Photodissociation of rare gas cluster ions: Ar+3

Abstract

The photodissociation spectrum of the mass selected cluster ion Ar+3, produced by electron impact ionization of a supersonic cluster beam, has been measured for the first time. Measurements over the wavelength range 539 to 620 nm show the cross section to rise and peak near 545 nm and then decrease steadily throughout the longer wavelength range; the magnitude of the cross section is found to be smaller than the corresponding 2Σ+u→2Σ+g transition of Ar+2 in agreement with some theoretical predictions. Interestingly, Ar+ is the only detected photoproduct.