RESONANCE-ENHANCED MULTIPHOTON IONIZATION SPECTRA OF THE E0(+)(P-3(2)) AND F0(+)(P-3(0)) ION-PAIR STATES OF ICL

The 2 + 1 resonance enhanced multiphoton ionization (REMPI) spectrum of ICI has been recorded in the two-photon energy region 57 500-64 200 cm(-1). A wide range of vibrational levels (nu' = 203-387) in the E0(+)-(P-3(2)) ion-pair state has been observed using jet-cooling, and data for these levels are reported and analyzed. Pronounced dip-resonance structure was observed which results from coupling: between the E0(+)(P-3(2)) ion-pair state and the b(6)0(+) Rydberg state. Parts of the b(6), b'(6) <- X Rydberg systems have also been observed directly. Double-resonance ionization nozzle-cooled spectroscopy (DRINCS) has been used to populate nu' = 96-129 of the E0(+)(P-3(2)) State and nu' = 40-75 of the f0(+)(P-3(0)) state. These levels, combined with the REMPI data, produce improved vibrational constants for both states.