Transcript ILC Accelerator Activities in North America (cooperation with France) Presentation at IRFU Linear Collider Days prepared by: Marc Ross (SLAC) November 29, 2013 2013 IRFU.

ILC Accelerator Activities in North America
(cooperation with France)
Presentation at IRFU Linear Collider Days prepared by:
Marc Ross (SLAC)
November 29, 2013
2013 IRFU Linear Collider Days
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Completing the ILC Technical Design Phase
 TDP Goals:
» R & D to enable Project Proposal and updated Value estimate –
with Cost Containment
» SC RF Technology Transfer
• development of a strong industrial base
 Technical Design Report:
» Consists of two parts: 1) R & D Report and 2) Design Description
 Beam Test Facilities:
» SRF Linac: Fermilab NML, DESY E-XFEL and FLASH, KEK STF
» Beam Dynamics: Cornell CesrTA (2008 – 2010)
» Beam Tuning: KEK ATF2
 Production / Industrialization:
» CEBAF Upgrade and E-XFEL
2013 IRFU Linear Collider Days
January 22013
Completing the TDP: Outline
 TDP Goals:
» R & D to enable Project Proposal and updated Value estimate –
with Cost Containment
» SC RF Technology Transfer
• development of a strong industrial base
 Technical Design Report:
» Consists of two parts: 1) R & D Report and 2) Design Description
 Beam Test Facilities:
» SRF Linac: Fermilab NML, DESY E-XFEL and FLASH, KEK STF
» Beam Dynamics: Cornell CesrTA (2008 – 2010)
» Beam Tuning: KEK ATF2
 Production / Industrialization:
» CEBAF Upgrade and E-XFEL
2013 IRFU Linear Collider Days
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Present
ILC Accelerator Activities: Outline
 SC RF Technology Transfer
» Development of a strong industrial base
 Production / Industrialization:
» CEBAF Upgrade and E-XFEL
By the end of the XFEL
Production > 1000 cavities
will have been fabricated by
industry and processed
using the basic TESLA –
recipe.
 Beam Test Facilities:
» SRF Linac: Fermilab NML, DESY E-XFEL and FLASH, KEK STF
» Beam Dynamics: Cornell CesrTA (2008 – 2010)
» Beam Tuning: KEK ATF2
 US contribution to ‘Linear Collider Collaboration’ (LCC)
 ‘P5’ prioritization activity
2013 IRFU Linear Collider Days
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EU - XFEL
 Cavity production lines fully functioning: 8 cavities / week
» Two companies
 Cryomodule production:
• Three pre-series CM (XM-3, XM-2, XM-1) in process; typical
time to construct 4 months; time to test unknown
• Production series of 81 each started Sep. 02, 2013;
• One CM / week nominal; one production line (CEA-Saclay)
 24 cavities to be used for high – gradient development
» (See E. Elsen)
2013 IRFU Linear Collider Days
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Jefferson Lab CEBAF 12 GeV Upgrade
'BB Lunch', M. Ross (SLAC)
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'BB Lunch', M. Ross (SLAC)
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Slide dated late 09.2013
All C100 cryomodules are
now installed (11.2013)
'BB Lunch', M. Ross (SLAC)
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'BB Lunch', M. Ross (SLAC)
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SLAC Proposal:
 Following BESAC (Basic Energy Sciences Advisory) report
in late July 2013:
» Shakeup of US accelerator construction projects:
» SLAC LCLS-II project redefined
» ANL APS upgrade program redefined
 SLAC Proposal:
» 4 GeV CW SRF Linac-based FEL
» Use ILC / XFEL 1.3 GHz technology
» Installed in the upstream 1/3 of the SLAC linac housing
» (50 year old S-band linac to be completely removed)
» First light end of FY 2019
2013 IRFU Linear Collider Days
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SLAC Director Chi-Chang Kao, 27 September 2013:
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Chi-Chang Kao, 27 September 2013:
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LCLS-II and ILC
Much LCLS-II construction will be done at Fermilab, using
infrastructure intended for ILC
18 CM? (50%)
Other CM to be made at JLab (and Cornell)
Saclay CM assembly industrial experience unique
US team have made ~ two ILC CM. LCLS-II effort will help
understand US-domestic technical, cost, and
industrialization
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RF Parameters:
2013 IRFU Linear Collider Days
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RF Parameters (2)
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LCLS-II - Linac and Compressor Layout for 4 GeV
L0
j0
V0  97 MV
L1
HL
j =-26° j =-170°
L2
j = -28°
L3
j=0
V0 =235 MV V0 =40 MV
V0 = 1448 MV
