Abstract
Doppler-free isotope shift measurements of the stable even Os184-192 and Os-187,Os-189 odd isotopes have been performed for the first time on the 5d (6)6s (2) (5)D(4 ->)5d (6)6s6p F-7(4) (305.9 nm) transition in the neutral atom by atomic beam laser spectroscopy and on the ionic 5d (6)6s (5)D(9/2 ->)5d (6)6p D-6(7/2) (228.2 nm) transition by fast collinear ion-laser spectroscopy. The measurements were carried out in Manchester and at the IGISOL facility in Jyvaskyla in Finland, respectively. The results presented are the most precise measurements to-date of the absolute isotope shifts.