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Status on HQ Coil Design and Fabrication. Helene Felice 11/16/2011 LARP Collaboration Meeting 17 1 st HiLumi Collaboration Meeting CERN. HQ01 series Overview. HQ01a. HQ01b. HQ01c. HQ01d. HQ01e. Coils Test. 1-2 -3-4 April 2010. 1 - 4 -5-6 June 2010. 1 -5-7- 8 Oct. 2010. - PowerPoint PPT Presentation
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Helene Felice11/16/2011
LARP Collaboration Meeting 171st HiLumi Collaboration Meeting
CERN
Status on HQ Coil Design and Fabrication
2
HQ01 series Overview
11/16/2011 H. Felice - 1st HiLumi/ LARP Collaboration Meeting
HQ01a HQ01b HQ01c HQ01d HQ01eCoilsTest
1-2-3-4April 2010
1- 4 -5-6June 2010
1 -5-7-8Oct. 2010
5-7-8-9April 2011
5-7-8-9July 2011
80
90
100
110
120
130
140
150
160
170
180
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30
Grad
ient
(T/m
)
Quench #
HQ01aHQ01bHQ01c - regular trainingHQ01c - 30 to 50 A/s or profileHQ01d HQ01e
HQ01a – 157 T/m – 79 % Iss – unusual ramp-rateHQ01b – 153 T/m – 77 % Iss – electrical failureHQ01c – 138 T/m – 70 % Iss – unusual ramp-rateHQ01d – 170 T/m – 86 % Iss - mechanical limitHQ01e – 170 T/m – 86 % Iss
9 coils (54/61 or 108/127 RRP) 5 tests at 4.4 K at LBNL
H. Felice - 1st HiLumi/ LARP Collaboration Meeting 3
Overview of HQ01 coil fabrication
11/16/2011
Coil Strand Cable Core Magnet Note
1 54/61 992R No HQ01 a-b-c (LBL) Limiting coil
2 54/61 992R No HQ01 a (LBL) Electrical failure
3 108/127 991R No HQ01 a (LBL) Limiting coil
4 108/127 1000R No HQ01 a-b (LBL)
5 108/127 1000R No HQ01 b-c-d-e (LBL)
6 108/127 1000R No HQ01 b (LBL) Electrical failure
7 108/127 1000R No HQ01 c-d-e (LBL)
8 54/61 996R No HQ01 c-d-e (LBL)
9 54/61 996R No HQ01 d-e (LBL)
10 54/61 996R No Not impregnated Broken strands
11 108/127 (Ti) 1010R No Not tested
12 54/61 1012 SS - 25 mm HQM01 FNAL Special coil
13 54/61 1008 No HQM02 FNAL Special coil
H. Felice - 1st HiLumi/ LARP Collaboration Meeting 4
HQ01b Electrical breakdown possible causes
11/16/2011
• Extensive mechanical analysis performed ruled out the participation of the support structure
• Autopsy of coil #6 revealed origin of the short in the interlayer pointed out end design weakness both Lead end and Return end
• Review of the coil fabrication process: high compaction
• Combination of these effects => electrical failure in HQ01b
Lead endView of the return end
H. Felice - 1st HiLumi/ LARP Collaboration Meeting 5
High compaction: a common symptom of HQ01 coils
11/16/2011
• 9 coils tested in HQ01 : same observations during fabrication very high compaction after reaction tendency to spring out of the reaction fixture (unlike TQ/LQ)
• Broken strands in coil 10observed post-reaction
Coil 3
Coil 7
Coil 10
• Some corrective actions taken to reduce the compaction
reduction of the radial build-up of material in the cavity
• Coil / cavity size mismatch post reaction? Nb3Sn formation?• Not seen in TQ/LQ
H. Felice - 1st HiLumi/ LARP Collaboration Meeting 6
Dimensional changes during heat treatment
Study on unconfined cables
Study on sections of LQ - TQ and HQ coils
ThicknessLQ and TQ: 5.6 and 6% of increaseHQ: only 1 to 2 % of increase
WidthLQ and TQ => 1 to 2 % of increaseHQ => 1 % of increase
Meas. Performed at FNAL D. Bocian, M. Bossert
11/16/2011
width
Meas. performed at LBNL by J. Krishnan
axial contraction: 0.1 to 0.3 % thickness increase: 1.4 to 4 % width increase: 1.5 to 2 %
H. Felice - 1st HiLumi/ LARP Collaboration Meeting 7
What is different in HQ?
