LIF and CRDS techniques for the study of helium and argon relaxation effects on the CaBr ground state formed via chemical reaction

Abstract

The effect of the nature of the buffer gas on the rotational and vibrational relaxation of the population distribution of CaBr in the X²Σ⁺ state has been studied by laser-induced fluorescence and cavity ring down spectroscopy. The CaBr radical was formed in a Broida oven by reaction with gaseous CHBr₃, and two different carrier gases, Ar and He, were used. Although the two carrier gases have a similar effect on the rotational population distributions, helium is observed to strongly relax the vibrational distribution.

Keywords:

• LIF
• CRDS
• Relaxation
• He
• Ar
• CaBr

Acknowledgements

We thank J. Rostas for very helpful collaboration and discussions and Professor R.W. Field for a very efficient reading of the manuscript.