Improvements in the MCNPX-PoliMi Post-processing Code for Determining Detector Response

摘要

Monte Carlo simulations are commonly used tools for analyzing radiation transport problems related to nuclear material detection and characterization. However, standard tallies from MCNP and MCNPX do not provide sufficient information because the underlying physics of detector response is complex and can depend on multiple individual collision events. For these types of applications, MCNPX-PoliMi is a better suited Monte Carlo code because it provides detailed event-by-event particle tracking that is essential for determining detector response. In order to determine detector response information from the MCNPX-PoliMi results, a post-processing code is required. In the past, such codes have been created by individuals for their specific applications. However, a generalized post processor, MPPost, has been written in Fortran 90 which utilizes the detailed information provided by MCNPX-PoliMi to accurately generate detector response. It is capable of simulating detector response for a variety of detector types including organic scintillators, inorganic scintillators, He-3 detectors, and others. MPPost takes into account the effect of individual collision events in a detector while implementing energy and time resolution in order to provide an accurate portrayal of the information that is retrievable from detectors. Additionally, it has modules that are capable of simulating the output from advanced detector configurations such as time-of-flight, cross-correlation, and multiplicity measurements. In the full paper, we will detail the features of the currently available version of MPPost and provide some validation with measured data.