OPTIMIZATION OF BREMSSTRAHLUNG CHARACTERISTICS FOR IRRADIATING THICK OBJECTS

Abstract

The characteristics of bremsstrahlung (BS) irradiated at different angles from a three-layer converter made of Ta, water, and Fe, the electron energy is 7.5 MeV, was investigated. It is shown that Ta thickness increasing leads to increasing of Eav – the average energy of BS, but Eav decrease with increasing BS emitted angle relative to the electron trajectory. It is shown that the depth-dose distribution of the irradiated polyethylene depends on both the incident angle on the surface and the spectral composition of BS. For double-side irradiation, the maximum object thickness depends on the BS angle interval at a fixed dose inhomogeneity DUR. The use of BS filters made of heavy materials was proposed for irradiation of materials requiring high depth-dose uniformity (small DUR values).