M. Movre et al., Mixing and quenching of the Cs 5D(J) states induced by collisions with caesium ground-state atoms, J PHYS B, 33(16), 2000, pp. 3001-3012
Citations number
14
Categorie Soggetti
Physics
Journal title
JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS
Applying the cw laser absorption and fluorescence method the cross sections
for the fine-structure mixing and quenching of the caesium 5D(J) states ha
ve been measured in pure caesium vapour. Caesium atoms were optically excit
ed to the 5D(5/2) slate via the quadrupole-allowed 6S(1/2) --> 5D(5/2) tran
sition. The ground-state caesium density N-0, obtained from the absorption
at the pumped quadrupole transition, and the fluorescence intensity I-689 o
f the sensitized 5D(3/2) --> 6S(1/2) emission were measured simultaneously
in the range 3 x 10(14) cm(-3) less than or equal to N-0 less than or equal
to 1 x 10(16) cm(-3) at constant temperature T = 585 K. It was found that
the quantity N-0(2)/I-689 exhibited a parabolic dependence on N-0, confirmi
ng that the quenching of the Cs 5D(J) states is due to collisions with Cs g
round-state atoms, not molecules. The coefficients of the second-order poly
nomial fitted through the measured data yielded the cross sections sigma(5/
2-->3/2) = (57 +/- 19) X 10(-16) cm(2) and sigma(D) = (35 +/- 10) x 10(-16)
cm(2) for the Cs 5DJ fine-structure mixing and quenching, respectively, du
e to collisions with caesium ground-state atoms. Using recently calculated
Cs* + Cs potentials we performed an analysis which shows good agreement bet
ween the measured values and the theoretical predictions.