Computer Simulation Of Proton Shielding And Radiation Damage In CdZnTe

Irradiation is the process by which a object interacts with radiation,causing structural and compositional change.Irradiation damage,as its name suggests,is the damage to the object caused by radiation while interacting with the object.CdZnTe is playing a main role in the missions of space exploration as a kind of rising detector material.The space environment is filled with electrons,protons and heavy ions from the planet radiation belts?solar cosmic rays,galactic cosmic rays and other particle sources,the irradiation damage caused by which is one of the important reasons for electronic device failure.As an important part of aviation safety issues,radiation shielding plays a role in the protection of spacecraft operation and,more crucially,in the protection of astronauts' lives.Proton is one of the main components of the charged particles in the space radiation environment,the radiation damage caused by which results in electronic device failure in spacecrafts,as well as threatens the health of the astronauts seriously.Therefor the irradiation damage for protons in CdZnTe and the shielding of space protons are selected and studied in this paper.MCNP is a Monte Carlo N-Particle code that can be used for neutron,proton,and electron transport with the Monte Carlo method.SRIM is a software which simulate the interaction between ions beam and matter with Monte Carlo method.In this paper MCNPX code is used to simulate protons shielding effectiveness of different materials,and SRIM code is used to simulate irradiation damage for protons in CdZnTe,which purposes to study shielding of protons and irradiation damage for protons in CdZnTe and obtain the reference data for related applies and experiments.Aluminum,silicon and iron are used as shielding materials and SPE spectrum is used as incident spectrum in MCNP simulation,results of which show the proton transmission spectrum after aluminum?silicon or iron shield,According to which it is found while the thickness of the shield increases,the low energy proton fluence is reduced,the transmission rates are reduced and the average energy of the transmission protons is increased;results from the simulation show that iron has the highest proton shielding ability in these three kind of materials.Before SRIM code is used to for simulation the SRIM-calculated nuclear stopping power?electronic stopping power and proton range in aluminum are compared with the data from NIST,the results of which show that the SRIM-calculted data is credible.Use SRIM code to simulate the radiation damage for protons in CdZnTe,ionization loss and displacement loss for protons in CdZnTe is calculated firstly,the results of which show that ionization loss is much greater than displacement loss;Then radiation damage caused by protons at different incident angles and energies is calculated in CdZnTe,the results of calculation show that the number of vacancies introduced by proton radiation in CdZnTe increases with increasing energy of protons,and the number of vacancies decreases quickly while the incident angle of protons increases more than 60°;the radiation damage for protons in CdZnTe is compared with silicon and diamond semi-conductor material,the results of that show CdZnTe has the lowest radiation resistance;At last sputtering yield for protons at different energies and incident angles in CdZnTe target of different thicknesses is calculated,the results show that sputtering yield is much lower than the number of vacancies produced by protons in CdZnTe,sputtering yield increases first and then decreases with increasing energy of protons,sputtering yield increase with increasing incident angle of protons,sputtering yield increases totally with increasing thickness of CdZnTe target.