700

900
1100
1300
Bunch position in the train (ps)

1500

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

10

1500

100% Filling: Phase Shift/Bunch Length/Landau/Lifetime

Relative Phase (Deg)

Ibeam=315mA,
Uniform Filling

Bunch length along the train for different tuning
1499,050 MHz
1499,025 MHz

RMS Bunch Length (ps)

200
180

1499,040 MHz
1499,020 MHz

1499,030 MHz
1499,015 MHz

Phase Shift along the train for different tuning

50
45
40
35
30
25
20
15
10

1499,040 MHz

1499,030 MHz
1499,020 MHz

1499,025 MHz
1499,015 MHz

1499,014 MHz
0

1499,014 MHz

160

1499,050 MHz

200

400

600

800

Bunch position in the train (ps)

Bunch overstretching

140
120
100
80
60
40
20
0

200

400

600

Bunch position in the train (ps)

800

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

11

100% Filling: Phase Shift/Bunch Length/Landau/Lifetime
The Bunch Profile Averaged on the bunch train in the case of Uniform
Filling is shown below for different tuning positions of 3HC. The “nominal
tuning” of 3HC would be around +75 kHz. Beyond this postion the Bunch

begins to show an overstreched profile. Beam Lifetime increases until the
position of +62 kHz, which is the operating position. A few kHz beyond that,
lifetime starts to decay to a few hours; further the beam is lost.
Df= +92 kHz

Df= +82 kHz

Df= +72 kHz

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

Df= +62 kHz

12

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime

Deg

Phase Shift along the bunch train

45

Uniform Filling
Filling at 98%
Filling at 96%
Filling at 90%
Filling at 80%
Filling at 70%

40
35
30
25
20
15
10
5
0

1499.010 1499.015 1499.020 1499.025 1499.030 1499.035 1499.040 1499.045 1499.050 1499.055 1499.060 1499.065 1499.070

3HC Frequency (MHz)

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

13

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime

Bunch length along the train

<> (ps)
140

Filling at 70%
Filling at 80%
Filling at 90%
Filling at 96%
Filling at 98%
Uniform Filling

130
120
110
100
90
80
70
60
50
40
30
1499.010

1499.015

1499.020

1499.025

1499.030

1499.035

1499.040

1499.045

1499.050

1499.055

1499.060

1499.065

1499.070

3HC Frequency (MHz)

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

14

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
The Landau damping seems to be influenced by the different contribution of the
increasing gap width and of the average bunch length, which is reduced as the
gap increases.

Scale is
different!

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

15

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
These strak camera images show the different effect of 3HC on the beam
between 90% filling (on the left) and uniform filling (on the right). The Landau
damping effect is similar in both cases, the 90% filling shows the expected effect
of the phase modulation along th ebunch train.
Phase
Modulation
present.
Stronger
Phase
Modulation
Bunches are
longer in the
train centre.

Df= +112 kHz

Longitudinal
UNSTABLE
Beam

Df= +92 kHz

Longitudinal
STABLE
Beam
Bunch
Length is
Uniform

Df= +62 kHz

90% Filling

Uniform Filling

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

16

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
The best performance in terms of lifetime is obtained with a fractional filling of 96%. By
further increasing the filling, the maximum obtained lifetime is lower, suggesting that the
optimum setting for ELETTRA requires a small amount of “empty gap”.
The 96% filling is now taken as the new standard filling pattern for User’s Operation
Mode (320mA, 2.0GeV). In this condition 3HC is usually tuned from 1499.050 MHz
(Df=92kHz) to 1499.020MHz (Df=62kHz).

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

17

Machine Upgrades and Ultimate Lifetime Value
During 2003 and 2004 several new vacuum
chamber installations were performed. In June
2003 a new Aluminum-NEG coated chamber
was installed in section ID10. In pre-3HC
conditions the nominal lifetime was recovered at
a dynamic pressure of about 10-11 mbar/mA. In
the example of the ID10 chamber this took
about 70 Ah, i.e. about 2,5 weeks operation.

In fact the ultimate lifetime with 3HC
active, i.e. about 27 hours at 2.0
GeV 320 mA, was reached mid of
September 2003, that is about 6
weeks of operation after the ID10
installation (there were 2 weeks
shutdown in August).
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

18

Conclusions
• 3HC routinely in operation at Elettra
• Stable Beam, refill every 36 hours
• Operability and Reliability good
• Careful maintenance to prevent
faults, recovery time can be long!
• Experiments at different fillings
confirm expected effects (phase
modulation, bunch lengthening)
• New standard filling set to 96%
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

19


Slide 12

SUPER-3HC at ELETTRA Update
G.Penco, M.Svandrlik
• Operation
• Uptime
• Maintenance
• Performance vs filling

• Conclusions

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

1

Operation/Uptime/Maintenance/Performance vs Filling
• 3HC is routinely in operation during user’s shifts.
• Lifetime depends on ultimate vacuum conditioning and
filling pattern, highest value we can obtain is 27 hrs
(320 mA; 2.0 GeV)
• Filling pattern set to 96%
• During refill and energy ramping 3HC set at +94 kHz
(from 3rd harmonic) - Transverse Feedbacks ON
• Once beam is at 2.0 Gev 3HC is activated by tuning it at
+64 kHz

• Longitudinal Coupled Bunch Instabilities are cured by 3HC,
Transverse Instabilities are cured by Feedbacks.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

2

Operation/Uptime/Maintenance/Performance vs Filling
• The increase in Beam Lifetime obtained when 3HC is
active, allows us to refill ELETTRA every 36 hrs instead
of 24 hrs, as it used to be in the past.

3HC tuned:only 3 refills
in 5 days operation

How it was
before 3HC

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

3

Operation/Uptime/Maintenance/Performance vs Filling
• General uptime of the system is good. Since September
2003 only one event caused significant User’s downtime,
on Saturday, 31/01/2004.
Users' downtime caused by 3HC, in hours
30
25
20
15,8
15
10
5
0

0,0

0,0

0,0

0,0

0,6

0,0

RUN 85
RUN 86
RUN 87
RUN 88
RUN 89
RUN 90
RUN 91
AUG - SEP 03 SEP - OCT 03 NOV - DEC 03 JAN - FEB 04 MAR - APR 04 APR - MAG 04 JUN - JUL 04

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

4

Operation/Uptime/Maintenance/Performance vs Filling
• The event on 31/01/04 was related to a failure of a rough
pumping unit of the valve-box insulation vacuum. This was a
temporary installation, replaced during the next shutdown
with a fail-safe one.
• The uptime statistics does not include systems stops due to
electrical
power
interruptions,
mostly
caused
by
thunderstorms in the surroundings. In this case most
machine systems are stopped and the restart time of the
cryogenic plant is hidden in the general restart of the
systems. For this reason the idea of connecting 3HC to a new
UPS has not yet been implemented (also financial reasons).

• We still do not have a He recovery system, the experience
made so far shows that we can survive without it, not
affecting the uptime of the system.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

5

Operation/Uptime/Maintenance/Performance vs Filling
• Several important maintenance interventions have been
successfully performed in the last 12 months.
• In November 2003 the leaky gate valve between 3HC
and the superconducting wiggler was substituted.
This required to break
the cavity vacuum. A
clean area was therefore
created inside the
storage ring tunnel. The
replacement followed
clean room procedures
and was done by CEA
and Elettra staff.
The field performance of
the cavity has not been
affected by this
intervention.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

6

Operation/Uptime/Maintenance/Performance vs Filling
• In December 2003 the tuning system of cell 1 failed for
the 2nd time (1st time in March). In January 2004 the tuning
system was replaced with an upgraded version.
• The tuning system is under vacuum, at cold. The gear box
was found to be blocked.
• Tests at Saclay showed that the reason could be a heating
problem (from the motor).
• Even if the number of cycles
after which this shows up is
huge, we are limiting the
movements of the system.
• No problem since January 04
• CEA is studying a solution to
move the motor outside the
cryomodule.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

7

Operation/Uptime/Maintenance/Performance vs Filling

• During the January shutdown the cryogenic plant annual
maintenance was performed.
• After this maintenance the nominal performance is back to
the original, i.e. about 30-35 litres/hour at 13 bar of HP.
• In August 2004 the cryomodule has been warmed-up again
in order to replace a coaxial cable which takes out the
voltage signal of cell 2.
• In this occasion also the fundamental mode rejection of the
dipolar HOM couplers has been improved. In fact on one of
them some over-heating effects were observed when tuning
the cell.

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

8

Operation/Uptime/Maintenance/Performance vs Filling
• ELETTRA used to operate with a partial filling of the bunch
train: typically a 10% empty gap was present.

• As well known, with such a gap the passive third harmonic
cavity induces a phase modulation over the bunch train.
• Several STREAK CAMERA experiments were performed for
various fillings, measuring the effect on:
– Phase Shift
– Bunch lengthening
– Landau Damping

– Beam Lifetime

• As a result, a new optimum filling was set for operations.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

9

80% Filling: Phase Shift/Bunch Length/Landau/Lifetime
Phase Shift along the train for different tuning
60

Ibeam=315mA,
Filling at 80%

Relative Phase (Deg)

50
40
1499,070 MHz
1499,060 MHz

30

1499,050 MHz
1499,025 MHz

20

Bunch length along the train for different tuning
1499,070 MHz

1499,020 MHz
1499,015 MHz

10
1499,060 MHz
600
700
800

RMS Bunch Length (ps)

90

1499,050 MHz

80

900

1000

1100

1200

1300

1400

Bunch position in the train (ps)

1499,025 MHz

70

1499,020 MHz

60

1499,015 MHz

50
40
30
700

900
1100
1300
Bunch position in the train (ps)

1500

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

10

1500

100% Filling: Phase Shift/Bunch Length/Landau/Lifetime

Relative Phase (Deg)

Ibeam=315mA,
Uniform Filling

Bunch length along the train for different tuning
1499,050 MHz
1499,025 MHz

RMS Bunch Length (ps)

200
180

1499,040 MHz
1499,020 MHz

1499,030 MHz
1499,015 MHz

Phase Shift along the train for different tuning

50
45
40
35
30
25
20
15
10

1499,040 MHz

1499,030 MHz
1499,020 MHz

1499,025 MHz
1499,015 MHz

1499,014 MHz
0

1499,014 MHz

160

1499,050 MHz

200

400

600

800

Bunch position in the train (ps)

