Eur. Phys. J. D 1, 139-147 (1998)
https://doi.org/10.1007/s100530050074

Energy pooling to the Ba 6s6p ¹P₁⁰ level arising from collisions between pairs of metastable Ba 6s5d ³D_J atoms

¹ Institute of Physics, Bijenicka 46, 10000 Zagreb, Croatia
² Institut für Spektrochemie und Angewandte Spektroskopie (ISAS), Bunsen-Kirchhoff-Strasse 11, 44129 Dortmund, Germany

Corresponding author: ^a vadla@ifs.hr

Received: 11 April 1997
Revised: 24 September 1997
Accepted: 10 December 1997
Published online: 15 February 1998

Abstract

The energy-pooling rate coefficient for the process has been measured. The barium atoms were excited by a cw diode laser tuned to the frequency of the 791.3 nm intercombination line and the metastable atoms in the 6s5d  state were produced due to radiative and collisional depopulation of the laser-excited 6s6p  state. The measurements were performed at number densities of about and at 30 mbar argon as the buffer gas. Most of the barium ground state atoms in the excitation zone were transferred to the triplet metastable state at the laser pump power applied. The energy pooling rate coefficient was determined by comparing the fluorescence intensity of the barium 553.6 nm resonance line and the fluorescence intensity of the intercombination line 791.3 nm. In addition, the populations of the metastable atoms were probed with low intensity laser radiation from a single mode ring dye laser. The rate coefficient was found to be .