Theoretical Studies Of Dielectronic Recombination Rate Coefficients For Re³⁰⁺ Ions

Dielectronic recombination?DR?process is considered as one of important inelastic phenomenon of electron-ion collision,It is crucial for the study of ionization balance of highly ionized elements in hot plasmas.The process plays an important role in the theoretical modeling of plasmas,whether in the laboratory high temperature plasma or astronomy plasma.This work is based on the Dirac equation of flexible relativistic atomic code method,namely Flexible Atomic Code?FAC?package,Detailed calculation have been made for DR rate coefficients of Re³⁰⁺and Gd¹⁹⁺ions capture electron from the ground state 4s²4p⁶4d⁹ to double excited states channel?4s²4p⁶4d⁹?^-1nln'l'?n=4-6,n'=4-23,l=0-5,l'=0=11?,the main contents include:Firstly,this article studies DR process of Re³⁰⁺.Consider excitation channel's contribution to the DR rate coefficient,with intermediate double excited state j=?4s²4p⁶4d⁹?^-14l10f as an example,The contributions from 4s?4p and 4d excited are discussed.With double excited state among j=?4p⁶4d⁹?^-1nl10l'as an example,The contributions from 4d,4p electronic excitation to different shell for DR rate coefficient,In the whole temperature range,the study found that maximum DR rate coefficient of n=4,minimum of n=6,and with the increase of n,the corresponding contribution drastically reduced;Consider radiation channel's contribution to the DR rate coefficient,with intermediate double excited state j=4d⁸4f10f as an example,analyzed the contribution of radiative transition to different shell of DR rate coefficient;Analysis compares the configuration interaction contribution to the DR rate coefficient,with intermediate double excited state j=4d⁸4f10l'as an example,In the high temperature area,due to the different l'of the increase and decrease effects cancel eventually lead to sum after double electronic composite rate coefficient has almost no effect,for the other in the middle of the double excited states have similar conclusions,so the total DR rate coefficient can be ignored in the calculation of the configuration interaction effect;By analyzing DR rate coefficient with high n rate coefficient of the electron orbital angular momentum change,high n electron orbital angular momentum l'>11 contribution can be ignored;In the comprehensive analysis of Re³⁰⁺ions DR process has obvious contribution of various factors,further get the total DR rate coefficient.Among them,considering radiative cascades?DAC?effect of DR rate coefficient has great influence,the biggest contribution is 12.9%;By means of compared total DR rate coefficients to radiative recombination?RR?rate coefficients and three-body recombination?TBR?rate coefficients,it shows that the maximum value of the RR rate coefficient is22.6%of the DR rate coefficient and the maximum value of the TBR rate coefficient is only 0.3%of the DR rate coefficient.The total DR rate coefficient is greater than either the RR or TBR coefficients in the whole temperature range.The corresponding DR process is very important for plasma ionization distribution,population level and spectrum simulation.In addition to facilitate the application,the total DR rate coefficients for the ground state and the first excited state are fitted to an empirical formula.Secondly,this article studies DR process of Gd¹⁹⁺ions.The contribution of excitation channel,radiation channel and DAC effect to DR rate coefficients was investigated,which was similar to the DR process of Re³⁰⁺ions.The difference between the rate coefficient of DAC transition and the DR rate coefficient of Auger transition in Gd¹⁹⁺ions without the consideration of Auger transition was up to70.7%,It indicates that the influence of DAC effect increases with the decrease of atomic number.