Bunch overstretching

140
120
100
80
60
40
20
0

200

400

600

Bunch position in the train (ps)

800

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

11

100% Filling: Phase Shift/Bunch Length/Landau/Lifetime
The Bunch Profile Averaged on the bunch train in the case of Uniform
Filling is shown below for different tuning positions of 3HC. The “nominal
tuning” of 3HC would be around +75 kHz. Beyond this postion the Bunch

begins to show an overstreched profile. Beam Lifetime increases until the
position of +62 kHz, which is the operating position. A few kHz beyond that,
lifetime starts to decay to a few hours; further the beam is lost.
Df= +92 kHz

Df= +82 kHz

Df= +72 kHz

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

Df= +62 kHz

12

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime

Deg

Phase Shift along the bunch train

45

Uniform Filling
Filling at 98%
Filling at 96%
Filling at 90%
Filling at 80%
Filling at 70%

40
35
30
25
20
15
10
5
0

1499.010 1499.015 1499.020 1499.025 1499.030 1499.035 1499.040 1499.045 1499.050 1499.055 1499.060 1499.065 1499.070

3HC Frequency (MHz)

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

13

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime

Bunch length along the train

<> (ps)
140

Filling at 70%
Filling at 80%
Filling at 90%
Filling at 96%
Filling at 98%
Uniform Filling

130
120
110
100
90
80
70
60
50
40
30
1499.010

1499.015

1499.020

1499.025

1499.030

1499.035

1499.040

1499.045

1499.050

1499.055

1499.060

1499.065

1499.070

3HC Frequency (MHz)

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

14

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
The Landau damping seems to be influenced by the different contribution of the
increasing gap width and of the average bunch length, which is reduced as the
gap increases.

Scale is
different!

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

15

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
These strak camera images show the different effect of 3HC on the beam
between 90% filling (on the left) and uniform filling (on the right). The Landau
damping effect is similar in both cases, the 90% filling shows the expected effect
of the phase modulation along th ebunch train.
Phase
Modulation
present.
Stronger
Phase
Modulation
Bunches are
longer in the
train centre.

Df= +112 kHz

Longitudinal
UNSTABLE
Beam

Df= +92 kHz

Longitudinal
STABLE
Beam
Bunch
Length is
Uniform

Df= +62 kHz

90% Filling

Uniform Filling

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

16

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
The best performance in terms of lifetime is obtained with a fractional filling of 96%. By
further increasing the filling, the maximum obtained lifetime is lower, suggesting that the
optimum setting for ELETTRA requires a small amount of “empty gap”.
The 96% filling is now taken as the new standard filling pattern for User’s Operation
Mode (320mA, 2.0GeV). In this condition 3HC is usually tuned from 1499.050 MHz
(Df=92kHz) to 1499.020MHz (Df=62kHz).

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

17

Machine Upgrades and Ultimate Lifetime Value
During 2003 and 2004 several new vacuum
chamber installations were performed. In June
2003 a new Aluminum-NEG coated chamber
was installed in section ID10. In pre-3HC
conditions the nominal lifetime was recovered at
a dynamic pressure of about 10-11 mbar/mA. In
the example of the ID10 chamber this took
about 70 Ah, i.e. about 2,5 weeks operation.

In fact the ultimate lifetime with 3HC
active, i.e. about 27 hours at 2.0
GeV 320 mA, was reached mid of
September 2003, that is about 6
weeks of operation after the ID10
installation (there were 2 weeks
shutdown in August).
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

18

Conclusions
• 3HC routinely in operation at Elettra
• Stable Beam, refill every 36 hours
• Operability and Reliability good
• Careful maintenance to prevent
faults, recovery time can be long!
• Experiments at different fillings
confirm expected effects (phase
modulation, bunch lengthening)
• New standard filling set to 96%
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

19


Slide 13

SUPER-3HC at ELETTRA Update
G.Penco, M.Svandrlik
• Operation
• Uptime
• Maintenance
• Performance vs filling

• Conclusions

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

1

Operation/Uptime/Maintenance/Performance vs Filling
• 3HC is routinely in operation during user’s shifts.
• Lifetime depends on ultimate vacuum conditioning and
filling pattern, highest value we can obtain is 27 hrs
(320 mA; 2.0 GeV)
• Filling pattern set to 96%
• During refill and energy ramping 3HC set at +94 kHz
(from 3rd harmonic) - Transverse Feedbacks ON
• Once beam is at 2.0 Gev 3HC is activated by tuning it at
+64 kHz

• Longitudinal Coupled Bunch Instabilities are cured by 3HC,
Transverse Instabilities are cured by Feedbacks.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

2

Operation/Uptime/Maintenance/Performance vs Filling
• The increase in Beam Lifetime obtained when 3HC is
active, allows us to refill ELETTRA every 36 hrs instead
of 24 hrs, as it used to be in the past.

3HC tuned:only 3 refills
in 5 days operation

How it was
before 3HC

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

3

Operation/Uptime/Maintenance/Performance vs Filling
• General uptime of the system is good. Since September
2003 only one event caused significant User’s downtime,
on Saturday, 31/01/2004.
Users' downtime caused by 3HC, in hours
30
25
20
15,8
15
10
5
0

0,0

0,0

0,0

0,0

0,6

0,0

RUN 85
RUN 86
RUN 87
RUN 88
RUN 89
RUN 90
RUN 91
AUG - SEP 03 SEP - OCT 03 NOV - DEC 03 JAN - FEB 04 MAR - APR 04 APR - MAG 04 JUN - JUL 04

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

4

Operation/Uptime/Maintenance/Performance vs Filling
• The event on 31/01/04 was related to a failure of a rough
pumping unit of the valve-box insulation vacuum. This was a
temporary installation, replaced during the next shutdown
with a fail-safe one.
• The uptime statistics does not include systems stops due to
electrical
power
interruptions,
mostly
caused
by
thunderstorms in the surroundings. In this case most
machine systems are stopped and the restart time of the
cryogenic plant is hidden in the general restart of the
systems. For this reason the idea of connecting 3HC to a new
UPS has not yet been implemented (also financial reasons).

• We still do not have a He recovery system, the experience
made so far shows that we can survive without it, not
affecting the uptime of the system.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

5

Operation/Uptime/Maintenance/Performance vs Filling
• Several important maintenance interventions have been
successfully performed in the last 12 months.
• In November 2003 the leaky gate valve between 3HC
and the superconducting wiggler was substituted.
This required to break
the cavity vacuum. A
clean area was therefore
created inside the
storage ring tunnel. The
replacement followed
clean room procedures
and was done by CEA
and Elettra staff.
The field performance of
the cavity has not been
affected by this
intervention.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

6

Operation/Uptime/Maintenance/Performance vs Filling
• In December 2003 the tuning system of cell 1 failed for
the 2nd time (1st time in March). In January 2004 the tuning
system was replaced with an upgraded version.
• The tuning system is under vacuum, at cold. The gear box
was found to be blocked.
• Tests at Saclay showed that the reason could be a heating
problem (from the motor).
• Even if the number of cycles
after which this shows up is
huge, we are limiting the
movements of the system.
• No problem since January 04
• CEA is studying a solution to
move the motor outside the
cryomodule.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

7

Operation/Uptime/Maintenance/Performance vs Filling

• During the January shutdown the cryogenic plant annual
maintenance was performed.
• After this maintenance the nominal performance is back to
the original, i.e. about 30-35 litres/hour at 13 bar of HP.
• In August 2004 the cryomodule has been warmed-up again
in order to replace a coaxial cable which takes out the
voltage signal of cell 2.
• In this occasion also the fundamental mode rejection of the
dipolar HOM couplers has been improved. In fact on one of
them some over-heating effects were observed when tuning
the cell.

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

8

Operation/Uptime/Maintenance/Performance vs Filling
• ELETTRA used to operate with a partial filling of the bunch
train: typically a 10% empty gap was present.

• As well known, with such a gap the passive third harmonic
cavity induces a phase modulation over the bunch train.
• Several STREAK CAMERA experiments were performed for
various fillings, measuring the effect on:
– Phase Shift
– Bunch lengthening
– Landau Damping

– Beam Lifetime

• As a result, a new optimum filling was set for operations.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

9

80% Filling: Phase Shift/Bunch Length/Landau/Lifetime
Phase Shift along the train for different tuning
60

Ibeam=315mA,
Filling at 80%

Relative Phase (Deg)

50
40
1499,070 MHz
1499,060 MHz

30

1499,050 MHz
1499,025 MHz

20

Bunch length along the train for different tuning
1499,070 MHz

1499,020 MHz
1499,015 MHz

10
1499,060 MHz
600
700
800

RMS Bunch Length (ps)

90

1499,050 MHz

80

900

1000

1100

1200

1300

1400

Bunch position in the train (ps)

1499,025 MHz

70

1499,020 MHz

60

1499,015 MHz

50
40
30
700

900
1100
1300
Bunch position in the train (ps)

1500

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

10

1500

100% Filling: Phase Shift/Bunch Length/Landau/Lifetime

Relative Phase (Deg)

Ibeam=315mA,
Uniform Filling

Bunch length along the train for different tuning
1499,050 MHz
1499,025 MHz

RMS Bunch Length (ps)

200
180

1499,040 MHz
1499,020 MHz

1499,030 MHz
1499,015 MHz

Phase Shift along the train for different tuning

50
45
40
35
30
25
20
15
10

1499,040 MHz

1499,030 MHz
1499,020 MHz

1499,025 MHz
1499,015 MHz

1499,014 MHz
0

1499,014 MHz

160

1499,050 MHz

200

400

600

800

Bunch position in the train (ps)

Bunch overstretching

140
120
100
80
60
40
20
0

200

400

600

Bunch position in the train (ps)

800

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

11

100% Filling: Phase Shift/Bunch Length/Landau/Lifetime
The Bunch Profile Averaged on the bunch train in the case of Uniform
Filling is shown below for different tuning positions of 3HC. The “nominal
tuning” of 3HC would be around +75 kHz. Beyond this postion the Bunch

begins to show an overstreched profile. Beam Lifetime increases until the
position of +62 kHz, which is the operating position. A few kHz beyond that,
lifetime starts to decay to a few hours; further the beam is lost.
Df= +92 kHz

Df= +82 kHz

Df= +72 kHz

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

Df= +62 kHz

12

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime

Deg

Phase Shift along the bunch train

45

Uniform Filling
Filling at 98%
Filling at 96%
Filling at 90%
Filling at 80%
Filling at 70%

40
35
30
25
20
15
10
5
0

1499.010 1499.015 1499.020 1499.025 1499.030 1499.035 1499.040 1499.045 1499.050 1499.055 1499.060 1499.065 1499.070

3HC Frequency (MHz)

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

13

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime

Bunch length along the train

<> (ps)
140

Filling at 70%
Filling at 80%
Filling at 90%
Filling at 96%
Filling at 98%
Uniform Filling

130
120
110
100
90
80
70
60
50
40
30
1499.010

1499.015

1499.020

1499.025

1499.030

1499.035

1499.040

1499.045

1499.050

1499.055

1499.060

1499.065

1499.070

3HC Frequency (MHz)

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

14

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
The Landau damping seems to be influenced by the different contribution of the
increasing gap width and of the average bunch length, which is reduced as the
gap increases.

