CO vibrational distributions to high levels in low-pressure CO/He mixtures

Experimental measurement of the first- and second-overtone spontaneous-emissions spectrum in a low-pressure CO/He plasma has enabled determination of the vibrational distribution up to v=30. The variation in the CO distribution as a function of CO and He partial pressure and plasma current has been correlated by a detailed model of the steady-state energy-transfer dynamics. The agreement between calculated and measured distributions has generated a consistent set of rate coefficients for CO/He mixtures for a temperature around 150 K.