电子密度对非局域热动平衡金等离子体离化分布影响的实验研究

The charge state distribution is an essential parameter for plasma as it determines the EOS, the opacity and the energy distribution of the plasma. Non-local-thermodynamic-equilibrium(NLTE) plasmas widely exist in nature and in laboratory systems. Predicting the correct charge state distributions of NLTE high-Z plasmas plays an important role in research fields such as inertial confinement fusion and astrophysics. In the theoretical aspect, several models have been established to calculate the charge state distributions of NLTE high-Z plasmas, but disagreement persists among models especially for open-shell high-Z ions. On the other hand, there are few benchmark measurements. This project will study the techniques of producing quasi-1D NLTE plasmas by Shenguang high-power laser facility, and aim at producing uniform NLTE gold plasmas under different conditions. Precision diagnostic techniques will be developed to diagnose the plasma conditions include the temperature, the density, and the charge state distribution. The effects of electron density on the charge state distribution and the emission spectra will be studied, and the mechanism will be elucidated. This work will improve the understanding of NLTE high-Z plasmas, promote the development of NLTE models, and lay the foundation of solving the problems met in inertial confinement fusion and other application fields.

离化分布是表征等离子体微观状态并决定其状态方程、辐射不透明度、以及能量分配等宏观物理性质和物理过程的关键参数。非局域热动平衡（NLTE）等离子体的离化分布研究对惯性约束聚变、天体物理等研究领域具有重要的基础研究意义和应用价值。理论计算NLTE高Z等离子体的离化分布非常复杂，通常采用近似模型，而模型的精度可能给应用带来较大偏差；实验测量方面，基准实验数据较少。本项目拟通过激光加载的方式，发展准一维NLTE等离子体产生技术，获得不同状态的均匀NLTE金等离子体；全面表征NLTE金等离子体的温度、密度、离化态分布等状态参数；研究电子密度对离化分布及发射谱的影响，阐明其中的物理机制。本项目将有助于提高对NLTE高Z等离子体物理规律的认识，推动相关理论模型的发展，为深入理解并解决困扰惯性约束聚变等应用研究领域的诸多难题提供科学实验基础。

非局域热动平衡（NLTE）等离子体广泛存在于惯性约束聚变、天体物理等研究领域，其离化态分布是表征等离子体微观状态并决定其宏观物理性质和物理过程的关键参数。本项目通过束匀滑激光加热埋点/埋层靶的方式，建立了准一维NLTE等离子体产生方法；实验产生了状态均匀的NLTE金等离子体，并诊断了其温度、密度、离化态分布等参数。项目获得的温度在2keV附近、电子密度在2e21cm-3附近的NLTE Au等离子体M带发射谱及其离化态分布数据已用于校验理论模型。实验结果与基于DCA层次的碰撞辐射模型的理论计算结果符合较好，并研究了自电离/双电子俘获对Au等离子体离化分布的影响。在本实验条件下，自电离/双电子俘获过程对等离子体离化态分布具有较大影响。本项目的研究成果推动了国内NLTE等离子体辐射特性研究相关实验技术的发展，所获得的相关实验数据为解决惯性约束聚变点火物理建模等应用研究领域的诸多难题提供了科学实验基础。