高电荷态锡离子极真空紫外波段自吸收光谱轮廓的细致分析  

Detailed analysis of self-absorption profiles of highly-charged tin ions in the EUV region

作　　者：苏茂根 敏琦 曹世权 孙对兄 董晨钟 

机构地区：[1]西北师范大学物理与电子工程学院,甘肃省原子分子物理与功能材料重点实验室,兰州730070

出　　处：《中国科学：物理学、力学、天文学》2017年第12期54-61,共8页Scientia Sinica Physica,Mechanica & Astronomica

基　　金：国家自然科学基金(编号:11064012,11364037,11274254,U1332206,11564037);甘肃省高等学校基本科研业务费;甘肃省自然科学基金(编号:1308RJZA166,1104WCGA186)资助

摘　　要：等离子体动力学模拟是一种非常有效的等离子体状态诊断和光谱分析方法,已被广泛应用于激光等离子体光谱的解释和演化分析中.本文基于流体动力学方程和辐射输运方程,并结合稳态的碰撞辐射模型,提出了一种简化的能够分析模拟中高Z元素高电荷态离子极真空紫外(Extreme Ultraviolet,EUV)波段光谱的辐射流体动力学模型,并成功应用于激光产生的锡等离子体EUV光谱的分析和模拟.结果表明,理论模拟光谱与激光功率密度为1.90×10^(11)?W/cm^2的实验光谱之间具有良好的一致性.通过比较Sn^(7+)–Sn^(11+)离子的4d-4f,4p-4d和4d-5p,5f跃迁阵列的发射轮廓和自吸收轮廓,明确了不透明度效应对发射光谱轮廓的影响,成功解释了13.5?nm附近自吸收带和自吸收峰的成因.相关研究预期能够为极真空紫外辐射在光刻、计量、生物成像等领域的应用研究提供参考.Plasma dynamics simulation is a very effective method for the spectral diagnosis and analysis of plasmas, which has been widely used in the interpretation of spectral structure and evolution analysis of the laser-produced plasmas. In this paper, a simplified radiation hydrodynamic model based on the fluid dynamic equations and the radiative transfer equation, and combined with a steady-state collisional-radiative model was presented and used to analyze the origin of extreme ultraviolet （EUV） spectrum of middle- and high-Z highly charged ions from laser-produced plasma, and has been successfully applied to analyze and simulate the spectrum of laser-produced tin plasma in the EUV spectral region. The results show that there is a good agreement between theoretical simulation and experimental spectrum at a laser power density of 1.90×1011 W/cm2. By comparison of the emission profiles and self-absorption profiles of 4d-4f, 4p-4d and 4d-5p, 5f transition arrays from Sn7＋ to Sn11＋ ions, the influence of opacity effect to the emission profile was identified. We are succeeded in explaining the origin of self-absorbed band and self-absorbed dips around 13.5 nm in tin spectrum. Our results are expected to provide a reference for the applications of extreme ultraviolet radiation in the fields of lithography, metrology and biological imaging.

关 键 词：激光等离子体 高电荷态离子 辐射流体动力学模型 自吸收效应 

分 类 号：O53[理学—等离子体物理]