Scale is
different!

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

15

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
These strak camera images show the different effect of 3HC on the beam
between 90% filling (on the left) and uniform filling (on the right). The Landau
damping effect is similar in both cases, the 90% filling shows the expected effect
of the phase modulation along th ebunch train.
Phase
Modulation
present.
Stronger
Phase
Modulation
Bunches are
longer in the
train centre.

Df= +112 kHz

Longitudinal
UNSTABLE
Beam

Df= +92 kHz

Longitudinal
STABLE
Beam
Bunch
Length is
Uniform

Df= +62 kHz

90% Filling

Uniform Filling

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

16

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
The best performance in terms of lifetime is obtained with a fractional filling of 96%. By
further increasing the filling, the maximum obtained lifetime is lower, suggesting that the
optimum setting for ELETTRA requires a small amount of “empty gap”.
The 96% filling is now taken as the new standard filling pattern for User’s Operation
Mode (320mA, 2.0GeV). In this condition 3HC is usually tuned from 1499.050 MHz
(Df=92kHz) to 1499.020MHz (Df=62kHz).

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

17

Machine Upgrades and Ultimate Lifetime Value
During 2003 and 2004 several new vacuum
chamber installations were performed. In June
2003 a new Aluminum-NEG coated chamber
was installed in section ID10. In pre-3HC
conditions the nominal lifetime was recovered at
a dynamic pressure of about 10-11 mbar/mA. In
the example of the ID10 chamber this took
about 70 Ah, i.e. about 2,5 weeks operation.

In fact the ultimate lifetime with 3HC
active, i.e. about 27 hours at 2.0
GeV 320 mA, was reached mid of
September 2003, that is about 6
weeks of operation after the ID10
installation (there were 2 weeks
shutdown in August).
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

18

Conclusions
• 3HC routinely in operation at Elettra
• Stable Beam, refill every 36 hours
• Operability and Reliability good
• Careful maintenance to prevent
faults, recovery time can be long!
• Experiments at different fillings
confirm expected effects (phase
modulation, bunch lengthening)
• New standard filling set to 96%
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

19


Slide 14

SUPER-3HC at ELETTRA Update
G.Penco, M.Svandrlik
• Operation
• Uptime
• Maintenance
• Performance vs filling

• Conclusions

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

1

Operation/Uptime/Maintenance/Performance vs Filling
• 3HC is routinely in operation during user’s shifts.
• Lifetime depends on ultimate vacuum conditioning and
filling pattern, highest value we can obtain is 27 hrs
(320 mA; 2.0 GeV)
• Filling pattern set to 96%
• During refill and energy ramping 3HC set at +94 kHz
(from 3rd harmonic) - Transverse Feedbacks ON
• Once beam is at 2.0 Gev 3HC is activated by tuning it at
+64 kHz

• Longitudinal Coupled Bunch Instabilities are cured by 3HC,
Transverse Instabilities are cured by Feedbacks.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

2

Operation/Uptime/Maintenance/Performance vs Filling
• The increase in Beam Lifetime obtained when 3HC is
active, allows us to refill ELETTRA every 36 hrs instead
of 24 hrs, as it used to be in the past.

3HC tuned:only 3 refills
in 5 days operation

How it was
before 3HC

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

3

Operation/Uptime/Maintenance/Performance vs Filling
• General uptime of the system is good. Since September
2003 only one event caused significant User’s downtime,
on Saturday, 31/01/2004.
Users' downtime caused by 3HC, in hours
30
25
20
15,8
15
10
5
0

0,0

0,0

0,0

0,0

0,6

0,0

RUN 85
RUN 86
RUN 87
RUN 88
RUN 89
RUN 90
RUN 91
AUG - SEP 03 SEP - OCT 03 NOV - DEC 03 JAN - FEB 04 MAR - APR 04 APR - MAG 04 JUN - JUL 04

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

4

Operation/Uptime/Maintenance/Performance vs Filling
• The event on 31/01/04 was related to a failure of a rough
pumping unit of the valve-box insulation vacuum. This was a
temporary installation, replaced during the next shutdown
with a fail-safe one.
• The uptime statistics does not include systems stops due to
electrical
power
interruptions,
mostly
caused
by
thunderstorms in the surroundings. In this case most
machine systems are stopped and the restart time of the
cryogenic plant is hidden in the general restart of the
systems. For this reason the idea of connecting 3HC to a new
UPS has not yet been implemented (also financial reasons).

• We still do not have a He recovery system, the experience
made so far shows that we can survive without it, not
affecting the uptime of the system.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

5

Operation/Uptime/Maintenance/Performance vs Filling
• Several important maintenance interventions have been
successfully performed in the last 12 months.
• In November 2003 the leaky gate valve between 3HC
and the superconducting wiggler was substituted.
This required to break
the cavity vacuum. A
clean area was therefore
created inside the
storage ring tunnel. The
replacement followed
clean room procedures
and was done by CEA
and Elettra staff.
The field performance of
the cavity has not been
affected by this
intervention.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

6

Operation/Uptime/Maintenance/Performance vs Filling
• In December 2003 the tuning system of cell 1 failed for
the 2nd time (1st time in March). In January 2004 the tuning
system was replaced with an upgraded version.
• The tuning system is under vacuum, at cold. The gear box
was found to be blocked.
• Tests at Saclay showed that the reason could be a heating
problem (from the motor).
• Even if the number of cycles
after which this shows up is
huge, we are limiting the
movements of the system.
• No problem since January 04
• CEA is studying a solution to
move the motor outside the
cryomodule.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

7

Operation/Uptime/Maintenance/Performance vs Filling

• During the January shutdown the cryogenic plant annual
maintenance was performed.
• After this maintenance the nominal performance is back to
the original, i.e. about 30-35 litres/hour at 13 bar of HP.
• In August 2004 the cryomodule has been warmed-up again
in order to replace a coaxial cable which takes out the
voltage signal of cell 2.
• In this occasion also the fundamental mode rejection of the
dipolar HOM couplers has been improved. In fact on one of
them some over-heating effects were observed when tuning
the cell.

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

8

Operation/Uptime/Maintenance/Performance vs Filling
• ELETTRA used to operate with a partial filling of the bunch
train: typically a 10% empty gap was present.

• As well known, with such a gap the passive third harmonic
cavity induces a phase modulation over the bunch train.
• Several STREAK CAMERA experiments were performed for
various fillings, measuring the effect on:
– Phase Shift
– Bunch lengthening
– Landau Damping

– Beam Lifetime

• As a result, a new optimum filling was set for operations.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

9

80% Filling: Phase Shift/Bunch Length/Landau/Lifetime
Phase Shift along the train for different tuning
60

Ibeam=315mA,
Filling at 80%

Relative Phase (Deg)

50
40
1499,070 MHz
1499,060 MHz

30

1499,050 MHz
1499,025 MHz

20

Bunch length along the train for different tuning
1499,070 MHz

1499,020 MHz
1499,015 MHz

10
1499,060 MHz
600
700
800

RMS Bunch Length (ps)

90

1499,050 MHz

80

900

1000

1100

1200

1300

1400

Bunch position in the train (ps)

1499,025 MHz

70

1499,020 MHz

60

1499,015 MHz

50
40
30
700

900
1100
1300
Bunch position in the train (ps)

1500

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

10

1500

100% Filling: Phase Shift/Bunch Length/Landau/Lifetime

Relative Phase (Deg)

Ibeam=315mA,
Uniform Filling

Bunch length along the train for different tuning
1499,050 MHz
1499,025 MHz

RMS Bunch Length (ps)

200
180

1499,040 MHz
1499,020 MHz

1499,030 MHz
1499,015 MHz

Phase Shift along the train for different tuning

50
45
40
35
30
25
20
15
10

1499,040 MHz

1499,030 MHz
1499,020 MHz

1499,025 MHz
1499,015 MHz

1499,014 MHz
0

1499,014 MHz

160

1499,050 MHz

200

400

600

800

Bunch position in the train (ps)

Bunch overstretching

140
120
100
80
60
40
20
0

200

400

600

Bunch position in the train (ps)

800

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

11

100% Filling: Phase Shift/Bunch Length/Landau/Lifetime
The Bunch Profile Averaged on the bunch train in the case of Uniform
Filling is shown below for different tuning positions of 3HC. The “nominal
tuning” of 3HC would be around +75 kHz. Beyond this postion the Bunch

begins to show an overstreched profile. Beam Lifetime increases until the
position of +62 kHz, which is the operating position. A few kHz beyond that,
lifetime starts to decay to a few hours; further the beam is lost.
Df= +92 kHz

Df= +82 kHz

Df= +72 kHz

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

Df= +62 kHz

12

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime

Deg

Phase Shift along the bunch train

45

Uniform Filling
Filling at 98%
Filling at 96%
Filling at 90%
Filling at 80%
Filling at 70%

40
35
30
25
20
15
10
5
0

1499.010 1499.015 1499.020 1499.025 1499.030 1499.035 1499.040 1499.045 1499.050 1499.055 1499.060 1499.065 1499.070

3HC Frequency (MHz)

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

13

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime

Bunch length along the train

<> (ps)
140

Filling at 70%
Filling at 80%
Filling at 90%
Filling at 96%
Filling at 98%
Uniform Filling

130
120
110
100
90
80
70
60
50
40
30
1499.010

1499.015

1499.020

1499.025

1499.030

1499.035

1499.040

1499.045

1499.050

1499.055

1499.060

1499.065

1499.070

3HC Frequency (MHz)

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

14

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
The Landau damping seems to be influenced by the different contribution of the
increasing gap width and of the average bunch length, which is reduced as the
gap increases.

