单端驱动银球腔的激光能量耦合和分配  

Laser energy coupling and partitioning of silver spheral hohlraum with one laser entrance hole

作　　者：余波[1,2] 尹传盛[1] 孙传奎 侯立飞[1] 宋天明[1] 杜华冰[1] 关赞洋 张文海[1] 袁铮[1] 李朝光[1] 董云松[1] 蒋炜[1] 黄天晅[1] 蒲昱东[1] 晏骥[1] 陈忠靖[1] 杨家敏[1] 江少恩[1] Yu Bo;Yin Chuan-Sheng;Sun Chuan-Kui;Hou Li-Fei;Song Tian-Ming;Du Hua-Bing;Guan Zan-Yang;Zhang Wen-Hai;Yuan Zheng;Li Chao-Guang;Dong Yun-Song;Jiang Wei;Huang Tian-Xuan;Pu Yu-Dong;Yan Ji;Chen Zhong-Jing;Yang Jia-Min;Jiang Shao-En(Laser Fusion Research Center,China Academy of Engineering Physics,Mianyang 621900,China;Department of Modern Physics,University of Science and Technology of China,Hefei 230026,China)

机构地区：[1]中国工程物理研究院激光聚变研究中心,绵阳621900 [2]中国科学技术大学近代物理系,合肥230026

出　　处：《物理学报》2019年第23期217-223,共7页Acta Physica Sinica

摘　　要：将高功率激光注入单孔球形银黑腔,产生的高温辐射源能够驱动超声速冲击波,在实验室模拟各种天体物理现象.利用神光Ⅲ原型装置上四路3.2 kJ激光,聚焦注入F800μm、注入口F650μm的球形银腔,可以产生峰值温度为240 eV的高温辐射源,驱动剩余球壳在气体区产生超声速冲击波.实验结果显示,银腔的激光-X光转换效率为0.68,银反照率为0.83.散射光份额约为15%,超热电子份额小于1%,从注入口漏失的辐射流约占总能量的30%,从厚度5.6μm的Ag和10μm的CH球壳漏失的辐射流约占总能量的9%,约45%的能量转换为剩余球壳的动能和内能.黑腔等离子体约在950 ps开始聚心,基本不会影响1 ns脉宽激光注入.在神光Ⅲ原型装置开展的银球腔激光能量耦合和分配实验,为后续超声速冲击波实验奠定了基础.The matter can be instantaneously heated up to a high energy density state by the high power laser. When the high power laser is injected into silver spherical hohlraum, the high temperature radiation source formed in the hohlraum can drive the high velocity blast wave in the laboratory to study various astrophysical phenomena such as supernova remnants, stellar jets, etc. As the basis of laser driven blast wave experiments, the first experimental results of energy coupling and partitioning of silver spherical hohlraum with one laser entrance hole(LEH) on Shenguang Ⅲ prototype laser facility are introduced in this work. Four beams with 3.2 kJ of laser energy in a 1 ns square laser pulse from the upper hemisphere are used to heat the silver spherical hohlraum targets. The silver spherical hohlraum targets are 800 μm-diameter and 650 μm-diameter LEH, and are fabricated by electroforming silver onto an acrylic mandrel. The laser coupling and partitioning to the targets are investigated by using the optical and X-ray diagnostics. The experimental results show that the radiation temperature is beyond 240 eV, the laser-to-X-ray conversion efficiency of silver hohlraum is 0.68 and the silver albedo is 0.83. With the driving of the high temperature radiation source, most of laser energy is coupled to the residual shell, and the high velocity blast wave can be generated. The laser energy not coupled to the target is lost through scattering light, emitting hot electrons and radiating X-rays. The experimental results show that the fraction of energy lost due to the scattering light is 15%, that due to emitting the total hot electrons is less than 1%, almost 30% of the laser energy is lost from the LEH by radiating the X-ray flux,almost 9% of the laser energy leaks from the spherical shell consisting of the 5.6 μm-thick Ag layer and 10 μmthick CH layer through the X-ray radiation flux, and 45% of the laser energy is converted into the kinetic energy and internal energy of the remaining spherical shell. Therefore, more

关 键 词：球形黑腔 辐射流 激光能量耦合 激光能量分配 

分 类 号：G63[文化科学—教育学]