抄録
When the X-ray emission from a finite temperature plasma is analyzed, we require detailed information about an atomic structure of the plasma under various plasma conditions. The spectroscopic diagnostics using the X-ray emission from the plasma is a powerful tool to estimate the plasma parameters.
The objective of this paper is to present the results of calculation of electronic conditions in a finite temperature plasma. This is achieved by the following two methods: [1] the finite temperature Hartree-Fock method (FTHF) in which the Dirac equation is solved by using the Runge-Kutta method, and [2] the average ion model (AIM) with the simple Coulomb potential and More's shielding constant 1). In the FTHF, the potential energy for electron is estimated from the self-consistent electron density with the ion sphere model. We employ this potential in solving the Dirac equation. In the AIM, only one fictitious ion having Z exists. The average ion model has been widely used for analyzing the radiation from a laser irradiated high-Z target. In the AIM, the population Nn, z of each ion charge state z in the nth level is generally required to calculate X-ray emission from the plasma. However, for a high-Z plasma, the equation for this population is rarely solved. Consequently, in the AIM, Nn, z is averaged over Z and it is sufficient to solve only the equations for the level population Pn of an averaged atom.
We investigated the electronic conditions of finite temperature plasmas by using the FTHF and AIM methods. In the present paper, calculation results are presented for the Al13 and Fe26 atoms at T=100eV and the solid density. The results obtained by the FTHF method agrees with Rozsnai's results 2). We have also calculated the energy of bound electrons with the population from the FTHF calculations and with More's shelding constants 3); however, they are not in good agreement with the FTHF results. This suggests that we have to determine More's shielding constants more precisely.
