Development of Superconducting Magnets for Particle Accelerators and Detectors in High Energy Physics Takakazu Shintomi and Akira Yamamoto On behalf of US-Japan collaboration carried out with KEK, University of Tsukuba (Japan) and FNAL, BNL, LBNL (USA) 1 US-Japan HEP Collaboration 30th Anniversary Symposium

Progress and Achievement YearsProjectsContributionProgressParticipation High field dipoles 10 T dipole Nb 3 Sn dipole Superconductors Champion data Improvement of J c FNAL, BNL, LBNL, KEK 1980CDFCentral solenoid (prototype) Longest stable operation FNAL, U. Tsukuba, KEK SSCAccelerator magnets6.6 T 1m and 13 m dipoles SSC, FNAL, BNL, LBNL, KEK SDC detector solenoid2 T, thin solenoid prototype FNAL, KEK Muon G-2SR magnets and Inflector BNL, KEK LHC IRQFNAL, KEK, CERN (not funded by US-J) LHC upgrade Nb 3 Al conductor and cabling NIMS, FNAL, BNL, KEK, CERN (not funded by US-J) J-PARCT2K, neutrino beam line Corrector magnet Coil winding and Conductive cooling BNL, KEK 2 US-Japan HEP Collaboration 30th Anniversary Symposium

Objective To develop superconducting magnets for high energy accelerators and particle detectors The program was performed between KEK and BNL, FNAL and LBNL since 1981 to present ◦ Development of superconducting accelerator and detector magnets ◦ Development of superconducting wires And succeeded to further programs 3 US-Japan HEP Collaboration 30th Anniversary Symposium

Development of Superconducting Magnets High field magnets with Nb-Ti wire ◦ 10 tesla dipole reached to B m = 10.4 tesla (left) ◦ SSC dipole: 5 cm ID, 6.6 tesla, 13 m long High field magnets with Nb 3 Sn wire ◦ W&R race track coil: 800 mm long ◦ Double shell dipole: 600 mm long, 132 mm ID (right) Al stabilized SC coil, and inflector magnet for g-2 at BNL 10 T dipole Nb 3 Sn dipole 4 US-Japan HEP Collaboration 30th Anniversary Symposium

g-2 Experiment at BNL Ring SC Coil Cross-Section View of Storage Ring Inflector 5 US-Japan HEP Collaboration 30th Anniversary Symposium Contribution to very high precision magnetic field in main muon storage ring: - SC coil, Iron pole piece, and SC inflector

SSC Dipole Magnet R&D Developed eleven 1 m model dipoles ◦ Successfully tested Developed one 13 m full size dipole ◦ Successfully tested and reached 6.6 tesla nominal magnetic field 6 US-Japan HEP Collaboration 30th Anniversary Symposium

Successive Programs in 2 nd Stage The program for the LHC insertion region quadrupole (IRQ) magnet started in 1995, and was completed successfully in 2006 The technologies achieved were succeeded to superconducting magnets for KEK-B IRQ, and the J-PARC neutrino beam line Also, these technologies have been succeeded to magnet development for the LHC luminosity upgrade, high intensity muon beam, and so on 7 US-Japan HEP Collaboration 30th Anniversary Symposium

Collaboration with CERN for LHC-IRQ The collaboration for LHC Insertion Region Quadrupole (IRQ) magnets started in 1995 and was successfully completed in 2006 by collaboration with KEK, FNAL and CERN Sixteen IRQ magnets plus four spares were fabricated KEK designed and developed technologies which were transferred to an industry KEK tested all the quads and they satisfied the LHC- IRQ requirements The magnets were assembled into cryostat at FNAL and delivered to CERN on schedule 8 US-Japan HEP Collaboration 30th Anniversary Symposium

G = 215 T/m, Aperture = 70 mm, B ~ 9 T L= 5.5 m (FNAL) or 6.37 m (KEK) Higher Order Multipoles < 1 unit (10 -4 ) Beam Heating: 5 ~ 10 W/m KEK FNAL LHC-IRQ LHC-IRQ 9 US-Japan HEP Collaboration 30th Anniversary Symposium

LHC-IRQ Production Production was on schedule in just 3years 10 US-Japan HEP Collaboration 30th Anniversary Symposium

LHC-IRQ Performance Test 1.9 K: 230 T/m (~ 9 T) Training quench  230 T/m (~ 9 T) Full energy T/m Fast ramp A/s Field measurement To reach 220 T/m w/o quench Electrical insulation test K He-gas 11 US-Japan HEP Collaboration 30th Anniversary Symposium

LHC-IRQ Quench History Warm bore tube for field measurement attached to the coil and coil temperature increased Quench history is one of the most important characteristics with field quality 12 US-Japan HEP Collaboration 30th Anniversary Symposium

Summary The program for development of superconducting magnets for high energy accelerators and particle detectors was successful and various technologies have been achieved The technologies developed by the Japan-US Collaboration Program were succeeded to the Japan-CERN collaboration for LHC-IRQ The successive programs such as the J-PARC neutrino beam line magnet stand on these technologies The future programs for superconducting magnet development such as the LHC upgrade are important for high energy physics The successful development of these programs is owing to the collaboration with industries 13 US-Japan HEP Collaboration 30th Anniversary Symposium

Appendices 14 US-Japan HEP Collaboration 30th Anniversary Symposium

Development of Superconducting Wires Development of Nb-Ti wire with industry Development of Nb-Ti (Ta) wire Development of Nb 3 Sn wire for high field magnet beyond 10 tesla The effort has been succeeded to develop Nb 3 Al wire for higher field magnet Ni-Ti wire 15 US-Japan HEP Collaboration 30th Anniversary Symposium

LHC-IRQ Field Quality Allowance Coil oval deformation 16 US-Japan HEP Collaboration 30th Anniversary Symposium

LHC-IRQ Production ①, ② ☞ Test ③ ☞ Assembly ④ ☞ Installation ⑤ ① ② ③ ⑤ ④ 17 US-Japan HEP Collaboration 30th Anniversary Symposium