热等离子体内的光电截面研究

PH0TOIONIZATION CROSS SECTION IN PLASMAS BASED ON THE ION-SPHERE

考虑温度、物质密度效应，用相对论Ｄｉｒａｃ自洽场含温有界原子模型，给出了热物质中连续态电子波函数的能态密度。通过研究Ａｕ、Ｆｅ、Ａｒ、Ｋｒ等元素，分析了光电截面随温度、物质密度的变化规律。

AbstractConsidering the effects of temperature and density of plasmas environment on the atom,the density of states for continuum wavefunctions with confined boundary conditions inrelativistic HFS self-consistent field ion-sphere model is presented. The density of states forcontinuum wavefunction may be seen formula(3). The authors normalized the continuum wavefunction by .Not only issuch foimula fit to the bounded atom but also fit to free atom. Using this formula,authors canget the density of states for continuum wavefunction accurately is all energy range, includingphotoionization threshold energy.In the single-electron and centrical field approximation,using the multipole expansion of plane wave radiation,the photoionization cross section σ_(nl_j)of an electron in the initial state n_(l_j) is got [see formula(8)].In order to check our model,the free atom and calculate the photoionization crosssections of several elemental atoms is simulated at low tepperature and thin density. In a fewspecific cases,a direct comparison with other results is done. These results are shown in Fig.1～Fig.2.The good agreement can be found for both the absolute values of the cross sectionsand the curve. Fig.3 show the effects of temperature and matter densities on the 2p_(1/2)and 4p_(1/2)photoionization cross sections of Au atom. Obviously, the effects on the outer shell4p_(1/2) are more serious than on the inner shell 2p_(1/2). Meanwhile, the effects of temperature onthe cross sections are more critical than ones of density.