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arXiv · 2203.12974

Spin-state-controlled chemi-ionization reactions between metastable helium atoms and ground-state lithium atoms

Tobias Sixt·Frank Stienkemeier·Katrin Dulitz
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Abstract

We demonstrate the control of $^4$He(2$^3$S$_1$)-$^7$Li(2$^2$S$_{1/2}$) chemi-ionization reactions by all-optical electron-spin-state preparation of both atomic species prior to the collision process. Our results demonstrate that chemi-ionization is strongly suppressed (enhanced) for non-spin-conserving (spin-conserving) collisions at thermal energies. These findings are in good agreement with a model based on spin angular momentum coupling of the prepared atomic states to the quasi-molecular states. Small deviations from the model indicate the contribution of the $^4\Sigma^+$ channel to the reaction rate which is in violation of spin conservation.

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Tobias Sixt, Frank Stienkemeier, Katrin Dulitz. 2022-03-24. Spin-state-controlled chemi-ionization reactions between metastable helium atoms and ground-state lithium atoms. https://doi.org/10.1063/5.0083842

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