Feasibility study of compact accelerator-based neutron generator for multi-port BNCT system

Authors:   Koay H.W., Fukuda M., Toki H., Seki R., Kanda H., Yorita T.
Journal: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
https://doi.org/10.1016/j.nima.2018.05.025
Abstract: As Boron Neutron Capture Therapy (BNCT) grows to become a good alternative for radio-resistant tumours, long preparation and irradiation time limit the number of treatments possible. To resolve this issue, this work aims to propose implementing a compact accelerator-based neutron generator which can provide multiple neutron beams of at least 10/s/cm for multi-port BNCT, while maintaining low gamma and fast-neutron contamination. This study applies a 50 MeV proton beam at a realizable current of 500 A from an AVF cyclotron with a W target to sustain a high neutron yield for multiple extractions. A beam shaping assembly (BSA) is also studied to moderate and shape the neutron beam for BNCT. A cylindrical BSA surrounding the W target is proposed to make multiple gates extraction plausible. The BSA
consists of a moderator assembly (Fe, Al and Teflon), Pb reflector, Li thermal neutron filter (TNF), and borated-polyethylene coupled with Pb which act as
neutron and gamma shielding. The proposed design managed to deliver about 2  10 epithermal-neutron/cm/s with satisfactory beam quality at 4 ports for multiple BNCT. Thus, the neutron generator for multi-port BNCT proposed in this study has been
proven to be feasible.