[2M01-05] Neutron Measurement

[2M01] Development of Real-Time Neutron Beam Monitor for Boron Neutron Capture Therapy

(1) Characterization of Beam Monitor

*Masashi Takada¹, Natsumi Yagi¹, Satoshi Nakamura², Kenji Shimada³, Masaru Nakamura³, Ryo Fujii³, Jyun Itami^2,5, Hiroshi Igaki², Kei Aoyama⁴, Tomoya Nunomiya⁴ (1. Natl. Defense Academy of Japan, 2. National Cancer Center Japan, 3. CICS, 4. Fuji Electric, 5. Shinmatsudo Hospital)

Keywords:Boron neutron capture therapy, Neutron, Gamma ray, Si diode detector, Real-time measurement

A real-time neutron beam monitor has been developed to measure neutron beams in a real time for the boron neutron capture therapy (BNCT). The neutron beam monitor consists of a thin Si pin diode and a thin film LiF neutron converter. The neutron beam monitor was located on the neutron target without interrupting neutron beam profiles and energy spectra. The neutron monitor measured not only neutrons but also gamma rays emitted from the neutron target by using an advantage of particle discrimination property between neutrons and gamma rays without any second neutron detector. Neutron beams at a neutron irradiation position for a patient were measured simultaneously using a same-type neutron detector. The experimental results indicated that there was a good correlation between neutron count rates on the neutron target and those at the patient position. The neutron beam monitor enables to measure BNCT neutron beam in a real time.