Presentation Information
[2F08]Characterization of online BNCT beam monitor for p(8MeV)-Be neutron source
*Masashi Takada1, Hiroaki Kumada2, Susumu Tanaka2, Toshiyuki Ohba3, Tetsuro Matsumoto5, Akihiko Masuda5, tomoya nunomiya4 (1. Natl. Defense Academy of Japan, 2. Univ. of Tsukuba, 3. NAT, 4. Fuji Electric, 5. AIST)
Keywords:
Boron Neutron Capture Therapy,Real-Time Neutron Beam Monitoring,Silicon Diode,Fast Neutron Detection
We have developed an online neutron beam monitor for the neutron source of Boron Neutron Capture Therapy (BNCT) at the Tsukuba of University, complementing the main proton beam current measurement. This monitor detected fast neutrons backscattered from the beryllium target. Photon events were successfully separated, resulting in less than 1% contamination of neutron events. Through repeated neutron measurements, the monitor provided the neutron intensity with a reproducilibity of 1.2% (1sigma). However, the monitor showed a periodical fluctuation during long-term neutron irradiation. Attemps to identify the cause of this fluctuation and mitigate it are currently ongoing but incomplete. Moving forward, we will continue to monitor the neutron beam intensity, and the monitor will be used to supplement the main proton current measurement.