A comparative study of neutron stimulated emission computed tomography based on D-D/D-T neutron source

In this paper, we investigated the applications of D-D and D-T neutron sources in Neutron Stimulated Emission Computed Tomography (NSECT). Four NSECT models were established, including the TiT/TiD targets to generate neutron sources and the presence/absence of iron balls in water phantom to mimic tumors. NSECT system was simulated by using MCNP software, in which the D-D and D-T neutron sources were generated, collimated, transported, and recorded. We studied flux distributions and typical spectrum of both outgoing neutrons and the characteristic gamma-rays for D-D and D-T NSECT. Results show that the optimized NSECT gamma-ray detector locations will be in the direction from 43.6° to 50.9° along the neutron beam propagation direction. The best NSECT gamma-ray detector locations for D-D and D-T NSECT are slightly different, but in both cases the detectors should be aligned in the direction from 43.6° to 50.9°. We found the characteristic peaks of 56Fe and 16O from the energy spectrum of characteristic gamma-ray. This demonstrates that NSECT has the ability to identify elements, which would be very useful in tracking the treatment process and in studying the molecular process of living body (including human-beings). This study gives a comprehensive understanding on the selection of neutron sources and the placement of gamma-ray detectors in NSECT applications.