Monte Carlo simulation of neutron shielding for proton therapy facilities

Abstract

A study was performed to develop a Monte Carlo method of modeling neutron shielding of proton therapy facilities in a complex, realistic environment. The bulk neutron shielding of the Northeast Proton Therapy Center (Massachusetts General Hospital, Boston, MA) was used as the basis of the design work. A geometrical model of the facility was simulated using the LAHET Code System, a set of Monte Carlo codes developed at Los Alamos National Laboratory. Additional software tools for reading and analyzing the simulation data that the model provides have been developed and tested. In order to verify the computer simulations, neutron detection and data acquisition systems have been assembled, modified, and thoroughly tested in order to monitor the neutron dose equivalent during proton beam operation at several locations on a continuous basis. Preliminary tests show that the geometry and physics models proposed in this work are valid.