Inelastic collisions of CaH with He at cryogenic temperatures

Singh, Vijay and Hardman, Kyle S. and Lu, Mei-Ju and Ellis, Aja and Morrison, Muir J. and Weinstein, Jonathan D. 2013. Inelastic collisions of CaH with He at cryogenic temperatures. Molecular Physics: An International Journal at the Interface Between Chemistry and Physics. 111 (12-13): pp. 1711-1715.

Source Title

Molecular Physics

DOI

10.1080/00268976.2013.772668

ISSN

0026-8976

Remarks

This is an Author's Accepted Manuscript of an article published in the Molecular Physics: An International Journal at the Interface Between Chemistry and Physics, (2013), copyright Taylor & Francis, available online at: <a href="http://www.tandfonline.com/">http://www.tandfonline.com/</a>. doi: 10.1080/00268976.2013.772668

URI

http://hdl.handle.net/20.500.11937/29030

Collection

Curtin Research Publications

Abstract

Using helium buffer gas cooling, we have prepared dense samples of ground-state molecular calcium monohydride (CaH X 2Σ) at cryogenic temperatures. We have used optical pumping to polarise the spin state of the CaH molecules and we have measured the inelastic collisions of molecular CaH with atomic helium at temperatures from 2 to 7 K. The measured CaH electronic spin depolarisation rate coefficient increases rapidly with increasing temperature, increasing from 2 × 10−13 cm3 s−1 to over 10−11 cm3 s−1. The strong dependence of rate coefficient on temperature is attributed to the CaH population in the first excited rotational state.