High field magnet R D status goals and directions

High field magnet R&D status, goals and directions Bruce Strauss August 26, 2013 Fermilab Batavia, Illinois 1

It really started in 1961 Phys Rev Letters 6, 89 (1961), submitted January 9, published February 1, 1961!

Woodstock - 1968 § 1968 Brookhaven Summer Study – 46 th Anniversary this year http: //www. bnl. gov/magnets/Staff/Gupta / 3

Direction… “Buy it by the ton. ” Paul Reardon, Fermilab

Tevatron Dipole B operating = 4. 33 T 5

LHC Conductor Statistics 1200 metric tons of Cu/Nb. Ti composite, Containing about 400 tons of Nb-Ti ingots. Yield: About 7, 000 km of large cable, or 300, 000 km of SC wire of 0. 8 -1 mm strands. (9 x 1010 Ampere-Meters) 6

History Summary § The vision of 10 T magnets in Chicago in 1913, 2 years after discovery – Bad places in the wire were NOT the cause of Onnes’ wire leaving the superconducting state – Glimpses of the emergence of negative surface energy superconductivity (Shubnikov 1936, Landau 1940 s, Abrikosov 1957) § Experimental validation by Kunzler et al. in 1961 made – finally – superconductivity technological from a bulk materials standpoint. § Stability models had by 1968 established the engineering fundamentals for the design of conductors. § The Tevatron development established cryogenics, mechanical engineering and strain management in dipole and quadrupole magnets. The Tevatron changed the SCALE of superconductivity. § Tevatron (FNAL) is finished in 1983 followed by HERA, SSC, RHIC & LHC. 7

In 1997 when I started at the Department of Energy there were two dipole magnets reported in the literature that had exceeded 11 Tesla, constructed with Nb 3 Sn, and had real bore tubes… 9

MSUT Magnet “At the very first high-field ramp the current was ramped with 2 A/s to the first quench at a current of 18. 7 k. A, corresponding to a record central dipole field of 11. 03 T. ” A. den Ouden et. al. , “Application of Nb 3 Sn Superconductors in High-Field Accelerator Magnets, ” IEEE Transactions on Applied Superconductivity, V 7, No. 2, June 1977 10

D 20 magnet at LBNL 11

Events and Change— 1997 to 2002 • • Construction of the LHC at CERN MSUT at Twente and D 20 at LBNL US leaves ITER. At DOE HEP we wondered what to about the three magnet groups at national labs. • Sutter gets $500, 000/year from John O’Fallon for industrial development of Nb 3 Sn. • Conductor Development Group is formed. • HEP Nb 3 Sn magnet development resumes with surplus ITER strand. • Sutter remarks… 12

A Convert… “… 20 tesla or bust!” Dave Sutter, DOE 13

Taking Stock As a result of the DOE programs in AARD, GARD, CDP and LARP: • Jc of Nb 3 Sn doubles • Deff minimized • RRR optimized • Scaling • ITER • Asymptotic improvements presently • A series of dipole and quadrupole magnets have been constructed. • Peak field appears to have hit an asymptote. 14

At 53, LTS’s have reached maturity splendor US-CDP ITER wires HL-LHC wires Data by courtesy of J. Parrell (OST)

“Industrialization” = bridging the gap The Business of Science® The Innovation Cycle Customer acceptance Manufacturing scale up Process optimization Product optimization © Oxford Instruments 2014

Nb 3 Sn development for HEP: 10+ years of steady improvement 1999 The Business of Science® US HEP GOAL Jc(12 T)>3000 A/mm 2 2007 Ds<40 microns with high RRR 2001 2002 Piece length: full billet, no breaks 2004 ACHIEVED 2013 Increasing stack count, smaller Ds Progress continues 2002 2005 2008 2011 2012 2014 → Materials development is a long term exercise. Sustained customer support (in this case the US DOE) has been key to enabling advances in the field. © Oxford Instruments 2014

LBNL holds Nb 3 Sn dipole magnet records in 3 configurations … but are hitting a wall at ~14 T with a realistic bore ➯ Need a new paradigm Field performance is correlated with Conductor performance • • • D 20 RD HD Record dipole fields>~14 T in each configuration Incorporating bore reduces peak field attained Detailed investigation suggests limitation is mechanical: Stresses approach 200 MPa (Nb 3 Sn limit) Shear stresses / interface stress issues Courtesy of Soren Prestemon (LBL)

