Radiation-Resistant Magnets for the J-PARC

Continuity R&D work is reported here on the radiation resistant magnets for the Japan Proton Accelerator Research Complex (J-PARC). The main accelerator of the J-PARC is the 50 GeV-15 mA proton synchrotron (50 GeV-PS) with beam power of 750 kW. The radiation resistant magnet is the key technology to realize the external beam lines and experimental facilities of the J-PARC 50 GeV-PS. The radiation resistant technologies we have selected for the J-PARC are; (1) Polyimide Resin Insulation (PI) for up to 10
⁸
Gy and, (2) Mineral Insulation magnet Cables (MICs) with larger cross sections for higher radiation dose up to 10
¹¹
Gy. Approximately 20 polyimide insulation magnets and 10 MIC magnets are designed for the external beam lines of the 50 GeV-PS. The fabrication of those magnets has already started in 2005 and will continue until the end of 2007