M. Movre et al., Caesium 6P fine-structure mixing and quenching induced by collisions with ground-state caesium atoms and molecules, J PHYS B, 32(19), 1999, pp. 4647-4666
Citations number
27
Categorie Soggetti
Physics
Journal title
JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS
Applying the cw laser fluorescence method, the cross sections for the fine
structure mixing and quenching of the Cs 6P state, induced by collisions wi
th ground-state caesium atoms and molecules, have been measured. Caesium at
oms were optically excited to the 5D(J) stares via quadrupole-allowed 6S(1/
2) --> 5D(J) transitions, while the resonance states were populated by the
radiative and collisional 5D(J) --> 6P(J) transitions. The relative populat
ions of the Cs 6P(J) sublevels, as well as ratio of the 5D(3/2) to 6P(3/2)
populations, were measured as a function of the caesium ground-state number
density. From these measurements we obtained the cross section of (14 +/-
5) x 10(-16) cm(2) at T = 585 K for the process CS(6P(1/2)) --> Cs(6P(3/2))
induced by collisions with ground-state caesium atoms. The applied experim
ental approach enabled the determination of the effective spontaneous rates
for the 6P(J) states which are in agreement with the predictions of Holste
in's theory. The cross sections for quenching of 6P(J) by caesium atoms and
molecules were measured at T = 635 K and the obtained values are (1.6 +/-
1.4) x 10(-16) cm(2) and (1210 +/- 260) x 10(-16) cm(2), respectively. Usin
g recently calculated Cs* + Cs potentials we performed an analysis which sh
ows a good agreement between the measured values and the theoretical estima
tes.