Transcript Slide 1

Field Quality of MB.
Alignment and Field Quality of SSS.
Presented by: Stephane Sanfilippo
AT-MTM-AS
Inputs from L.Bottura, M.Buzio, V.Chohan, M.Calvi,
M.Coccoli, J.Garcia, N.Sammut, N.Smirnov,E.Todesco,
W.Venturini, L.Walckiers, E. Wildner, J. Beauquis and
A.Verweij.
Data from AT-MTM and AT-MAS.
Review of tests of superconducting magnets in SM18 - Stephane Sanfilippo AT-MTM-AS
Overview

Status of field quality for the MB.





Warm/cold correlation-sampling.
Dipole families.
Standard vs extended test program.
Test plan for 2005-2006: proposal.
Field quality and magnetic axis of the MQ in the SSS.




Standard tests-status of the warm/cold correlation.
Strategy for the other tests for the MQ and correctors.
Warm/cold correlation for the magnetic axis in the MQ.
Test plan for 2005-2006 : proposal.
Review of tests of superconducting magnets in SM18 - Stephane Sanfilippo AT-MTM-AS
Dipoles measured.

140


3 producers
three X-sections
 7 cable combinations (over 14)
80
60
40
20
you can have access to the data through
http://sma.cern.ch
Cable combinations
100
0
To
ta
l

120
02B5
02B8
02C0
02C8
02C9
02D
02G
02K
01B-02X measured
50
0
5
0
NO
0
7
59
01E-02X measured
0
3
0
NO
0
0
3
10
01B-02X delivered
expected
225
60
33
36
24
36
0
24
NO
NO
12
60
109
0
158
0
01E-02X delivered
expected
12
72
48
18
24
36
NO
NO
24
117
48
36
51
12
10
0
Review of tests of superconducting magnets in SM18 - Stephane Sanfilippo AT-MTM-AS
O
1
O
2
O
3

160
XS
1
XS
2
XS
3

Sample : 143 dipoles cold tested.
2004: ~ 56 dipoles (14% of the cold tests)
264 apertures considered in the statistics
(some data missing)
fair mix of (dipoles)
magnets number

Dipoles tested
Courtesy
A.Verweij.
-10
-5
0
-2
-4
-6
flat top (91 magnets)
-8
flat top (132 magnets)
-10
-12
b2
b9
b7
b11
harmonic
b5
a4
b4
a3
b3
a2
b2
b1
injection (132 magnets)
15
0
b1/10
offset (units @ 17 mm)
injection (91 Magnets)
10
warm b3-units @ 17 mm
Warm (CM)/cold- offsets
10
8
6
4
2
0
-2
-4
-6
-8
5
harmonic
Stable offsets and s: Quality of the w/c correlation did not change since 2003.
Batches of 50 magnets for each population variant (firms, X-section, cables…):
With 50x8 (octants) = 400 cold tests minimum to meet the commissioning specs.
Review of tests of superconducting magnets in SM18 - Stephane Sanfilippo AT-MTM-AS
b11
warm TF - Tm / kA
b9
10.15
b7
10.1
-5
b5
10
10.05
NOM
a4
BOI
0
b4
10.05
b3
5
a3
Transfer
Function
injection
nominal
10
b3
10.1
15
a2
cold b3 (units @ 17 mm)
10.15
offset (units @ 17 mm)
cold TF (Tm / kA)
Warm/cold correlation evolution (dipole).
Searching for the different behaviour….

No dependence of the W/C correlation on the X-section, on the manufacturer.

