大气NLTE辐射传输中分子光谱参数间的关系

讨论Ｅｉｎｓｔｅｉｎ参数、谐振子强度、权重跃迁矩的平方、线强及吸收系数等分子光谱多数的定义，导出了它们之间的关系，为计算上层大气辐射提供了物理基础。

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.

X-ray calculations for a NLTE Ar plasma

A model is developed to calculate emission spectrum of non-local thermodynamic equilibrium(NLTE) plasmas. The Collisional-Radiative model is adopted for non-LTE population calculations. Configuration-averaged rate coefficients that needed in the rate equations are obtained based on the first order perturbation theory. The Hatree-Fock-Slater self-consistent-field method is used to calculate electron wave functions. The present model is applied to the calculation of emissivity from a Ar plasma. The features of the spectra are in good agreement with those calculated by other theoretical models, but the data of the integrated emissivity differ by a factor 2～8.

非平衡大气辐射强度与透过率的Line-By-Line计算模式

导出了非局域热力学平衡（ＮＬＴＥ）大气辐射强度与透过率的基本公式，以及ＮＬＴ和ＬＴＥ的线强、光学厚度和透过率的关系。假设转动能级是热力学平衡（ＬＴＥ）的，建立了一个精确的ＬｉｎｅｂｙＬｉｎｅＮＬＴＥ辐射强度与透过率的有效算法来计算较高层行星大气红外活跃样品的辐射强度。计算了地球大气１６Ｏ３９６μｍ带在白天、夜晚和ＮＬＴＥ、ＬＴＥ条件下的临边光谱辐射强度、线积分辐射强度、带积分辐射强度和合成光谱辐射强度，揭示了ＮＬＴＥ辐射强度对ＬＴＥ辐射强度有显著而重要的偏离。

非平衡行星大气发射与透射的Line-by-Line计算模式

导出了非局域热力学平衡（ＮＬＴＥ）行星大气发射与透射的基本公式，假设转动能级是热力学平衡（ＬＴＥ）的，建立了一个精确的Ｌｉｎｅ－ｂｙ－Ｌｉｎｅ（ＬＢＬ）ＮＬＴＥ发射与透射的有效算法计算较高层行星大气红外活跃样品的辐射强度．用本算法计算了地球大气１２Ｃ１６Ｏ２４．３μｍ和１５μｍ带在白天、夜晚和ＮＬＴＥ、ＬＴＥ条件下的临边辐射强度，揭示了ＮＬＴＥ辐射强度对ＬＴＥ辐射强度有显著而重要的偏离．

Emissivity Calculations Under DCA-UTA Approximation for NLTE Plasmas

A model is developed to calculate emission spectrum from plasmas in nonlocal-thermodynamic-equilibrium(NLTE).The populations are obtained with a Collisional Radiative Model and the spectrum is calculated with the Unresolved-TransitionArray(UTA)approximation.The present model is applied to the calculation of emissivity from low-,medium-and high-Z plasmas.The integrated emissivity and the spectra are compared with those calculated by other theoretical models.In general speaking,the present results of the mean charge state and emissivity agree well with some theoretical ones while large differences are found when all the theoretical results are included.

Ionization Equilibrium and NLTE Effects on Compact Circumstellar HII Regions

This paper presents the results of an extensive set of calculations about ionization equilibrium and NLTE effects on compact circumstellar HII regions embedded in clouds. In the mode! of a spherically symmetric and isothermal wind with a steady mass loss, pure hydrogen composition as well as Sobolev approximation, our research indicates that compact HII regions are far away from LTE state. The collisional ionization and photoionization from excited levels have great effects on the size of an HII region, the distribution of departure coefficients and the flux ratio of observed spectral lines. They can be used to explain the infrared line excess and the line deficit problems of YSOs. We conclude that it is unreasonable to infer the spectral type, mass loss rate and foreground extinction of the central star from optically thin line recombination theory.

考虑吸收效应后对Z-pinch产生Al等离子体发射谱的非局域热动平衡模拟

本工作在采用细致能级模型计算等离子体布居数的基础上,细致地计算了等离子体的发射系数和吸收系数,采用简化的NLTE(非局域热动平衡)一维定态辐射输运近似计算了考虑吸收效应以后Z-pinch产生的Al等离子体的细致能谱并作了分析,结合考虑吸收与不考虑吸收时等离子体发射谱结构的改变,初步分析了等离子体不透明度对等离子体X光谱的影响.计算结果表明,不透明度效应对等离子体的光谱改造非常明显,等离子体不透明度对共振线有明显的影响,而对伴线的影响较小.我们的计算结果还表明,Z-pinch等离子体K线的有效吸收半径约为100–200 m.

Collisional-Radiative Calculations of Optically Thin and Thick Plasmas Using the Computational Package ABAKO/RAPCAL

Non-local thermodynamic equilibrium(NLTE)conditions are universal in laboratory and astrophysical plasmas and,for this reason,the theory of NLTE plasmas is nowadays a very active subject.The populations of atomic levels and radiative properties are essential magnitudes in the study of these plasmas and the calculation of those properties relies on the so-called collisional-radiative(CR)models.However,the complexity of these models has led to the development of numerous collisionalradiative codes and this is a current research topic in plasmas.In this work is presented a versatile computational package,named ABAKO/RAPCAL,to calculate the populations of atomic levels and radiative properties of optically thin and thick,lowto-high Z,NLTE plasmas.ABAKO/RAPCAL combines a set of analytical approximations which yield substantial savings in computing running time,still comparing well with more elaborated codes and experimental data.In order to show the capabilities of the code and the accuracy of its results,calculations of several relevant plasma magnitudes for various plasma situations are shown and compared.