本文将完全线性化方法同非局部热动平衡计算方法进行了比较,考察了用完全线性化方法确定光谱参数的可靠性,并研究了光谱分析中经常用的“共空间发射”等假设的合理性。本文研究结果表明,用完全线性化方法可以唯一确定谱线多普勒宽度,线...本文将完全线性化方法同非局部热动平衡计算方法进行了比较,考察了用完全线性化方法确定光谱参数的可靠性,并研究了光谱分析中经常用的“共空间发射”等假设的合理性。本文研究结果表明,用完全线性化方法可以唯一确定谱线多普勒宽度,线心光学厚度和源函数线性变化系数,其中多普勒宽度和源函数线性变化系数反映了日珥中H_a和CaⅡH. K线线翼附近所对应形成区的物理状况。H_a线同C_aⅡ H. K线是共空间发射的,从共空间发射求出的温度反映了日珥中上述区域的运动温度。本文结果还表明,一般来说,日珥中CaⅢ粒子数大于CaⅡ粒子数,从CaⅡ H、K线求氢原子密度必须考虑两次电离钙的贡献。展开更多
The classic two-level or equivalent two-level model that includes only the statistical equilibrium of radiative and thermal processes of excitation and quenching between two vibrational energy levels is extended by ad...The classic two-level or equivalent two-level model that includes only the statistical equilibrium of radiative and thermal processes of excitation and quenching between two vibrational energy levels is extended by adding chemical production to the rate equations. The modifications to the non-local thermodynamic equilibrium source function and cooling rate are parameterized by ϕ<SUB>c</SUB>, which characterizes the ratio of chemical production to collisional quenching. For applications of broadband emission of O<SUB>3</SUB> at 9.6 μm, the non-LTE effect of chemical production on the cooling rate and limb emission is proportional to the ratio of O to O<SUB>3</SUB>. For a typical [O]/[O<SUB>3</SUB>], the maximum enhancements of limb radiance and cooling rate are about 15%–30% and 0.03–0.05 K day<SUP>−1</SUP>, respectively, both occurring near the mesopause regions. This suggests that the broadband limb radiance above ∼80 km is sensitive to O<SUB>3</SUB> density but not sensitive to the direct cooling rate along the line-of-sight, which makes O<SUB>3</SUB> retrieval feasible but the direct cooling rate retrieval difficult by using the O<SUB>3</SUB> 9.6 μm band limb emission.展开更多
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, c...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.展开更多
The spectral character of X-ray emitted from laser-irradiated gold disk is studied by using the one-dimensional non-LTE multigroup radiation transport hydrodynamics code RDMG. The applicability of the “three-temperat...The spectral character of X-ray emitted from laser-irradiated gold disk is studied by using the one-dimensional non-LTE multigroup radiation transport hydrodynamics code RDMG. The applicability of the “three-temperature” model in which the radiation is described with thermal conduction approximation is checked. The simulation results show that the X-ray emitted from the laser-produced gold plasma is in non-LTE, and that the atom model has significant effect on the structure of X-ray spectrum. However, the plasma states, laser absorption efficiency and X-ray conversion efficiency, which are calculated with the “three-temperature” model, are almost the same as those with non-LTE multigroup radiation transport model. This fact indicates that the “three-temperature” model can be used to study plasma states and the energy distributions produced by a laser-irradiated high-Z target. This is meaningful to the 2-D or 3-D simulation.展开更多
文摘本文将完全线性化方法同非局部热动平衡计算方法进行了比较,考察了用完全线性化方法确定光谱参数的可靠性,并研究了光谱分析中经常用的“共空间发射”等假设的合理性。本文研究结果表明,用完全线性化方法可以唯一确定谱线多普勒宽度,线心光学厚度和源函数线性变化系数,其中多普勒宽度和源函数线性变化系数反映了日珥中H_a和CaⅡH. K线线翼附近所对应形成区的物理状况。H_a线同C_aⅡ H. K线是共空间发射的,从共空间发射求出的温度反映了日珥中上述区域的运动温度。本文结果还表明,一般来说,日珥中CaⅢ粒子数大于CaⅡ粒子数,从CaⅡ H、K线求氢原子密度必须考虑两次电离钙的贡献。
基金This research was supported by NSF grant ATM-0091514in part by NASA grant NAG5-11962 to The Johns Hopkins University Applied Physics Laboratory.
文摘The classic two-level or equivalent two-level model that includes only the statistical equilibrium of radiative and thermal processes of excitation and quenching between two vibrational energy levels is extended by adding chemical production to the rate equations. The modifications to the non-local thermodynamic equilibrium source function and cooling rate are parameterized by ϕ<SUB>c</SUB>, which characterizes the ratio of chemical production to collisional quenching. For applications of broadband emission of O<SUB>3</SUB> at 9.6 μm, the non-LTE effect of chemical production on the cooling rate and limb emission is proportional to the ratio of O to O<SUB>3</SUB>. For a typical [O]/[O<SUB>3</SUB>], the maximum enhancements of limb radiance and cooling rate are about 15%–30% and 0.03–0.05 K day<SUP>−1</SUP>, respectively, both occurring near the mesopause regions. This suggests that the broadband limb radiance above ∼80 km is sensitive to O<SUB>3</SUB> density but not sensitive to the direct cooling rate along the line-of-sight, which makes O<SUB>3</SUB> retrieval feasible but the direct cooling rate retrieval difficult by using the O<SUB>3</SUB> 9.6 μm band limb emission.
基金This work is supported by the National Natural Science Foundation of China(10175011).
文摘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.
文摘The spectral character of X-ray emitted from laser-irradiated gold disk is studied by using the one-dimensional non-LTE multigroup radiation transport hydrodynamics code RDMG. The applicability of the “three-temperature” model in which the radiation is described with thermal conduction approximation is checked. The simulation results show that the X-ray emitted from the laser-produced gold plasma is in non-LTE, and that the atom model has significant effect on the structure of X-ray spectrum. However, the plasma states, laser absorption efficiency and X-ray conversion efficiency, which are calculated with the “three-temperature” model, are almost the same as those with non-LTE multigroup radiation transport model. This fact indicates that the “three-temperature” model can be used to study plasma states and the energy distributions produced by a laser-irradiated high-Z target. This is meaningful to the 2-D or 3-D simulation.
