Investigation of simulation of cherenkov light with egs

When a charged particle moves at velocity faster than the speed of light in water, a faint radiation is produced from water. It is called Cherenkov light. This phenomenon is mostly used in study of engineering and physics. However, it is not very useful in study of medicine. Therefore, we thought whether Cherenkov light can be used in medical treatment and we carried out many experiments where we measured Cherenkov light. In this study, in order to check the accuracy of the experimental result we tried to simulate Cherenkov light with EGS. In comparison with Cherenkov photon calculated with EGS, the measured value was almost the same as it in the irradiation field, however, outside the irradiation field, a difference was found. The discrepancy between calculated and measured values was considered to be caused by the measurement deviation. Moreover, not taking account of the decrease of the light by water in simulation may also influence the difference. The Cherenkov photon calculated with EGS5 were closer to an actual measurement than those calculated with EGS4. It is thought that, by introducing Energy hinge and MS hinge, transportation of the electron in the simulation became close to transportation of an original electron, and the calculated value might approach the measured value.