Photofragmentation of third-row hydrides following photoexcitation at deep-core levels

The relaxation dynamics of HCl, DCl, H2S, and D2S following photoexcitation in the vicinities of the Cl and 8 K-shell thresholds (similar to 2.8 keV for Cl, similar to 2.5 keV for S) were studied by means of ion time-of-flight mass spectroscopy. In all cases; the onset of pre-edge core-shell photoionization precedes the formation on resonance of a significant amount of neutral hydrogen as well as postcollision-interaction effects above threshold. Examination of the width of the H+ peak in spectra taken with the analyzer parallel and perpendicular to the polarization vector of the incident light indicates that on resonance, the photofragmentation asymmetry parameter, beta, is approximately two for HCl, and is clearly positive for H2S. [S1050-2947(98)08211-0].