1 / 26

WBS 2.4.2 STRAND PROCUREMENT

WBS 2.4.2 STRAND PROCUREMENT. Arup K. Ghosh BNL. Outline. Present status of strand procurement Future strand for LARP Smaller Filament D eff PIT strand Tolerance of RRP conductors to cabling degradation Filament Spacing Rolled strand Revisit strand specification.

ordell
Télécharger la présentation

WBS 2.4.2 STRAND PROCUREMENT

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. WBS 2.4.2 STRAND PROCUREMENT Arup K. Ghosh BNL

  2. Outline • Present status of strand procurement • Future strand for LARP • Smaller Filament Deff • PIT strand • Tolerance of RRP conductors to cabling degradation • Filament Spacing • Rolled strand • Revisit strand specification

  3. Procurement PlanNov-05

  4. Nb3Sn Strand SpecificationRRP-54/61 Spec. No.: LARP-MAG-M-8001-RevB

  5. Procurement Status3-30-06

  6. Strand Purchase and Inventory as of 4-20-06

  7. RRP 54/61 –Piece Length • 250 kg of wire produced for LARP and CDP in the last 12 months, single billet yield is ~ 35kg • 93 % in lengths >1Km, 57% in lengths >3 km • With the following HT 665C/50 hrs • Average Jc(12T)=2880 A/mm2 • Average RRR= 189

  8. Procurement Plan For FY07 3-30-06

  9. Projected Inventory

  10. Towards a more “flux-jump” stable conductor • Why ? • Intrinsic (Adiabatic) stability of wire • Field quality in magnets • Reduce Effective Filament Diameter Deff • Deff< 30 mm (adiabatic limit not established experimentally for high Jc wire ) • For Deff > 35 mm, maintain high RRR after reaction  prevent Sn-leakage • OST-RRP- 91 and 127 sun-element billet design • Cabling Effects • Shearing of sub-elements RRR degradation • SMI-PIT- 288 • 50 mm at 1.25 mm wire • 32 mm at 0.8 mm wire

  11. Decreasing the sub-element size • Pack increasing number of sub-elements into Re-stack • Increasing number of bundles  packing more difficult • More cold work increases the hardness of non-Sn parts • Additional Cu-Cu surfaces  worse bonding  yield ?

  12. 91-127-217 series made with Nb-Ta for CDP R&D • High Jc design (3000 A/mm2): • Objective was to only vary the sub-element size • same sub element billet for all restacks • all restacks ~53% non-Cu, 0.7 mm strand • Significant wire breakage for all, 217-stack the worst • For a reaction at 665 C/50hrs (Jc, RRR) • 91-stack 2920, 134 • 127-stack 2720, 110 • 217-stack 2660, 7 (Many broken barriers) • Suggests there is some size effect controlling the maximum Jc

  13. Future RRP Strand • Is OST ready to produce 91 and 127 sub-element billets ? “Further to our discussions today about 61  127 stack designs for LARP, this year we are producing 91-stack material for the EFDA dipole. The sub-element design is for lower Jc and uses Nb-Ti (Jc ~2400 @ 12 T), but the work will give us some yield data on our way to 127 stacks.” Based on CDP R&D billet 8079 (90/91) and FNAL billet 8195 (108/127) both of which uses the same sub-elements of Nb/Nb-47Ti

  14. EFDA Dipole Project E. Salpietro Strand based on 90/91-stack design using Nb/ Nb-47Ti rods Due dates Delivery One (30 kg strand): delivered Delivery Two (120 kg strand): 9 months Delivery Three (280 kg strand): 15 months

  15. Future RRP Strand • Is OST ready to produce 91 and 127 sub-element billets ? • At present the lower Jc ( > 2000 A/mm2) 91-design billet is moving into production  EFDA Order of 400 kg • Under CDP R&D this year, a high Jc 108/127 billet is being processed (Nov-06) • FNAL has OST fabricating a R&D billet using 120/127 design (Dec-06)

  16. Powder-in-Tube (NbTa)3Sn (PIT)Shape Metal Innovation (SMI) J. Lindenhovious B179

  17. PIT -Strand Luc Oberli (CERN) WAMDO-06 • NED is pushing SMI-VAC to develop strand. • Latest billet B207 is 288 filament, similar to B179 • Strand Diameter 1.25 mm • Cu/Non-Cu= 0.96 • Jc > 2400 A/mm2 At 12 T B179 B 207

  18. SMI – 288 filament Luc Oberli (CERN) WAMDO-06 Jc = 2077 A/mm2 at 12 T Jc = 1118 A/mm2 at 15 T HT = 84 hours at 675 0C Jc non Cu lower than B179 by ~ 10 - 15 % due to powder preparation which underwent by mistake an additional HT. • Stability measurements performed by LASA : Field rate ~ 15 mT/s • At 1591 A, no quench in the field range : 0 - 5 T

  19. SMI-PIT B-207 Wire drawn to 0.8 mm Jc(12T) : 2145 A/mm2 , Js > 4500 A/mm2 (Is >1200A) Filament size : 32 mm (No flux-jump observed in magnetization)

  20. Cabling Degradation • Strand Deformation at the cable edges • Filament Distortion • Simulate by rolling strands • E. Barzi (FNAL) • Filament Merging • Microscopy, Ic and Is measurements

  21. Rolled Strands RRP 54/61 Def=28% Def=14%

  22. SMI : Strand deformation by rolling Luc Oberli (CERN) WAMDO-06 B 179 B 201 Deformation of 25 %, i.e. d0 - t = 0.25 mm. “Distribution of Cu within the strand important in order the strand can sustain heavy mechanical deformation as in cabling.”

  23. SMI – Deformation by rolling on B207 Luc Oberli (CERN) WAMDO-06 Ic Degradation of 15 – 17 % on samples with a deformation level of 28% RRR value dropped to 80 indicating Sn diffusion in the Cu matrix Def = 28 % No HT Def = 28 % after 84 h at 675 0C With HT 2.8 at. % Sn

  24. Re-visit Strand Specification

  25. Summary • There is sufficient RRP 54/61 strand for the magnets in the near term • 91-filament is moving into production • 127 filament can be in production within 12 months. • PIT strand with 288 filaments is “flux-jump” stable at 0.8 mm wire diameter with Jc ~ 2100 A/mm2 at 12 T • Cabling Degradation from filament shearing • Optimization of cabling parameters • Optimization of strand design • Increase filament spacing ? (FNAL has already ordered a 60/61 billet with larger Cu-spacing, evaluation in progress)

More Related