Article BSA designs Dosimetry Year 2011

Experimental verification of beam characteristics for cyclotron-based epithermal neutron source (C-BENS)

Applied Radiation and Isotopes, 2011

Authors:   Tanaka H., Sakurai Y., Suzuki M., Masunaga S., Mitsumoto T., Fujita K., Kashino G., Kinashi Y., Liu Y., Takada M., Ono K., Maruhashi A.
Journal: Applied Radiation and Isotopes
Abstract: A cyclotron-based epithermal neutron source has been developed for boron neutron capture therapy. This system consists of a cyclotron accelerator producing 1.1-mA proton beams with an energy of 30MeV, a beam transport system coupled with a beryllium neutron production target, and a beam-shaping assembly (BSA) with a neutron collimator. In our previous work, the BSA was optimized to obtain sufficient epithermal neutron fluxes of ~109cm-2s-1 using a Monte Carlo simulation code. In order to validate the simulation results, irradiation tests using multi-foil activation at the surface of a gamma-ray shield located behind the collimator and water phantom experiments using a collimated epithermal neutron beam were performed. It was confirmed experimentally that the intensity of the epithermal neutrons was 1.2×109cm-2s-1.