QUANTUM NUMBER AND TEMPERATURE DEPENDENCE OF THE LINE BROADENING IN THE $\nu_{1}$ AND $\nu_{3}$ BANDS OF $SO_{2}$

Abstract

We present results on the line broadening in the $\nu_{1}$ and $\nu_{3}$ bands of $SO_{2}$, studied with a three-channel diode laser spec-trometer. We obtained the pressure broadening coefficients $\gamma$ for the perturbers $SO_{2}$, $N_{2}$, and air at room temperature for 30 lines with $5 \leq J^{\prime\prime} \leq 44$ and $0 \leq {K_{a}}^{\prime\prime} \leq 23$ of the $\nu_{1}$ band and 6 lines with $4 \leq J^{\prime\prime} \leq 60$ and $0 \leq K_{a}^{\prime\prime} \leq 18$ of the $\nu_{3}$ band. The quantum number dependence of $\gamma$ will be compared with theoretical calculations for collisions with $SO_{2}$ and $N_{2}$ by $Tejwani^{-1}$ using Anderson-Tsao-Cumutte theory. Especially, the $K_{4}^{\prime\prime}$ dependence of $\gamma$ in the case of self-broadening is well reproduced, whereas for nitrogen the deviations are remarkable. Beside this we will present our first results on the temperature dependence $(250K < T < 300K)$ of the broadening coefficient for some lines of the $\nu_{3}$ band for collisions with $N_{2}$ and $SO_{2}$. For these perturbers we tried to determine line shift coefficients by measuring the line position at a fixed pressure and the position of the same line at different higher pressures.