Oct , 2013, CDP D.R. Dietderich LARP Conductor & Cable Review 1 Conductor Development Program Support for LARP and HiLumi LARP- HiLumi Conductor and Cable Internal Review Oct , 2013 by Video D.R. Dietderich LBNL

Oct , 2013, CDP Outline CDP History Development of RRP 169 stack Development of RRP 217 stack Other conductor issues being addressed

Oct , 2013, CDP CDP Wire Development History After achieving a J c greater than 3,000 A/mm 2 in 2005 in RRP 54/61 conductor CDP focused it efforts on reducing the sub-element size and help to develop the 127 stack CDP supplied the 90 kg of RRP 108/127 to LARP. –The wire was used in the successful magnet TQS03 that achieved ~95% of its expected current. During this time it was becoming apparent that the sub- element had to be changed to achieve both a high J c and high RRR in wire with a 217 stack or greater. –CDP supported the development of a new sub-element with a thicker diffusion barrier. –The first successful billet was fabricated last year. This will be discussed later. CDP is now focusing establishing the RRP 169 stack with both high J c and RRR. D.R. Dietderich LARP Conductor & Cable Review 3

Oct , 2013, CDP D.R. Dietderich LARP Conductor & Cable Review 4 Data for new CDP sub-element for 217 Stack with 30% thicker barrier RRP 192/217 stack –19 element removed from center –1 from each apex J c (12 T, 4.2K) ~ 2,700 A/mm 2 for 0.85 mm diameter 3 billets are being fabricated to reproduce the results of billet –Expect delivery next spring. CDP Billet Billet at mm diameter

Oct , 2013, CDP D.R. Dietderich LARP Conductor & Cable Review 5 CDP 192/217 Properties No SF correction CDP billet C/50 hrs

Oct , 2013, CDP D.R. Dietderich LARP Conductor & Cable Review 6  m Sub-element Diameter,  m R=Cu/Non-Cu=1.15, 46.5% SC, 53.5 % Cu A. Ghosh, Formalized Now LARP and Oxford Standard What about CERN and Bruker? 132/ microns What sub-element size is needed? At 0.85 mm:  m 108/127 = 56  m 132/169 = 50  m 11% smaller Cost increase 10-15% $20 M + $2-3 M Piece Length will decrease - Impacts cabling usage - More wire scrap - Therefore need to procure more wire

Oct , 2013, CDP D.R. Dietderich LARP Conductor & Cable Review 7 CDP Plans – RRP 169 Stack In place – Fixed price order for 180 kg (6 billets) of RRP 144/169 or 132/169 –Standard barrier thickness –Standard Sn and Reduced Sn (-5%) Improved RRR –OST is going to deliver ~25 kg with Standard Sn (Jan. 2014) Two diameters of 0.85 and 0.90 mm R&D Contract -- Sub-element with 30% thicker barrier –3 billet of RRP 144/169 or 132/169 Standard Sn –Improve RRR –Retain high RRR after cabling

Oct , 2013, CDP D.R. Dietderich LARP Conductor & Cable Review 8 CDP (LARP) Qualification Plan Strand tests for cabling –Self bend test –Spring back –Annealing and rolling studies Cabling behavior with OXF parameters –Inspect for shearing of sub-elements –Measurements of RRR at edge of cable

Oct , 2013, CDP D.R. Dietderich LARP Conductor & Cable Review 9 CDP Ti-Doped Wire Development CDP started developing the Nb- 47Ti rod doping process with OST in –The main driver was to reduce cost but there are other benefits Ti-doping has shown to increase the strain to fracture in tension –Results by Cheggour at NIST show that higher reaction temperatures increases the strain to fracture. Resent observations at LBNL by Pong show that there is Ti segregation in the Nb 3 Sn –This suggest that the wires may not yet be optimally doped. Images courtesy of Ian Pong, LBNL Unpublished N. Cheggour, et al. EuCAS 2013 – Poster 2P-WT2-17v

Oct , 2013, CDP Ti vs. Ta Strain Effects N. Cheggour, et al. EuCAS 2013 – Poster 2P-WT2-17v Ta Irr. Strain Limit is off the slide only 0.05 % strain, About a factor of 7 less

Oct , 2013, CDP D.R. Dietderich LARP Conductor & Cable Review 11 CDP Plans to Support LARP Cost Reduction Scale-up billets from 35 kg to ~70 kg (longer term) Sub-elements would be at larger diameter during billet assemble Easier to assemble billets with stacks of 169 and 217, or greater Should lead to increased piece length R&D Task already in place to improve roundness of Nb rods for sub-element Should lead to increased piece length Possible increase J c Improved Strand Ti - R&D Task – Increase spacing between sub-elements Expected to make sub-elements more robust for cabling Evaluate wire with different Local Area Ratios (LAR) be the Nb filaments to determine Smaller LAR may make sub-elements more robust to cabling (Discuss more tomorrow with cabling)

Oct , 2013, CDP Questions? Do the results of HQ magnets show that we need to transition from 108/127 to 132/169? Statement by Ezio: “We are considering reducing the operational gradient since we can not protect the magnets.” –This is an important statement. –Sub-elements with small difference in architure can significantly increase wire piece lengths for a small reduction in Jc.

Oct , 2013, CDP D.R. Dietderich LARP Conductor & Cable Review 13 Conductor Selection “After exhausting all other possibilities the Americans usually do the right thing.” Winston Churchill