Development of high-power 4K Nb3Sn superconducting RF electron linac for medical radioisotope production

Various types of radioisotopes (RIs) are used in the field of nuclear medicine for diagnosis, such as PET and SPECT. In recent years, RIs are applied to therapy of cancer and the Ac-225 has been confirmed to be effective in the treatment of advanced cancer. One of the promising RI production methods for medical application is the use of high-intensity beam in accelerators. In the case of an electron accelerator, a photonuclear reaction is used in the RI production process. We have started research and development of a 4K niobium-tin (Nb3Sn) superconducting RF (SRF) electron accelerator system for RI production, which can be operated with a compact conduction cooling system and does not require a large-scale cooling system. As a first step, we plan to develop a single-cell Nb3Sn superconducting cavity and a cryomodule, and to demonstrate its performance by beam acceleration experiments. In this presentation, we report the basic design of the SRF electron linac and R&D project of the 35 MeV SRF linac for the medical RI production.