PUMP-AND-PROBE STUDIES OF THE E1(6(3)S1)[-A0+(5(3)P1) EXCITATION SPECTRUM OF CDAR IN A SUPERSONIC BEAM

The pump-and-probe method of laser spectroscopy in conjunction with a jet-expansion molecular beam was used to record the excitation spectrum arising from E1(6S-3(1)) <-- A0+(5P-3(1)) vibronic transitions in the CdAr excimer. Two lasers were employed for the two-step excitation. A Nd:YAG (where YAG denotes yttrium aluminum garnet) laser-pumped dye laser (pump laser) was tuned to the A0+(v = 5) <-- X0+(v = 0) transition, producing a population of the A0+ state that was subsequently excited with a N2 laser-pumped dye laser (probe laser) to the E1(6S-3(1)) state. The probe laser was scanned in the range 4735-5060 angstrom, producing a vibronic excitation spectrum that consisted of about 20 components. The spectrum was subjected to vibrational analysis, and the assignments of the components were made with the aid of a computer-simulated spectrum based on Franck-Condon factors calculated assuming the Morse potential as representative of the upper and lower states. The analysis yielded D(e), omega(e), omega(e)x(e), and r(e) for the E1 state. The potential-energy curve for the E1 state is compared with a theoretical curve calculated by Czuchaj and Sienkiewicz [J. Phys. B 17, 225 (1984)] and by Czuchaj, Stoll, and Preuss [J. Phys. B 20, 1487 (1986)].