| Abstrakt: |
The photoionization efficiency (PIE) and pulsed field ionization–photoion (PFI-PI) spectra for sulfur atoms S(3P2,1,0) and S(1D2) resulting from the 193.3 nm photodissociation of CS2 have been measured using tunable vacuum ultraviolet (vuv) laser radiation in the frequency range of 82 750–83 570 cm-1. The PIE spectrum of S(3P2,1,0) near their ionization threshold exhibits steplike structures. On the basis of the velocity-mapped ion-imaging measurements, four strong autoionizing peaks observed in the PIE measurement in this frequency range have been identified to originate from vuv excitation of S(1D2). The PFI-PI measurement reveals over 120 previously unidentified new Rydberg lines. They have been assigned as Rydberg states [3p3(4S°)nd3D° (n=17–64)] converging to the ground ionic state S+(4S°) formed by vuv excitations of S(3P2,1,0). The converging limits of these Rydberg series have provided more accurate values, 82 985.43±0.05, 83 162.94±0.05, and 83 559.04±0.05 cm-1 for the respective ionization energies of S(3P0), S(3P1), and S(3P2) to form S+(4S°). The relative intensities of the PFI-PI bands for S(3P0), S(3P1), and S(3P2) have been used to determine the branching ratios for these fine structure states, S(3P0):S(3P1):S(3P2)=1.00:1.54:3.55, produced by photodissociation of CS2 at 193.3 nm. [ABSTRACT FROM AUTHOR] |
