Ω-type doubling reversal in the B 3II1 state of 200HgAr as a probe of the long-range potential of the A 3II0+ state

Abstract

The mass-resolved excitation spectrum of the B 3II1-X 1Σ+ transition of HgAr was measured by the two-color resonantly enhanced two-photon ionization method using a high-resolution reflectron time-of-flight mass spectrometer. The rotational structures were recorded with high spectral resolution (∼0.05 cm-1) for the (υB,0) bands (υB = 0-9) of a single isotopomer 200HgAr. From the rotational analysis, the presence of an Ω-type doubling was identified for the first time, which is caused by the rotational perturbation from the nearby highly excited vibrational levels of the A 3Π0+ state. The spacing between the Ω-type doublets was found to exhibit a characteristic reversal as a function of υB. From the deperturbation of the Ω-type doubling, the vibrational level energies of the A state in the vibrationally highly excited region were derived, from which its long-range interaction potential was determined. © 1998 American Institute of Physics.