CII的光电离截面的理论计算

 使用R-矩阵方法，对CII基态的光电离截面进行了六态和十态的密耦计算，得到了入射光子能量从1.8Ry到4.3Ry的总光电离截面，长度与速度表示符合很好。计算得到的截面包含了复杂的共振结构。与由英法等国联合开展的不透明度工程的理论计算结果进行了比较，两者在电离阈附近符合得比较好。计算表明，收敛于较高电离阈的共振系列对收敛于较低电离阈的共振系列有较大的干扰。由分波和电离后处于特定靶态的光电离共振峰的位置可确定CII单双高激发态能级的位置。

The Calculation of Photoionization Cross Section for CII

Six- and ten-state close-coupling calculations are carried out by using the R-matrix method to obtain photoionization cross section of the ground state of C II ion. The incident photon energy ranges from 1.8Ry to 4.3Ry. The calculated results in Length and Velocity formulations agree very well. The cross sections contain complicated resonance structure. Our results are also in good agreement with those of the Opacity Project. The difference between the six-and ten-state close-coupling calculations shows that the resonance series converging to higher ionization thresholds will disturb the lower Rydberg resonances. The energy levels of singly and doubly excited states can be determined by the resonance structures of partial and individual cross sections.