PHOTODETACHMENT OF TRAPPED NEGATIVE GOLD IONS - II - OBSERVATION OF WINDOW RESONANCES

We present measurements of photodetachment cross sections of negative gold ions stored in a RF trap, in the energy range from about 4000 cm( -1) to 13 750 cm(-1) above threshold. A number of different laser devi ces have been used. The results complement those described in a previo us paper. The photodetachment spectrum exhibits a strong resonance, lo cated at 23 550 cm(-1) above Au- ground level and a much fainter one a t 24 200 cm(-1). These resonances can be represented as Fano profiles and reveal the presence of autodetaching excited levels of Au- (most p robably 5d(10)6s6p P-3(1) and 5d(9)(5/2)6s(2)6p(3/2) J = 1). Furthermo re, the opening of a new photodetachment channel near 360 nm (correspo nding to the first excited level of neutral Au) is accompanied by an i ncrease of the photodetachment yield.