Differences generated by the variation of Rc in the cable production: coupling
currents effects, decay via transport current redistribution.
no correlation visible for the moment between Rc and decay.
N.Sammut and L.Bottura, A.Verweij, “classification of LHC dipole at injection” (part II), EDMS 501792

2 classes are emerging characterized by the magnetization in the inner layer
cables : different effects of the persistent current and the decay of b1.
NB: influence of the different outer layers not visible for the moment.
V.Granata et al., “a strategy for sampling in the FQ of the LHC dipoles” , EPAC 2004 .
N.Sammut and L.Bottura, “classification of LHC dipole at injection” EDMS 501792.
Review of tests of superconducting magnets in SM18 - Stephane Sanfilippo AT-MTM-AS
Decay of b1 magnetization at injection.
N.Sammut and L.Bottura, “classification of LHC dipole at injection”, EDMS 501792
Family 1 : Magnets with 01B- 02X combination
Family 2 : Magnets with 01E-02X combination.
ex : 01 E-02 K
Study on 10 magnets only
ex : 01 B-02 B5
ex : 01B-02 K
Decay of these magnets not scalable yet.
Decay of these magnets follows the scaling law: c
decay
n
t t inj
t t inj
 Δ



Δ 
τ 

 Δn a 1  e
 (1  a ) 1  e 9τ 



 



Magnets with the combination 01E-02 X to be measured in priority (50 minimum).
Test of the other 01B-02X combinations to confirm the scaling properties.
Review of tests of superconducting magnets in SM18 - Stephane Sanfilippo AT-MTM-AS
Standard program of magnetic measurements

Quantities measured for MB and MQ:




Main field integral strength (rotating coil, SSW), magnetic length, as a function of the current.
Integrated and local harmonics as a function of the current (rotating coil).
Magnetic axis for the MQ and the correctors in the SSS (SSW)
Two measurement cycles:
Duration of the cycle : 3 h
Duration of the cycle : 2h 30 mn
11850 A
11850 A
1000 s
saturation
5000 A
760 A
11850 A
Geometric
magnetization
Load-line (static measurements)
Quench
1000 s
760 A
Simulated Machine Cycle with a reference pre-cycle.
Measurements performed after the training of the MB or MQ.
Review of tests of superconducting magnets in SM18 - Stephane Sanfilippo AT-MTM-AS
What do we get from…

Standard program






Transfer function, multipoles.
Geometric component.
DC magnetization from
persistent currents.
iron saturation component.
decay of multipoles at injection
for a reference cycle.
snap-back at acceleration
(amplitude only).
But not sufficient for the
knowledge of the machine
behaviour…

Extended tests





Powering history effect on the
decay (scaling laws).
2 tests in 2004!
Snapback studies (b3/b5 hall
probe).
2 tests in 2004!
Coupling currents effects.
2 tests in 2004!
Degaussing effect on multipoles
2 tests in 2004!
Geometry changes due to
storage, Lorentz force…
1 test in 2004!
Review of tests of superconducting magnets in SM18 - Stephane Sanfilippo AT-MTM-AS
Ex1:Powering History Dependence (PHD) of the decay.

main parameters:

flat-top current
 flat-top duration
 waiting time before injection
b3 (units) vs time (s) at Injection
3
2.5
b3 (units)
2
Decay
amplitude
1.5
2054ap2
1
0.5
0
-0.5
0
200
400
600
800
1000
1200
1400
Test
Tim e (s)
b3decay
t

 FT


IFT A  Be 
 n  std

n 
t
 std
Istd 

A  Be 
t p rep aration


C  De  
t



 std


 C  De  
std
 f decay std
n
n,i

Ift(kA)
tft(minutes)
1
2
3
4
5
6
7
8
9
10
Precycle Parameters
I Flat-Top t Flat-top t pre-injection
4000
1000
0
8000
1000
0
10000
1000
0
11850
60
0
11850
300
0
11850
600
0
11850
1800
0
11850
1800
60
11850
1800
300
11850
1800
1800
up to 2000A
up to 2000A
up to 2000A
up to 2000A
up to 2000A
up to 2000A
up to 2000A
up to 2000A
up to 2000A
up to 2000A
 Test duration for a complete scan (10 tests) : 70 hrs
Review of tests of superconducting magnets in SM18 - Stephane Sanfilippo AT-MTM-AS

