高位钾分子态之间的碰撞转移

Collisional Transfer between High-Lying States of K_2

脉冲激光710nm线双光子激发K2基态到高位1Λg态,研究了K2(1Λg)+K碰撞转移过程。K密度由光学吸收法测量。记录不同K密度下1Λg态发射的时间分辨荧光强度,得到1Λg的有效寿命,从描绘出的有效寿命的倒数与K密度关系直线的斜率得出1Λg态总的碰撞猝灭截面为2.5±0.3×10-14cm2,从截距得到其辐射寿命为20±2ns。测量了K2的3Λg→13 Σ+u在不同K密度下的时间分辨和时间积分荧光强度,得到了K2(1Λg)+K→K2(3Λg)+K碰撞转移截面为1.1±0.3×10-14cm2。

Potassian vapor was irradiated in a glass fluorescence cell with pulses of radiation from a optic parametric oscillator （OPO） laser ,populatingK2（1Λg） state by two-photon absorption. Energy transfer in K2（1Λg）＋K collision is studied by using molecular fluorescence. The K number density was determined by the optical absorption measurement. The decay signal of time-resolved fluorescence from 1Λg→11Σ＋u transition was monitored. The effective lifetimes of the 1Λg state can be resolved. The plot of reciprocal of effective lifetimes of the 1Λg state against K densities yielded the slope that indicated the total cross section for deactivation and the intercept that provided the radiative lifetime of the state. The radiative lifetime 20±2 ns is obtained. The cross section for deactivation of the K2（1Λg）molecules by collisions with K is 2.5±0.3×10-14 cm 2. At the different K densities ,the time resolved and the time-integrated intensities of the resulting K23Λg→13Σ＋u line were measured. The absolute values for K2（1Λg）＋K→K2（3Λg） ＋K collisional transfer cross section has been obtained. The cross section is1.1±0.3×10-14 cm2.