Rotational analysis of high resolution F.T. spectrum of a’ 3Σ- a 3Π transition of CS molecule

The F. T. Spectrum of CS molecule was recorded with Bruker IFS 120 HR spectrometer at a spectral resolution of 0.03 cm$^{-1}$ using liquid nitrogen cooled InSb detector in the region 10500 - 1800 cm$^{-1}$. Intense spectrum of CS radical was excited by DC discharge of mixture of CS$_{2}$ (120 mTorr) and He (2 Torr) in flowing condition. Two hours integration time was used for obtaining a good S/N ratio. For the first time seven bands of a’ $^{3}$$\Sigma$ - a $^{3}$$\Pi$ transition of CS molecule are observed lying between 8000 - 4800 cm$^{-1}$ region. Rotational analysis of these bands, viz. 7-1, 6-1, 5-0, 4-0, 3-0, 2-0, and 3-1 will be presented