Journal of Atomic and Molecular Physics
Rb(5 P_J)+(He,N_2) collisional energy transfer
Yifan Shen
Abstract
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 case,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→5P1/2 transfer in collision with He is 2.23×10-12 cm3 s-1.By comparing the relative fluorescence intensities for He and N2 case,and fitting the experimental results to the rate equation analysis,we estimate that the rate coefficient for 5P3/2→5P1/2 transfer in collision with N2 is 4.38×10-11 cm3 s-1.The quenching rate coefficient out of the 5PJ state is 5.45×10-11 cm3 s-1.The results are discussed in relation to those of other experiments.