Je Sensitive to Operating Temperature Engineering Critical Current Density (A/mm²) 1200 3. 3 K 1100 3. 6 K 1000 3. 9 K 900 4. 2 K RRP® data scaled using Nb 3 Sn Scaling Spreadsheet - Matthijs Mentink, Diego Arbelaez, Arno Godeke [LBNL] 4. 5 K 800 4. 8 K 700 5. 1 K Available from http: //fs. magnet. fsu. edu/~lee/pl ot/plot. htm 600 500 400 300 200 15 16 17 18 Applied Magnetic Field (T) 19 20 Nb 3 Sn (RRP®): Non-Cu Jc Internal Sn OI-ST RRP® 1. 3 mm, Parrell, J. A. ; Youzhu Zhang; Field, M. B. ; Cisek, P. ; Seung Hong; , "High field Nb 3 Sn conductor development at Oxford Superconducting Technology, " Applied Superconductivity, IEEE Transactions on , vol. 13, no. 2, pp. 3470 - 3473, June 2003. doi: 10. 1109/TASC. 2003. 812360 and Nb 3 Sn Conductor Development for Fusion and Particle Accelerator Applications J. A. Parrell, M. B. Field, Y. Zhang, and S. Hong, AIP Conf. Proc. 711, 369 (2004), DOI: 10. 1063/1. 1774590.

1986, the 75 th Anniversary…Change! § • • POSSIBLE HIGH-TC SUPERCONDUCTIVITY IN THE BA-LA-CU-O SYSTEM BEDNORZ JG, MULLER KA Z FUR PHYSIK B-CONDENSED MATTER 64, 189193 1986 , Times Cited: 7, 656 Superconductivity induced by doping carriers into an insulating anti-ferromagnetic state Non-Fermi liquid behavior, but strong correlations that still prevent any generally accepted model for superconductivity in the cuprates 21

HTS MAGNETS ARE. . .

Magnet R&D Issues Conductor Magnet Field Engineering Electrical Insulation Mechanical Engineering Safety and Protection Cryogenics 23

Magnet R&D Issues Conductor Magnet Field Engineering Electrical Insulation Mechanical Engineering Safety and Protection Cryogenics 24

HTS Conductors… What do magnet builders want? üThe highest Hirr/Hc 2, Jc(H, T) and JE(H, T), Tc üFabricability into wires with flexible architectures üLow cost/performance ratio üSmall environmental footprint üHigh strength üAbility to wind as is üLong lengths üHigh Current Cables üLow ramping losses and magnet protection What do we have now……. ? 19

Nb 47 Ti (OST) Internal Sn Nb 3 Sn (OST) Bi-2212 (OST) Bi-2223 (AMSC) YBCO coated conductors next…………… Preferred conductor features: Multifilament Round or lightly aspected shape with no Jc anisotropy Capability to wind in unreacted form while conductor fragility is minimized Mg. B 2 (Hypertech)

And coated conductors of YBCO which approximate single crystals by the mile……. The IBAD approach – ion-beamassisted deposition of the textured template The RABi. TS CC 40 mm Cu 2 mm Ag ~ 1 mm YBCO ~ 30 nm LMO Copper Stabilizer 50 -75 mm ~ 30 nm Homo-epi Mg. O Copper Stabilizer 50 -75 mm ~ 10 nm IBAD Mg. O Ag (<1 mm) ~ 7 nm yttria Ag (<1 mm) ~ 80 nm alumina 50 mm substrate YBCO (1 -5 mm) 40 mm Cu Ce. O 2 (~75 nm) Pilot production of 100 -500 m lengths. Now approaching 1 km Metallurgical Texture introduced here (RABi. TS) Ce. O 2 (~75 nm) YSZ (~75 nm) Y 2 O 3 (~75 nm) Textured Ni-W alloy (50 -75 mm) 0. 4 - 1 cm – 100 m 27

Market Demand

Screening Currents in HTS Tapes RIKEN experience with 2223 and REBCO in their 500 MHz solution NMR system (100 MHz HTS + 400 MHz LTS) Quite different shielding current patterns in multi- and single filament conductors Outcome: • • Non-linear, hysteretic effects in REBCO coil Slide 29 Bi-2223 insert gave signals equivalent to LTS magnet By contrast, great difficulty stabilizing and shimming the REBCO magnet Maeda and Yanagisawa IEEE TAS 24, 4602412 (2014) Larbalestier - NHMFL EAC Mtg. , July 22 -23, 2014 – confidential – do not distribute

