Summary of the High Temperature Superconductor Magnet Workshop, IAS Program on High Energy Physics

Transcription

1 Summary of the High Temperature Superconductor Magnet Workshop, IAS Program on High Energy Physics Soren Prestemon Director, Berkeley Center for Magnet Technology Lawrence Berkeley National Laboratory October, 2016 Soren Prestemon Summary of HTS Magnet 1 Workshop, IAS Program on HEP 2017

2 Outline Focus and goals of the Workshop Summary of talks - HEP magnet developments - Fusion magnet developments - Superconductor development in Asia Outcomes: - Opportunities for collaboration - Summary discussions 2

3 The workshop focused on Superconductors and Superconducting Magnets for Future Colliders Overarching agenda: Identify challenges in developing HTS magnets, and how those challenges can be addressed through potential collaborations High Energy Physics Accelerator Magnets Superconducting Magnets for Fusion Underpinning Superconductor Technology - HTS focus 3

4 Summary of HEP-related magnet talks: Setting the context Magnets dominate the cost of the next future collider Low temperature superconductors: - NbTi: workhorse conductor for the community; all existing colliders utilize this in their superconducting magnets - Nb3Sn: lead candidate for fields beyond NbTi (~10T); first application to colliders will be the HL-LHC interaction region quadrupoles High temperature superconductors: - For accelerator application these are being investigated for operation at low temperature, high field (beyond that of Nb3Sn) - Bi2212: exists as isotropic round wire; can be Rutherford cabled; - REBCO: exists in tape form; properties are anisotropic Whole Wire Cri*cal Current Density (A/mm², 4.2 K) : B Tape Nb-Ti 1.9K MgB 2 : 2nd Gen. AIMI 18+1 Filaments, The OSU/ HTRI, 2013 YBCO B Tape Plane Iron-based Superconductor SuperPower "Turbo" Double Layer Tape, measured at NHMFL 2009 Iron-based Superconductor 2025 YBCO B Tape Plane High-J c Nb 3 Sn Compiled from ASC'02 and ICMC'03 papers (J. Parrell OI-ST) Significant lower cost and beqer mechanical proper*es expected 666 filament OST strand with NHMFL 100 bar Over-Pressure HT YBCO: Tape Tape plane YBCO: Tape Tape plane Bi-2212: OST NHMFL 100 bar OP Bi-2223: B Tape plane (carrier cont.) Bi-2223: B Tape plane (prod.) Nb₃Sn: Internal Sn RRP Nb-Ti: LHC 1.9 K NbTi: Nb 3 Sn 4543 filament (Nb 3 High Al) Sn Nb-Ti: LHC 4.2 K K Bronze-16wt.%Sn-0.3wt%Ti 17 (Miyazaki-MT18-IEEE 04) 4.2 K MgB₂: 18+1 Fil. 13 % Fill 10 Iron-based Superconductor Iron-based Superconductor 2025 Applied Magne*c Field (T) 4

5 Ongoing R&D in the US is focused on high-field magnets and understanding training and margin The US HEP Magnet Development Program (HEP/MDP) is structured as a premier national effort to develop high-field accelerator magnets - One key focus of HEP/MDP is to investigate the feasibility of HTS magnet technology Bi-2212 round wire and REBCO tapes 5

6 Ongoing efforts in China are focused on developing mid-to-high field magnets, and exploring HTS potential Near term: - 12T NbTi/Nb3Sn hybrid magnet (2017) - 12T Nb3Sn magnet, 22mm bore (end 2017) - 12T Nb3Sn/HTS hybrid magnet, 32mm bore (end 2018) Longer term: - Starting to develop HTS magnet technology before applicable iron-based wire is available (in 5~10 years): model magnet R&D with ReBCO (or Bi-2212) and LTS conductors to study: stress management, quench protection, field quality control and fabrication methods. - Latest baseline: 12T all-hts (iron-base superconductor) magnets with 100km circumference and >70TeV center-ofmass energy. - Upgrading phase: 20~24T all-hts (iron-base superconductor) magnets with 100km circumference and >125TeV center-of-mass energy. 3d coil layout 6