Scale is
different!

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

15

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
These strak camera images show the different effect of 3HC on the beam
between 90% filling (on the left) and uniform filling (on the right). The Landau
damping effect is similar in both cases, the 90% filling shows the expected effect
of the phase modulation along th ebunch train.
Phase
Modulation
present.
Stronger
Phase
Modulation
Bunches are
longer in the
train centre.

Df= +112 kHz

Longitudinal
UNSTABLE
Beam

Df= +92 kHz

Longitudinal
STABLE
Beam
Bunch
Length is
Uniform

Df= +62 kHz

90% Filling

Uniform Filling

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

16

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
The best performance in terms of lifetime is obtained with a fractional filling of 96%. By
further increasing the filling, the maximum obtained lifetime is lower, suggesting that the
optimum setting for ELETTRA requires a small amount of “empty gap”.
The 96% filling is now taken as the new standard filling pattern for User’s Operation
Mode (320mA, 2.0GeV). In this condition 3HC is usually tuned from 1499.050 MHz
(Df=92kHz) to 1499.020MHz (Df=62kHz).

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

17

Machine Upgrades and Ultimate Lifetime Value
During 2003 and 2004 several new vacuum
chamber installations were performed. In June
2003 a new Aluminum-NEG coated chamber
was installed in section ID10. In pre-3HC
conditions the nominal lifetime was recovered at
a dynamic pressure of about 10-11 mbar/mA. In
the example of the ID10 chamber this took
about 70 Ah, i.e. about 2,5 weeks operation.

In fact the ultimate lifetime with 3HC
active, i.e. about 27 hours at 2.0
GeV 320 mA, was reached mid of
September 2003, that is about 6
weeks of operation after the ID10
installation (there were 2 weeks
shutdown in August).
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

18

Conclusions
• 3HC routinely in operation at Elettra
• Stable Beam, refill every 36 hours
• Operability and Reliability good
• Careful maintenance to prevent
faults, recovery time can be long!
• Experiments at different fillings
confirm expected effects (phase
modulation, bunch lengthening)
• New standard filling set to 96%
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

19


Slide 15

SUPER-3HC at ELETTRA Update
G.Penco, M.Svandrlik
• Operation
• Uptime
• Maintenance
• Performance vs filling

• Conclusions

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

1

Operation/Uptime/Maintenance/Performance vs Filling
• 3HC is routinely in operation during user’s shifts.
• Lifetime depends on ultimate vacuum conditioning and
filling pattern, highest value we can obtain is 27 hrs
(320 mA; 2.0 GeV)
• Filling pattern set to 96%
• During refill and energy ramping 3HC set at +94 kHz
(from 3rd harmonic) - Transverse Feedbacks ON
• Once beam is at 2.0 Gev 3HC is activated by tuning it at
+64 kHz

• Longitudinal Coupled Bunch Instabilities are cured by 3HC,
Transverse Instabilities are cured by Feedbacks.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

2

Operation/Uptime/Maintenance/Performance vs Filling
• The increase in Beam Lifetime obtained when 3HC is
active, allows us to refill ELETTRA every 36 hrs instead
of 24 hrs, as it used to be in the past.

3HC tuned:only 3 refills
in 5 days operation

How it was
before 3HC

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

3

Operation/Uptime/Maintenance/Performance vs Filling
• General uptime of the system is good. Since September
2003 only one event caused significant User’s downtime,
on Saturday, 31/01/2004.
Users' downtime caused by 3HC, in hours
30
25
20
15,8
15
10
5
0

0,0

0,0

0,0

0,0

0,6

0,0

RUN 85
RUN 86
RUN 87
RUN 88
RUN 89
RUN 90
RUN 91
AUG - SEP 03 SEP - OCT 03 NOV - DEC 03 JAN - FEB 04 MAR - APR 04 APR - MAG 04 JUN - JUL 04

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

4

Operation/Uptime/Maintenance/Performance vs Filling
• The event on 31/01/04 was related to a failure of a rough
pumping unit of the valve-box insulation vacuum. This was a
temporary installation, replaced during the next shutdown
with a fail-safe one.
• The uptime statistics does not include systems stops due to
electrical
power
interruptions,
mostly
caused
by
thunderstorms in the surroundings. In this case most
machine systems are stopped and the restart time of the
cryogenic plant is hidden in the general restart of the
systems. For this reason the idea of connecting 3HC to a new
UPS has not yet been implemented (also financial reasons).

• We still do not have a He recovery system, the experience
made so far shows that we can survive without it, not
affecting the uptime of the system.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

5

Operation/Uptime/Maintenance/Performance vs Filling
• Several important maintenance interventions have been
successfully performed in the last 12 months.
• In November 2003 the leaky gate valve between 3HC
and the superconducting wiggler was substituted.
This required to break
the cavity vacuum. A
clean area was therefore
created inside the
storage ring tunnel. The
replacement followed
clean room procedures
and was done by CEA
and Elettra staff.
The field performance of
the cavity has not been
affected by this
intervention.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

6

Operation/Uptime/Maintenance/Performance vs Filling
• In December 2003 the tuning system of cell 1 failed for
the 2nd time (1st time in March). In January 2004 the tuning
system was replaced with an upgraded version.
• The tuning system is under vacuum, at cold. The gear box
was found to be blocked.
• Tests at Saclay showed that the reason could be a heating
problem (from the motor).
• Even if the number of cycles
after which this shows up is
huge, we are limiting the
movements of the system.
• No problem since January 04
• CEA is studying a solution to
move the motor outside the
cryomodule.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

7

Operation/Uptime/Maintenance/Performance vs Filling

• During the January shutdown the cryogenic plant annual
maintenance was performed.
• After this maintenance the nominal performance is back to
the original, i.e. about 30-35 litres/hour at 13 bar of HP.
• In August 2004 the cryomodule has been warmed-up again
in order to replace a coaxial cable which takes out the
voltage signal of cell 2.
• In this occasion also the fundamental mode rejection of the
dipolar HOM couplers has been improved. In fact on one of
them some over-heating effects were observed when tuning
the cell.

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

8

Operation/Uptime/Maintenance/Performance vs Filling
• ELETTRA used to operate with a partial filling of the bunch
train: typically a 10% empty gap was present.

• As well known, with such a gap the passive third harmonic
cavity induces a phase modulation over the bunch train.
• Several STREAK CAMERA experiments were performed for
various fillings, measuring the effect on:
– Phase Shift
– Bunch lengthening
– Landau Damping

– Beam Lifetime

• As a result, a new optimum filling was set for operations.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

9

80% Filling: Phase Shift/Bunch Length/Landau/Lifetime
Phase Shift along the train for different tuning
60

Ibeam=315mA,
Filling at 80%

Relative Phase (Deg)

50
40
1499,070 MHz
1499,060 MHz

30

1499,050 MHz
1499,025 MHz

20

Bunch length along the train for different tuning
1499,070 MHz

1499,020 MHz
1499,015 MHz

10
1499,060 MHz
600
700
800

RMS Bunch Length (ps)

90

1499,050 MHz

80

900

1000

1100

1200

1300

1400

Bunch position in the train (ps)

1499,025 MHz

70

1499,020 MHz

60

1499,015 MHz

50
40
30
700

900
1100
1300
Bunch position in the train (ps)

1500

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

10

1500

100% Filling: Phase Shift/Bunch Length/Landau/Lifetime

Relative Phase (Deg)

Ibeam=315mA,
Uniform Filling

Bunch length along the train for different tuning
1499,050 MHz
1499,025 MHz

RMS Bunch Length (ps)

200
180

1499,040 MHz
1499,020 MHz

1499,030 MHz
1499,015 MHz

Phase Shift along the train for different tuning

50
45
40
35
30
25
20
15
10

1499,040 MHz

1499,030 MHz
1499,020 MHz

1499,025 MHz
1499,015 MHz

1499,014 MHz
0

1499,014 MHz

160

1499,050 MHz

200

400

600

800

Bunch position in the train (ps)

Bunch overstretching

140
120
100
80
60
40
20
0

200

400

600

Bunch position in the train (ps)

800

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

11

100% Filling: Phase Shift/Bunch Length/Landau/Lifetime
The Bunch Profile Averaged on the bunch train in the case of Uniform
Filling is shown below for different tuning positions of 3HC. The “nominal
tuning” of 3HC would be around +75 kHz. Beyond this postion the Bunch

begins to show an overstreched profile. Beam Lifetime increases until the
position of +62 kHz, which is the operating position. A few kHz beyond that,
lifetime starts to decay to a few hours; further the beam is lost.
Df= +92 kHz

Df= +82 kHz

Df= +72 kHz

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

Df= +62 kHz

12

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime

Deg

Phase Shift along the bunch train

45

Uniform Filling
Filling at 98%
Filling at 96%
Filling at 90%
Filling at 80%
Filling at 70%

40
35
30
25
20
15
10
5
0

1499.010 1499.015 1499.020 1499.025 1499.030 1499.035 1499.040 1499.045 1499.050 1499.055 1499.060 1499.065 1499.070

3HC Frequency (MHz)

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

13

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime

Bunch length along the train

<> (ps)
140

Filling at 70%
Filling at 80%
Filling at 90%
Filling at 96%
Filling at 98%
Uniform Filling

130
120
110
100
90
80
70
60
50
40
30
1499.010

1499.015

1499.020

1499.025

1499.030

1499.035

1499.040

1499.045

1499.050

1499.055

1499.060

1499.065

1499.070

3HC Frequency (MHz)

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

14

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
The Landau damping seems to be influenced by the different contribution of the
increasing gap width and of the average bunch length, which is reduced as the
gap increases.

