DETECTION OF DCL BY MULTIPHOTON IONIZATION AND DETERMINATION OF DCL AND HCL INTERNAL STATE DISTRIBUTIONS

A study of the 2 + 1 resonantly enhanced multiphoton ionization (REMPI ) spectrum of DCl is reported. Transition energies for excitation of t he F-1 Delta-X(1) Sigma(+) (0,0) and (1,0) bands, as well as the V-1 S igma(+)-X(1) Sigma(+)(upsilon',0) bands, for upsilon' = 15-19, are pre sented. The derived molecular constants for the F-X (0,0) and the V-X bands agree well with those previously obtained from analysis of the o ne-photon VUV absorption spectrum [A. E. Douglas and F. R. Greening, C an. J. Phys. 57, 1650 (1979)]. The ion signals for excitation through various rotational lines in the E-X (0,0) and F-X (0,0) and (1,0) band s are compared with theoretical two-photon line strengths. Extensive p ower- and J'-dependent ion fragmentation is observed for the former ba nd. No fragmentation is observed in the F-X bands; however, the ion si gnal strengths are found to vary strongly with J'. This variation of R EMPI signal strengths vs J' was shown to be due to an indirect prediss ociation, as in HCl. Tables of experimental line strength factors for the F-X (0,0) and (1,0) bands of HCl and DCl are reported. Finally, th e relative REMPI detection sensitivities for HCl and DCl, through thei r respective F-X (0,0) R(1) Lines, are compared. (C) 1996 American Ins titute of Physics.