Scheme design for neutron beam shaping assembly based on D-Be compact fast neutron source

BackgroundBoron Neutron Capture Therapy (BNCT) is a binary radiation therapy with strong targeting and high energy transfer line density at the cellular scale. It has the advantages of short treatment cycle and minimal damage to surrounding healthy tissues, making it a promising cancer treatment method.PurposeThis study aims to design beam shaping assembly (BSA) to make the neutron beam of D-Be neutron source suitable for BNCT and ensure neutron directionality.MethodsThe Monte Carlo simulation programs GEANT4 and FLUKA were employed to simulate the generation of 9Be(d,n)10B reaction neutron sources and subsequent neutron moderation. Then, a scheme design for BSA was carried out using a 1.45 MeV, 30 mA deuterium beam to bombard a 9 μm thin beryllium target, and set a basis BSA model with a cylindrical structure as a whole.ResultsThe simulation results show that using a 20 cm thick BiF3 and 30 cm thick MgF2 combined slowing layer, a 30 cm thick Pb reflector layer, a 9 cm thick MgF2 supplementary slowing layer, and a 0.2 mm thick Cd thermal neutron absorption layer, the outlet is ensured to γ and fast neutron composition, Φepi/Φth, Φepi/Φfast meets the recommended values of the IAEA (International Atomic Energy Agency).ConclusionsThis study obtained the neutron spectra and BSA specific design scheme of low-energy deuterium beams and thin beryllium targets, providing data reference for the slowing shaping of neutrons in D-Be neutron sources and supporting subsequent research on D-Be sources.