A spectroscopic study of the level population dynamics in a resonantly pumped barium vapour

J. LEONARD BOWEN, A. P. Thorne

A. Kallenbach, Manfred Kock

A numerical model has been developed, which is well suited to describe the kinetics of a laser-pumped barium vapour. The numerous processes essential for the temporal evolution in the population of the various barium levels are outlined in detail. A number of approximations and simplifications have to be introduced to adapt the complex problem to a numerical solution at an economical expense. Since the authors consider all substantial features of the laser-pumped barium vapour like the population development of low-lying levels, the ionisation of the vapour, stimulated infrared emission and radiative transfer, the requirement for a quantitative interpretation of experimental data is fulfilled.

Charles H. Skinner, H. P. Palenius

A. Kallenbach, M Gunther, Rainer Künnemeyer +1 more

Dense barium vapour (10 19 -10 21 m -3 ) produced in a heat-pipe oven is irradiated by pulsed laser light tuned to the Ba I, 6s 2 1 S 0 -6s6p 1 P 1 0 , resonance transition at 553.55 nm. The transient population densities of various Ba I and Ba II states are measured and time-resolved by means of the hook method. Simultaneously, the IR forward scattering (1.5, 1.13, 2.55 mu m) in the barium vapour is measured. Emphasis is laid on the investigation and the interpretation of the IR emission, the 'anomalous' 6p 3 P 2 0 level overpopulation, and of processes which are responsible for the initiation of ionisation. In addition, the radial diffusion of excitation and ionisation energy in a barium vapour pumped with a focused laser pulse is investigated, as well as the energy transfer in a Ba-Sr vapour.

Witold Chałupczak, Wojciech Gawlik, Jerzy Zachorowski

Hans‐A. Bachor, Manfred Kock

A dense barium vapour is illuminated by an intense (2 kW), 1 mu s long, dye laser pulse. The hook technique using an N 2 laser pumped dye laser as a background light source is demonstrated as a fast tool to measure the temporal change in level populations of neutral and ionised barium atoms, with a time resolution of 10 ns.