In Japan BNCT had been studied by using experimental reactors until the great earthquake in 2011. However, it is not practical to use reactor based BNCT facilities at hospitals. Moreover, after the Fukushima nuclear accident, it becomes difficult for us to continue the study by using reactors. Accelerator based BNCT facilities are more suitable to hospitals and can produce not only thermal but also epithermal neutrons that are more effective for the treatment. In this talk, after the introduction of the principle of BNCT, I describe the present status of the accelerator based BNCT at Tokai Japan. This system consists of a 50 KeV high-intensity proton source, a 3 MeV 324 MHz RFQ followed by 5 MeV 324 MHz DTL, and a Be target. The parameters of the beam are 8 MeV, 50 mA, 1 msec pulse length, 200 Hz repetition rate, 20 % duty factor, and 80 kW average beam power. By this linac and a moderator we expect a few x 10E9 neutrons/s/cm^2 at patient position.
We plan to have the first beam in this summer, and get 1 x 10E9 neutrons/s/cm^2 neutrons by the summer of 2015.
