[Energy transfer in Cs(6P) + (Ne, N2) collisions].

The collisional energy transfer process Cs(6P(3/2)) + M, where M = Ne, N2, under gas cell conditions has been investigated. The Cs(6P(3/2)) state was excited by a diode laser. The direct 6P(3/2) --> 6S(1/2) fluorescence and the sensitized 6P(1/-2) --> 6S(1/2) fluorescence as a function of quenching gas pressure were measured. For quenching by Ne only energy transfer from the electronic to translational is possible. However, in the N2 case, energy transfer from the electronic to vibrational or rotational is important. Using a two-state rate equation model, the quenching rate coefficients for Cs(6P(3/2)) were obtained. The fine structure energy transfer rate coefficient for Ne is 1.45 x 10(-12) cm3 x s(-1). By comparing the relative fluorescence intensities for Ne and N2 case, the authors estimate that the rate coefficient for 6P(3/2) --> 6P(1/2) transfer in collision with N2 is 1.64 x 10(-2) cm3 x s(-1). The quenching rate coefficient for the 6P state is 4. 88 x 10(-12) cm3 x s(-1).