7 Efforts in US and China are complementary: focused on different structure concepts + Cos(θ) Most common accelerator magnet concept Wedges used for field quality Soren Prestemon - US MDP + - Common coil Starts with two racetracks=> simplicity Naturally provide two beam pipes for pp collider Field quality requires more complicated additional coils D T@1.9K + CERN China IHEP + US MDP RD3B 14.7T@1.9K Block design Starts with two racetracks=> simplicity To get a beam through, need flared ends=>complications HD1 (16T@4.2K; no bore) HD2 (13.7T@4.2K; ~40mm bore) HD3 (13.4T@4.4K; 43mm bore) Canted Cos(θ) Tilting a solenoid winding results in Cos(θ) distribution, but need 2n layers to compensate the solenoid component Efficiency hit due to solenoidal compensation Record magnets in each configuration show no clear winner Summary of HTS Magnet Workshop, IAS Program on HEP

8 Fusion continues to drive high-field magnet developments a push by MIT to leverage HTS MIT group is aggressively pursuing a high-field tokamak approach HTS can dramatically reduce fusion reactor size SPAR - performance scaling shows power density RB4 ARC ITER - HTS is critical - will see B>20T on conductor Human for scale - Conductor performance is there, but need additional technologies: High magnetic field opens attractive design space The ARC conceptual design: with the same high confidence in physics àdemountable Tape Superconductors Demountable Coils à Joints for modular, design Magnetic field = 9.2 T Fusion power = 500MW Energy gain = 10 cables for high current to address protection Fusion power at small size = Power density Open the Magnetic Bottle! B. Sorbom et al FED MW fusion power But these were previously ~200 MW electricity ~ 4 MW/m2 fusion inaccessible power density due to limitations New HTS magnet at~23 T, 20 K Magnetic field = 5.3 T Fusion power = 500MW Energy gain = 10 ITER in the superconductor. HTS enables smaller reactors to be built using the same proven Replaceable physics. replaceable Auxiliary part detail core module module ARC Machine would operate ~20 K and allow resistive joints R=3.2 meters Soren Prestemon F. Mangiorotti, MIT Ph.D. thesis Summary of HTS Magnet Workshop, IAS Program on HEP

9 Cable configurations based on tape superconductors, and the ability to test them, is critical for the MIT fusion approach Large stored energy (10s of GJ) - need large current to reduce inductance, minimize voltage during energy extraction Large, complex force environment - need strong conductor with measured data of performance under various loads TSTC Conductor : Scale-up industrial fabrication H-Channel TSTC Conductor CICC mockup of TSTC conductor One channel cable Multiple-stage conductor By Supercon 3x3 cable Hexa-cable CICC 40 tape dual-stack cable 40 YBCO tapes 3 channel cable N. Yanagi, et al., 3rd HTS4Fusion, ENEA/Tratos, September, Max. Field: 13 T Bore: 700 mm Sample Current: 50 ka Temperature: 4-50 K 20 YBCO tapes in each helical groove 12 sub-cable conductor 3 x 6 CICC 9