11/16/2011
• Comparison of the coil fabrication tooling between TQ/LQ and HQ
consistency with a constant cavity size at each step of the fabrication
• Comparison of the coil cross-sections difference in the nominal design insulation
125 mm in LQ 100 mm in HQ
Creating a buffer of 80 mm per turn in LQ ~ 6% of LQ cable thicknessCreating a buffer of 30 mm per turn in HQ ~ 2% of HQ cable thickness
Effective insulation: 86 mm thick
More room in the cavity required for radial and azimuthal expansion
H. Felice - 1st HiLumi/ LARP Collaboration Meeting 8
Accounting for axial dimensional changes
11/16/2011
• Axial tension in the conductor ~ 5MPa => Relaxation due to winding tension• Contraction during reaction• Axial gaps in the pole pieces during winding
Axial contraction due to reaction estimated to be 2 to 3 mm/m
Total gap size 3 to 4 mm/m
Winding relaxation estimated to 1mm/m
Modulus vs. Stress for 100lb Cycle
2500
7500
12500
17500
22500
27500
32500
3 13 23Stress (MPa)
Mod
ulus
(MP
a)1000R
1010R1014R5
1014S
1014P1
1014P2
Stress (MPa)
Mod
ulus
(MPa
)
Measured by Brett Collins
Young modulus measured on various HQ unreacted cables:
H. Felice - 1st HiLumi/ LARP Collaboration Meeting 9
Test Coils
11/16/2011
Coil 12 – 54/61 – cored cable• By adjusting mid-plane shimming
~3 % per turn of additional space
• Assembled and tested in FNAL HQM01 Limited by mid-plane turn Improved performance at 150 A/s
=> 82 % Iss
“Compaction theory” tested with test coils• Increase of the azimuthal space in the cavity• Still radial compaction
• Unusual coil size => FNAL mirror test
Rodger Bossert & Guram Chlachidze
Coil 13 – 54/61 – no core• By removing the mid-plane turn in both layers
~5 % per turn of additional space Axial gap increased from 0.8 mm to 2 mm
Þ closed after reactionÞ contraction of ~ 3mm/m
• Assembled in HQM02 tested at FNAL 91 % of Iss at 4.6 K 89 % of Iss at 2.2 K
H. Felice - 1st HiLumi/ LARP Collaboration Meeting 10
HQ02 coils: reduced compaction
11/16/2011
• A new series of HQ magnets: HQ02
• Main requirement: using the same tooling as HQ01• Interlayer insulation increased to 500 mm • Accounting for dimensional changes and interlayer insulation
Smaller cable with smaller strand => 0.778 mm => 14.8 mm x 1.375 mm Axial gap size 4 mm/m
• All coils made with 108/127 conductor • Revision of the end parts design
• New approach for the magnetic cross-section Reacted cable dimension based on some assumptions
on cable dimensional changes Conductor alignment on the OD of the pole piece
H. Felice - 1st HiLumi/ LARP Collaboration Meeting 11
Overview of HQ02 coil fabrication
11/16/2011
Coil Strand Cable Core Status Magnet
14 108/127 1017 No Completed To be tested in mirror
15 108/127 1020B SS / 8 mm / 25 mm Wound & cured To be tested in mirror / HQ02
16 108/127 1020D SS / 8 mm / 25 mm To be tested in HQ02
Coil 14 post-reaction: limited protrusion ~1.5 / 2 mm
Total axial contraction: 3.5 mm/m • Gap: ~4 mm/m • 0.5 mm/m post curing
Coil 15 post-curing:
Total axial contraction: NA• Gap: 4 mm/m • 1 mm/m post curing
Ongoing cored cable measurement to get reference numbers for cored cable dimensional changes
H. Felice - 1st HiLumi/ LARP Collaboration Meeting 12
HQ persisting electrical weaknesses
Coil Coil to island Coil to endshoe IL endshoe to OL endshoe Magnet
5 LE – 290 V HQ01 b-c-d-e
7 12.5 kW LE 700-800 V LE – high leakage current HQ01 c-d-e
8 RE – 7.6 kW HQ01 c-d-e
9 RE - 340 V HQ01 d-e
11 Not tested
12 20 kW LE 700-900 V LE – 500 MW HQM01
13 Dead short HQM02
14 LE IL(35 V) / OL (0.5 W) LE – 35 V Not tested
• Despite increased interlayer insulation• Despite outer layer end-shoe revision• Despite reduced compaction
ÞTask force set up to address this issueÞ Possible revision in HQ and LHQ
11/16/2011
H. Felice - 1st HiLumi/ LARP Collaboration Meeting 13
Damaged insulation post-reaction
11/16/2011
Insulation fragmentation after reactionPossibly caused by the use of CTD binder
Decision to stop using “precured” glass or Nextel ceramic for the interlayer insulation in the new generation of coils
S-glass placed on the OD of the coil
during reaction (combination of
the brittleness and high
compaction)
Nextel ceramic interlayer insulation, not treated with binder
H. Felice - 1st HiLumi/ LARP Collaboration Meeting 14
Summary
• 11 coils fabricated with the HQ01 design Observations: coil high compaction, electrical breakdown, somewhat limited
performance Possible cause of limitations
initial coil design – fabrication process: high compaction
• 2 test coils with reduced compaction tested in FNAL mirror
• HQ02 design implemented in coils 14 and 15 108/127 conductor, smaller cable, OL end-shoe revision Introduction of SS cored cable in all coils starting with coil 15
11/16/2011
H. Felice - 1st HiLumi/ LARP Collaboration Meeting 15
Some open questions
• Electrical weaknesses observed in almost all the coils Failure of the hipot coil to metallic components
• Some insulation issues – compatibility with binder
• Some uncertainties about the coil dimensional changes
• Need to understand if the HQ somewhat limited performance come only from the coil high compaction
urgency to get HQ02 coils ready for test
• Ongoing investigation Dimensional changes in cored cables Task force for end-shoe redesign and improvement
11/16/2011