Resonant Laser Ionization and Fine-Structure Study of Silver in an Ablation Plume

We report on a laser photo-ionization study of silver in relation to the Selective Production of Exotic Species (SPES) project at INFN-LNL in the off-line laser laboratory. In this study, two dye lasers and an ablation laser operating at 10 Hz are used alongside a time-of-flight mass spectrometer (TOF-MS). Isotopic separation of the natural, stable isotopes Ag-107 and Ag-109 was clearly observed in the TOF signal. Resonant photo-ionization of silver was achieved with the use of the scheme 4d(10)5s S-2(1/2)-> 4d(10)5p (2P)(3/2)-> 4d(10)6d (2)D(3/2 )with transition wavelengths of 328.163 nm and 421.402 nm, respectively. Doppler-suppressed spectroscopy of these transition lines was performed in an ablation plume. Doppler broadening with collinear injection of excitation lasers and the effect of the linewidths of the excitation lasers were investigated. The fine-structure splitting of the level 4d(10)6d D-2 (J = 5/2 and J = 3/2) was confirmed to be 186 +/- 2 pm, corresponding to 314 +/- 3 GHz.