激光驱动纳米须靶产生X射线转换效率研究（英文）  

Multi-ke V X-ray conversion efficiencies of laser-irradiated nano-velvet Cu targets

作　　者：王洪建[1,2] 阳庆国[2] 叶雁[2] 彭其先[2] 粟敬钦[3] 李泽仁[2] 

机构地区：[1]重庆工商大学制造装备机构设计与控制重点实验室,重庆400067 [2]中国工程物理研究院流体物理研究所,四川绵阳621900 [3]中国工程物理研究院激光聚变研究中心,四川绵阳621900

出　　处：《红外与激光工程》2016年第11期118-123,共6页Infrared and Laser Engineering

基　　金：国家高技术研究发展计划;强场激光物理国家重点实验室(中国科学院上海光学精密机械研究所)开放项目;重庆市教委科学技术研究项目(KJ120710,KJ1600633);国家智能制造服务国际科技合作基地项目(1456043)

摘　　要：在研究超强激光与物质相互作用中,研究的焦点通常需要高质量的光源来诊断动态物质的结构。为了获得高亮度、准单能和高对比度X射线光源,改变物质及其结构来增强吸收激光能量和提高激光X射线的转换效率。利用多孔结构原理,设计了直径为200 nm、密度为铜70%的纳米铜靶。在中国工程物理研究院激光聚变研究中心星光-Ⅲ激光装置上进行实验,作用于靶表面的飞秒激光强度大于2×10^(18)Wcm^(-2),利用单光子计数型X射线CCD测量了Ka特征X射线,获得的Ka光子峰值产额达到了3.6×10~8photons·sr^(-1)·s^(-1),X射线最大转换效率达到0.008 68%,是平面铜靶转换效率的1.2倍。实验表明纳米须结构能够有效增强飞秒激光的能量吸收,增强了超强激光转换成电子和X射线的转换效率。In the study of the interaction between the ultra intense laser and material, it is often focused on the needed quality light source to diagnose the dynamic material structure. In order to obtain a high- quality X-ray source featured with high luminance, quasi-monchromaticity and good contrast, the changes in the structure of matters and materials are often investigated to enhance the absorbability of the ultra intense laser energy and improve the conversion efficiency from the laser radiation to the X-ray. Based on a porous structure principle, the velvet Cu targets were developed with a diameter of 200 nm and the density ratio of 70% solids of Cu. Experiments had been carded out on XG-II1 laser facility in Laser Fusion Research Center, China Academy of Engineering Physics. The laser intensities in these experiments ranged from 4.3 J to 6 J on the target surface. A single-photon- counting X-ray CCD was used to measure Ka spectrum of the X-ray source. The X-ray yield was counted to achieve Ka peak photons of 3.6×10^8 photons .sr^-1 .s^-1 from femtosecond irradiated velvet Cu target. The Ka X-ray conversion efficiency （CE） reaches the maximum value 0.008 68%. Compared with the average CE of the pressed foil Cu target, that of velvet Cu increased 1.2 times. The experimental data showed that the velvet structure can effectively enhance the energy absorption of femtosecond laser and improve the conversion efficiency from the ultra-intense laser to the hot electron and X-ray.

关 键 词：激光与物质相互作用 纳米须 转换效率 X射线源 

分 类 号：TN248.1[电子电信—物理电子学]