Rb(5 P_J)+(He、N_2)碰撞能量转移

Rb(5 P_J)+(He,N_2) collisional energy transfer

在气体样品池条件下,研究了Rb(5PJ)+(He、N2)碰撞能量转移过程.调频半导体激光器稍微调离共振线,激发Rb原子至Rb(5P3/2)态,在不同的He或N2气压下,测量了直接5P3/2→5S1/2荧光和转移5P1/2→5S1/2荧光.对于5PJ与He的碰撞.电子态能量仅能转移为He原子的平动能.在与N2的碰撞中,向分子振转态的转移是重要的.利用速率方程分析,可以得到碰撞转移速率系数,对于He,5P3/2→5S1/2转移速率系数为2.23×10-12cm3s-1.对于N2,测量5PJ+He和5PJ+N2二种情况下荧光的相对强度比,利用最小二乘法确定5P3/2→5S1/2转移速率系数为4.38×10-11cm3s-1,5PJ态猝灭速率系数为5.45×10-11cm3s-1.与其他实验结果进行了比较.

The collisional energy transfer process Rb（5PJ） ＋ M, where M = He, N2 under gas cell conditions has been investigated. The Rb（5P3/2） state was excited by a diode laser, the laser is tuned slightly off resonance. The direct 5P3/2^→5S1/2 fluorescence and the sensitized 5P1/2→5S1/2 fluorescence as a function of quenching gas pressure had been measured. For collision with He where only electronic to translational energy transfer is possible. However, in the N2 ease, electronics to vibrational or rotational transfer is important. Using a two-state rate equation model the transfer rate coefficients from Rb （5PJ） had been obtained. The rate coefficient for 5P3/2→5S1/2 transfer in collision with He is 2.23×10^-12cm^3s^-1. By comparing the relative fluorescence intensities for He and N2 ease, and fitting the experimental results to the rate equation analysis, we estimate that the rate coefficient for 5P3/2→5S1/2 transfer in collision with N2 is 4.38×10^-11cm^3s^-1. The quenching rate coefficient out of the 5PJstate is 5.45×10^-11cm^3s^-1. The results are discussed in relation to those of other experiments.