Field parameters and operational quantities for ICRU sphere with reference photon beams: Monte Carlo and experimental evaluation of angular dependence of dose equivalent quantities. Part 4

摘要

The present report is the last of four technical reports dealing with the characterization of photon radiation fields for the calibration of personal dosemeters. The analyses, carried out up to now on the ICRU sphere for five different x-ray reference series as stated by ISO (International Standard Organization) and by BIPM (Bureau International des Poids et Mesures), are concerned with a comprehensive study of air kerma backscatter factors for the ICRU sphere; the characterization of backscattered radiation field in terms of backscattered fluence spectrum and mean energy, with an additional study of the dependence on the incident angle; the theoretical and experimental study of the RS-1 tissue substitute material developed at the University of Gottingen; finally a study of the air kerma to directional dose equivalent conversion factors at the three depths of 0.07, 3 and 10 mm in the ICRU sphere, that are summarised in the present report. The results of the analysis in each specific case have been discussed by comparing them with the results obtained in analogous conditions in other European research laboratories and, whereas possible, with experimental data. The present work has been carried out under the CEC contract F13P-CT920064H and is connected with the activities of the EURADOS WG-4 (Numerical Dosimetry).