[20a-A304-1~12] 2.2 Detection systems

[20a-A304-11] The development of prompt gamma rays imaging detector using LaBr₃(Ce) scintillator and MPPC array for Boron Neutron Capture Therapy

〇Keita Okazaki¹, Kiyotaka Akabori², Takushi Takata³, Yoshinori Sakurai³, Hiroki Tanaka³ (1.Kyouto Univ., 2.Sumitomo Heavy Inds., 3.KURRI)

Keywords:LaBr3(Ce) scintillator, MPPC, Boron Neutron Capture Therapy

To improve the treatment quality of BNCT and further progress the research and development, a system that can measure boron concentration in real-time in two and three dimensions is paramount. Current methods to measure boron concentration include prompt gamma-ray analysis or the induced coupled plasma. However, these procedures are not able to obtain the information of the boron concentration during BNCT irradiation. The detection of boron concentration in real-time, two and three-dimension can be achieved by measuring the prompt gamma rays emitted from the reaction between boron-10 and thermal neutrons. However, there are 511 keV annihilation gamma rays in BNCT irradiation field, it is required to discriminate between prompt gamma rays of 478 keV and annihilation gamma rays, which requires a detector with an energy resolution below 6.5 %. A prompt gamma-ray imaging detector system, which consists of a LaBr₃(Ce) scintillator, MPPC, 64 channels amplifiers and ADCs, was developed. The characteristics of the system were obtained by irradiating thermal neutrons to samples, each having a different boron concentration.