Study Of The Radiation Field And The Maze Optimization For An Electronaccelerator-based Irradiator

In recent years,accelerator technology has made great progress and is widely used in tumor therapy,radioisotope production,material irradiation cross-linking,food and medical disinfection and sterilization and so on,creating great social and economic benefits.Due to its safe and controllable,effective,environmental protection and other advantages,accelerator irradiation device has gradually become the mainstream equipment of radiation processing industry.However,accelerator irradiation device radiation field is complex,requiring special consideration about shielding design problems.The goal of this work was to study the design of shielding around electronic radiation accelerator.In this project,the radiation field around the cable transmission pipeline of the electronic accelerator was studied.First,the Monte Carlo simulation was used to optimize the factors that influenced the dose rate inside of the pipe and outside of the shielding wall.After the improvement,the radiation doserate was found to have significantly reduced.And the attenuation curve of 0-3MeV single energy photon in the pipeline was calculated according to these optimization parameters and the characteristics of energy spectrum of 1-3MeV electronic targeting were obtained.These data can be used to estimate the dose rate attenuation in buried pipe of an electrpn accelerator that has different energies and shield designs.The estimation results are found to be in good agreement with the direct electron transport calculations,and the estimated values are also found to be consistent with the overall trend of the measured data,showing that the estimation method can be useful as a practical reference.In this thesis,the problem of designing the thickness of medial wall of 2.5MeV"L" type labyrinth was analyzed.Through the simulation analysis of the maze doserate and the theoretical calculation,the thickness of the inner wall of the labyrinth is set to be 60-80 cm in the first maze,in the second maze is set to be 100-120 cm or so.In this thesis,the theoretical calculation and actual measurement of the radiation field around a 2.5MeV irradiation cable type accelerator are described.The theoretical calculation results were compared with the measured data,and it was found that the difference between the two results were very small.This thesis also compared the measured doserate data in the pipeline with those from Monte Carlo calculation and the theoretical calculation data.Finally,2.5 MeV electron accelerator maze radiation field was simulated and it was found that the thickness of the inner wall in the first maze should be set to be 60-80 cm,in the second maze should be set to be 100-120 cm.The study of radiation field around buried pipe for electronic irradiation device is expected to provide usful reference for related shielding design and dose evaluation involving electron irradiators.