Molecular emission in the electron-impact excitation of sulphur dioxide

Abstract

Electron-impact excitation of sulphur dioxide at energies greater than the threshold energy (3.85 ± 0.4 eV) results in optical emission mainly from the B¹B₁ state of sulphur dioxide. Optical emission excitation functions have been determined at several wavelengths and demonstrate that the primary excitation process(es) is dominated by production of optically forbidden triplet states. The observed emission arises from intersystem crossing from these triplet states into the fluorescing B¹B₁ state.