10 Significant planning in China at IPP-CAS for Chinese Fusion Engineering Testing Reactor (CFETR) and associated magnet and conductor R&D Introduction Mission: Bridge gaps between ITER and EAST Tokamak Multiple-ITER contributions to ITER of fusion energy application DEMO, realization Background in China From ITER to DEMO, via CFETR 600t Nb3Sn 275t NbTi A good complementarities with ITER 储能 51GJ Demonstration of full cycle of fusion energy with Pf = 200MW Demonstration of full cycle of T self-sustained with TBR 1.0 Long pulse or steady-state operation with duty cycle time 0.3 ~ 0.5 Propose full-cycle Tokamak to I Q=1-5, steady state, TBR>1, >200MW, <10dpa complement ITER, II DEMO validation, Q>10, CW, 1GW, >50dpa procurement allocation among the ITER partner-magnet system prior to DEMO 4 Core technology-ybco Core technology-cs coil Developing CICC technologies North China Electric Power University Max.20 T (a) ITER CC package TestThe facility A vision for a large magnet test facility Aluminum sheath 上海超导带材 Test facility Superconducting conductor The conductor package Copper sheath Superconducting The Feedermagnet package (b) SS sheath 8 Max.20 T Max.2 (c) 6 SS sheath Aluminum sheath Copper sheath Test facility with superconducting transformer Max.20 T 电流 58kA 磁场 1.83T 耦合系数 0.8 超导变压器 低温液体管路 Test facility 22 背场磁体 CFETR CS model coil Soren Prestemon Summary of HTS Magnet Workshop, IAS Program on HEP

11 NMR SQUID ESR MS Specifiction of High Cable Elongate twist pitch of the first stage Decrease electro-magnetic pressure Significant experience in high-field magnet technology being developed at the CHMFL FTIR FIB Raman SMA XRD PPMS ((2Sc+1Cu) 3 ((1Sc+2Cu) (2Sc+1Cu) (1Sc+2Cu)) + (1Sc+2Cu)) 3 + 3Cu) 电缆配置 Resistive Magnets ( 25T/Φ50) 线圈B pressure 线圈C 线圈A Low temperat 线圈D ure Provide better mutual support betwe superconducting strands in the CICC a prea v e 导体 nt degradation of stran B 导体 performances. 超导股线数目 Superconducting Magnets 36 Hybrid Magnets 铜股线数目 (27.5T/Φ32) D 导体 CSimulation 导体 of CICC structure Specification of CICC 20T/ 线圈A Φ54(NMR) 线圈B 导体尺寸(mm mm) 铠甲材料 铠甲厚度(mm) 空隙率(%) 2.2 ~ 最大磁压(Mpa) ( 39T/Φ32) (20T/Φ200 ) (36T/ Φ50) SC Coils Modified 316LN ~30 ~30 ~ T/Φ52(SMA) (45T/Φ32) 9.4T/ 线圈CΦ 400(MRI) 线圈D 8T/ Φ100/D100 High Magnetic Field Lab,CAS Provides a suite of high field magnets for experiments Developing CICC technology Magnet Supporting Test of Superconducting Magnet System Developing coil fabrication expertise Power Supply First hybrid magnet in China Envisioning a facility for HTS development and testing Deionized Water System Cryogenic System High YBCO High Magnetic Field Lab,CAS Superconducting coil Prestemon winding Soren A best test facility for HTS Insert 23 Central Control System Magnetic Field Lab,CAS 内插磁体 3 低温杜瓦 High Magnetic Field Lab,CAS 水冷磁体实验平台 Summary of HTS Magnet Workshop, IAS Program on HEP

12 Presentations from Asian industrial suppliers of REBCO conductors showed impressive performance improvements and potential cost reduction "Recent Highlights from Shanghai Superconductor" Yue Zhao (Shanghai Superconductor Technology Co., Ltd.) Shanghai Superconductor Developed strategic blueprint for the commercialization of 2G HTS Technology Co., Ltd. established Sep 2013 Successfully Fabricated the first 1000metre 2G HTS wire in China 2010 Jun 2013 Mar 2015 New headquarter at Zhangjiang Successfully fabricated the first 100- Realized autonomous manufacturing Hi-tech Park put into service metre 2G HTS wire (193 A) in China of the entire production line of 2G HTS SuNAM : Superconductor, Nano & Advanced Materials (서남, ታ廠) Business Area "Recent Highlights from SuNAM" Hunju Lee (SuNAM Co., Ltd.) Establishment , for commercialization of H TS wire CEO Seung-Hyun Moon Registered Capital ~$6M No. of Employees ~ 33 (7 Ph.Ds) H.Q. Gyeonggi-do, Korea Current Production Capacity ~ 60 km / month (4 mm > 150 A) Core Technology 2G HTS manufacturing te chnology based on RCEDR process HTS Coils & Magnets HTS Electric Pow er Engineering Cryocooling Solutions Cost-effective Route Developed at Shanghai Uni. & Shanghai Creative Supercond. Technol. Co.(SCSC) Joint Technology Development at Shanghai Uni. "Recent Highlights from Shanghai University" Chuanbing Cai (Shanghai University) xture Properties for Bilayer and Triple HTS Tapes Soren Prestemon In-plane texture Coating and Summary of HTS Low-temperature Pyrolysis Overseas 12 Magnet Workshop, IASMOD Program on HEP 2017 Cost-effective

