不同复合阳极靶轫致辐射场参数的数值模拟  

Numerical simulation of the radiation field parameters of different composite anode targets

作　　者：李进玺[1] 吴伟[1] 程引会[1] 郭景海[1] LI Jinxi;WU Wei;CHENG Yinhui;GUO Jinghai(National Key Laboratory of Intense Pulsed Radiation Simulation and Effect,Northwest Institute of Nuclear Technology,Xi´an 710024,China)

机构地区：[1]西北核技术研究所强脉冲辐射环境模拟与效应国家重点实验室,西安710024

出　　处：《辐射研究与辐射工艺学报》2023年第3期107-112,共6页Journal of Radiation Research and Radiation Processing

摘　　要：电子束辐照材料后发生轫致辐射可以产生脉冲X射线,轫致辐射产生X射线的能谱、转化效率等参数与电子束能量,靶材料及其结构相关。利用二极管的电压、电流波形计算了电子束参数,建立了复合靶蒙特卡罗粒子输运计算模型,模拟了电子和光子在不同材料中的输运规律,研究了钽和有机玻璃组成的复合阳极靶对X射线辐射场的影响,结果对于产生低能、高注量、高转化效率、低透射电子能量用复合阳极靶的设计具有指导意义。计算结果表明:复合阳极靶中有机玻璃具有软化电子能谱、衰减透射电子的作用;采用慢化电子靶比相同厚度薄靶产生的X射线能谱相对要硬;减小钽的厚度有利于减小平均光子能量,而增加钽的厚度有助于提高能量转化效率;选用有机玻璃2 cm、钽10μm的薄靶时,X射线平均能量为133.22 keV,光子能量转化效率为0.055%。Bremsstrahlung radiation can produce pulsed X-ray,and the energy spectra and conversion efficiencies of X-ray produced by such radiation are related to the electron beam energy,target material,and structure of this material.In this study,electron beam spectra were obtained from the voltage and current waveforms of diodes,and the particle transport Monte Carlo calculation model of a composite target was established.Using the resulting model,the transport laws of electrons and photons in different materials were simulated,and the influence of composite targets was studied.The results were found to be useful in the design of composite anode targets to achieve low energy,high fluence,high conversion efficiency,and low transmission electron energy.The results also revealed that an organic glass softened the electron spectrum and attenuated transmission electrons in the composite anode target.The X-ray energy spectrum produced by the same thickness of a moderated target was found to be much harder than that produced by a thin target with the same thickness.Decreasing the thickness of tantalum was deemed to be good for reducing the average photon energy,while increasing the thickness was found to be good for improving the energy conversion efficiency.When a thin target with 2 cm organic glass and 10μm tantalum was chosen,the average energy of the X-ray was 133.22 keV,and the conversion efficiency of the photon energy was 0.055%.

关 键 词：粒子输运 轫致辐射 X射线 

分 类 号：TL501[核科学技术—核技术及应用]