Radiation Protection Design Of Sesri In Low Energy Range

Natural radiation is everywhere in the space environment and it will interact with the exterior of spacecraft,the inner parts and other creatures,causing the change of total dose radiation effect,displacement damage,single event effect and cytometaplasia.These will pose threat to the safe running of spacecraft and the health of astronauts.Therefore,it is of great importance to study the mechanism and solution of the space radiation to the spacecraft and the living body,improving the stability,reliability of the spacecraft and the safety of astronauts.Accelerator is to be used for simulating the space ion radiation environment.It is a convenient,fast and controllable experimental platform to study the mechanism of particle radiation on materials,devices and living body.In accordance with China’s documents,Harbin Institute of Technology(HIT)and China Aerospace Science and Technology Corporation will jointly build Space Environment Simulation Equipment(SESRI),with low energy range and high energy range.The design on radiation protection for low energy range is mainly introduced in this paper.A feasible radiation protection scheme,which takes into account the characteristics of the distribution of accelerator,different accelerated particles,energy,beam current density,the distribution of beam loss and secondary radiated field for the low energy range in the SESRI,is designed in this paper complying with China’s specifications and guidance.It is required to reach the optimum effect of radiation protection under the legitimate practice in this scheme.The content of this study is mainly about four parts: the calculation of radionuclide activity in low energy region,the shielding design in low energy range,the radiation dose monitoring system and safety interlocking system.The first one is used to calculate the radionuclide activity left in the target material and wall after the accelerator is shut down.The second one is designed to calculate whether the thickness of concrete of the room in low energy range complies with China’s standard criteria.The third system is aimed at monitoring the radiation dose of the running accelerator in radiation range and working range in real time,thereby checking the effectiveness of shielding and finding out the changesof radiation dose quickly when the running parameter of accelerator is changed.This system is used to provide the staff with the approximate location of the beam loss.The last system is introduced to prevent the staffs from entering the radiation range and avoid accidental radiation exposure when the accelerator is running.Finally,other auxiliary ancillary safety measures are adopted to reduce the radiation dose for the staffs and the public.