superior performance. powerful technology. Progress in Scale-up of 2G HTS Wire at SuperPower Part I V. Selvamanickam & Y. Xie Y. Chen, X. Xiong, M. Martchevski, Y. Qiao, A. Rar, B. Gogia, R. Schmidt, A. Knoll, and K. Lenseth DOE funding through Title III Program & UT-Battelle Leveraged funding from AFRL. Supported by CRADAs with Los Alamos, Oak Ridge, & Argonne National Laboratories FY28 Superconductivity for Electric Systems Peer Review, Arlington, VA, July 29 31, 28 SuperPower, Inc. is a subsidiary of Royal Philips Electronics N.V.
SuperPower s 2G wire is based on high throughput processes & superior substrate High throughput is critical for low cost 2G wire and to minimize capital investment SuperPower s 2G wire is based on high throughput IBAD MgO and MOCVD processes Use of IBAD as buffer template provides the choice of any substrate Advantages of IBAD are high strength, low ac loss (non-magnetic, high resistive substrates) and high engineering current density (ultra-thin substrates) <.1 mm 2μm Cu 2 μm Ag 1 μm YBCO - HTS (epitaxial) ~ 3 nm LMO (epitaxial) ~ 3 nm Homo-epi MgO (epitaxial) ~ 1 nm IBAD MgO 1 nm 5μm Hastelloy substrate 2μm Cu YBCO LaMnO 3 MgO (IBAD + Epi layer) Y 2 O 3 Al 2 O 3 Hastelloy C-276 2
SuperPower s 2G pilot manufacturing facility has been operational since 26 Majority of investment already made for 1 km/year capability Pilot Substrate Electropolishing Pilot MOCVD Pilot IBAD Pilot buffer Sputtering 3
Major achievements in FY 27 World s first demonstration of pilot-scale manufacturing of 2G HTS wire Delivery of 16, m of 2G wire to customers including nearly 1, m wire delivery to Sumitomo Electric for the Albany HTS Cable project Crossed 1, amp-meter threshold in long-length wire performance Splice-free piece lengths > 5 m Ic over 1 meter nearly 6 A/cm Linear tape speeds of 18 to 36 m/h* in key deposition processes (IBAD, Buffer, MOCVD) Ic of 116 A/cm at 77 K, 1 T (perpendicular to wire) and 18 A/cm at 65 K, 3 T, (perpendicular to wire) Reduced wire price to $65/m from 26 price of $1/m *4mm wide equivalent 4
Our main objective in 28 was to meet market requirements for 2G wire Replace 1G wire in large HTS device demonstration projects in the U.S. and around the world Key requirements: Long length, availability, Ic, price Supply large volumes of 2G wire to customers who have been waiting to take advantage of the superior performance of 2G Key requirements: Long length, Ic, additional performance metrics such as in-field Ic, ac losses, joints, insulation, FCL metrics Advance towards medium-term goal of replacing copper wire in commercial HTS projects and challenge LTS wire in high-field applications Key requirements: Long length, availability, Ic, price, in-field performance and other additional performance metrics 5
Goals for FY8 were very ambitious & aggressive, and focused towards market requirements 27 Review Goals for FY8 Splice-free length 595 m, Ic of 173 A/cm Reach 1, m, Ic of 2 A/cm Critical current over long lengths 3 A/cm over 1 m in Research MOCVD system at linear speed of 15 m/h Ic in short lengths 595 A/cm over 1 m 1 A/cm In-field performance Capacity 18 A/cm at 65 K and 3 T (perpendicular to wire) Estimated at 72 km/year based on tape speed Over 3 A/cm & then 5 A/cm over long lengths in Pilot MOCVD system at high tape speeds 3 A/cm at 65 K and 3 T (perpendicular to wire) Focus on actual capacity to be comparable with 1G Customer delivery Delivery of ~ 1, m for Albany cable project Focus on meeting customer requirements worldwide Wire cost $ 65/m for 4 mm Focus on Yield, QC & Process Control to drive down wire cost 6
Outline of Presentation Long-length metric High-current metric In-field performance metric Meeting customer performance requirements for 2G wire Ac losses Joints Insulation FCL Wire deliveries to customers Reducing wire cost Quality Control for high-yield manufacturing Production capacity metric Performance against plans Goals for FY9 7
