Anomalous line shapes associated with the 33Pstate of atomic oxygen

Abstract
The 33P–53S transition in atomic oxygen at 725.4 nm has been studied in a weak discharge using the optogalvanic effect with a cw tunable dye laser. The transition appears as a superposition of at least two components with different centroids and widths. The anomalous line shape is probably due to the long-range interaction of 3P oxygen with 4 S0 oxygen ions.