质子在氮化镓中产生位移损伤的Geant4模拟

摘要

材料受到辐照时产生的位移损伤会导致其微观结构发生变化,从而使其某些使用性能退化,影响其使用效率,减短其使用寿命.利用Geant4模拟了质子在氮化镓中的输运过程,计算了1、10、100、500 MeV能量质子入射氮化镓材料产生的初级撞出原子的种类、能量信息及离位原子数.获得了10 MeV质子产生的位移缺陷分布;计算了4种能量质子入射氮化镓材料产生的非电离能量损失(NIEL);研究了质子产生位移损伤过程的影响要素.研究发现,入射质子能量对其在材料中产生的初级撞出原子的种类、能量、离位原子数等信息有着非常大的影响;单位厚度所沉积NIEL随着入射质子能量的增大而减小;10 MeV质子入射氮化镓所产生的离位原子数随入射深度的增加而增加,但在超出其射程范围以外有一巨大回落;能量并不是影响质子与氮化镓靶材料相互作用的唯一因素.%The efficiency of employment will be influenced and the life span of use will be reduced when the material is irradiated and the displacement damage which will change its microstructure and degenerate its character of service is produced within the material .The transport of proton in GaN was simulated with Geant 4 .The information of the type and the energy of the primary knock-on atoms (PKA ) created in GaN and the number of displacement damage were calculated with protons for energy of 1 ,10 , 100 and 500 MeV . The distribution of displacement damage of 10 MeV proton was calculated .The non-ionization energy loss (NIEL) was studied and calculated for these four kinds of energy protons irradiating GaN and the factors impacting the production of displacement damage were deliberated .The information of the type and the energy of the PKA created in GaN and the number of displacement damage are influenced heavily by the energy of the irradiating proton .The NIEL deposited per thickness of the materi-al decreases along with the increase of the energy of the irradiating proton .The number of the dislocation atoms increases along with the penetration depth within the projected range but will fall tremendously and further reduce when it is beyond the projected range with 10 MeV proton irradiating GaN .The energy of the proton is not the only factor which can influence the interaction between the proton and the GaN .