Absorption Spectroscopy of (8,1) Band in d³△-a³ПSystem of CS Radical

The CS radical was generated by discharging the mixture gas of CS₂ and Helium. The Doppler limited spectra of CS were recorded in the region of 12350～12950 cm^-1 using optical heterodyne concentration modulation absorption spectroscopy. Three hundred and twenty-six lines were recorded and assigned to the d³△-a³П(8,1) band, in which eighty-three transitions were first observed. A set of improved molecular constants for the d³△(v=8) and a³П(8,1)(v=1) levels were determined by a non-linear least-squares fitting of all the lines to the effective Hamiltonian.