R&D Efforts Towards High Field Accelerator Magnets at KEK

KEK has emphasized efforts to develop the RHQ-Nb 3 Al superconductor and a 13 T sub-scale magnet towards the LHC upgrade in last years. In addition, relevant R&D regarding radiation resistance has been carried out. For realization of higher field magnets beyond 15 T, thorough understanding of strain behavior of HTS and A15 superconductors is truly desired. KEK has launched a new research subject on stress/strain sensitivity of HTS and A15 superconductors in collaboration with the neutron diffraction facility at J-PARC and the High Field Laboratory in Tohoku University.