Bi-2212 cable transverse pressure tests in Twente A. Godeke, J. Jiang, E.E. Hellstrom, D.C. Larbalestier – MS&T & ASC – NHMFL - FSU L.D. Cooley, T. Shen – FNAL A.K. Ghosh – BNL D.R. Dietderich – LBNL For the BSCCo collaboration Sept. 23, 2014

Reaction holder requires ~80 cm 1 cable sample ~ 80 cm Reaction holder height ~41 cm

Cable options LBNL cable 988 (wire manufactured 2007) – OST billet PMM – Used in coils LBNL HTS-SC08 and SC10 (7 m / coil) – 5 leakage spots (~1mm)/coil side at 1 bar – Remaining length = 1.4 m m (4 samples) – Potential central bundle burst issue – 17 strands, 1.46 × 7.80 mm 2, 2,600 A in coil (1 T) About 150 A/ strand at 1 T Pro: Well characterized, low leakage at 1 bar, coils reach 85% of RW along coil load-line Con: Limited length left, older generation, potential central bundle issues, lower current

Cable options (cont.) FNAL VHFSMC cables – VHFSMC wire: OST billets PMM??? (2010 or 2011 wire) – Leakage issues? Large voids in Bi-2212 fraction – Lengths: 11.3 m x mm 6.7 m x mm 7.0 m x mm – Similar cable sections (10.37x1.555, 10.38x1.492, 10.40x1.418): Barzi et al., TAS (2011) 25 strands, around 7,000 A at 1 T: 280 A/strand Pro: Available lengths, newer generation, no central bundle, higher currents Con: Larger width compaction for remaining lengths, leakage less well defined

Cable choice (preliminary) FNAL cable 11.3 m x mm – Longest length, more modern wire, least compacted of remaining VHFSMC lengths Sufficient length is needed to develop sealing of cable ends. – Widest cable: Smaller widths fit in same reaction holder and pressure block (thickness is flexible) – Check: Confirm billet: Comparable to published results? Confirm available length Ask Barzi for leakage experience – Test react short lengths of extracted strands at 1 bar? – Confirm Ic of these short lengths?

Experiment Phase 1 (preliminary) Twente – Design reaction holder for mm wide cable (keep in mind cable Phase 2) Need mullite sleeve around cable to prevent contact with Inconel 600. Iterate with LBNL on available sleeve thicknesses – Send drawings to CERN CERN – Machine 4 reaction holders from Inconel 600 (Berkalloy’s not yet ready for “prime-time”) Use Alloy C276 (?CHECK) for nuts and bolts (used successfully in LBNL subscale program) – Send holders to FSU FNAL – Send cable lengths to FSU LBNL – Determine suitable mullite sleeve and send to FSU FSU – Develop cable end seal procedure – Mount cables in reaction holders – Reaction: 2 samples at 1 bar, 2 at 100 bar 1 bar: TBD: FSU 100 bar furnace (preferred), FNAL (continuously operational), LBNL (intermittent reactions, new operators) 100 bar: FSU 100 bar furnace – Send reacted cables to Twente for transverse pressure tests Twente – Transverse pressure tests on cables (11 T, 4.2 K)

Experiment Phase 2 (preliminary) CERN – Define desired cable dimensions and strand count for EUCARD2 program – Iterate with LBNL on suitable cable dimensions – Arrange for wire for cable to be send to LBNL(?) Alternative: Use wire from BSCCo/CDP/EUCARD collaboration(?) LBNL – Fabricate cable and insulate with mullite sleeve from LBNL stock – Send insulated cable to FSU for mounting on reaction holders and reaction FSU – Mounting on reaction holders and reaction as per phase 1 Potential cable geometries for tests in FRESCA? – Where to react since lengths > available 100 bar furnace(s)