类He的Y离子双电子复合计算

DIELECTRONIC RECOMBINATION INTO EXCITED LEVELS OF Li-LIKE YTTRIUM IONS FROM He-LIKE GROUND STATE

采用准相对论的多组态Hartree-Fock(HFR)方法计算了类Li的Y离子(Z=39)的能级和振子强度,并且通过采用扭曲波方法计算自由电子的波函数,我们得到了由类He的基态到类Li的双激发态的自电离几率和双电子复合系数。在计算中,相对论质量—速度和Darwin修正都包含在哈密顿中。为了便于等离子体细致能级占据数密度的动力学计算,我们用一个解析表达式来表示作为自由电子温度函数的双电子复合速率系数,这个表达式精确地描写了从类He的基态到类Li的单激发态的双电子复合。

Energy levels, wavelengths, oscillator strengths, Auger rates and level-to-level dielectronic recombination rate coefficients describing dielectronic recombination into excited levels of Li-like yttrium ions from He -like ground state are calculated. Our calculations are based on Dr. R. D. Cowan's semi -relativistic multi-configuration Hartree-Fock (HFR) code, where the relativistic mass -velocity and Darwin corrections are included in the Hamiltonian, and the distorted-wave model is used for the calculation of free electron wavefunctions. The dielectronic recombination rate coefficients as a function of free electron temperatures are given in an analytical form which is not only very convenient in practice but also accurate enough compared with the exactly calculated numerical results.