Machine cycle
Ex 2: B3/b5 snap/back studies. Hall-probe device for 10 Hz b3
inclinometer
b3
sensors
b5
sensors
(and b5) measurement
64 pin
connector
Snap-back
waveform.
Electrical
connection
card
snapback
3
b
t   b3e

I t  I injection
I
With Rotating Coils
One point very 10-20 s…
Not enough for a phenomena study
Snapback Law Correlation
7
6
Varying pre-cycle conditions.
delta b3 (units)
5
b3decay =fsnapback Isnapback
4
3
2
1
0
0
5
10
15
20
delta I (A)
Review of tests of superconducting magnets in SM18 - Stephane Sanfilippo AT-MTM-AS
25
30
35
Sextupole decay/snap-back studies : optimization.
Uncertainties calculated by
ucommissioning  (uwc )  (uPHD )
2
Required for
b3~ 0.35 units
u  t ( , n  1)
s
n
1
n
N
t=2.6 for 99% confidence level
And n big.
ucommissioning  (uwc ) 2  (usnapback ) 2
2
Optimization of the test number
to meet the commissioning specs:
ratio between standard
and extended tests.
Required for
b3~ 0.35 units
See N.Sammut : FQWG of 14 December 2004.
But Ntests-optimal= 3 PHD measurements for
every 70 standard tests.
Ex for 300 standard tests : 12 PHD tests
for all production (2 already done)!
Ntest_optimal = 3 snap back measurements for
every 60 standard tests.
Ex for 300 standard tests : 15 snapback
tests for all production (2 already done)!
~1 PHD of the decay or Snapback study every month
for the two years.
Review of tests of superconducting magnets in SM18 - Stephane Sanfilippo AT-MTM-AS
Test plan proposal: Field quality in dipoles

Standard Tests of dipoles with O1E-02X
cables (6 comb=60 MB)

17hrs×60 = 1020 hrs
Standard Tests of dipoles with O1B-02X
cables (5 comb =50 MB)
17hrs×50 = 850 hrs
110 MB (~14%). Total standard = 1870 hrs for 2005-2006

Powering history dependence of the decay
(12 MB)
70hrs×12 = 840 hrs

Coupling current effects and field
advance (10 MB)
6hrs×10 = 60 hrs

Snapback studies with B3/b5 HP+
degaussing cycles (12 MB)

Effect of powering, storage on FQ (6
MB).
10hrs×6 = 60 hrs
30hrs×12 = 360 hrs

40 MB Total extended = 1320 hrs for 2005-2006.
In 2004
Total time needed :
Standard tests:
17hrs×56 = 952 hrs
3190 hrs.i.e.1595 hrs per year

Special Tests:
236 hrs
3190 hours / 12 benches /24 h =
Total = 1224 hrs
11 days on the whole SM18 program.
20/21
Review of tests of superconducting magnets in SM18 - Stephane Sanfilippo AT-MTM-AS
Field quality of the MQ in the SSS.

49 arc SSS tested at cold in December 2004.

Field gradient :40 MQ measured.
 7 MQ measured with the scanner (rotating coils), 33 MQ with the SSW system.
 But analysis performed on 22 MQ.

Field Quality (multipoles) :16 MQ cold tested
 15 X-section 1+1 X-section 2.
 7 MQ measured with the scanner, 9 with the long shafts.
 Small number of dynamic effects studies on multipoles (decay, no cable coupling currents).
 No study of dynamic effects on b2 (decay, cable coupling currents).
 No special cycle performed (pre-cycling dependence of the b2-b6 decay)
 Only one type of cable tested : 03B. other types are coming (03C, 03G, 03K)
Already differences of integrated field gradient observed at warm between 03B,03G and
O3C.

