5:30 PM - 5:45 PM
[18p-231B-17] Development of thermal neutron irradiation field for basic research of BNCT using PET cyclotron and beryllium target
Keywords:boron neutron capture therapy, accelerator based neutron source, thermal neutron
Introduction:A 20 MeV, 100uA proton PET cyclotron was installed at Aomori Prefecture Quantum Science Center. The amount of neutron yield from the reaction between 20 MeV, 100uA protons and beryllium is 1013(n / s). If fast neutrons are optimally moderated, there is a possibility of the realization of an irradiation field for basic research of BNCT. In this research, we optimized the moderator to be adaptable to basic research of BNCT using PET cyclotron.
Material and Methods:In the basic research of BNCT, it is desirable that the thermal neutron flux is sufficient and the contamination of fast neutrons and gamma rays is as low as possible. In this study, the quantitative targets of thermal neutron flux and the contamination of fast neutron or gamma ray were set by referring to the pre-clinical test of Cyclotron-Based Epithermal Neutron Source(C-BENS) using 30 MeV proton cyclotron. Irradiation conditions of thermal neutron flux were more than 5 × 108 (n / cm2 / s). Irradiation conditions of fast neutron and gamma ray contamination rate were less than 6 × 10-13, 1 × 10-12(Gy cm2), respectively.
Results: Heavy water was selected for moderating while reducing the generation of prompt gamma rays. Graphite reflector was set around a moderator in order to increase the thermal neutron flux at the irradiation position. A bismuth was installed as gamma ray shield. Thermal neutron flux was estimated to 6.7 × 108 (n / cm2 / s). The fast neutron and gamma ray contamination were 5.7 × 10-13, 5.8 × 10-13(Gy cm2),respectively.
Conclusion:The thermal neutron irradiation field for basic research of BNCT was designed by using a combination of 20 MeV, 100 uA proton cyclotron and a beryllium target. It was confirmed that irradiation of cells / small animals was possible.
Material and Methods:In the basic research of BNCT, it is desirable that the thermal neutron flux is sufficient and the contamination of fast neutrons and gamma rays is as low as possible. In this study, the quantitative targets of thermal neutron flux and the contamination of fast neutron or gamma ray were set by referring to the pre-clinical test of Cyclotron-Based Epithermal Neutron Source(C-BENS) using 30 MeV proton cyclotron. Irradiation conditions of thermal neutron flux were more than 5 × 108 (n / cm2 / s). Irradiation conditions of fast neutron and gamma ray contamination rate were less than 6 × 10-13, 1 × 10-12(Gy cm2), respectively.
Results: Heavy water was selected for moderating while reducing the generation of prompt gamma rays. Graphite reflector was set around a moderator in order to increase the thermal neutron flux at the irradiation position. A bismuth was installed as gamma ray shield. Thermal neutron flux was estimated to 6.7 × 108 (n / cm2 / s). The fast neutron and gamma ray contamination were 5.7 × 10-13, 5.8 × 10-13(Gy cm2),respectively.
Conclusion:The thermal neutron irradiation field for basic research of BNCT was designed by using a combination of 20 MeV, 100 uA proton cyclotron and a beryllium target. It was confirmed that irradiation of cells / small animals was possible.