强激光与固体靶相互作用所致硬X射线剂量和能谱的实验测量  

X-ray Dose and Spectrum Measurement in Intense Laser-irradiated Solid Target

作　　者：杨博[1] 邱睿[1] 李君利[1] 于明海 路伟[1,3] 矫金龙 张辉[1] 武祯 李春艳 闫永宏[2] 周维民[2] 马弛[2] 

机构地区：[1]清华大学工程物理系粒子技术与辐射成像教育部重点实验室,高能辐射成像重点学科实验室,北京100084 [2]中国工程物理研究院激光聚变研究中心,四川绵阳621900 [3]军事医学科学院疾病预防控制所,北京100071 [4]同方威视技术股份有限公司,北京100084

出　　处：《原子能科学技术》2017年第4期732-739,共8页Atomic Energy Science and Technology

基　　金：国家自然科学基金资助项目(11275110,11375103);国家科技重大专项子课题资助项目(2013ZX06002001-007)

摘　　要：为了研究强激光与固体靶相互作用产生的电离辐射危害,本文在星光Ⅲ300TW强激光装置上开展了一系列激光打靶实验。实验使用的激光功率密度为5×10^(18)~4×10^(19)W/cm^2,激光脉冲能量为60~153J,靶为直径1mm、厚度1mm的Ta圆柱,本文分别对X射线剂量、X射线能谱和超热电子能谱进行了测量。实验结果表明,测量到的单发最大X射线剂量约为16.8mSv,靠近激光传播方向(0°),距靶50cm处;激光0°方向的X射线剂量随激光功率密度的增加而显著增加,激光90°方向的X射线剂量随激光功率密度的变化相对较小;测量到的X射线能谱可大致用含有两个X射线温度的指数分布函数描述,其中0°方向测量到的X射线温度为0.4~1.15 MeV,90°方向测量到的X射线温度为0.25~0.54 MeV;实测超热电子温度与Wilks定标率符合较好。To study the radiological hazards from a series of laser-target experiments were carried Intense out on laser-solid target interactions, the XG Ⅲ 300 TW laser sys-tems. The laser intensity is 5×10^18-4×10^19W/cm^2 and the laser energy is 60-153 J. The target is Ta cylinder with thickness of 1 mm and diameter of 1 mrn. The X-ray dose, X-ray spectrum, and hot electron spectrum were measured respectively. The results show that the X-ray dose up to 16.8 mSv is measured at 50 cm close to the laser propagation direction （0°）. The X-ray dose at 0° increases significantly with the laser intensity, while the X-ray dose at 90° is less correlated to the laser intensity. The meas- ured X-ray spectrum can be approximately described as an exponential distribution with two X-ray temperatures ranged from 0.4 to 1.15 MeV at 0° and from 0.25 to 0.54 MeV at 90°. The measured hot electron temperature is consistent with the predicted electron temperature by Wilks law.

关 键 词：强激光 固体靶 超热电子 X射线剂量 X射线能谱 

分 类 号：TL81[核科学技术—核技术及应用]