MCNP能峰展宽的NaI探测效率.doc

毕业设计（论文） 题 目 MCNP能峰展宽的NaI探测效率 英文题 MCNP Peak Broadening Simulation of the Detection Efficiency of NaI 学生姓名： 专 业：核工程与核技术 班 级： 指导教师： 二零一一年六月摘 要 本论文主要通过对伽马射线与物质的相互作用、NaI探测器的工作原理、蒙特卡罗方法及MCNP模拟程序的详细介绍，使本论文有了充分的理论支撑，在此基础上对NaI探测器进行合理建模。用光子和电子藕合输运MC程序的电子脉冲计数类型的能峰展宽模拟计算了NaI（Tl）探测器的γ能谱，与来自参考文献的实验结果符合较好，显示了通过能峰展宽的电子脉冲计数在能谱模拟方面有很大的优越性。通过改变能峰高斯展宽系数大小可以用于模拟任意分辨率NaI（Tl）晶体探测γ射线的能谱。MCNP程序提供能峰高斯展宽的模拟方法也可以用于计算NaI（Tl）晶体对γ射线的探测效率等方面研究，对实验结果的可靠性和准确性提供依据。然后利用MCNP计算了NaI（Tl）对不同能量γ射线的探测效率(峰总比)，结果与参考文献的实验结果一致，验证了这种计算方法用于模拟NaI（Tl），对能谱的探侧效率是可行的。 关健词: NaI；MCNP能峰展宽；γ射线； 探测效率； 峰总比 Abstract The γ-ray interaction with matter, the working principle of NaI detector , the monte carlo method and the simulation program of MCNP have been described detailedly in this paper, which supplied ample theories for the research work. On basis of it, NaI detector has been modeled reasonablely. In the article, Monte Carlo method for Photon-Electrons coupling transport was used to calculate the γ spectra of NaI(Tl) detector by peak broadening of electronic pulse height tally，which was completely fit with the experiment date of reference documents. It showed that the peak pulses have great advantages of simulation by counting the spectrum stretcher of electronic. The detection of NaI (Tl) crystal gamma-ray spectrometry would be simulated randomly through changing the size of Gaussian detuning coefficient. The simulation method of the peak of gaussian which MCNP program has provided not only was used to calculate NaI (Tl) crystal gamma-ray detection efficiency and so on, but also provided