Lifetime measurement of the NaI 4d level using the selective excitation of fast ion beams by a laser

Abstract

The technique of stepwise excitation of a fast ion beam is used for lifetime measurements. The 42D level of a sodium atom in a fast beam is populated by the gas laser two-step excitation process. The lifetime is determined from the single decay curve of the fluorescence light intensity downstream. The result obtained for the NaI 4d level is 50.7 ± 0.5 nsec.