FLUORESCENCE EXCITATION-SPECTRA OF JET-COOLED HGBR RADICALS

Fluorescence excitation spectra of HgBr radicals produced and rotationally cooled in a corona-excited supersonic jet discharge are presented. Both the C2PI1/2 <-- X2SIGMA+ transition near 287.6 nm and the B2SIGMA+ <-- X2SIGMA+ transition near 350.0 nm were studied. Transitions from X2SIGMA+ (v(X) = 0-2) probe very high vibrational levels in the B2SIGMA+ ion-pair state (v(B) = 34-90). Analysis of the vibrationally and isotopically resolved spectral features has yielded an unambiguous vibrational numbering for the B <-- X spectrum and precise B-state vibrational constants which are valid between v(B) =0-90.