Cable Test at CERN Giorgio Ambrosio Fermilab

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Cable Test at CERNGiorgio AmbrosioFermilab
LARP Collaboration Meeting 13 Nov. 4-6,
2009 Port Jefferson
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Cable Sample Holder
FRESCA collars
Pre-load by bolts through the collars
Voltage taps
Report with sample holder description is on the
plone
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FRESCA field parallel to self-field between
cables
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Cable self-field

• COMSOL model 0.113 T/kA
• ANSYS model 0.107 T/kA

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Coil 08 Cable Sample

• Sample 4-FRESCA-FNAL-RRP54/61-0909
• Cables 27 strands Keystoned
• Strand diameter 0.7 /- 0.002 mm
• Strand Nb3Sn RRP 54/61 made by OST (billet
  9560)
• width (bare cable) 10.077 0.000 -0.100 mm
• mid thickness (bare cable) 1.26 /- 0.010 mm
• keystone angle 1.0 /- 0.01 deg.
• Sample length 1725 mm (splices included)
• Cable spool 983R (used for LQ coil 08)
• LQ HT (cables reacted with LQ coil 08)
• Insulation S2-sleeve (0.1 mm thick) with
  palmitic acid
• Expected Ic 16041 A _at_ 11.41 T (9.6T FRESCA
  1.81T self-field) 4.33 K
• Prestress 40 MPa _at_ 300 K (3000 Kg per bolt)
• 0.5 mm Kapton added after impregnation

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Example of V-I ramp
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Ramp Rate Study at 4.3K

• small effect of Ramp Rate
• small effect of waiting time

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Max Quench Current
Note the Iq was lower every time the field was
changed!
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Strand Cable Ic Comparison

• Started comparison of strand and cable Ic
  measurement with feedback to SSL computation
• Include strand self-field how much?
• ? Yes 0.483 T/kA (Vadim assuming current
  redistribution within each filament)
• Take strain into account how?
• ? Yes Perform best fit of cable Ic data using
  parameterization (Arnos model) based on
  extracted witness samples (BNL and FNAL data),
  and strain as fit parameter
• -0.085 additional thermal strain in cable test
  (SS sample holder)

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Witness Sample Test Summary
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SSL at 4.33K 13880A 13433 A assuming the same
add. strain of the cable ? -3 per -0.085 strain
(sensitivity)
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PS limit 32 kA
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LQ 08 V-I and V-H tests _at_ 4.2 K
Good match of stability threshold in 0-9T range
Sample IsA range 0-4T IsA range 4-8T IsA range 8-10T Ic _at_15T Ic _at_12 T Tc0K Bc20T
9560 Round Ti 1112.5 12.5 1087.5 12.5 837.5 12.5 290 589
9560 extr. 983 Ti 1 837.5 12.5 462.5 12.5 412.5 12.5 Iq 225 Iq 472
9560 extr. 983 Ti 2 1040 15 1012.5 12.5 858 15 276 559 17.197 26.286
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Extracted Comparison _at_ 4.2 K
Sample IsA Range 0-4T IsA Range 4-8T IsA Range 8-10T Ic _at_ 12T C Tc0 Bc2
LQ 06 9533 Extr 978 Ti 812 12.5 612.5 12.5 562.5 12.5 562 10082 16.239 27.05
LQ 07 9532 Extr 979R SS 912.5 12.5 837.5 12.5 787.5 12.5 516 10149 16.472 25.873
LQ 08 9560 Extr 983 Ti 1040 15 1012.5 12.5 858 15 564 10321 17.198 26.286
LQ 09 9534-5 Extr 984 Ti 937.5 12.5 1012.5 12.5 862.5 12.5 574 10166 17.048 26.677
D. Turrioni
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Coil 06 BNL Witness Samples
FNAL sample with Is 563 A reached the critical
surface at B 10 T ? variability? Other factors?
BNL witness samples of coil 06 show Is 950 A
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Performance at 1.9 K is better than at 4.3
K TQ02-series behaved differently Why?
strain, transv. pressure, more conductor,
disturbance spectrum,
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Extracted Comparison _at_ 1.9 K
Strand stability at 1.9K is between cable and
magnet
Sample IsA range 0-4T IsA range 4-8T IsA range 8-10T Ic _at_15T Ic _at_12 T
LQ 06 9533 extr. 978R Ti 887.5 12.5 637.5 12.5 562.5 12.5 435 Iq 627 
LQ 07 9532 Extr. 979R SS 937.5 12.5 687.5 12.5 612.5 12.5 378 Iq 682
LQ 09 9534-5 Extr 984 Ti 1287.5 12.5 525 25 775 25 431 760
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Conclusions

• The test at FRESCA of the LQ cable was very
  successful
• Seen transition at B 9T
• Triggered an interesting comparison with strand
  tests
• The comparison with TQ02-series models suggests
  that other factors may contribute to 1.9K
  stability
• Disturbance spectrum?
• Strain (long. and/or due to transverse pressure)?
• Micro-cracks?
• Variability of long strand/cable lengths?