Expected~ 40 MQ with mr of the collars out of tolerance, ranging from 1.005 and 1.04.
 Effect on b2 (30 units/0.01 of mr ) and on b6 (-2.5 units/0.01 of mr ) observed at warm.
Review of tests of superconducting magnets in SM18 - Stephane Sanfilippo AT-MTM-AS
Warm/cold correlation status (MQ).
58.5
MQ 120
Nominal current
45 units
17 units
58.3
MQ66?
cold b6 (units @ 17 mm)
MQ60?
58.4
cold TF (T / kA)
10
MQ56?
MQ120?
58.2
SSW
Scanner (rotating coil)
injection
nominal
5
0
-5
-5
58.1
58
58.1
58.2
58.3
58.4
0
5
warm b6- units @ 17 mm
warm TF (T / kA)
Offset of~17 units between the two systems.
MQ 120 (X section-2) out of the correlation.
sw/c~3 units (scanner), sw/c~5 units (SSW)
MQ 120 (X section-2) out of the correlation.
2.3 units of shift.
Nominal : Offset of -0.34 units. sw/c~0.22 units.
Injection : Offset of -3.8 units. sw/c~0.33 units.
Origin of the offset between the two systems not found under investigation.
 Magnet with mr out of tolerance out of the correlation.
Review of tests of superconducting magnets in SM18 - Stephane Sanfilippo AT-MTM-AS
10
W/C correlations status for MQ and sampling.
Warm (CM)/Cold (nominal)
Transfer function
b6
Warm-cold offset (units)
23
-0.34
s w/c (units)
5
0.22
(MQ 120 with high m excluded)
Keep the W/C uncertainty (3sW/C) below specs and
unknowns u= e sspec


sspec (b2 )~10 units
 e=0.2, measure ≈ 50 magnets minimum.
sspec (b6 ) ±1 units
 e=0.1, measure ≈ 36 magnets minimum.
Review of tests of superconducting magnets in SM18 - Stephane Sanfilippo AT-MTM-AS
General strategy for the other tests for the MQ and the
correctors .

Limit the measurements in SM18 (time constraint).

Integrate statistics with measurements in the vertical cryostat (Block
4), cross calibrated with SM18.

Vertical tests can provide:
Integrated TF and field harmonics for MQ and associated correctors
(in particular TF at injection field). Goals: confirm W/C offsets
(b2,b6 persistent)
Dynamic behaviors (decay and snapback of b2, field advance,
degaussing, powering history effects).
o
o
Review of tests of superconducting magnets in SM18 - Stephane Sanfilippo AT-MTM-AS
Cross calibration strategy.

2 MQ measured in Block 4 with the new shafts in before March shutdown.

Integration in SSS and measurement in SM18 with SSW and/or long
shafts (April/May?).

Work out correction coefficients, according to quality of the 3 sets of data.

Determination of sampling rate, share between SM18 and Block 4
according to workloads.

Correction of all available data (manual).

Same for MSCB, MQT and MO (Transfer function).
Review of tests of superconducting magnets in SM18 - Stephane Sanfilippo AT-MTM-AS
Alignment of SSS: Magnetic-Mechanical Axes

Measurements

Warm in Bldg 904 with AC mole (now including fiducialization)
 Warm in SM18 with SSW (cold benches): now stopped!
 Cold in SM18 with SSW.
Correlation: Warm Bldg 904 Cold SM18

Status

Bldg. 904: 35 SSS measured (up to 5/week now).



