Neutron-beam-shaping assembly for boron neutron-capture therapy

A neutron-beam-shaping assembly consisting of a moderator, a reflector, and an absorber is used to form a therapeutic neutron beam for the boron neutron-capture therapy of malignant tumors at accelerator neutron sources. A new structure of the moderator and reflector is proposed in the present article, and the results of a numerical simulation of the neutron spectrum and of the absorbed dose in a modified Snyder head phantom are presented. The application of a compositemoderator and of a composite reflector and the implementation of neutron production at the proton energy of 2.3MeVare shown to permit obtaining a high-quality therapeutic neutron beam.