Progress of SC High Field Magnet Program for CEPC-SPPC

Transcription

1 Progress of SC High Field Magnet Program for CEPC-SPPC Qingjin XU On behalf of the SPPC Magnet Working Group Institute of High Energy Physics (IHEP) Chinese Academy of Sciences (CAS) HKUST,

2 SPPC Magnet Design Scope Conceptual Design of the SPPC Dipole Magnets R&D of Superconducting Rutherford Cables NbTi, Nb 3 Sn, HTS Contents R&D of 12-T Twin-aperture Dipole Magnet Design, Fabrication and test plan Domestic Collaboration Towards HTS SPPC International Collaboration Summary

3 SPPC Magnet Design Scope (V201701) SPPC 100 km in circumference C.M. energy (Upgrading) TeV Timeline Pre-study: R&D: Eng. Design: Construction: E[ GeV ] = 0.3 B[ T ] ρ[ m] Main dipoles Field strength: 12~24 (Upgrading) Tesla Aperture diameter: 40~50 mm Field quality: 10-4 at the 2/3 aperture radius Outer diameter: mm in a 1.5 m cryostat Tunnel cross section: 6 m wide and 5.4 m high 6-m Tunnel for CEPC-SPPC Conceptual design of the SPPC 12-T magnet with IBS and common coil configuration SPPC collider CEPC booster CEPC collider

4 Baseline design SPPC Magnet Design Scope Tunnel circumference: 100 km Dipole magnet field: 12 T, iron-based HTS technology (IBS) Center of Mass energy: >70 TeV Injector chain: 2.1 TeV Upgrading phase Dipole magnet field: 20-24T, IBS technology Center of Mass energy: >125 TeV Top priority: reducing cost! Instead of increasing field Injector chain: 4.2 TeV (adding a high-energy booster ring in the main tunnel in the place of the electron ring and booster) Development of high-field superconducting magnet technology Starting to develop HTS magnet technology before applicable iron-based wire is available ReBCO & Bi-2212 and LTS wires be used for model magnet studies and as options for SPPC: stress management, quench protection, field quality control and fabrication methods

5 J e of IBS: Nb-Ti 4.2 K LHC insertion quadrupole strand (Boutboul et al. 2006) Whole Wire Critical Current Density (A/mm², 4.2 K) Nb-Ti 4.22 K High Field MRI strand (Luvata) Nb 3 Sn: Bronze Process 4543 filament High Sn Bronze-16wt.%Sn-0.3wt%Ti (Miyazaki-MT18-IEEE 04) REBCO B Tape Plane Nb 3 Sn: High J c Compiled from ASC'02 and ICMC'03 papers (J. Parrell OI-ST) SuperPower tape, 50 μm substrate, 50 μm Cu, 7.5% Zr, measured at NHMFL REBCO: B Tape plane REBCO: B Tape Plane Bi-2212: 50 bar OP Nb₃Sn: Internal Sn RRP Nb₃Sn: High Sn Bronze Nb-Ti: LHC 4.2 K Nb-Ti: High Field MRI 4.22 K IBS Ma IEECAS IBS Ma IEECAS Applied Magnetic Field (T) Modified version by Q. Xu in Oct August 2017 IBS- Iron Based Superconductor Much lower cost and better mechanical properties expected Expected IBS 2025 Y. Ma (IEECAS) IBS 2016 Y. Ma (IEECAS) filament B-OST strand with NHMFL 50 bar Over-Pressure HT. J. Jiang et al. REBCO B Tape Plane

6 World s First 100 m Fe-based Superconductor by IEE, CAS, China (Aug. 2016) 115 m long 7-filament wire Yanwei Ma (IEECAS) Dr. Yao s talk this afternoon Minimum J c >12000A/cm 4.2K At 4.2K, 10T, transport Jc distribution along the length of the first 115 m long 7-filament Sr122 tape

7 The 12-T Fe-based Dipole Magnet E. Kong (USTC), C. Wang, Q. Xu et al. I o =9500A Yoke OD 500mm Design with expected J e of IBS in 2025 Strand diam. cu/sc RRR Tref Bref Jc@ BrTr djc/db IBS The required length of the 0.8 mm IBS is 6.1 Km/m For 100-km SPPC accelerator, 3000 tons of IBS is needed Target cost of IBS: 20 RMB (~2.6 Eur) T

8 The 12-T Fe-based Dipole Magnet ROXIE simulation results 2D E. Kong (USTC), C. Wang, Q. Xu et al. <10-4 field quality within 2/3 aperture 3D optimization to be completed With 500 mm Yoke OD Stray field around the dipole with R= 500 mm

9 R&D of Superconducting Rutherford Cables Collaboration between WST, NIN, Toly Electric and IHEP Y. Zhu (WST), Y. Zhao (Toly), C. Li (NIN) and Q. Xu et al. Superconducting Rutherford cable Insulated cable Rutherford cabling machine at Toly Nb 3 Sn Rutherford cable Cable insulation Bi-2212 Rutherford cable Dielectric strength test ~5kV

