高n双电子复合伴线对类氦镁离子K_α共振线贡献的理论计算

Calculation of the contributions from high-n dielectronic satellites to the K_α resonance line in helium-like magnesium

利用多组态Dirac-Fock方法计算了类氦镁离子的双电子复合截面.分析了类氦镁离子的高n双电子伴线结构及其对类氦镁离子Kα共振线的影响.结果表明类氦镁离子的高n双电子伴线几乎都分布于Kα共振线的长波一侧.随着n的增加,DS强度呈现明显减小的趋势.虽然来自KLM(n=3)的发射线最强,但n>3的部分依然给出了非常重要的贡献.即便是来自n>10的共振的贡献也是不可忽略的.并且高n双电子伴线随着n的增加不断接近Kα共振线,导致和Kα共振线的强烈混合.在实验测量中会使Kα共振线峰位的测量值向长波方向移动,使谱形加宽,并且增强了Kα共振线测量值强度.

Based on the multi-confignration Dirac-Fock method, theoretical calculations have been made for the dielectronic recombination cross-sections and the high-n dielectronic satellites to Ka resonance line in helium-like magnesium ions. It is found that high-n dielectronic satellites are always locating on the red wings, and approaching to the resonance line gradually and become weaker with increase of n value. In this consequence, the accumulation of high-n dielectronic satellites can be very important resulting in a serious mixing with resonance line. These satellites give a significant increase in both the apparent width and the apparent intensity of the resonance line and also induce a positional shift of Ka resonance line.