Le Journal de Physique Colloques
OBSERVATION OF THE 5dnl EVEN DOUBLY-EXCITED STATES IN NEUTRAL BARIUM USING TWO-STEP OPTOGALVANIC SPECTROSCOPY
Pierre Camus, M. Dieulin, A. El Himdy
Abstract
Even parity levels of neutral barium above the 6s ionization limit have been investigated by using a two-step pulsed laser excitation associated with optogalvanic detection of the optical resonances. From the metastable states, 5d6s, populated by a d.c. discharge in a heat-pipe vapour, the doubly excited 5dnl Rydberg series with J values ranging from 0 to 5 and the 6p2 1S0 levels have been observed in the continuum between the first 6s and the second 5d ionization limits of Ba I.