Present status of iBNCT accelerator

An accelerator-based boron neutron capture therapy (BNCT) has been studied intensively in recent years as one of new cancer therapies. In the iBNCT (Ibaraki BNCT) project, its accelerator is consisted of an RFQ and a DTL which have a proven track record in J-PARC. Meanwhile, a high duty factor is required to have a sufficient thermal neutron flux for BNCT. After a failure of the klystron power supply in February 2019, beam operation has been resumed in May 2020. To date, average current of 2.1 mA with beam repetition rate of 75 Hz is achieved in the stable operation. Neutron beam characteristic measurements and irradiation tests with cells and mice are on-going for non-clinical tests to be started in September 2021. In addition, we are gradually improving the equipment such as cooling water and vacuum system of the accelerator for further stability. In this contribution, present status and future prospect of the iBNCT accelerator are reported. (author)