航空γ能谱低能谱段与地质体岩性相关性模拟

摘要

为了研究航空γ能谱低能谱段与地质体岩性的相关关系,基于蒙特卡罗方法,应用MCNP5程序模拟天然γ射线穿过不同地质体(辉绿岩、砂岩、白云岩、玄武岩、黑云母花岗岩、花岗斑岩),且经过100 m高度空气介质散射后γ能谱的变化.模拟结果显示:地质体的有效原子序数对航空γ能谱低能谱段能量＜ 150 keV的能量段影响较大,低能散射峰峰位、不同能量段峰面积之比与原子序数均有一定的相关性.地质体的密度不会改变低能段散射峰峰位.%Hie paper simulated the changes of low energy airborne gamma - ray spectrometry after gamma photons eitted by natural source through mediums,such as diabase、sandstone、doloinite、basah、biotite granite 、granite porphyry and so on. The result showed that the effective atomic number of medium has great influence on low energy spectrum( < 150 keV). The position of peak ,as well as the peak area ratio of different energy,has a certain relationship with effective atomic number of medium, the Medium density has little influence on peak situation of low energy spectrum.