13 SuNAM is a well-established Korean Company providing REBCO tape superconductor for a variety of applications Quality control is critical - multiple QC elements: RHEED Vision System with feedback on MgO intensity and angle (Reflection High Energy Electron Diffraction) RCE Vision Inspection System being introduced to control uniformity via RGB image Before optimization After optimization RCE-DR : Reactive Co-Evaporation by Deposition & Reaction (SuNAM, R2R) High rate co-evaporation at low temperature & pressure to the target thickness(> 1 µm) at once in deposition zone (6 ~ 10nm/s) Fast (<< 30 sec. ) conversion from amorphous glassy phase to superconducting phase at high temperature and oxygen pressure in reaction zone Simple, higher deposition rate & area, low system cost Easy to scale up :single path 13

14 SuNAM has paths towards higher performance by increasing REBCO and decreasing substrate thickness Speed (m/min) Turns Thickness ( ) I C (A/cm) J C (MA/cm 2 ) Achieved Plan 2 > 20 2 ~ 2.5 > 1,000 > 5 For Je, substrate thickness must be thin Stabilizer Superconductor layer Substrate Stabilizer Superconductor layer Substrate I C (A/4 mm) I C (A/4 mm) mm-thick (brass) Improvement of Je mm-thick Position (m) Position (m) Soldering thin substrate on top of CC Remove bottom substrate - Easily reduce the thickness ~ < 20 mm - Choice of any materials(sus, Copper ) 14

15 Shanghai Superconductor is the first 2G HTS tape production line in China developing high performance REBCO conductors Height (nm) Low cost SDP (Solution deposition planarization) Dramatically improves surface roughness to facilitate quality of IBAD applied layers (c) (d) Distance (µm) Advanced lamination technique Superior delamination resistance Ic loss after epoxy impregnation 10% in the worst case, no deterioration in most cases Enhanced electromechanical performance Soren Prestemon Summary of HTS Magnet Workshop, IAS Program on HEP

16 Further work by SSTC to develop reliable, high quality joints with low resistivity, high strength, and minimal cross section impact Various techniques developed for joints - Lamination technique: Superior performance of the joint (resistance <2.3 nω) Adjustable joint resistance No reduction of critical tension strength - Diffusion technique: small joint resistance 1-3 nω Less overlap length (around 10 cm) Applicable for closed-loop 16

17 Shanghai University efforts in REBCO Tape Development have led to the foundation of Shanghai Creative Supercond. Technol. Co. Ltd. (SCSC) Significant development towards cost-effective, scalable fabrication On-line QC: In-situ RHEED pattern To increase the production rate - Shorter Pyrolysis Time: Low-fluorine; Additions such as DEA/TEA... - Less Crystallization Time: Low ambient pressure; Fast gas flow To improve performance - Increased thickness of YBCO layer - Enhanced flux pinning via doping - Improved morphology via doping Solution Preparation Oxygenation Coating + Low temperature Pyrolysis High-temperature Crystallization 17

