Bremsstrahlung Photons in KIRAMS Electron Microbeam Cell-Irradiation System

The KIRAMS electron microbeam Cell-Irradiation System (KEMCI) provides a well-defined electron beam for single-cell irradiation. The system has been devoted to the low-dose radiation effect studies for the cultured cells. Especially, the bystander effect, which is one of the main fruits of high-LET radiation microbeam study, is also the crucial issue in the electron microbeam study although its limitations such as large angle scattering and low linear energy transfer in the medium existing. The radiation dose due to the electrons and their secondary radiations like Bremsstrahlung should be estimated for the radiobiological interpretation. In this paper, the influence of the photons generated in the peripherals including the pinhole frame on the dose profile around the target cell is simulated using Monte Carlo method