SPECTROCHIMICA
ACTA
PART A
ELSEVIER Spectrochimica Acta Part A 52 (1996) 409-418
Analysis and transition probabilities of the BlI-Iu X Zg
system of Na2 excited by the 5017 A line of the argon ion laser
J.M.L. Poyato*, J.J. Camacho, A.M. Polo, A. Pardo
Departamento de Quimica-Fisica Aplicada, Facultad de Ciencias, Universidad Autonoma de Madrid, Cantoblanco, E-28049 Madrid,
Spain
Received 14 June 1995; revised 4 October 1995; accepted 14 September 1995
Abstract
The fluorescence spectrum of Na2 induced by the 5017.16 A line of an argon ion laser has been analyzed. This work
extends previous observations on Na2 by using this excitation line. We have observed seven fluorescence series for the
BtFIu~X~E~, band system corresponding to the excitation transitions: v'= 5, J' = 37~v"= 6, J"= 38; v' = 5,
J' = 88 4---v "= 5, J" = 87; v'= 5, J'= 124.-#'=3, J"= 125; v'=O, J' = 42.-- v" = 2, J" = 43; v'= 10, J'= 78~v" =
9, J"=77; v'=14, J'=68~v"= 12, J"=68 and v'=15, J'=58*--v"= 13, J"=58. The latter four series are
reported for the first time. The radiative transition probabilities for the observed fluorescence series are calculated by
using hybrid Perturbed-Morse-Oscillator (PMO)-Rydberg-Klein-Rees (RKR)-long range potential energy curves
for the BtFIu and X~Y~g states and ab initio transition dipole moment function. Radiative lifetimes of the
rovibrational levels of the upper state pumped by the laser line have also been calculated. The transition probabilities
and lifetimes are in good agreement with the corresponding observed measurements usually within the experimental
uncertainty. From the rotational satellite structure of some bands, collision-induced transition rates and average cross
sections have been determined.
Keywords: Fluorescence; Laser; Na2; Rotational satellite; Transition probability
1. Introduction
The spectroscopy of alkali dimer molecules has
been of considerable interest. In the last few years
the development of the new optically pumped
laser has given additional importance to the laser
induced fluorescence studies of these molecules.
Especially, the fluorescence intensity data are im-
* Corresponding author.
portant in this new development. Owing to the
high absorption and emission cross section and
ease of production, the Na2 is of particular inter-
est for laser systems in the visible region. A
literature review of papers published up to 1982
on Na2 can be found in Verma et al. [1]. The laser
induced fluorescence spectra of Na2 for the
B~Ho--.X1Z + band system induced by several
Ar + laser lines have been analyzed by different
authors [2-4]. Kusch and Hessel [4] especially,
have reported a very accurate and extensive anal-
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