Accelerator based BNCT using solid Li target at OIST

Matsumoto, Hiroshi*; Suzuki, Fumiko*; Sugawara, Hirotaka*; Yoshioka, Masakazu*; Higashi, Yasuo*; Matsumoto, Noriyuki*; Hasegawa, Kazuo; Kondo, Yasuhiro   ; Uchida, Kazuhide*; Kurokawa, Shinichi*

BNCT (Boron Neutron Capture Therapy) is a kind of radiation therapy for cancer. Boron is accumulated inside the tumor before the injection of the neutron beam to the target tumor. For long time BNCT researchers have been utilizing the neutron beam provided by nuclear reactors. The problem here is that appropriate nuclear reactors are scarce in the whole world. Recently, however, another source of neutron beam has been studied using high intensity, low energy proton accelerator. The intensity of the proton beam is 10 to 50 mA, which is rather high but the energy is always less than 10 MeV. The cost of the accelerator is about 1/7 of the heavy ion machine and it has a potential to become a standard machine as a tool for cancer radiotherapy in medium-sized to large hospitals. OIST BNCT will design a new and commercially affordable Linac (3 MeV beam energy) and solid Li target system. As a first step, we will concentrate to develop ECR ion source (60 mA of peak output current at 50 - 60 kV, 1 ms pulse width and 200 Hz of repetition rate) and LEBT (Low Energy Beam Transport).