Models of photonic sources of radiological facilities for use in Monte Carlo irradiation dose calculations

The purpose of the present work is to develop a method for calculating the characteristics of photon bremsstrahlung of a virtual source or developing a model of a source for use in Monte Carlo calculations. Two methods for reconstructing the initial spectrum of the bremsstrahlung of radiotherapeutic facilities are proposed. One is based on analysis of the phase space of particles under the collimator plane, and the other is based on analysis of the experimental dose distribution. The proposed methods for reconstructing the effective spectrum satisfactorily describe the real particle spectrum of radiotherapeutic facilities. The proof for this assertion is a simulated dose distribution, which agrees with the experimental data.