The Transmission Of Medical Heavy Ions Beam Was Simulated By Geant4

This work was prepared the transport pross in the material of the particles with the Mote Carlo simulation procedures using Geant4 toolkit.And the Linear Energy Transfer density of photon,proton and ¹²C ions,¹⁶O ions was calculated in tissue-like material. Through the visualization of the simulation program the each particle track and the physical process can be clearly observed.Based on these physical characteristics of the particles we study the application in medicine,the main works are as follows:First,we introduce the development of radiation therapy as well as the present state of heavy ions therapy in China.Then it mainly studies the theory of radiation physics and radiation biology.The idea of process of programming as well as data-processing work was one of an important aspect in the content.In this part we discussed the overall structure of the designed procedures,the structural modal of the human body and the realization of particles source.We study the application of the protons and ¹²C ions in medicine by using the visualization of the process to observe the track and characteristics of the ions transporting procedure.Particles with different energy and different kinds of particles with different energy have their own characteristics in the transporting process. According to these different physical characteristics,we could study their difference in the applications of medicine.This work focused on the contribution from the part of the fragments of the ¹²C ions to the total dose in the transporting process and studied the mechanisms of the energy loss of the secondary neutrons in the whole process and its impact on radiotherapy.