Scale is
different!

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

15

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
These strak camera images show the different effect of 3HC on the beam
between 90% filling (on the left) and uniform filling (on the right). The Landau
damping effect is similar in both cases, the 90% filling shows the expected effect
of the phase modulation along th ebunch train.
Phase
Modulation
present.
Stronger
Phase
Modulation
Bunches are
longer in the
train centre.

Df= +112 kHz

Longitudinal
UNSTABLE
Beam

Df= +92 kHz

Longitudinal
STABLE
Beam
Bunch
Length is
Uniform

Df= +62 kHz

90% Filling

Uniform Filling

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

16

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
The best performance in terms of lifetime is obtained with a fractional filling of 96%. By
further increasing the filling, the maximum obtained lifetime is lower, suggesting that the
optimum setting for ELETTRA requires a small amount of “empty gap”.
The 96% filling is now taken as the new standard filling pattern for User’s Operation
Mode (320mA, 2.0GeV). In this condition 3HC is usually tuned from 1499.050 MHz
(Df=92kHz) to 1499.020MHz (Df=62kHz).

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

17

Machine Upgrades and Ultimate Lifetime Value
During 2003 and 2004 several new vacuum
chamber installations were performed. In June
2003 a new Aluminum-NEG coated chamber
was installed in section ID10. In pre-3HC
conditions the nominal lifetime was recovered at
a dynamic pressure of about 10-11 mbar/mA. In
the example of the ID10 chamber this took
about 70 Ah, i.e. about 2,5 weeks operation.

In fact the ultimate lifetime with 3HC
active, i.e. about 27 hours at 2.0
GeV 320 mA, was reached mid of
September 2003, that is about 6
weeks of operation after the ID10
installation (there were 2 weeks
shutdown in August).
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

18

Conclusions
• 3HC routinely in operation at Elettra
• Stable Beam, refill every 36 hours
• Operability and Reliability good
• Careful maintenance to prevent
faults, recovery time can be long!
• Experiments at different fillings
confirm expected effects (phase
modulation, bunch lengthening)
• New standard filling set to 96%
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

19


Slide 16

SUPER-3HC at ELETTRA Update
G.Penco, M.Svandrlik
• Operation
• Uptime
• Maintenance
• Performance vs filling

• Conclusions

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

1

Operation/Uptime/Maintenance/Performance vs Filling
• 3HC is routinely in operation during user’s shifts.
• Lifetime depends on ultimate vacuum conditioning and
filling pattern, highest value we can obtain is 27 hrs
(320 mA; 2.0 GeV)
• Filling pattern set to 96%
• During refill and energy ramping 3HC set at +94 kHz
(from 3rd harmonic) - Transverse Feedbacks ON
• Once beam is at 2.0 Gev 3HC is activated by tuning it at
+64 kHz

• Longitudinal Coupled Bunch Instabilities are cured by 3HC,
Transverse Instabilities are cured by Feedbacks.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

2

Operation/Uptime/Maintenance/Performance vs Filling
• The increase in Beam Lifetime obtained when 3HC is
active, allows us to refill ELETTRA every 36 hrs instead
of 24 hrs, as it used to be in the past.

3HC tuned:only 3 refills
in 5 days operation

How it was
before 3HC

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

3

Operation/Uptime/Maintenance/Performance vs Filling
• General uptime of the system is good. Since September
2003 only one event caused significant User’s downtime,
on Saturday, 31/01/2004.
Users' downtime caused by 3HC, in hours
30
25
20
15,8
15
10
5
0

0,0

0,0

0,0

0,0

0,6

0,0

RUN 85
RUN 86
RUN 87
RUN 88
RUN 89
RUN 90
RUN 91
AUG - SEP 03 SEP - OCT 03 NOV - DEC 03 JAN - FEB 04 MAR - APR 04 APR - MAG 04 JUN - JUL 04

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

4

Operation/Uptime/Maintenance/Performance vs Filling
• The event on 31/01/04 was related to a failure of a rough
pumping unit of the valve-box insulation vacuum. This was a
temporary installation, replaced during the next shutdown
with a fail-safe one.
• The uptime statistics does not include systems stops due to
electrical
power
interruptions,
mostly
caused
by
thunderstorms in the surroundings. In this case most
machine systems are stopped and the restart time of the
cryogenic plant is hidden in the general restart of the
systems. For this reason the idea of connecting 3HC to a new
UPS has not yet been implemented (also financial reasons).

• We still do not have a He recovery system, the experience
made so far shows that we can survive without it, not
affecting the uptime of the system.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

5

Operation/Uptime/Maintenance/Performance vs Filling
• Several important maintenance interventions have been
successfully performed in the last 12 months.
• In November 2003 the leaky gate valve between 3HC
and the superconducting wiggler was substituted.
This required to break
the cavity vacuum. A
clean area was therefore
created inside the
storage ring tunnel. The
replacement followed
clean room procedures
and was done by CEA
and Elettra staff.
The field performance of
the cavity has not been
affected by this
intervention.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

6

Operation/Uptime/Maintenance/Performance vs Filling
• In December 2003 the tuning system of cell 1 failed for
the 2nd time (1st time in March). In January 2004 the tuning
system was replaced with an upgraded version.
• The tuning system is under vacuum, at cold. The gear box
was found to be blocked.
• Tests at Saclay showed that the reason could be a heating
problem (from the motor).
• Even if the number of cycles
after which this shows up is
huge, we are limiting the
movements of the system.
• No problem since January 04
• CEA is studying a solution to
move the motor outside the
cryomodule.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

7

Operation/Uptime/Maintenance/Performance vs Filling

• During the January shutdown the cryogenic plant annual
maintenance was performed.
• After this maintenance the nominal performance is back to
the original, i.e. about 30-35 litres/hour at 13 bar of HP.
• In August 2004 the cryomodule has been warmed-up again
in order to replace a coaxial cable which takes out the
voltage signal of cell 2.
• In this occasion also the fundamental mode rejection of the
dipolar HOM couplers has been improved. In fact on one of
them some over-heating effects were observed when tuning
the cell.

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

8

Operation/Uptime/Maintenance/Performance vs Filling
• ELETTRA used to operate with a partial filling of the bunch
train: typically a 10% empty gap was present.

• As well known, with such a gap the passive third harmonic
cavity induces a phase modulation over the bunch train.
• Several STREAK CAMERA experiments were performed for
various fillings, measuring the effect on:
– Phase Shift
– Bunch lengthening
– Landau Damping

– Beam Lifetime

• As a result, a new optimum filling was set for operations.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

9

80% Filling: Phase Shift/Bunch Length/Landau/Lifetime
Phase Shift along the train for different tuning
60

Ibeam=315mA,
Filling at 80%

Relative Phase (Deg)

50
40
1499,070 MHz
1499,060 MHz

30

1499,050 MHz
1499,025 MHz

20

Bunch length along the train for different tuning
1499,070 MHz

1499,020 MHz
1499,015 MHz

10
1499,060 MHz
600
700
800

RMS Bunch Length (ps)

90

1499,050 MHz

80

900

1000

1100

1200

1300

1400

Bunch position in the train (ps)

1499,025 MHz

70

1499,020 MHz

60

1499,015 MHz

50
40
30
700

900
1100
1300
Bunch position in the train (ps)

1500

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

10

1500

100% Filling: Phase Shift/Bunch Length/Landau/Lifetime

Relative Phase (Deg)

Ibeam=315mA,
Uniform Filling

Bunch length along the train for different tuning
1499,050 MHz
1499,025 MHz

RMS Bunch Length (ps)

200
180

1499,040 MHz
1499,020 MHz

1499,030 MHz
1499,015 MHz

Phase Shift along the train for different tuning

50
45
40
35
30
25
20
15
10

1499,040 MHz

1499,030 MHz
1499,020 MHz

1499,025 MHz
1499,015 MHz

1499,014 MHz
0

1499,014 MHz

160

1499,050 MHz

200

400

600

800

Bunch position in the train (ps)

Bunch overstretching

140
120
100
80
60
40
20
0

200

400

600

Bunch position in the train (ps)

800

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

11

100% Filling: Phase Shift/Bunch Length/Landau/Lifetime
The Bunch Profile Averaged on the bunch train in the case of Uniform
Filling is shown below for different tuning positions of 3HC. The “nominal
tuning” of 3HC would be around +75 kHz. Beyond this postion the Bunch

begins to show an overstreched profile. Beam Lifetime increases until the
position of +62 kHz, which is the operating position. A few kHz beyond that,
lifetime starts to decay to a few hours; further the beam is lost.
Df= +92 kHz

Df= +82 kHz

Df= +72 kHz

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

Df= +62 kHz

12

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime

Deg

Phase Shift along the bunch train

45

Uniform Filling
Filling at 98%
Filling at 96%
Filling at 90%
Filling at 80%
Filling at 70%

40
35
30
25
20
15
10
5
0

1499.010 1499.015 1499.020 1499.025 1499.030 1499.035 1499.040 1499.045 1499.050 1499.055 1499.060 1499.065 1499.070

3HC Frequency (MHz)

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

13

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime

Bunch length along the train

<> (ps)
140

Filling at 70%
Filling at 80%
Filling at 90%
Filling at 96%
Filling at 98%
Uniform Filling

130
120
110
100
90
80
70
60
50
40
30
1499.010

1499.015

1499.020

1499.025

1499.030

1499.035

1499.040

1499.045

1499.050

1499.055

1499.060

1499.065

1499.070

3HC Frequency (MHz)

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

14

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
The Landau damping seems to be influenced by the different contribution of the
increasing gap width and of the average bunch length, which is reduced as the
gap increases.

Scale is
different!

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

15

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
These strak camera images show the different effect of 3HC on the beam
between 90% filling (on the left) and uniform filling (on the right). The Landau
damping effect is similar in both cases, the 90% filling shows the expected effect
of the phase modulation along th ebunch train.
Phase
Modulation
present.
Stronger
Phase
Modulation
Bunches are
longer in the
train centre.

