Modeling of the Characteristics of Electron Beams and Generated Photon Fluxes on the M-30 Microtron

Ensuring optimization of the radiation treatment process of experimental samples at electron accelerators and effective prediction of the results of the interaction of electron beams with irradiation objects requires the most accurate information about the characteristics of the beams. The initial (primary) characteristics of accelerator electron beams during transportation to irradiation objects will change due to their interaction with the external environment (air). Thus, secondary particles are also generated - bremsstrahlung photons, which also interact with samples. The paper presents the results of studies on modeling the influence of air layers on the change in the initial characteristics of electron beams during their transportation to irradiation objects and on the parameters of the generated bremsstrahlung photon fluxes in the plane of placement of experimental samples. The studies used the Monte Carlo code ‒ GEANT4. The modeling was carried out for the electron accelerator of the IEP NAS of Ukraine - the M-30 microtron, taking into account its technical parameters. The results of studies of the characteristics (energy spectrum, their integral values, transverse distributions in the 10×10 cm plane) of the electron beam and secondary photons at the output of the electron accelerator are presented. The influence of the thicknesses of the air layers (0.1÷500 cm) between the electron output unit and the potential plane (100×100 cm) of the placement of experimental samples for irradiation on the characteristics of the primary electron beams and generated bremsstrahlung photons (for the energy range of 6÷20 MeV) is studied.