nvestigation of the electron energy span spectrum on absorbed dose in tissue

Electron-therapy is a therapeutic method for brain tumors that in this method, absorption dose has a high energy dependency. The purpose of this study is to determine the dependency of energy doses. To do this, first of all, by using the MCNP code, a simple whole phantom has simulated according to existing standards , here the phantom has called MAS. Here we consider two textures for Phantom MAS, a bone structure and a soft texture made of water.Then we have designed an electron source as a beam or a disk that is located at a distance of 5 cm from the patient’s head with an energy of 10MeV, at a distance of 50 cm, so we have examined the absorbed dose and healthy texture and then we have changed the energy of the spring to 5 MeV and have examined it again.The nonlinear logarithmic diagram, indicates that less energy is absorbed in lower energy (5 MeV), of course this also depends on the size and location of the tumor, but the positive point is that the texture or structure still remains more healthy, in other words In electron beam with (5 MeV) of energy, the healthy texture is damaged less than (10 MeV) of energy. Also, the linear diagram indicates that the surface tumor with (5 MeV) of energy is cured better.