双脉冲激光锡等离子体数值模拟研究  

Numerical Simulation of Dual-Pulse Laser Produced Tin Plasma

作　　者：陈柳安 吴涛[1] 王新兵 马修泉 陆培祥 CHEN Liuan;WU Tao;WANG Xinbing;MA Xiuquan;LU Peixiang(School of Optical Information and Energy Engineering,Wuhan Institute of Technology,Hubei Key Laboratory of Optical In-formation and Pattern Recognition(Wuhan Institute of Technology),Wuhan 430205,China;Wuhan National Laboratory for Optoelectronics,Huazhong University of Science and Technology,Wuhan 430074,China;Guangdong Intelligent Robots Institute,Dongguan 523808,China)

机构地区：[1]武汉工程大学光信息与能源工程学院,湖北省光信息与模式识别重点实验室,湖北武汉430205 [2]华中科技大学武汉光电国家研究中心,湖北武汉430074 [3]广东省智能机器人研究院,广东东莞523808

出　　处：《武汉工程大学学报》2023年第4期442-449,共8页Journal of Wuhan Institute of Technology

基　　金：广东省重大基础与应用基础研究项目(2019B030302003)。

摘　　要：为了提高13.5 nm激光锡等离子体光源的极紫外辐射转换效率,双脉冲技术是一种行之有效的方法,通过数值模拟获得基于双脉冲激光驱动的液滴锡靶等离子体参数的演化行为与辐射机理对设计优化实验方案具有重要意义。利用Flash代码数值模拟研究了双脉冲激光辐照液滴锡靶产生的等离子体在不同波长组合及延时情形下的演化行为,研究结果表明:在双脉冲的时间延时间隔恒定时,主脉冲激光能量的增加会提高等离子体羽辉膨胀速度,导致更高的等离子体温度。随着CO_(2)激光与光纤激光脉冲之间延时的增加,靶材表面等离子体的峰值电子密度逐渐减少,渐趋于临界电子密度,等离子体冕区的电子温度呈下降趋势,且由等温膨胀转换为绝热膨胀的时间间隔增加。CO_(2)激光与光纤激光组合驱动的锡等离子体具有更加合适的极紫外辐射等离子体温度,具有获得较高极紫外辐射转换效率的潜力。To improve the conversion efficiency of 13.5 nm laser tin plasma light source in the extreme ultraviolet radiation,the double-pulse technique is a proved effective means,and it is important to obtain the evolutionary behavior and radiation mechanism of the plasma parameters of the tin droplet target based on the double-pulse laser drive through numerical simulations to design the optimal experimental scheme.In this paper,the numerical simulations of the evolutionary behaviors of the plasma generated by double-pulse laser irradiation of a tin droplet target at different wavelength combinations and delay time were investigated using Flash code.The results show that the increase of the main pulse laser energy increases the plasma plume expansion velocities and leads to higher plasma temperatures when the time delay intervals of the double pulses are constant.With the increase of delay time between CO_(2) laser and fiber laser pulses,the peak electron densities of the plasma on the target surface gradually decrease and tend to the critical electron density,while the electron temperatures in the plasma corona region tend to decrease,and the time intervals for conversion from isothermal to adiabatic expansion increase.The tin plasma driven by the combination of CO_(2) laser and fiber laser has a more suitable extreme ultraviolet radiation plasma temperature and has the potential to obtain a higher conversion efficiency of extreme ultraviolet radiation.

关 键 词：激光产生等离子体 光纤激光 CO_(2)激光 液滴锡靶 

分 类 号：O532[理学—等离子体物理]