Monte Carlo based formula for radiation shielding assessment in the forward direction

Abstract

Monte Carlo simulations of 800-MeV proton beam spills in common shielding materials show that neutron dose equivalent rates in the forward direction can be characterized by a Moyer Model-like formula. Particle transport codes were used to determine the neutron flux at depths up to 6 meters and for production angles from 0/spl deg/ to 30/spl deg/ for primary proton-beam spills on cylindrical beam stops. The flux was then converted to dose equivalent rate as a function of depth and angle. The results for three common shielding materials were combined and the resulting fitted formula provides a quick method for estimating the dose equivalent rates and shielding effectiveness outside thick shielding at forward angles.<>