神光Ⅱ间接驱动内爆实验ArX射线谱线模拟研究

ICF内爆物理研究中,示踪元素X射线谱诊断方法是推测内爆压缩温度、 密度以及燃料混合状态的有效方法.针对其中的非平衡物理过程, 研制了非局域热动平衡(non-LTE)下一维谱线输运程序Alpha.程序以辐射流体计算给出的温度、 密度等量为输入条件,求解细致组态(DCA)模型下的原子动力学方程和辐射输运方程, 自洽给出谱线不透明度,和成像面上的X射线谱分布.
利用该程序,模拟了神光Ⅱ装置上的掺Ar靶丸内爆示踪元素X射线谱诊断实验, 研究结果表明,谱线的自吸收效应影响发射的X射线谱的强度和形状, 谱线的宽度对自吸收效应的强弱也有影响.因此,在对X射线谱的数值模拟中应该考虑自吸收效应. 另外,与LTE近似下的发射谱的比较表明, LTE近似下,等离子体电离度大～1, 发射谱的形状与non-LTE的结果不同,且LTE近似下,谱线的强度比non-LTE的谱线强度大5-10倍, 采用LTE近似是不合适的.     

ICP－AES初级专家系统中的谱线模拟

本文阐述了ＩＣＰ－ＡＥＳ初级专家系统中谱线模拟的理论基础，模拟了Ｃａ、Ｍｇ和Ａｌ在ＬＴＥ和ｎｏｎ－ＬＴＥ情况下的离子线与原子线，证明在ｎｏｎ－ＬＴＥ条件下，离子线与原子线的强度比增强了，比ＬＴＥ条件下的结果更接近实际扫描谱图。本研究模拟计算了Ｃａ和Ｍｇ离子线的跃迁上能级能量对离子线强度的影响。     

激光腔靶耦合二维辐射输运数值模拟

间接驱动激光聚变过程中,黑腔内物质处于非局域热动平衡(non-LTE)状态,而且辐射传输具有非平衡、各向异性等特点。为了精确描述黑腔辐射场的演化及其与物质的相互作用,最新研制的激光聚变二维总体LARED集成程序,基于non-LTE的多群辐射输运建模,首次实现了激光黑腔靶实验的全过程数值模拟。数值结果表明,辐射输运计算较好地反映了黑腔辐射场均匀性变化,腔壁光斑区与非光斑区X光发射强度比与实验测量值接近,靶丸压缩形状与实验图像定性一致。     

Non-LTE Argon Plasma Composition at Atmospheric Pressure

The knowledge of plasma composition is very important for various plasma applications and the prediction of other plasma properties. Most of the plasma currently used in plasma-aided processing is in the non-LTE (Local Thermodynamic Equilibrium) state. In this paper, the Saha equations, Debye-length equation, lowering-of-ionization-energy equation and pressure-correction equation, used to calculated the non-LTE plasma composition, are analyzed. The recently published theoretical results are compared with experimental data.     

Investigation on non-LTE radiation emitted from a laser-irradiated Au disk

1 Introduction The laser-target coupling physics is a key topic in indirect-driven inertial confinement fusion (ICF) and X-ray application research[1―3]. When intense laser light irradiates the solid target, the plasmas are produced rapidly on the surface of the target. The laser en-ergy is mainly absorbed by inverse bremsstrahlung absorption, and a coronal region with high-temperature and low-density plasma is formed. Electron thermal conduction proc-ess transfers energy into over-dense re…     

Non-LTE Argon-plasma Composition

In this paper theory of calculation of non-LTE plasma composition is presented. The calculations are conducted for argon plasma for temperature ranges from 500 K to 30, 000 K and T _e/T _h ratios from 1 to 10. The effect of different versions of the Saha equation, Debye length, lowering of ionisation energy and pressure correction on the argon-plasma composition is evaluated. It was concluded that the modified Saha equation could not be used for calculation of non-LTE plasma composition. Application of various Debye lengths can change the electron number density by 8%. The lowering of the ionisation energy decreases the electron number density by 18%. For LTE-plasma pressure correction has a negligible effect on the electron number density.     

Opacity calculations for Non-Local-Thermodynamic-Equilibrium plasmas

In this paper, we presented a method to calculate the spectral-resolved opacity for Non-Local-Thermodynamic-Equilibrium (non-LTE) plasmas. By solving the rate equations, we get the population. In the rate equations, configuration-averaged rate coefficients are used and the cross sections are calculated based on the first-perturbation theory. Using the detailed configuration accounting with the term structures treated by the unresolved transition array model, we calculated the spectral-resolved opacity of Al plasmas. The results are compared with those of other theoretical models. From the comparison, we can see that the present results fit well with other models for low-Z plasmas. For high-Z plasmas, we will give detailed discussion in the future.