Outline

1. LBNL Cable Experience for HiLumi HiLumi LARP/LHC Strand and Cable Internal ReviewOct. 16-17, 2013by Video D.R. Dietderich, A. Godeke, LBNL and A. Ghosh, BNL 1

2. Outline Fabrication of a Rutherford cables Review of the cable parameters for the LARP TQ/LQ, HQ/LHQ and QXF parameters Strand damage scoring methodology What is it and how is it calculated. Strand damage scores in cables for TQ/LQ, HQ/LHQ, and QXF Discuss TQ and HQ strand data and metallurgical observations. First QXF cable parameters are place in context with the TQ and HQ parameters Options for next generation of QXF cable HiLumi Conductor and Cable Review 2

3. Cabling Objectives • Want to convert assemble of many stands into a Rutherford cable for winding into a coils • Typically dipoles and quadrupole magnets Side roll HiLumi Conductor and Cable Review

4. QXF cable with Stainless Steel Core Thick edge Thin Edge Cable 1042Z-12 HiLumi Conductor and Cable Review

5. Cabling Trade-offs • Minimize the amount of strand damage • Less compaction • Can lead to mechanically unstable cable for coil winding • Developed cable winding score • Increase mechanical stability of cable • More compaction and deformation of strands • More strand damage - Reduced critical current and RRR (resistance increase of Cu matrix) • Developed strand damage Score D.R.Dietderich HiLumi Conductor and Cable Review

6. Cable Risk and Impact on Magnets – LBNL View • Strand stability (High risk) • Want high Is > 1,200 • RRR > 60 at kinks of extracted strands • RRR > 150 in strand to assist in getting RRR > 60 at kinks • Should the RRR specification be increased to 175 to 200? • Stress sensitivity of cable with damaged strands (Unknown Risk) • Only data is for older generation wire • Cable winding stability (Medium risk) • Assume cable can be managed cable during coil winding • Strand Ic loss due to cabling, < 5 % (Low risk) • Icof extracted strands at 12T ~850 A • Ic at operation of 12 T ~400A HiLumi Conductor and Cable Review D.R.Dietderich

7. Cable Design - Thickness q KS Angle Minor Edge Mid Major Edge Aspect ratios of cables TQ = 8.2 HQ = 10.6 QXF = 11.1 (9.0 mm) QXF = 12.2 (8.5 mm) Use thickness “strain” at edges to determine parameters D.R.Dietderich HiLumi Conductor and Cable Review 7

8. HQ Cable Experience Width Thickness Keystone from LBNL cable calculations • Final parameter for HQ cable with 0.778 mm diameter strand D.R.Dietderich HiLumi Conductor and Cable Review

9. Suggested QXF Cable Parameters • Mid-thickness = 1.525 mm +/- 0.010 mm • Width = 18.15 mm +/- 0.050 mm • K.S. angle = 0.55 deg. +/- 0.10 deg. • Adjustable Parameters • Pitch Length = 109 mm +/- 3 mm • Annealed or un-annealed wire • Should reduce residual twist in cables • At this time LARP assumes that cables will need to be managed during coil winding • By using either the Berkeley winding block or CTD binder D.R.Dietderich HiLumi Conductor and Cable Review

10. Winding Score of Cable • Popped strand winding score of cables • Strand goes in easy and stays in place • Strand goes in easy but needs handling to stay in place • Strand goes in easy but will not stay in place • Difficult to put strand back into cable, will not stay in place • Can put strand or strands back into cable • The “Berkeley Block” CCW CW D.R.Dietderich HiLumi Conductor and Cable Review

11. 2 Objectives One was to determine the fit of prototype coil parts Second was to test the winding stability of a QXF cable with the target parameters QXF cable 1045Z-13 Insulated with 3 layers of E-glass tape ~150 mm Winding tension 25-30 lbs No popped strands Cable was stable Used Berkeley Block Did not try without block SQXF Practice Winding LBNL Oct. 2013 HiLumi Conductor and Cable Review

12. The strand in Image at left has 10 shear sub-elements plus ruptured barrier If it is a triple strand configuration at cable edge one would divide by 3. For a rectangular strand configuration one would divide by 2. Damage Scoring Methodology HiLumi Conductor and Cable Review

13. Cable in TQS03 • Cable 982R • RRP 108/127 • Two pass cabling process • No stainless steel core • No sheared sub-elements D.R.Dietderich HiLumi Conductor and Cable Review

14. HQ Cable Damage Score HQ-01 2 pass cables HQ-02 1 pass Cables SS-core D.R.Dietderich HiLumi Conductor and Cable Review

15. Target = 18.15 mm Damage Score vs. OXF Cable Width for Pitch Length of 109 mm RRP 108/127, ~1.50 mm thick 1042Z-13 18.47 mm calc. width for 109 mm Need 17.95 mm width for Winding score of zero D.R.Dietderich HiLumi Conductor and Cable Review

16. -1.75 % Critical Current (11T, 4.2K) vs. Width Ratio Only 1.2% loss of Ic RRP 108/127 D.R.Dietderich MT23 July 17, 2013 HiLumi Conductor and Cable Review

17. RRR of QXF Strands Extracted from Cable • Virgin round strand has RRR of 317 Ave. RRR of ES • RRR of kink (edge of cable) 150-160 , Cable width 17.94 mm • Even with loss of RRR the Is was still > 1,200 A • Wire specification is 150. Should we increase it? D.R.Dietderich HiLumi Conductor and Cable Review

18. 0.85 mm Cable 1046 Z with 0.90 mm Diameter Wire Cable 1046Z 1.63 mm thick 18.15 mm wide 0.53 deg. KS 117 mm PL Aspect ratios of cables TQ = 8.2 HQ = 10.6 QXF = 11.1 (9.0 mm) QXF = 12.2 (8.5 mm) HiLumi Conductor and Cable Review

19. Transverse Pressure on Nb3Sn Cable Hans van Oort Thesis, U. Twente TW 5 – 150 MPa TW 5 – 0 MPa Cables with little damage HiLumi Conductor and Cable Review

20. 0.85 mm diameter wire Fine tuning of machine cable Parameters not changed Need RRP 132/169 Adjust strand tension Annealed wire Reduce residual twist Reduce shearing Modify mandrel trip 3-6 months but not impact on schedule 0.90 mm diameter wire Major cross section change – Thicker cable Need RRP 132/169 Used RRP 84/91 in R&D Cable very stable with first parameters Winding score of 1 Damage score of 0-1.5 Time 6 months with impact on magnet schedule Future Cable Modifications HiLumi Conductor and Cable Review

21. Summary • Critical current loss is small and not a major concern • However, past measurements on cables with sheared sub-elements showed they were more susceptible to transverse stress. • RRR drop at edge of cable is a concern but should be manageable if RRR of wire is high • However, should attempt to reduce the number of sheared sub-elements • Local RRR at kinks (edge of cable) dominates electrical stability • May NOT have to improve cable mechanical stability • First 25 m practice winding at LBNL cable had no issues. • Used Berkeley block for winding • Would like to consider thicker cable with 0.90 mm diameter wire to reduce aspect ratio of cable and sub-element shearing D.R.Dietderich HiLumi Conductor and Cable Review 21 21 21