Neutron detection time distribution is an important factor for the dead-time correction for moderator type neutron detectors used in pulsed radiation fields. Measurements of the neutron detection time distributions of multisphere LiI detectors (2Ó, 3Ó, 5Ó, 8Ó, 10Ó and 12Ó in diameter) and AB remmeter were made inside a ANL 20-MeV electron Linac room. Calculations of the neutron detection time d...

Accuracy of treatment planning systems may significantly influence the efficacy of brachytherapy. The purpose of this work is a detailed, varied and independent evaluation of an in-house brachytherapy treatment planning software called STPS. Operational accuracy of STPS was investigated. Geometric tests were performed to validate entry and reconstruction of positional information from scanned o...

Neutron transport through a special case stochastic mixture is examined, in which spheres of constant radius are uniformly mixed in a matrix material. A Monte Carlo algorithm previously proposed and examined in 2-D has been implemented in a test version of MCNP. The Limited Chord Length Sampling (LCLS) technique provides a means for modeling a binary stochastic mixture as a cell in MCNP. When i...

Commercially available radiochromic films are primarily designed for clinical X-ray dosimetry. These films change color upon exposures to radiation as a result of solid-state polymerization (SSP). Built on a previous model developed for SSP upon exposures to ultraviolet (UV) radiation, a new model was developed in the present work for X-ray-induced coloration in Gafchromic EBT3 films. Monte Car...

Commercially there is a growing interest in applications of neutrons. Currently the majority of neutron sources are based at research institutions from either reactors or spallation sources. Smaller portable sources contain either fissile isotope or sealed fusors are available, although they either use or produce tritium, or other long lived decay products. As an alternative to the large facili...

A great number of radioactive cesium were released into sea water after Fukushima Accident. We modified the Regional Oceanic Modelling System (ROMS) to reproduce the dispersion process of the cesium in oceans. The simulated water concentration was in good agreement with observation. In order to explore the nuclear impact of these contaminant in ocean, we established a food web model to calculat...