UV spectra of ArH and ArD as emitted by a neutralized ion beam

Abstract

UV spectra of ArH and ArD can be observed after neutralizing an ionic beam of ArH+ and ArD+, respectively, in Cs vapor. The spectra are continuous and range in wavelength from 200 to 450 nm. Earlier lifetime measurements suggested that at least the E2Π and B2Π states contribute to the UV continua, which is supported by simulating the UV spectra starting from ab initio calculated potential curves and dipole transition moments supplied by Theodorakopoulos and Petsalakis. Using the original potentials, the short-wavelength part [Formula: see text] of the spectra could be fitted well, but for longer wavelengths a discrepancy between theoretical and experimental spectra remained. A change of the dissociative ground-state potential curve improved the fit decisively for both ArH and ArD.