18 SCSC investigating performance improvements via multiple creasing Yield Rate of HTScoatings, Tapes Produced while at SCSC improving Texture MOD length andforthroughput Properties Bilayer and Triple HTS Tapes In-plane texture 93% 84% 78% 68% 65% 80% 63% 基带 47% 缓冲层 38% From bilayer to triple HTS layers 超导层 Long REBaCuO Tapes Developed at SCSC In case of Smooth Substrate (RMS<1nm High-textured buffer FWHM<7 ; High HTS performance Ic>200A-cm@77K, Self-field Significant improvements in yield and length Out-plane texture Critical Current for Typical MOD-HTS Tapes at SCSC Local JC (77K,self field > 2MA/cm2 Ic 320~387A, Average Ic: 361A Mean Derivation: 6.25A Dynamic Measurement (77K self field) Critical Current for Multiple MOD-Coating Tapes at SCSC C Ic 350~420A Soren Prestemon Inductive Measurement (77K self field) Ic 368A Summary of HTS Magnet Workshop, IAS Program on HEP

19 The Institute of Electrical Engineering, CAS is aggressively pursuing Fe Pnictides as a viable HTS superconductor for HEP Very high Hc2 potential for high field magnets Reasonably high Tc as well Can this be a viable competitor to REBCO & Bi2212? 1111 Phase LnOFeAs 122 phase AFe 2 As 2 (A=Ba, Sr, Ca) 111 phase LiFeAs 11 phase FeSe Li et al., Rep. Prog. Phys. 74 (2011) T c ~55 K T c ~38 K T c ~18 K T c ~8 K Z. A. Ren et al., Chin. Phys. Lett. 25, 2215 (2008) M. Rotter, et al., Phys. Rev. Lett. 101, (2008) X. C. Wang, et al., Solid State Commun. 148, 538 (2008). F. C. Hsu, et al., Proc. Natl. Acad. Sci. U.S.A. 105, (2008). Gurevich, Nature Mater. 10 (2011)

20 A long way to go for a viable industrial conductor, but tremendous progress is being made Transport J c (A/cm 2 ) Level for practical applications Nb 3 Sn Sr-122 tapes MgB 2 mono-filamentary Nb-Ti 7-filamentary 19-filamentary 4.2 K Highest J c value reported in literature! IEECAS 10 2 Zhang et al., APL 104 (2014) Lin et al., Sci. Rep. 4 (2014) Magnetic field (T) Pallecchi et al., SUST 28 (2015) Iron-based superconducting tapes 20

21 Areas for collaboration were explored, both for HEP and Fusion applications HEP Magnets: - The existing HEP international magnet programs are well balanced in how they are exploring different mechanical structures LTS and HTS superconductors - Some opportunities exist to work together on HTS insert designs compare/clarify magnet requirements, converge on priorities of conductor performance characteristics build on previous experience; e.g. apply lessons learned from RD3 series, etc. collaborate to speed up R&D, e.g. if a new diagnostic can be applied to more, and different, magnets, more data can be gathered, more rapidly, and we move the community forward - Continue student exchanges Both HEP and Fusion share HTS magnet technology issues: - Understanding quench detection, propagation, magnet protection 21

22 HEP conductor needs overlap significantly with Fusion conductor needs in the HTS realm Conductor testing, qualification, feedback - Testing capabilities for wires/tapes: Jc(B,T, e); current limitations, etc.; many facilities exist, may benefit from data checks (e.g. round-robbin) - Testing capabilities for cables and small magnets in-field: few facilities exist - strong interest in having a couple of facilities in the world with requisite capabilities - AC losses requires significant investment - large bore magnet (preferably dipole), high current for samples, variable temperature, etc - Current distribution in cables - Radiation damage on conductors 22

23 Summary view of discussions Useful to compare HEP and Fusion magnet needs in the HTS realm Impressive investments in REBCO conductors, and associated impressive progress in tape performance, indicates real potential of the conductor for future large projects such as HEP and Fusion, leading to discussion on cost Very useful discussion on conductor cost - and most importantly potential cost reduction - again gives some reason for optimism - Industry representatives see real potential for x5 to x10 reduction in cost if demand increases sufficiently 23