Development of Radiation-Resistant Magnets for JHF/J-PARC • K.H. Tanaka for the Hadron Beam Subgroup of the JHF Construction Team • KEK - TOKIN Corp. - Hitach Cable Ltd. Collaboration
Collaboration • KEK K. H. Tanaka, E. Hirose, H. Takahashi, K. Agari, A. Toyoda, Y. Sato, M. Minakawa, H. Noumi, Y. Yamanoi , M. Ieiri, Y. Katoh, Y. Yamada, Y. Suzuki, and M. Takasaki • TOKIN Y. Saitoh, N. Saitoh, K. Yahata, K. Kato, and H. Tanaka • Hitachi Cable T. Birumachi, and S. Tsukada
Menu on Oct. 21 st , 2003 • JHF/J-PARC • RR-Magnets…My History in Japan • Mineral Insulation Cable (MIC) • Q440MIC Fabrication • Summary
J-PARC: The Accelerator Complex NP-HALL • NP-Hall & Neutrino Facility for Experiments with 50GeV-15 μ A Beam – The First (Only One?) KAON FACTORY in the World • Handling of 1MW Beam (4MW in future!)
Artist’s Impression of the J-PARC Nuclear and Particle Experimental Facility Materials and Life Science Experimental Facility Nuclear Transmutation Neutrino to Kamiokande 3 GeV Synchrotron 50 GeV Synchrotron (25 Hz, 1MW) (0.75 MW) Linac (350m) J-PARC = Japan Proton Accelerator Research Complex
World’s Proton Accelerators Under Proposed Existing construction 10000 ESS Materials-Life Sciences PSI This Project 1000 SNS (CW) 3 GeV Power ISIS Nuclear-Particle 100 TRIUMF Physics Current ( µ A) This Project IPNS 50 GeV 10 AGS KEK-500MeV FNAL-MI 1 MW Booster CERN-PS 1 SPS 0.1 MW KEK- 12GeV PS U70 0.1 Tevatron 0.01 0.1 1 10 100 1000 10000 Energy (GeV)
Schedule • 2001: Approval by Japanese Government • 2002: Digging Started • Now Accelerators are under Construction – Experimental Facilities are Final Stage of their Design Work • 2004: Start of NP-Hall Construction • 2007: Completion of NP-Hall • 2008: The First Beam
High Intensity Beam handling • Radiation Resistant Magnet is the key technology • Radiation Resistant Magnets → Radiation Resistant Coil Insulation • We continued ~20 years R/D of Radiation Resistant Magnet.
History of Radiation Resistant Magnets R&D in Japan Polyimide resin + Boron free Glass tape (MT11) – Great Success, up to 10 9 Gy – All the JHF Accelerator Magnets Employed Polyimide Insulation. • High Alumina Cement + Asbestos Tape(MT11) • Ceramic Binder + Ceramic Fiber Tape(MT13) – Success, up to 10 11 Gy – Technology was Established. • MIC(MT14 → ) – Great Success, up to 10 11 Gy
Status of Mineral Insulation Cable
Construction of actual magnet Q440MIC • 20cm bore diam., 200cm pole length • 43T/pole, 1.3T@pole • Nominal current/voltage=2200 A/200V • Cooling water=290 L/min.@1MPa Cooling water Temp. rise=30 ℃ • • Approximate Weight=33ton
Q440MIC Coil Design • 4+14+25 turns • Total 43 turns • 6 Conductors • 4 water path/coil • • Limited area at both magnet ends • Small bending radius •
Unwanted inward width expamsion wrinkles Bending Tests at small radius
R/T=1.5 ↑ ,2.0 ↓ R/T=2.5 ↑ ,3.0 ↓
How much did MIC become thicker? Increase width/Original width Handle Bending Bender Bending R/T • 8-13% for R/T=1.5 • Employ “Bending Tool” and R/T~2
Leakage Current Check for 2500A-Class MIC Bent Samples • No difference from Straight Leak Current (mA) for AC1kV Samples • Proportional to Long MIC • Electrically NO PROBLEM even for R/T=1. MIC Length (m)
Tools for fat-free bending.
Coil Winding 25 turn coil ↑ , Final assembly ↓ 4turn coils ↑ , 14turn coil ↓ ,
Terminal Treatments
Q440MIC Magnet Assembly
Q440MIC Completed!
Shield & Service Space Ceiling Shield Blocks are Permanent removed at the maintenance Concrete Shield Water Cooled Bus Duct: Concrete Block Electricity & Service Space: QD for Water, Interlock Power, Vacuum and Signal Cooling Signals Water Supply Concrete Block Iron Shield Magnet Trench
Summary • The actual Q magnet for 50 GeV proton beam transport has been fabricated successfully with 2500 A class MIC (24x24mm 2 ). • Some unwanted deformation problems were happened at small bending radius of the MIC. However electrically NO problem. • The fabrication technology for large scale window frame winding coils of MIC has been established. • Next step is the mass-production! For JHF/J-PARC
JAERI Tokai Campus, Early May 2003, II .
50GeV-PS Construction Status (August 2003) 3GeV Beam
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