Monte Carlo Simulation on PTFE-Bound MgB4O7:Dy Film for Neutron Dosimetry

Abstract

Magnesium borate (MgB4O7) is currently being studied as the material for neutron dosimetry. To become a proper dosimeter, magnesium borate is doped with dysprosium as the activator and PTFE (polytetrafluoroethylene) is used as the binder. To estimate the response of PTFE-bound MgB4O7:Dy for neutron dosimetry, Monte Carlo simulation was conducted by PHITS (Particle and Heavy Ion Transport Code System) software. The simulation consisted of dosimeter film of said materials attached to a simplified human phantom. The amount of PTFE ranged from 50% to 90% and the thickness of the film was varied from 0.5 mm to 2.5 mm. The result showed that this film dosimeter had high response to thermal neutrons and low response to fast neutrons, in contrast with the response of human body. Furthermore, it also suggested that the sample with the highest MgB4O7 content had the lowest absorbed dose due to self-shielding effect while on the thicker film, the effect of self-shielding also reduced the sensitivity of this film dosimeter.