10 R&D of Superconducting Rutherford Cables ~700 m NbTi and Nb 3 Sn cables have been fabricated at Toly Electric (Wuxi, China), Jc degradation <3%; R&D of HTS cable is ongoing. 38 股 NbTi 缆 142m 24 股 NbTi 缆 193m 20 股 Nb 3 Sn 缆 138m 18 股 NbTi 缆 300m

11 Superconducting Rutherford Cable R&D Bi-2212 cable fabrication with NIN strand Parameter Cable 1 Cable 2 Diameter Ф(mm) 1 1 Wire processing 300 退火 200 退火 Cabling Q. Hao, C. Li (NIN), Y. Zhao (Toly) et al. Bi-2212 Cable Number of Strands 8 8 Cable size(mm 2 ) Filling factor 70.5% 85.2% Length 2.5 米 2 米 Front view Side view 成功绞制两根 8 线电缆 绞制过程中电缆变形均匀 每根线材外观完整无破损 线材芯丝无明显破损 Before cabling After cabling

12 R&D of 12T Twin-aperture Dipole Magnet Operation load line at 12 T: 80% at 4.2K C. Wang, K. Zhang, Y. Wang, D. Cheng, E. Kong (USTC), Z. Zhang, S. Wei, Q. Xu et al. NbTi+Nb 3 Sn, 2*ф10 aperture All Nb 3 Sn, 2*ф20 aperture Nb 3 Sn+HTS, 2*ф30 aperture The 1 st high field accelerator magnet in China! Magnetic flux distribution 3d coil layout 3D magnetic field distribution Components and assembly

13 R&D of 12T twin-aperture dipole magnet Current decay D. Cheng et al. Magnet inductance Hotspot temp. Temperature distribution In coil after quench Voltage Resistance Quench heater Thickness (μm) Resistance (Ω) Quench simulation with dump resistor only Peak power (w/cm^2) Charge voltage (V) Max current (A) Capacitance (mf) Current decay Hotspot temp. Temperature distribution In coil after quench Voltage Heat delay Resistance Quench simulation with dump resistor and heaters

14 R&D of 12T Twin-aperture Dipole Magnet Fabrication of the coils and magnet Cabling Coil winding HT VPI Magnet assembly Test Cabling Machine Rutherford Cable Coil Winding NbTi Coil Nb 3 Sn Coil Coil Winding

15 R&D of 12T Twin-aperture Dipole Magnet Fabrication of the coils and magnet Heat Reaction Reacted Coil VPI Coil Package VPI System Magnet Assembly Impregnated Coil

16 R&D of 12T Twin-aperture Dipole Magnet Shipping to Hefei for the test

17 R&D of 12T Twin-aperture Dipole Magnet R&D Plan for Test of the High Field Model Dipole #1 (NbTi+ Nb 3 Sn) ~Feb. 2. Fabrication and test of the IBS insert coils ~May 3. Development of the ReBCO insert coils ~Aug. 4. Fabrication and test of the High Field Model Dipole # 2 (Nb 3 Sn) ~ Sep. 5. Fabrication and test of the High Field Model Dipole # 3 (Nb 3 Sn+ HTS) ~ Dec.

18 Domestic Collaboration for HTS R&D Applied High Temperature Superconductor Collaboration (AHTSC, 实用化高温超导材料产学研合作组 ) formed in Oct Goal: a) 1) To increase the J c of iron-based superconductor (IBS) by 10 times, reduce the cost to 20 12T & 4.2K, and realize the industrialization of the conductor; b) 2) To reduce the cost of ReBCO and Bi-2212 conductors to 20 12T & 4.2K; c) 3) Realization and Industrialization of IBS magnets and SRF cavities. Working groups:1) Fundamental sciences study; 2) IBS conductor R&D; 3) ReBCO conductor R&D; 4) Bi-2212 conductor R&D; 5) Performance evaluation; 6) Magnet and SRF technology. Collaboration meetings: every 3 months, to report the progress and plan for next months.

19 IHEP & CERN Collaboration A 0.5m model magnet to be fabricated and tested by May 2018 Glyn Kirby, Ezio Todesco (CERN)

20 Summary CDR of the SPPC magnet Completed: SPPC latest baseline: 12 T all- HTS (iron-base superconductor, IBS) magnets to reach 70TeV centerof-mass energy. SPPC Upgrading phase: 20~24 T all-hts (IBS) magnets to reach 125~150 TeV center-of-mass energy. R&D of superconducting Rutherford cables: 700 m NbTi and Nb 3 Sn cables have been fabricated; J c degradation <3%. R&D of HTS cables is ongoing. R&D of high field magnet technology: 12 T model dipole magnet to be tested soon; IBS insert coil to be fabricated and tested at high field in next 6 months. Domestic and international collaborations have been formed to pursue the advanced HTS superconductor and magnet R&D.

21 Thanks for your attention!