利用770 nm脉冲激光激发基态K原子到K(4P1/2)态, 在样品池中, 利用原子荧光光谱方法, 测量了K(4PJ)和N2、He碰撞的精细结构转移截面和碰撞猝灭截面。在不同N2、He气体密度下, 通过对4P1/2→4S1/2共振荧光与4P3/2→4S1/2转移荧光的时间积分荧光强度进行测量, 得到其荧光强度比与N2、He密度成线性关系。从荧光强度比R与 (Nv)-1线性关系图中的直线斜率可以得到4P1/2→4P3/2转移截面为(2.77±0.69)×10-15cm2和4P3/2→4P1/2的碰撞转移截面为(1.62±0.41)×10-15cm2, 从直线的截距计算出K(4P3/2)与N2、He的碰撞猝灭截面为(0.40±0.12)×10-15cm2和(0.60±0.18)×10-16cm2。

A K-N2(or He) mixture is irradiated in a fluorescence cell with pulses of 770 nm radiation from OPO-YAG laser and populated K(4P1/2) state. Cross sections for K(4P1/2)→ K(4P3/2) and quenching of the K(4P3/2) state is determined using the atomic fluorescence spectrometry. With the variable densities of N2 (or He), the intensities of time-integrated fluorescence from 4P1/2→4S1/2 (the direct fluorescence) and 4P3/2→4S1/2 (the transfer fluorescence) is measured . The ratio of the fluorescence intensity versus the densities of N2 (or He) can be fitted by a straight line, the cross sections are (2.77±0.69)×10-15cm2and(1.62±0.41)×10-15cm2 for K(4P1/2)→ K(4P3/2) by the slop, and the cross sections are (0.40±0.12)×10-15cm2and(0.60±0.18)×10-16cm2 for the K(4PJ) quenching from the intercept.