Beta-Ray Dose Assessment from Skin Contamination Using a Point Kernel Method

Abstract

In this study, a point kernel method to calculate beta-ray dose rate from skin contamination was introduced. The beta-ray doses rates were computed by performing numerical integration of the radial dose distribution around an isotropic point source of monoenergetic electrons called as point kernel. In this study, in-house code, based on MATLAB version 7.0.4 was developed to perform a numerical integration. The code generated dose distributions for beta-ray emitters from interpolated point kernel, and beta-ray dose rates from skin contamination were calculated by numerical integration. Generated dose distributions for selected beta-ray emitters agreed with those calculated by Cross et al within 20%, except at a longer distance where there are differences up to more than 100%. For a point source, calculated beta-ray doses were agreed well with those derived from Monte Carlo simulation. For a disk source, the differences were up to 17% at a deep region. Point kernel method underestimated beta-ray doses than Monte Carlo simulation. The code will be improved to deal with a three-dimensional source, shielding by cover material, air gap and contribution of photon to skin dose. For the sake of user’s convenience, the code will be equipped with graphic user interface.