Investigation on effects of quenching of Einstein A coefficient in plasmas

1)为了研究普林斯顿大学提出的“等离子体中爱因斯坦A系数的猝灭”这一论断Univ.group，我们尝试测量了低密度等离子体（ne&lt;10^ cm^）中He I np^3P-2s^3S，3s^3S（n= 6，7，8，9，10）的分支比<14><-3>，从而使我们能够测量总谱线强度而不产生斯塔克展宽的问题。在这里，我们使用非平衡复合等离子体，以观察从高激发态的跃迁，结果，观察到的分支比的变化高达50%。然而，这一结果可能不能直接归因于量子电磁效应引起的自发跃迁几率的猝灭。目前，高激发态的能级混合效应可能是导致分支比变化的一种可能机制。2）根据多重态结构间的分支比，一般证明了在低能级结构相同的情况下，原子分支比是一个常数，不依赖于上能级间的布居分布。

1) In order to investigate the claim : Quenching of Einstein A Coefficient in Plasmas which has been proposed by the Princeton Univ.group, we tried to measure the branching ratios of He I np^3P-2s^3S, 3s^3S (n=6,7,8,9,10) in low density plasmas (ne<10^<14> cm^<-3>), which enables us to measure the total line intensities without the problem of Stark broadening. Here, we used nonequilibrium recombining plasma, in order to observe the transitions from highly excited states.As the result, changes of branching ratios up to 50% were observed. However, this result may not be directly attributed to the quenching spontaneous transition probabilities caused by the quantum electromagnetic effect. At present, an effect of level mixing at highly excited states is a candidate for a possbile mechanism on the changes of branching ratio.2) According to a branching ratio between multiplet structures, it is generally demonstrated that the atomic branching ratio is a constant and does not depend on the population distribution among the upper sublevels, if the structures of lower levels are same.