PERSONNEL DOSIMETER ANGULAR RESPONSE PROPERTIES AND THE ADOPTION OF ICRU REPORT-39 QUANTITIES

A new set of quantities for applied health physics has been proposed by the International Commission on Radiation Units and Measurements with the recommendation that they be based on the ICRU sphere phantom model. The quantities proposed for individual monitoring, which incorporate specific nonisotropic angular response properties, are designed to provide an estimate of an individual's H(E) and are the individual dose equivalent, both superficial [effective dose equivalent, H(s)(d))] and penetrating [penetrating effective dose equivalent, H(p)(d)]. Our study of typical dosimeter wearing practices indicated that there were no consistent locations on or angular orientations of dosimeters to the wearer's body. This demonstrated a difficulty in the practical implementation of personnel dosimeters having an angular response approximating H(p)(d) for a specifically selected point on a body, rather than the traditionally assumed design goal of dosimeters using an isotropic response. It also indicated that it is important for dosimeters using a H(p)(d) response to have an adequate means of mounting the dosimeter to assure the required dosimeter orientation to the body under a wide range of conditions of application. Questions remain as to how the specified ICRU sphere reference phantom (or an approximation thereof) can be used as a practical testing laboratory phantom.