ROTATIONAL ANALYSIS OF THE $A ^{2}\Pi \rightarrow X^{2} \Pi$ SYSTEM OF THE SULPHUR MONOXIDE CATION

Author Institution: Department of chemistry, Dalhousie UniversityThe visible $A \rightarrow X$ emission system of $SO^{+}$ is excited by the reaction of $He^{+}$ ions with $SO_{2}$ in a fast flow system. Several bands of the $\nu^{\prime} = 0$ and $\nu^{\prime} = 1$ progressions have been recorded photoelectrically using a. 1.26 m spectrometer operated under computer control. The bands are free of any overlapping structure from other emitters, and the rotational structure is well resolved. Direct least-squares reduction of the measured wavenumbers using merging $techniques^{1,2}$ leads to well determined estimates of the rotational and spin orbit coupling constants in both states, which complement those from the photographic study of Cossart $et al^{2}$. $^{1}$D. L. Albritton, A. L. Schmeltekopf and R. N. Zare, J. Mol. Spectrosc 67, 132 (1977). ${^{2}}$. A. Coxon, J. Mol. Spectrosc. 72, 252 (1976). ${^{3}}$ D.Cossart, H. Lavendy and J. M. Robbe, to be published."