环境辐射对原子高激发能级Stark态寿命的影响

在外电场中用激光两步激发使Na原子在待测Stark态（n=17，m=0）上实现布居．用延迟脉冲场电离方法测量了部分Stark态的寿命及环境黑体辐射对其实际寿命的影响，并与理论计算值作了比较．实验和计算表明：对n=17的Stark簇各能态，室温下环境黑体辐射引起的受激跃迁对其寿命的影响与自发辐射跃迁已达同一数量级．寿命越长的Stark态，黑体辐射的影响程度越大，这一因素连同Stark混合效应均使同一Stark簇内各能态实际寿命的差异变小．关键词：

INFLUENCE OF ENVIRONMENTAL RADIATION ON LIFETIMES OF STARK STATES IN HIGHLY EXCITED ATOM

The populations of n=17,m=0 Stark states of sodium atom in static electric fields have been obtained by two step excitation using tunable lasers. The lifetimes of some selected Stark states and the influences of blackbody radiation on the lifetimes were measured by using delayed electric field ionization. The measured data were compared with the calculated values. The experimental and theoretical results exhibit following behaviours: The total rates of stimulated emission and absorption transitions induced by environmental radiations are of the same order of magnitude in comparison to those of spontaneous transition for the observed n=17 Stark manifold states at room temperature. And this effect is more remarkable for longer lived states. It, along with the effect of the Stark mixing of l sublevels, will reduce the differences among lifetimes of Stark states in a manifold.