Prior to 2012, all HTS Conductors (Bi-2223, REBCO) were Tapes Delivered in Reacted Form Bi-2212 upended this paradigm , delivering the highest conductor current density in round-wire The first HTS conductor to look like an LTS conductor 2012 with 20 -100 bar over-pressure (OP) Conductor must be wound, then reacted Big advantage – very flexible architecture, multifilament, twisted form Big disadvantage – reaction complexity 1990 -2012 2212 (25% sc) REBCO coated conductor (1% sc) 30 Slide 30 Larbalestier - NHMFL EAC Mtg. , July 22 -23, 2014 – confidential – do not distribute

Magnet R&D Issues Conductor Magnet Field Engineering Electrical Insulation Mechanical Engineering Safety and Protection Cryogenics 32

The essential role of the superconductors in the search for higher energy Proceedings of MT-23 Jeng 400 A/mm 2 Nb-Ti up to Nb 3 Sn up to HTS up to 8 T 13 T 20 T HTS: more than 1500 tons procurement by 2030 Concept and models now A. Ballarino 33 LTSW 2013, 4/11/2013

Magnet R&D Issues Conductor Magnet Field Engineering Electrical Insulation Mechanical Engineering Safety and Protection Cryogenics 34

Magnet R&D Issues Conductor Magnet Field Engineering Electrical Insulation Mechanical Engineering Safety and Protection Cryogenics 35

Mechanical Engineering… §Forces ~B 2 §Energy ~B 2 §Virial Theorem • M~E/σ 36

Magnet R&D Issues Conductor Magnet Field Engineering Electrical Insulation Mechanical Engineering Safety and Protection Cryogenics 37

High field does not improve propagation but reduces stability margin L. Ye, F. Hunte and J. Schwartz, Su. ST 26 055006 (8 pp) (2013)

Cost Considerations

JE(B) Data Used for Price/Performance Comparison Larbalestier, et al. Nat. Mat. 1038/nmat 3887

Price/Performance 2014 (Ag $20/oz. )

Price/Performance with Ag at $30/oz Ag at $20/oz

Price/Performance with Ag at $5/oz Ag at $30/oz Ag at $5/oz

Raw Materials Cost 2014 Wire type Raw materials cost $/kg Materials $/m Pfactor Price $/m Comments Nb. Ti LHC-type 0. 8 mm diam Nb. Ti alloy 280 OFHC 11. 5 Barrier 595 . 44 3. 3 (. 60) 1. 20 1. 45 Based on Cooley (2005) -Nb cost increased 2. 7 x (USGS MCS 2014) -Cu cost increased 2. 3 x (USGS MCS 2014) -P-factor well established Nb 3 Sn RRP-type 0. 8 mm diam Nb. Ta alloy 785 OFHC 11. 5 Barrier 595 1. 05 8 8. 40 YBCO Bi-2212 0. 8 mm diam Ag alloy 640 powder 1000 4. 50 10 40 45 Based on Cooley (2005) -Nb cost increased 2. 7 x (USGS MCS 2014) -Cu cost increased 2. 3 x (USGS MCS 2014) -P-factor reduced for increased product maturity Superpower 2014 Based on Cooley (2005) -Ag cost increased 3. 7 x (silverprice. org) -Powder price unchanged Bi-2212 4. 50 12 Use RRP fabrication cost (+$7. 50/meter)

Ag at $20/oz with RRP Fabrication Cost $20 Ag & RRP fab cost

Beyond Nb 3 Sn: Bi-2212 wire The Business of Science® (ASC 2004) The promise of 2212 has long been apparent… Voids – the signs have been there for some time …even if development has been slower than it might have been The difference from Nb 3 Sn? A lesser market pull © Oxford Instruments 2014

Progress, but “pushing” only goes so far… The Business of Science® (ASC 2006) (MT-2011) (ASC 2010) • Steady conductor improvement • Steady device improvement But limited opportunities… → Missing that virtuous circle © Oxford Instruments 2014

2212 – now ready to be “pulled”? The Business of Science® • Conductor development situation now similar to Nb 3 Sn in the early 2000’s • Performance may be good enough today to break into “real” applications – we now need that market pull • 2212: the workhorse material for cutting edge magnets at ASC 2024? © Oxford Instruments 2014