PDF《神光 -Ⅲ 原型高功率激光装置电磁脉冲辐射》

第14 卷第6期太赫兹科学与电子信息学报 Vo1.

14,No.6

2016 年12 月Journal of Terahertz Science and Electronic Information Technology Dec.,2016 文章编号:2095-4980(2016)06-0905-05 神光-Ⅲ原型高功率激光装置电磁脉冲辐射 杨为明

1 ,王传珂

1 ,易涛1* ,李廷帅

2 ,高崇信 1,2 , 王锐2,张 健1,王保清 1,2 ,刘慎业

1 ,丁永坤

1 ,江少恩

1 (1.中国工程物理研究院 激光聚变研究中心,四川 绵阳 621999;

2.电子科技大学 能源科学与工程学院,四川 成都 611731) 摘要:实验测量了神光-III 原型装置上脉冲强激光与金属靶相互作用产生的电脉冲辐射, 电脉冲峰值梯度为

3 kV/m,频谱范围大约在

50 MHz?2 GHz,在160 MHz 等处有明显的特征峰, 信号持续时间大约

60 ns.本文研究表明电偶极辐射是打靶过程产生电磁脉冲信号的来源之一,由 理论模型计算得到频率为

160 MHz 的特征峰,并计算出探测点电场脉冲峰值梯度约为

2 kV/m,辐 射总功率约

10 5 W,能量转换率约

10 -6 ,辐射功率近似正比于激光能量的 4/3 次方,可见激光能量 越大,功率密度越高,电脉冲的辐射强度越大.大型激光装置上的激光与靶作用产生的电磁脉冲 测量,对大型激光装置产生的电磁辐射的防护有重要指导作用,在等离子体诊断等领域也有潜在 应用价值. 关键词:激光等离子体相互作用;

电磁脉冲;

天线;

偶极辐射 中图分类号:TN73;

O536 文献标志码:A doi:10.11805/TKYDA201606.0905 Investigation of electromagnetic pulse emission from Shenguang high power laser facilities YANG Weiming

1 ,WANG Chuanke

1 ,YI Tao

1 ,LI Tingshuai2 ,GAO Chongxin1,2 ,WANG Rui2 ,ZHANG Jian1 , WANG Baoqing1,2 ,LIU Shenye1 ,DING Yongkun1 ,JIANG Shaoen1 (1.Research Center of Laser Fusion,China Academy of Engineering Physics,Mianyang Sichuan 621999,China;

2.School of Energy Science and Engineering,University of Electronic Science and Technology of China,Chengdu Sichuan 611731,China) Abstract:Electromagnetic pulse emission of Shenguang-III prototype laser facilities from pulse- laser-irradiated metallic target is evaluated by using B-dot. An electric signal lasting for about

60 ns is detected in the experiment, with radiated field up to

3 kV/m and frequency bins for 0.1 GHz-2 GHz which has an obvious peak at

160 MHz. The results demonstrate that the model of dipole radiation is one of the major mechanisms of electromagnetic pulse emission from laser-target interaction. The dipole radiation model can produce about

10 5 W,

160 MHz central frequency electromagnetic pulse with an energy conversion efficiency of

10 -6 according to the calculation, and the electric field of antenna position is about

2 kV/m. This experiment evaluates the electromagnetic pulse emission from pulse-laser-irradiated metallic target on Shenguang-III prototype laser facilities, which is of great significance for shielding electromagnetic disturbance of diagnostics on large laser facilities. Moreover, investigation of electromagnetic pulse emission may have many potential applications. Keywords:laser-target interaction;

electromagnetic pulse;

antenna;

dipole radiation 近年来,强激光与固体物质相互作用的研究已成为科学研究的热点.强激光与固体靶相互作用过程中会产 生丰富的物理现象,如电磁辐射、粒子发射等,这在惯性约束聚变(Inertial Confinement Fusion,ICF)[1?2] 、激光 等离子体基础上的新辐射源(THz,X-ray)[3?4] 以及高能量粒子(电子、离子)加速器[5?7] 中都有着广泛的应用前景. 收稿日期:2015-07-23;