First 7 measurements with 0.25mm resolution (optic problems)
Following measurements with 0.1mm resolution
SM18

SSW :15 MQ measured at warm and 45 MQ at cold with 0.1 mm
resolution.
Review of tests of superconducting magnets in SM18 - Stephane Sanfilippo AT-MTM-AS
Magnetic axes : warm /cold correlation
-0,6 -0,4 -0,2 0,0
0,0
H
V
Offset W/C
(ACmole/SSW)
-0.13
-1.37
s w/c
(ACmole/SSW)
0.21
Offset W/C
(SSW/SSW)
-0.02
s w/c
(SSW/SSW)
0.25
(mm)
0,2
0,4
SSW (warm)/SSW (cold)
-0,6 -0,4 -0,2 0,0
0,0
0,6
0,2
-0,2
-0,2
-0,4
-0,4
V (mm)
V (mm)
-0,8
-1,0
-1,0
0.14
swarm
(mech/mag)
0.13
0.12
stolerance
0.25
0.25
14 SSS
-0,6
-0,6
-0,8
-1.36
-1,2
-1,2
-1,4
-1,4
-1,6
-1,6
-1,8
-1,8
Average Displacement
H (mm)
s2
=
s2
0,6
AC mole/SSW (cold)
14 SSS
0.15
0,4
warm/cold+
s2
H (mm)
 sH = 0.25 mm = stolerance Limit spec!
mech/mag
 sv= 0.20 mm < stolerance In spec!
NB: The first part of measurements presented here performed during the system commissioning!
Review of tests of superconducting magnets in SM18 - Stephane Sanfilippo AT-MTM-AS
SSS: Results and alignment strategy
• Averages are good:
• H = -0.13mm
• V = -1.37mm
• Standard Deviation are:
The SSW
operation/data
analysis expertise
has increased
The data quality has
improved after the
AC mole system has
been tailored for the
operation in BLDG
904
• sH= 0.25mm Limit Spec
• sv = 0.20mm In Spec
The s are expected to drop
For the moment the correlation
are near the specification limits
Sampling of cold
measurements for the
follow up of the W/C.
Review of tests of superconducting magnets in SM18 - Stephane Sanfilippo AT-MTM-AS
Test plan for the MQ and the correctors in the SSS.

TF measurements : 50 MQ with SSW
system or long shafts.
(follow up of the W/C offsets, s)

Special tests :Dynamic effects on
multipoles and on b2 performed in block
4 (5 MQ).
Magnetic axis measurements :

at warm in 904 on 100% of the MQ
and correctors.

at cold on (~10% of the production)

Correctors :Transfer function +multipoles
at cold in Block 4 (size of sample to be
defined).


Multipole measurements in 5 MQ for
magnets with out of spec m of collars.

Standard multipole measurements in
MQ for each cable family (total of 30
MQ). Can be done partially in Block 4.
~ 50 MQ fully characterized at cold
in the SM18.
200-250 SSS can be tested without anti-cryostat.
Review of tests of superconducting magnets in SM18 - Stephane Sanfilippo AT-MTM-AS
21/21
ANNEX 1:Modeling of the persistent current at injection.
OK for 02B-01B, 02C-01B 02K-01B cable combination.
02K-01B
calculation
For the 02K-01E cable combination: b1 hysteresis not understood….
M  Jc D


1  B   B 
J c    1

B Bc   Bc 
~ 5 units of
discrepancy
between
calculation and
experimental data

calculation

Review of tests of superconducting magnets in SM18 - Stephane Sanfilippo AT-MTM-AS
courtesy V. Granata
ANNEX 2 :Warm/cold correlation status (MQ).
MQ 120
1
10
injection
nominal
5
cold b4 (units @ 17 mm)
cold b6 (units @ 17 mm)
0.8
0
0.6
injection
0.4
0.2
0
-0.2
-0.4
-0.6
-0.8
-5
-5
0
5
10
-1
-1
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
warm b6- units @ 17 mm
warm b4- units @ 17 mm
b6
b4
MQ 120 (X section-2) out of the correlation.
+2.3 units of difference.
0.6
0.8
Offset of -0.3 units. s w/c~0.36 units
Nominal : Offset of -0.34 units. sw/c~0.22 units
Injection : Offset of -3.8 units. sw/c~0.33 units
Review of tests of superconducting magnets in SM18 - Stephane Sanfilippo AT-MTM-AS
1