CHARACTERIZATION OF AN ACCELERATOR-BASED NEUTRON SOURCE FOR BNCT OF EXPLANTED LIVERS

An accelerator-based thermal neutron source for BNCT of the explanted liver was designed using the MCNP code. Neutrons are generated via (d, n) reactions by 7 MeV deuterons bombarding a beryllium target The ther apy constraints were approached by simulating an irradiation cavity pl aced inside a graphite reflector parallelepiped containing a heavy-wat er moderator in turn enclosing the beryllium target The experimental v erification was performed at the Laboratori Nazionali di Legnaro (Ital y). The thermal and epithermal neutron flux was measured at various po sitions in the irradiation cavity by means of activation techniques em ploying bare and cadmium covered indium foils. Further measurements we re performed with BF3 detectors. The fast neutron component of the dos e equivalent and the energy spectrum above 100 keV were assessed by me ans of a recently developed technique employing variable threshold sup erheated drop detectors. The prompt gamma ray dose was measured with ( LiF)-Li-7 TLDs.