DNA Radiation Environments Program - Spring 1990 2-meter box experiments and analyses

Abstract

This report summarizes the Spring 1990 2-m Box Experiments performed at the Army Pulse Radiation Facility (APRF) at Aberdeen Proving Ground, Maryland. These studies were sponsored by the Defense Nuclear Agency (DNA) under the Radiation Environments Program to obtain measured data for benchmarking the Adjoint Monte Carlo Code System, MASH, Version 1.0. MASH was developed as the Department of Defense and NATO code system for calculating neutron and gamma-ray radiation fields and shielding protection factors for armored vehicles and military structures against nuclear weapon radiation. In the experiments, neutron and gamma-ray dose and reduction factors were measured in the free-field and as a function of position on an anthropomorphic phantom that was placed outside and inside the steel-walled 2-m box. The data were acquired at a distance of 400-m from the APRF reactor. The measurements were performed by APRF, Bubble Technology Industries, the Defence Research Establishment Ottawa, Establishment Technique Central de l'Armement, and Harry Diamond Laboratory. Calculations were carried out by the Oak Ridge National Laboratory and Science Applications International Corporation. The purpose of these experiments was to measure the neutron and gamma-ray dose as a function of detector location on the phantom for cases when the phantom was standing in the free-field and inside of the box. Neutron measurements were made using a BD-IOOR bubble detector and gamma-ray measurements were made using thermoluminescent detectors (TLD). Calculated and measured data were compared in terms of the C/M ratio. DNA mandated that C/M values of {plus minus}20% define the acceptable limits for the comparison of the dose and reduction factor data and for qualifying the MASH code in replicating integral parameters.