CAVITY RING-DOWN SPECTROSCOPY OF PHOTOCHEMICALLY PRODUCED NAH FOR THEDETERMINATION OF RELATIVE DIPOLE TRANSITION MOMENTS

Cavity ring-down spectroscopy (CRDS) has been used for spectroscopic s tudies and to measure dipole transition moments of photochemically pro duced sodium hydride. In our experiment, NaH was formed within the cav ity after 3s-3p excitation of sodium in a hydrogen atmosphere with a s econd dye laser. The reaction product, sodium hydride, was probed in t he near-UV part of the absorption spectrum at 382 nm with a 4 mu s del ay to the excitation pulse using the cavity ring-down technique employ ing a pulsed laser source. Dipole transition moments of the order of 1 .0 x 10(-30) Cm of isolated lines in the A(1) Sigma(+) <-- X-1 Sigma() NaH transition band were measured.