Df= +112 kHz

Longitudinal
UNSTABLE
Beam

Df= +92 kHz

Longitudinal
STABLE
Beam
Bunch
Length is
Uniform

Df= +62 kHz

90% Filling

Uniform Filling

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

16

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
The best performance in terms of lifetime is obtained with a fractional filling of 96%. By
further increasing the filling, the maximum obtained lifetime is lower, suggesting that the
optimum setting for ELETTRA requires a small amount of “empty gap”.
The 96% filling is now taken as the new standard filling pattern for User’s Operation
Mode (320mA, 2.0GeV). In this condition 3HC is usually tuned from 1499.050 MHz
(Df=92kHz) to 1499.020MHz (Df=62kHz).

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

17

Machine Upgrades and Ultimate Lifetime Value
During 2003 and 2004 several new vacuum
chamber installations were performed. In June
2003 a new Aluminum-NEG coated chamber
was installed in section ID10. In pre-3HC
conditions the nominal lifetime was recovered at
a dynamic pressure of about 10-11 mbar/mA. In
the example of the ID10 chamber this took
about 70 Ah, i.e. about 2,5 weeks operation.

In fact the ultimate lifetime with 3HC
active, i.e. about 27 hours at 2.0
GeV 320 mA, was reached mid of
September 2003, that is about 6
weeks of operation after the ID10
installation (there were 2 weeks
shutdown in August).
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

18

Conclusions
• 3HC routinely in operation at Elettra
• Stable Beam, refill every 36 hours
• Operability and Reliability good
• Careful maintenance to prevent
faults, recovery time can be long!
• Experiments at different fillings
confirm expected effects (phase
modulation, bunch lengthening)
• New standard filling set to 96%
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

19


Slide 17

SUPER-3HC at ELETTRA Update
G.Penco, M.Svandrlik
• Operation
• Uptime
• Maintenance
• Performance vs filling

• Conclusions

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

1

Operation/Uptime/Maintenance/Performance vs Filling
• 3HC is routinely in operation during user’s shifts.
• Lifetime depends on ultimate vacuum conditioning and
filling pattern, highest value we can obtain is 27 hrs
(320 mA; 2.0 GeV)
• Filling pattern set to 96%
• During refill and energy ramping 3HC set at +94 kHz
(from 3rd harmonic) - Transverse Feedbacks ON
• Once beam is at 2.0 Gev 3HC is activated by tuning it at
+64 kHz

• Longitudinal Coupled Bunch Instabilities are cured by 3HC,
Transverse Instabilities are cured by Feedbacks.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

2

Operation/Uptime/Maintenance/Performance vs Filling
• The increase in Beam Lifetime obtained when 3HC is
active, allows us to refill ELETTRA every 36 hrs instead
of 24 hrs, as it used to be in the past.

3HC tuned:only 3 refills
in 5 days operation

How it was
before 3HC

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

3

Operation/Uptime/Maintenance/Performance vs Filling
• General uptime of the system is good. Since September
2003 only one event caused significant User’s downtime,
on Saturday, 31/01/2004.
Users' downtime caused by 3HC, in hours
30
25
20
15,8
15
10
5
0

0,0

0,0

0,0

0,0

0,6

0,0

RUN 85
RUN 86
RUN 87
RUN 88
RUN 89
RUN 90
RUN 91
AUG - SEP 03 SEP - OCT 03 NOV - DEC 03 JAN - FEB 04 MAR - APR 04 APR - MAG 04 JUN - JUL 04

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

4

Operation/Uptime/Maintenance/Performance vs Filling
• The event on 31/01/04 was related to a failure of a rough
pumping unit of the valve-box insulation vacuum. This was a
temporary installation, replaced during the next shutdown
with a fail-safe one.
• The uptime statistics does not include systems stops due to
electrical
power
interruptions,
mostly
caused
by
thunderstorms in the surroundings. In this case most
machine systems are stopped and the restart time of the
cryogenic plant is hidden in the general restart of the
systems. For this reason the idea of connecting 3HC to a new
UPS has not yet been implemented (also financial reasons).

• We still do not have a He recovery system, the experience
made so far shows that we can survive without it, not
affecting the uptime of the system.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

5

Operation/Uptime/Maintenance/Performance vs Filling
• Several important maintenance interventions have been
successfully performed in the last 12 months.
• In November 2003 the leaky gate valve between 3HC
and the superconducting wiggler was substituted.
This required to break
the cavity vacuum. A
clean area was therefore
created inside the
storage ring tunnel. The
replacement followed
clean room procedures
and was done by CEA
and Elettra staff.
The field performance of
the cavity has not been
affected by this
intervention.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

6

Operation/Uptime/Maintenance/Performance vs Filling
• In December 2003 the tuning system of cell 1 failed for
the 2nd time (1st time in March). In January 2004 the tuning
system was replaced with an upgraded version.
• The tuning system is under vacuum, at cold. The gear box
was found to be blocked.
• Tests at Saclay showed that the reason could be a heating
problem (from the motor).
• Even if the number of cycles
after which this shows up is
huge, we are limiting the
movements of the system.
• No problem since January 04
• CEA is studying a solution to
move the motor outside the
cryomodule.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

7

Operation/Uptime/Maintenance/Performance vs Filling

• During the January shutdown the cryogenic plant annual
maintenance was performed.
• After this maintenance the nominal performance is back to
the original, i.e. about 30-35 litres/hour at 13 bar of HP.
• In August 2004 the cryomodule has been warmed-up again
in order to replace a coaxial cable which takes out the
voltage signal of cell 2.
• In this occasion also the fundamental mode rejection of the
dipolar HOM couplers has been improved. In fact on one of
them some over-heating effects were observed when tuning
the cell.

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

8

Operation/Uptime/Maintenance/Performance vs Filling
• ELETTRA used to operate with a partial filling of the bunch
train: typically a 10% empty gap was present.

• As well known, with such a gap the passive third harmonic
cavity induces a phase modulation over the bunch train.
• Several STREAK CAMERA experiments were performed for
various fillings, measuring the effect on:
– Phase Shift
– Bunch lengthening
– Landau Damping

– Beam Lifetime

• As a result, a new optimum filling was set for operations.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

9

80% Filling: Phase Shift/Bunch Length/Landau/Lifetime
Phase Shift along the train for different tuning
60

Ibeam=315mA,
Filling at 80%

Relative Phase (Deg)

50
40
1499,070 MHz
1499,060 MHz

30

1499,050 MHz
1499,025 MHz

20

Bunch length along the train for different tuning
1499,070 MHz

1499,020 MHz
1499,015 MHz

10
1499,060 MHz
600
700
800

RMS Bunch Length (ps)

90

1499,050 MHz

80

900

1000

1100

1200

1300

1400

Bunch position in the train (ps)

1499,025 MHz

70

1499,020 MHz

60

1499,015 MHz

50
40
30
700

900
1100
1300
Bunch position in the train (ps)

1500

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

10

1500

100% Filling: Phase Shift/Bunch Length/Landau/Lifetime

Relative Phase (Deg)

Ibeam=315mA,
Uniform Filling

Bunch length along the train for different tuning
1499,050 MHz
1499,025 MHz

RMS Bunch Length (ps)

200
180

1499,040 MHz
1499,020 MHz

1499,030 MHz
1499,015 MHz

Phase Shift along the train for different tuning

50
45
40
35
30
25
20
15
10

1499,040 MHz

1499,030 MHz
1499,020 MHz

1499,025 MHz
1499,015 MHz

1499,014 MHz
0

1499,014 MHz

160

1499,050 MHz

200

400

600

800

Bunch position in the train (ps)

Bunch overstretching

140
120
100
80
60
40
20
0

200

400

600

Bunch position in the train (ps)

800

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

11

100% Filling: Phase Shift/Bunch Length/Landau/Lifetime
The Bunch Profile Averaged on the bunch train in the case of Uniform
Filling is shown below for different tuning positions of 3HC. The “nominal
tuning” of 3HC would be around +75 kHz. Beyond this postion the Bunch

begins to show an overstreched profile. Beam Lifetime increases until the
position of +62 kHz, which is the operating position. A few kHz beyond that,
lifetime starts to decay to a few hours; further the beam is lost.
Df= +92 kHz

Df= +82 kHz

Df= +72 kHz

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

Df= +62 kHz

12

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime

Deg

Phase Shift along the bunch train

45

Uniform Filling
Filling at 98%
Filling at 96%
Filling at 90%
Filling at 80%
Filling at 70%

40
35
30
25
20
15
10
5
0

1499.010 1499.015 1499.020 1499.025 1499.030 1499.035 1499.040 1499.045 1499.050 1499.055 1499.060 1499.065 1499.070

3HC Frequency (MHz)

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

13

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime

Bunch length along the train

<> (ps)
140

Filling at 70%
Filling at 80%
Filling at 90%
Filling at 96%
Filling at 98%
Uniform Filling

130
120
110
100
90
80
70
60
50
40
30
1499.010

1499.015

1499.020

1499.025

1499.030

1499.035

1499.040

1499.045

1499.050

1499.055

1499.060

1499.065

1499.070

3HC Frequency (MHz)

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

14

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
The Landau damping seems to be influenced by the different contribution of the
increasing gap width and of the average bunch length, which is reduced as the
gap increases.

Scale is
different!

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

15

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
These strak camera images show the different effect of 3HC on the beam
between 90% filling (on the left) and uniform filling (on the right). The Landau
damping effect is similar in both cases, the 90% filling shows the expected effect
of the phase modulation along th ebunch train.
Phase
Modulation
present.
Stronger
Phase
Modulation
Bunches are
longer in the
train centre.

Df= +112 kHz

Longitudinal
UNSTABLE
Beam

Df= +92 kHz

Longitudinal
STABLE
Beam
Bunch
Length is
Uniform

Df= +62 kHz

90% Filling

Uniform Filling

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

16

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
The best performance in terms of lifetime is obtained with a fractional filling of 96%. By
further increasing the filling, the maximum obtained lifetime is lower, suggesting that the
optimum setting for ELETTRA requires a small amount of “empty gap”.
The 96% filling is now taken as the new standard filling pattern for User’s Operation
Mode (320mA, 2.0GeV). In this condition 3HC is usually tuned from 1499.050 MHz
(Df=92kHz) to 1499.020MHz (Df=62kHz).

