强激光打固体靶所致硬X射线屏蔽模拟研究  

Shielding study of hard X-rays produced by high-intensity laser interaction with solid targets

作　　者：杨博[1] 邱睿[1] 路伟[1,2] 武祯[1,3] 李春艳[1,3] 张辉[1] 李君利[1] 

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]军事医学科学院疾病预防控制所,北京100071 [3]同方威视技术股份有限公司,北京100084

出　　处：《强激光与粒子束》2017年第7期34-39,共6页High Power Laser and Particle Beams

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

摘　　要：强激光与固体靶相互作用产生的硬X射线已被证实为一种新的电离辐射源,其辐射防护问题引起国内外相关领域的广泛关注。为了便于开展这类电离辐射源的屏蔽设计,研究了强激光打靶所致硬X射线在常用屏蔽材料中的剂量衰减曲线和十值层(TVL)。利用蒙特卡罗程序FLUKA建立了强激光打靶所致硬X射线的屏蔽计算模型,开发了专门的统计程序,解决了屏蔽层之间由于粒子反散射造成的重复统计问题,使得可以通过一次模拟得到不同屏蔽厚度下的光子剂量。计算结果表明:当电子温度为0.5~10 MeV时,X射线在混凝土中的十值层从24cm到56cm不等。其中X射线的十值层会随着电子温度的增加而增加,并逐渐趋于饱和。而对于铅屏蔽,除了第一个十值层(TVL1)外,平衡十值层随电子温度的变化较小,在4.7~5.4cm范围内。另外,当电子温度较高时,探测器到屏蔽体的距离不同会使得TVL1值存在明显的差异。Previous experiments have shown that high-intensity laser interaction with a solid target can be regarded as a new ionizing radiation source. The radioprotection issue attracts a growing concern worldwide. In order to effectively control the radiological hazard from the X-ray produced by high-intensity laser interaction with solid targets, transmission curves and tenth-value layer （TVL） values in common shielding materials are studied. In this paper, a shielding calculation model was established using Monte Carlo code FLUKA. A specialized routine was developed to solve the problem of repeated scoring caused by the backscat- tering of particles. Transimitted doses were then obtained for various shielding thicknesses in a single run. The results show that for electron temperatures of 0.5-10 MeV, the TVL value in concrete increases with the electron temperature and ranges from 24 to 56 cm; In lead, except for the first TVL, the equilibrium TVL value shows less correlation with the electron temperature and ranges from 4.7-5.4 cm. In addition, for the high electron temperature, the first TVL value is significantly affected by the distance between the shielding material and the detector.

关 键 词：强激光 固体靶 X射线 屏蔽 蒙特卡罗 

分 类 号：TL77[核科学技术—辐射防护及环境保护]