On the operator connecting thepq- andqp-symbols on a hyperboloid of one sheet

Abstract

We report direct measurements of the photodissociation of Na; ions created when a Na vapour in the density range 1012-1013 is irradiated by a pulsed laser with intensities in the 105-106 W cm-' range. The Na; ions, accelerated by a weak electric field, are photodissociated in a second laser beam tuned to 6040 A.In a preliminary experiment the Na; ions are formed in the lowest vibrational levels and the measured photodissociation cross section is compared with existing calculations.When the Na vapour is irradiated at one of the 3S1,2-3P1/2.3,2 resonances the photodissociation measurements show the existence of a distribution of rovibrational excited levels of the Na: ions. A discussion is given in terms of associative ionisation in collisions of two Na(3p) atoms.The origin of the Na' ions produced simultaneously with the Na; ions, in the vapour irradiated at resonance, is also discussed.