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

17

Machine Upgrades and Ultimate Lifetime Value
During 2003 and 2004 several new vacuum
chamber installations were performed. In June
2003 a new Aluminum-NEG coated chamber
was installed in section ID10. In pre-3HC
conditions the nominal lifetime was recovered at
a dynamic pressure of about 10-11 mbar/mA. In
the example of the ID10 chamber this took
about 70 Ah, i.e. about 2,5 weeks operation.

In fact the ultimate lifetime with 3HC
active, i.e. about 27 hours at 2.0
GeV 320 mA, was reached mid of
September 2003, that is about 6
weeks of operation after the ID10
installation (there were 2 weeks
shutdown in August).
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

18

Conclusions
• 3HC routinely in operation at Elettra
• Stable Beam, refill every 36 hours
• Operability and Reliability good
• Careful maintenance to prevent
faults, recovery time can be long!
• Experiments at different fillings
confirm expected effects (phase
modulation, bunch lengthening)
• New standard filling set to 96%
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

19


Slide 18

SUPER-3HC at ELETTRA Update
G.Penco, M.Svandrlik
• Operation
• Uptime
• Maintenance
• Performance vs filling

• Conclusions

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

1

Operation/Uptime/Maintenance/Performance vs Filling
• 3HC is routinely in operation during user’s shifts.
• Lifetime depends on ultimate vacuum conditioning and
filling pattern, highest value we can obtain is 27 hrs
(320 mA; 2.0 GeV)
• Filling pattern set to 96%
• During refill and energy ramping 3HC set at +94 kHz
(from 3rd harmonic) - Transverse Feedbacks ON
• Once beam is at 2.0 Gev 3HC is activated by tuning it at
+64 kHz

• Longitudinal Coupled Bunch Instabilities are cured by 3HC,
Transverse Instabilities are cured by Feedbacks.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

2

Operation/Uptime/Maintenance/Performance vs Filling
• The increase in Beam Lifetime obtained when 3HC is
active, allows us to refill ELETTRA every 36 hrs instead
of 24 hrs, as it used to be in the past.

3HC tuned:only 3 refills
in 5 days operation

How it was
before 3HC

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

3

Operation/Uptime/Maintenance/Performance vs Filling
• General uptime of the system is good. Since September
2003 only one event caused significant User’s downtime,
on Saturday, 31/01/2004.
Users' downtime caused by 3HC, in hours
30
25
20
15,8
15
10
5
0

0,0

0,0

0,0

0,0

0,6

0,0

RUN 85
RUN 86
RUN 87
RUN 88
RUN 89
RUN 90
RUN 91
AUG - SEP 03 SEP - OCT 03 NOV - DEC 03 JAN - FEB 04 MAR - APR 04 APR - MAG 04 JUN - JUL 04

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

4

Operation/Uptime/Maintenance/Performance vs Filling
• The event on 31/01/04 was related to a failure of a rough
pumping unit of the valve-box insulation vacuum. This was a
temporary installation, replaced during the next shutdown
with a fail-safe one.
• The uptime statistics does not include systems stops due to
electrical
power
interruptions,
mostly
caused
by
thunderstorms in the surroundings. In this case most
machine systems are stopped and the restart time of the
cryogenic plant is hidden in the general restart of the
systems. For this reason the idea of connecting 3HC to a new
UPS has not yet been implemented (also financial reasons).

• We still do not have a He recovery system, the experience
made so far shows that we can survive without it, not
affecting the uptime of the system.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

5

Operation/Uptime/Maintenance/Performance vs Filling
• Several important maintenance interventions have been
successfully performed in the last 12 months.
• In November 2003 the leaky gate valve between 3HC
and the superconducting wiggler was substituted.
This required to break
the cavity vacuum. A
clean area was therefore
created inside the
storage ring tunnel. The
replacement followed
clean room procedures
and was done by CEA
and Elettra staff.
The field performance of
the cavity has not been
affected by this
intervention.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

6

Operation/Uptime/Maintenance/Performance vs Filling
• In December 2003 the tuning system of cell 1 failed for
the 2nd time (1st time in March). In January 2004 the tuning
system was replaced with an upgraded version.
• The tuning system is under vacuum, at cold. The gear box
was found to be blocked.
• Tests at Saclay showed that the reason could be a heating
problem (from the motor).
• Even if the number of cycles
after which this shows up is
huge, we are limiting the
movements of the system.
• No problem since January 04
• CEA is studying a solution to
move the motor outside the
cryomodule.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

7

Operation/Uptime/Maintenance/Performance vs Filling

• During the January shutdown the cryogenic plant annual
maintenance was performed.
• After this maintenance the nominal performance is back to
the original, i.e. about 30-35 litres/hour at 13 bar of HP.
• In August 2004 the cryomodule has been warmed-up again
in order to replace a coaxial cable which takes out the
voltage signal of cell 2.
• In this occasion also the fundamental mode rejection of the
dipolar HOM couplers has been improved. In fact on one of
them some over-heating effects were observed when tuning
the cell.

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

8

Operation/Uptime/Maintenance/Performance vs Filling
• ELETTRA used to operate with a partial filling of the bunch
train: typically a 10% empty gap was present.

• As well known, with such a gap the passive third harmonic
cavity induces a phase modulation over the bunch train.
• Several STREAK CAMERA experiments were performed for
various fillings, measuring the effect on:
– Phase Shift
– Bunch lengthening
– Landau Damping

– Beam Lifetime

• As a result, a new optimum filling was set for operations.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

9

80% Filling: Phase Shift/Bunch Length/Landau/Lifetime
Phase Shift along the train for different tuning
60

Ibeam=315mA,
Filling at 80%

Relative Phase (Deg)

50
40
1499,070 MHz
1499,060 MHz

30

1499,050 MHz
1499,025 MHz

20

Bunch length along the train for different tuning
1499,070 MHz

1499,020 MHz
1499,015 MHz

10
1499,060 MHz
600
700
800

RMS Bunch Length (ps)

90

1499,050 MHz

80

900

1000

1100

1200

1300

1400

Bunch position in the train (ps)

1499,025 MHz

70

1499,020 MHz

60

1499,015 MHz

50
40
30
700

900
1100
1300
Bunch position in the train (ps)

1500

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

10

1500

100% Filling: Phase Shift/Bunch Length/Landau/Lifetime

Relative Phase (Deg)

Ibeam=315mA,
Uniform Filling

Bunch length along the train for different tuning
1499,050 MHz
1499,025 MHz

RMS Bunch Length (ps)

200
180

1499,040 MHz
1499,020 MHz

1499,030 MHz
1499,015 MHz

Phase Shift along the train for different tuning

50
45
40
35
30
25
20
15
10

1499,040 MHz

1499,030 MHz
1499,020 MHz

1499,025 MHz
1499,015 MHz

1499,014 MHz
0

1499,014 MHz

160

1499,050 MHz

200

400

600

800

Bunch position in the train (ps)

Bunch overstretching

140
120
100
80
60
40
20
0

200

400

600

Bunch position in the train (ps)

800

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

11

100% Filling: Phase Shift/Bunch Length/Landau/Lifetime
The Bunch Profile Averaged on the bunch train in the case of Uniform
Filling is shown below for different tuning positions of 3HC. The “nominal
tuning” of 3HC would be around +75 kHz. Beyond this postion the Bunch

begins to show an overstreched profile. Beam Lifetime increases until the
position of +62 kHz, which is the operating position. A few kHz beyond that,
lifetime starts to decay to a few hours; further the beam is lost.
Df= +92 kHz

Df= +82 kHz

Df= +72 kHz

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

Df= +62 kHz

12

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime

Deg

Phase Shift along the bunch train

45

Uniform Filling
Filling at 98%
Filling at 96%
Filling at 90%
Filling at 80%
Filling at 70%

40
35
30
25
20
15
10
5
0

1499.010 1499.015 1499.020 1499.025 1499.030 1499.035 1499.040 1499.045 1499.050 1499.055 1499.060 1499.065 1499.070

3HC Frequency (MHz)

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

13

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime

Bunch length along the train

<> (ps)
140

Filling at 70%
Filling at 80%
Filling at 90%
Filling at 96%
Filling at 98%
Uniform Filling

130
120
110
100
90
80
70
60
50
40
30
1499.010

1499.015

1499.020

1499.025

1499.030

1499.035

1499.040

1499.045

1499.050

1499.055

1499.060

1499.065

1499.070

3HC Frequency (MHz)

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

14

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
The Landau damping seems to be influenced by the different contribution of the
increasing gap width and of the average bunch length, which is reduced as the
gap increases.

Scale is
different!

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

15

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
These strak camera images show the different effect of 3HC on the beam
between 90% filling (on the left) and uniform filling (on the right). The Landau
damping effect is similar in both cases, the 90% filling shows the expected effect
of the phase modulation along th ebunch train.
Phase
Modulation
present.
Stronger
Phase
Modulation
Bunches are
longer in the
train centre.

Df= +112 kHz

Longitudinal
UNSTABLE
Beam

Df= +92 kHz

Longitudinal
STABLE
Beam
Bunch
Length is
Uniform

Df= +62 kHz

90% Filling

Uniform Filling

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

16

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
The best performance in terms of lifetime is obtained with a fractional filling of 96%. By
further increasing the filling, the maximum obtained lifetime is lower, suggesting that the
optimum setting for ELETTRA requires a small amount of “empty gap”.
The 96% filling is now taken as the new standard filling pattern for User’s Operation
Mode (320mA, 2.0GeV). In this condition 3HC is usually tuned from 1499.050 MHz
(Df=92kHz) to 1499.020MHz (Df=62kHz).

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

17

Machine Upgrades and Ultimate Lifetime Value
During 2003 and 2004 several new vacuum
chamber installations were performed. In June
2003 a new Aluminum-NEG coated chamber
was installed in section ID10. In pre-3HC
conditions the nominal lifetime was recovered at
a dynamic pressure of about 10-11 mbar/mA. In
the example of the ID10 chamber this took
about 70 Ah, i.e. about 2,5 weeks operation.