V0 = 2460 MV
CM01
GUN
0.75 MeV
CM2,3
CM04
3.9GHz
CM15
CM16
LH
BC1
BC2
98 MeV
R56 = -5 mm
Ipk = 12 A
Lb = 2.0 mm
sd = 0.006 %
270 MeV
R56 = -65 mm
Ipk = 60 A
Lb = 0.40 mm
sd = 1.4 %
1550 MeV
R56 = -65 mm
Ipk = 1000 A
Lb = 0.024 mm
sd = 0.50 %
CM35
LTU
4.0 GeV
R56 = 0
Ipk = 1000 A
Lb = 0.024 mm
sd  0.02 %
100 pC; Machine layout 26SEP2013; Bunch length Lb is FWHM
Linac
V
j
(MV) (deg)
Acc.
No. Cryo
Grad.
Mod’s
(MV/m)
No.
Cav’s
Spare
Cav’s
Cavities
per
Amplifier
L0
97
*
14.6
1
8
1
1
L1
235
-26
15.1
2
16
1
?
HL
-40
-170
-
3 (3.9GHz)
12
0
12?
L2
1448
-28
15.5
12
96
6
32?
L3
2460
0
15.7
20
160
10
32?
Linear
Collider Days
* L0 phases: (-40, -52, 0, 0, 0, 13, 33), with cav-2 at2013
20% IRFU
of other
L0 cav’s.
Includes 2-km RW wake
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First 800 m of SLAC linac (1964):
September 6, 2013
Marc Ross, SLAC LCLS-II
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ILC R & D initiative: Power Coupler development
Mandated by PAC (12.2012) technical review
Common activity with Orsay /LAL
Issues:
•
•
•
•
Cost
Copper coating / flaking
Complex Assembly
Plug-compatibility
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(1) Deep Technical Review of Input Couplers
TTF3/XFEL coupler
TDR coupler
STF-2 coupler
ILC specification
• Power requirements
–
–
–
–
–
–
We recommend to match the coupler to 30 MV/m for reduced filling time and smaller Qext range
Max coupler power at operation 450 kW (for 8.8 mA, 10Hz, Eacc=31.5 MV/m ±20%)
RF processing to at least four times max input power ~ 1.8 MW up to 500 us at test stand TW
Surface field not a problem for both designs, i.e. 40mm and 60mm are both ok
Should check flattop regulation at 25 MV/m and Qext ~ 1e7 (LFD)
TW testing on test stand up to 1.8MW has to be done for both: TTF3 and STF2
• Q-ext
–
–
–
–
Variable coupling is needed, remote operation
QL tuning range: 2-7x106 is needed, but we recommend 1-10 x 106
1-10∙106 is achieved with TTF3
STF2 has to be improved
• Antenna alignment:
– Design should be +-2mm
– For TTF3 coupler the most sensitive parameter is a horizontal antenna shift/tilt. 3mm shift
change QL by ~20%. Vertical tolerances are relaxed.
– For STF-2 coupler this is not issue, mechanical design guarantee small shift.
– TTF3 has to be improved
• Cryogenic loss:
– Coupler contribution to cryogenic losses at 2K is ~5%. = not critical.
– Major contribution from coupler is 70K
• Conditioning time
– Both designs are ok
– The nominal conditioning time of < 50h is achieved/demonstrated.
• Multipacting
– DESY and SLAC simulations, tests and operation show no problem with TTF3
– STF2 will be simulated, tests show no problem
• One vs. two windows
– Many single window coupler are successful under operation
– The single window would need to seal-off the cavity before the cavity-string
installation into the cryomodule.
– Single window coupler for ILC would need complete new development and test
program of coupler (and module)
– But it could be a significant cost saving
• Compatibility
– Cavity and attached parts (power coupler, tuner, HOM coupler, feedthroughs, He vessel,
thermal connections, magnetic shield…) are tuned/balanced, it is not easy to exchange only
parts of this composition
– STF2 coupler design does not fit in the compatibility requirements of the TDR (40mm cavity
coupler flange)
• Cost
–
–
–
–
CPI: STF2 price is 1.9 higher
Toshiba: STF2 slightly lower price
RI: about same price
Industrial study of STF2 for design optimization and cost reduction is
recommended
– The TTF3 coupler mass fabrication has to be investigated
Recommendation:
•
•
•
•
•
STF2 coupler has to demonstrate stable long time (>6 month) beam operation
in a CM (TTF3 coupler has a long history in FLASH)
The ILC management recommend an adapted STF2 design with 40mm cavity
flange. In this case more development steps have to follow in order to realize
the compatible design. The new design has to be proven with beam operation.
The concept of plug compatibility has to be further developed in view of a
spare part concept. We recommend spare modules, not individual parts.
An industrial study of mass production for both designs is recommended
Industrial study of STF2 for design optimization and cost reduction is
recommended.
ATF2 Program Status
Glen White, SLAC
January 2013
2013 IRFU Linear Collider Days
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Detector measures
measurable range
determined by fringe pitch
signal Modulation Depth “M”
M
N - N cos( ) exp - 2(k ys y ) 2
N  N-
 sy 