In-plane texture (degrees) Long-length metric: Routine manufacturing of kilometer lengths of fully buffered tape 1 9 8 7 6 5 4 3 2 1 1 2 3 4 5 As of Dec.7, 12 tapes with complete 5-layer buffer stack were produced in lengths of approximately 1,3 m with in-plane texture of 6 7 degrees and excellent uniformity of ~ 2% 6 7 8 9 1, 1,1 Tape 1 Tape 2 Tape 3 Tape 4 Tape 5 Tape 6 Tape 7 Tape 8 Tape 9 1,2 1,3 1,4 2μm Cu 2μm Cu Ag 5μm Hastelloy substrate HTS LMO Homo-epi MgO IBAD MgO Tape 1 Tape Length In-plane texture ( ) Uniformity (m) Average Min Max 1 1,1 6.79 6.2 7.84 6.2% 2 1,343 6.33 5.8 7.16 3.3% 3 1,346 6.85 6. 7.35 2.1% 4 1,372 6.2 5.83 6.68 2.2% 5 1,375 6.58 6.23 7.14 2.5% 6 1,277 6.59 5.8 7.9 2.1% 7 1,346 7.9 6.66 7.79 2.9% 8 1,265 6.81 6.3 7.12 1.7% 9 1,246 6.33 5.47 7.13 2.4% 1 1,369 6.18 5.95 6.26 1.2% 8
Continued routine manufacturing of kilometer lengths of fully buffered tape in CY 28 8 In-plane texture (degrees) 7 6 5 4 2 4 6 8 1 12 14 16 Tape position (m) Over 35 tapes with complete 5-layer buffer stack have been produced in lengths of 1,3 m to 1,5 with in-plane texture of 5 7 degrees and excellent uniformity of ~ 2% Manufacture of kilometer-lengths of high quality, fully-buffered tape was routine throughout FY8 9
Targeting kilometer lengths of complete 2G wire In FY7, we reported first demonstration of 5+m long 2G wire: 595 m with minimum Ic of 173 A/cm corresponding to 12,95 A-m. Demonstrated 79 m long wire in FY8 Critical current (A/cm) 35 3 25 2 15 1 5 77 K, Ic measured every 5 m using continuous dc currents over entire tape width of 12 mm (not slit) Voltage criterion =.2 microvolt/cm 1 2 3 4 5 6 7 8 Minimum Ic = 19 A/cm over 79 m Ic Length = 15,1 A-m Uniformity over 79 m = 9.7% Process (single pass) Speed of 4 mm tape (m/h) IBAD MgO 36 Homo-epi MgO 345 LMO 345 MOCVD ~ 1 1
Challenges in fabrication of complete, kilometer long 2G wire 25 25 Ic (A/cm) 2 15 1 5 Ic (A/cm) 2 15 1 5 2 4 6 8 1 2 4 6 8 1 4 Ic (A/cm) 3 2 1 Kilometer lengths limited by a few bad regions in an otherwise uniform wire 2 4 6 8 1 11
Major sources of problems responsible for Ic drops in kilometer tapes have been identified Ic drop over a broad distance (few meters) traced to fluctuations in MOCVD process 4 Critical current(a) 3 2 1 5 m 5 m 5 m Non contact Ic 1 mm intervals Transport Ic 5 m intervals 5 m Z-bend mechanical defects caused by sudden increase 21 215 22 225 23 235 24 245 25 255 in tape tension result in sharp Ic drop (few mm) 12
Reached kilometer-class lengths of 2G wire Critical current (A/cm 3 25 2 15 1 5 77 K, Ic measured every 5 m using continuous dc currents over entire tape width of 12 mm (not slit) Voltage criterion =.2 microvolt/cm 1 2 3 4 5 6 7 8 9 1 Minimum current (I c ) = 17 A/cm over 935 m Ic Length = 158,95 A-m Uniformity over 935 m = 1.6% Process (single pass) Speed of 4 mm tape (m/h) IBAD MgO 36 Homo-epi MgO 345 LMO 345 MOCVD 135 13
Crossed kilometer threshold in July 28 Ic (A/cm) 35 3 25 2 15 1 5 77 K, Ic measured every 5 m using continuous dc currents over entire tape width of 12 mm (not slit) Voltage criterion =.2 microvolt/cm 2 4 6 8 1 12 Length Minimum Ic (A/cm) (.2 μv/cm) Ic Length (A-m) 945 2 189, 1,25 163 196,415 1,311 153 2,58 14
Excellent & uniform n-values over kilometer lengths 5 4 n-value 3 2 1 Min n-value = 21 Max n-value = 37 average n-value = 31 Uniformity = 1% n-values measured every 5 m 2 4 6 8 1 12 14 15
Remarkable progress in 2G HTS wire scale-up over the last 6 years 2, 1,, 1, 1, 1, 1 1 May-2 Oct-2 Mar-3 Aug-3 Jan-4 Jun-4 Nov-4 Apr-5 Sep-5 Feb-6 Jul-6 Nov-6 Apr-7 Sep-7 Feb-8 Jul-8 Critical Current * Length (A-m) 16, 12, 8, 4, Nov-1 Jul-2 Mar-3 Nov-3 Aug-4 Apr-5 Dec-5 Aug-6 Apr-7 Jan-8 Sep-8 Critical Current * Length (A-m) Growth in FY8 1 m to 1,3 m in 6 years 1 m 26 m 18 m 62 m 158 m 97 m 935 m 1,311 m 595 m 427 m 322 m 79 m World Record 16