In fact the ultimate lifetime with 3HC
active, i.e. about 27 hours at 2.0
GeV 320 mA, was reached mid of
September 2003, that is about 6
weeks of operation after the ID10
installation (there were 2 weeks
shutdown in August).
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

18

Conclusions
• 3HC routinely in operation at Elettra
• Stable Beam, refill every 36 hours
• Operability and Reliability good
• Careful maintenance to prevent
faults, recovery time can be long!
• Experiments at different fillings
confirm expected effects (phase
modulation, bunch lengthening)
• New standard filling set to 96%
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

19


Slide 19

SUPER-3HC at ELETTRA Update
G.Penco, M.Svandrlik
• Operation
• Uptime
• Maintenance
• Performance vs filling

• Conclusions

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

1

Operation/Uptime/Maintenance/Performance vs Filling
• 3HC is routinely in operation during user’s shifts.
• Lifetime depends on ultimate vacuum conditioning and
filling pattern, highest value we can obtain is 27 hrs
(320 mA; 2.0 GeV)
• Filling pattern set to 96%
• During refill and energy ramping 3HC set at +94 kHz
(from 3rd harmonic) - Transverse Feedbacks ON
• Once beam is at 2.0 Gev 3HC is activated by tuning it at
+64 kHz

• Longitudinal Coupled Bunch Instabilities are cured by 3HC,
Transverse Instabilities are cured by Feedbacks.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

2

Operation/Uptime/Maintenance/Performance vs Filling
• The increase in Beam Lifetime obtained when 3HC is
active, allows us to refill ELETTRA every 36 hrs instead
of 24 hrs, as it used to be in the past.

3HC tuned:only 3 refills
in 5 days operation

How it was
before 3HC

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

3

Operation/Uptime/Maintenance/Performance vs Filling
• General uptime of the system is good. Since September
2003 only one event caused significant User’s downtime,
on Saturday, 31/01/2004.
Users' downtime caused by 3HC, in hours
30
25
20
15,8
15
10
5
0

0,0

0,0

0,0

0,0

0,6

0,0

RUN 85
RUN 86
RUN 87
RUN 88
RUN 89
RUN 90
RUN 91
AUG - SEP 03 SEP - OCT 03 NOV - DEC 03 JAN - FEB 04 MAR - APR 04 APR - MAG 04 JUN - JUL 04

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

4

Operation/Uptime/Maintenance/Performance vs Filling
• The event on 31/01/04 was related to a failure of a rough
pumping unit of the valve-box insulation vacuum. This was a
temporary installation, replaced during the next shutdown
with a fail-safe one.
• The uptime statistics does not include systems stops due to
electrical
power
interruptions,
mostly
caused
by
thunderstorms in the surroundings. In this case most
machine systems are stopped and the restart time of the
cryogenic plant is hidden in the general restart of the
systems. For this reason the idea of connecting 3HC to a new
UPS has not yet been implemented (also financial reasons).

• We still do not have a He recovery system, the experience
made so far shows that we can survive without it, not
affecting the uptime of the system.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

5

Operation/Uptime/Maintenance/Performance vs Filling
• Several important maintenance interventions have been
successfully performed in the last 12 months.
• In November 2003 the leaky gate valve between 3HC
and the superconducting wiggler was substituted.
This required to break
the cavity vacuum. A
clean area was therefore
created inside the
storage ring tunnel. The
replacement followed
clean room procedures
and was done by CEA
and Elettra staff.
The field performance of
the cavity has not been
affected by this
intervention.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

6

Operation/Uptime/Maintenance/Performance vs Filling
• In December 2003 the tuning system of cell 1 failed for
the 2nd time (1st time in March). In January 2004 the tuning
system was replaced with an upgraded version.
• The tuning system is under vacuum, at cold. The gear box
was found to be blocked.
• Tests at Saclay showed that the reason could be a heating
problem (from the motor).
• Even if the number of cycles
after which this shows up is
huge, we are limiting the
movements of the system.
• No problem since January 04
• CEA is studying a solution to
move the motor outside the
cryomodule.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

7

Operation/Uptime/Maintenance/Performance vs Filling

• During the January shutdown the cryogenic plant annual
maintenance was performed.
• After this maintenance the nominal performance is back to
the original, i.e. about 30-35 litres/hour at 13 bar of HP.
• In August 2004 the cryomodule has been warmed-up again
in order to replace a coaxial cable which takes out the
voltage signal of cell 2.
• In this occasion also the fundamental mode rejection of the
dipolar HOM couplers has been improved. In fact on one of
them some over-heating effects were observed when tuning
the cell.

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

8

Operation/Uptime/Maintenance/Performance vs Filling
• ELETTRA used to operate with a partial filling of the bunch
train: typically a 10% empty gap was present.

• As well known, with such a gap the passive third harmonic
cavity induces a phase modulation over the bunch train.
• Several STREAK CAMERA experiments were performed for
various fillings, measuring the effect on:
– Phase Shift
– Bunch lengthening
– Landau Damping

– Beam Lifetime

• As a result, a new optimum filling was set for operations.
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

9

80% Filling: Phase Shift/Bunch Length/Landau/Lifetime
Phase Shift along the train for different tuning
60

Ibeam=315mA,
Filling at 80%

Relative Phase (Deg)

50
40
1499,070 MHz
1499,060 MHz

30

1499,050 MHz
1499,025 MHz

20

Bunch length along the train for different tuning
1499,070 MHz

1499,020 MHz
1499,015 MHz

10
1499,060 MHz
600
700
800

RMS Bunch Length (ps)

90

1499,050 MHz

80

900

1000

1100

1200

1300

1400

Bunch position in the train (ps)

1499,025 MHz

70

1499,020 MHz

60

1499,015 MHz

50
40
30
700

900
1100
1300
Bunch position in the train (ps)

1500

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

10

1500

100% Filling: Phase Shift/Bunch Length/Landau/Lifetime

Relative Phase (Deg)

Ibeam=315mA,
Uniform Filling

Bunch length along the train for different tuning
1499,050 MHz
1499,025 MHz

RMS Bunch Length (ps)

200
180

1499,040 MHz
1499,020 MHz

1499,030 MHz
1499,015 MHz

Phase Shift along the train for different tuning

50
45
40
35
30
25
20
15
10

1499,040 MHz

1499,030 MHz
1499,020 MHz

1499,025 MHz
1499,015 MHz

1499,014 MHz
0

1499,014 MHz

160

1499,050 MHz

200

400

600

800

Bunch position in the train (ps)

Bunch overstretching

140
120
100
80
60
40
20
0

200

400

600

Bunch position in the train (ps)

800

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

11

100% Filling: Phase Shift/Bunch Length/Landau/Lifetime
The Bunch Profile Averaged on the bunch train in the case of Uniform
Filling is shown below for different tuning positions of 3HC. The “nominal
tuning” of 3HC would be around +75 kHz. Beyond this postion the Bunch

begins to show an overstreched profile. Beam Lifetime increases until the
position of +62 kHz, which is the operating position. A few kHz beyond that,
lifetime starts to decay to a few hours; further the beam is lost.
Df= +92 kHz

Df= +82 kHz

Df= +72 kHz

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

Df= +62 kHz

12

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime

Deg

Phase Shift along the bunch train

45

Uniform Filling
Filling at 98%
Filling at 96%
Filling at 90%
Filling at 80%
Filling at 70%

40
35
30
25
20
15
10
5
0

1499.010 1499.015 1499.020 1499.025 1499.030 1499.035 1499.040 1499.045 1499.050 1499.055 1499.060 1499.065 1499.070

3HC Frequency (MHz)

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

13

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime

Bunch length along the train

<> (ps)
140

Filling at 70%
Filling at 80%
Filling at 90%
Filling at 96%
Filling at 98%
Uniform Filling

130
120
110
100
90
80
70
60
50
40
30
1499.010

1499.015

1499.020

1499.025

1499.030

1499.035

1499.040

1499.045

1499.050

1499.055

1499.060

1499.065

1499.070

3HC Frequency (MHz)

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

14

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
The Landau damping seems to be influenced by the different contribution of the
increasing gap width and of the average bunch length, which is reduced as the
gap increases.

Scale is
different!

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

15

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
These strak camera images show the different effect of 3HC on the beam
between 90% filling (on the left) and uniform filling (on the right). The Landau
damping effect is similar in both cases, the 90% filling shows the expected effect
of the phase modulation along th ebunch train.
Phase
Modulation
present.
Stronger
Phase
Modulation
Bunches are
longer in the
train centre.

Df= +112 kHz

Longitudinal
UNSTABLE
Beam

Df= +92 kHz

Longitudinal
STABLE
Beam
Bunch
Length is
Uniform

Df= +62 kHz

90% Filling

Uniform Filling

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

16

Various Fillings: Phase Shift/Bunch Length/Landau/Lifetime
The best performance in terms of lifetime is obtained with a fractional filling of 96%. By
further increasing the filling, the maximum obtained lifetime is lower, suggesting that the
optimum setting for ELETTRA requires a small amount of “empty gap”.
The 96% filling is now taken as the new standard filling pattern for User’s Operation
Mode (320mA, 2.0GeV). In this condition 3HC is usually tuned from 1499.050 MHz
(Df=92kHz) to 1499.020MHz (Df=62kHz).

8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

17

Machine Upgrades and Ultimate Lifetime Value
During 2003 and 2004 several new vacuum
chamber installations were performed. In June
2003 a new Aluminum-NEG coated chamber
was installed in section ID10. In pre-3HC
conditions the nominal lifetime was recovered at
a dynamic pressure of about 10-11 mbar/mA. In
the example of the ID10 chamber this took
about 70 Ah, i.e. about 2,5 weeks operation.

In fact the ultimate lifetime with 3HC
active, i.e. about 27 hours at 2.0
GeV 320 mA, was reached mid of
September 2003, that is about 6
weeks of operation after the ID10
installation (there were 2 weeks
shutdown in August).
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

18

Conclusions
• 3HC routinely in operation at Elettra
• Stable Beam, refill every 36 hours
• Operability and Reliability good
• Careful maintenance to prevent
faults, recovery time can be long!
• Experiments at different fillings
confirm expected effects (phase
modulation, bunch lengthening)
• New standard filling set to 96%
8th ESLS RF Workshop
Daresbury 29-30 September 2004
SUPER-3HC - M.Svandrlik

19