Radiative lifetimes in MoI using a novel atomic beam source

Abstract

Radiative lifetimes of the 4d 5 (a 6S)5pz 7P o levels and the 4d 5 (a 6S)5pz 5P o levels in MoI are reported as follows: τ( z 7 P 4 O ) = 15.9 ns , τ( z 7 P 3 O ) = 17.0 ns , τ( z 7 P 2 O ) = 17.1 ns , τ( z 5 P 3 O ) = 22.3 ns , τ( z 5 P 2 O ) = 22.1 ns , and τ( z 5 P 1 O ) = 21.7 ns (±5%). The lifetimes are measured using time resolved laser induced fluorescence and a novel atomic beam source. This novel hollow cathode effusive beam source produces an intense beam of ground state Mo atoms and metastable Mo atoms. Our measurements on the z 7P O levels are in agreement with earlier lifetime measurements. Our measurements on the z 5P O levels are the first direct radiative lifetime measurements of these levels; the z 5P O measurements are of particular interest because the a 5S → z 5P O multiplet is used to determine the solar abundance of Mo.