Simulation of a proton beam facility in the TOPAS MC software package

The aim of this work is to simulate the formation system of therapeutic proton beams at the accelerator of the Institute of Nuclear Research, Russian Academy of Sciences, using the TOPAS MC software package and to calculate, on this basis, the characteristics of irradiation of biological objects. As such characteristics, the dependence of the absorbed dose and linear energy transfer (LET) on the proton range in water and the effective dose of irradiation of HT-29 and HCT-116 cell lines used in real experiments are considered. Also, the uniformity of irradiation with a high dose rate of the studied biological objects was evaluated during the operation of the radiation unit in FLASH-therapy modes. The research is aimed at preparing and conducting radiobiological experiments with proton beams with a record dose rate.