ACCELERATOR PRODUCTION OF EPITHERMAL NEUTRONS FOR BNCT

A NEW EPITHERMAL NEUTRON SOURCE WILL BE USED IN BORON NEUTRON CAPTURE THERAPY (BNCT). THE USE OF EPITHERMAL INSTEAD OF THERMAL NEUTRONS FOR BNCT IS ADVANTAGEOUS DUE TO THE GREATER PENTRATION DEPTH OF EPITHERMAL NEUTRONS IN TISSUE, WHICH SPARES SKIN DURING TUMOR IRRADIATION. EPITHERMAL NEUTRONS ARE PRODUCED BY BOMBARDING A LITHIUM TARGET WITH AN INTENSE PROTON BEAM FROM A CASCADE TANDEM ACCELERATOR (CTA). THE CTA IS A NOVEL ELECTROSTATIC ACCELERATOR THAT COMBINES TWO EXISTING TECHNOLOGIES INTO A SIMPLE, COMPACT PROTON ACCELERATOR SUITABLE FOR OPERATION IN A HOSPITAL ENVIRONMENT. PRELIMINARY CALCULATIONS INDICATE THAT A 1-MA, 2- TO 2.5-MEV PROTON BEAM INCIDENT ON THE TARGET WILL PROVIDE SUFFICIENT EPITHERMAL NEUTRON FLUX FOR BIOLOGICAL STUDIES AND FOR TUMOR IRRADIATION. IN THIS STUDY, TARGET AND NEUTRON MODERATOR GEOMETRY WILL BE MODELED USING MONTE CARLO TECHNIQUES TO DETERMINE THE OPTIMUM TARGET ASSEMBLY DESIGN AND PROTON BEAM PARAMETERS. THIS SYSTEM WILL BE CAPABLE OF PROVIDING A WIDE RANGE OF NEUTRON ENERGY SPECTRA, INTENSITIES, AND IRRADIATION TIMES FOR BOTH LABORATORY AND CLINICAL BNCT STUDIES.