d
2
 cos( )
2 ln
 M





d

ky


2 sin( / 2)
depend on
crossing angle θ (and λ )
Focused Beam ： large M
N+
Small σy
N[rad]
N: no. of Compton photons
Convolution between e- beam profile and fringe intensity
Dilluted Beam ： small M
Large σy
13/05/29
[rad]
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Crossing
angle θ
Fringe pitch
d

ky

174°
30°
8°
2°
266 nm
1.03 μm
3.81 μm
15.2 μm

2 sin( / 2)
Lower limit
20 nm
80 nm
350 nm
1.2 μm
Upper limit
110 nm
400 nm
1.4 μm
6 μm
Expected Performance
Measures
σy* = 20 nm 〜few μm
with < 10% resolution
sy 
d
2
 cos( )
2 ln
 M




σy and M
for each θ mode
select appropriate mode
according to beam focusing
13/05/29
2013 IRFU Linear Collider Days
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174 deg.
optical
delay
Laser transported to IP
30 deg.
beam
pipe
half
mirror
2 - 8 deg
Vertical table
1.7 (H) x 1.6 (V) m
•
•
Crossing angle
continuously
adjustable by
prism13/05/29
Interferometer
Phase control (piezo stage)
path for each θ mode
（auto-stages + mirror actuators ）
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2013 IRFU Linear Collider Days
Role of IPBSM in Beam Tuning
transverse ：laser
13/05/29
wire scan
laser spot size
σt,laser = 15 – 20 μm
beforehand ….
Construct & confirm laser paths, timing alignment
precise position alignment by remote control
Longitudinal：z
scan
2013 IRFU Linear Collider Days
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After all preparations ……….
continuously measure σy
using fringe scans
 Feed back to
multi-knob tuning
Beam time status in 2012
Spring run
Feb； 30 deg mode commissioned
( 1st M detection on 2/17)
stable measurements of M 〜 0.55
•
•
2 - 8 ° mode: clear contrast （Mmeas ～0.9)
Prepared 174 deg mode commissioning
M = 0.52 ± 0.02 (stat) (10 x bx*, 3 x by* optics)
σy = 166.2 ± 6.7 (stat) [nm]
preliminary
Major optics reform of 2012 summer
By IPBSM group@KEK
 Suppress systematic errors
 Higher laser path stability / reliability
Winter run
High M measured at 30 ° mode
Contribute with stable operation to
ATF2 beam focusing / tuning study
12/20 :
1st success in M detection
at 174 deg mode
10 x βx* , 1 x βy*
preliminary
Last 2 days in Dec run
Measured many times M = 0.15 – 0.25
（correspond to σy 〜 70 – 82 nm）
* IPBSM systematic errors uncorrected
** under low e beam intensity (〜 1E9 e / bunch)
Large step towards achieving ATF2 ‘s goal !!
error studies ongoing aimed at deriving “true beamsize”
13/05/29
2013 IRFU Linear Collider Days
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Beam time status in 2013 Spring
Stable IPBSM performance  major role in beam tuning
measured M over continuous reiteration of linear
/nonlinear@ tuning knobs @ 174 ° mode
dedicated data for error studies under analysis
174 ° mode ”consistency scan”
preliminary
10 x bx*, 1 x by*
measure M vs time
after all conditions optimized
M 〜 0.306 ± 0.043 (RMS)
correspond to σy 〜 65 nm
Best record
preliminary
from Okugi-san’s Fri
operation meeting slides
ex） consecutive 10 fringe scans
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Time passed
moving
towards goal of σy = 37 nm :
13/05/29
IRFU Linear
Collider
Days
higher IPBSM precision and stability &2013
looser
current
limits
of normal / skew sextupoles current
The Reality… May 2 week Cont. Run
• Summary of all scans during 2 week ops period
– Summary plot courtesy of Edu.
2013 IRFU Linear Collider Days
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