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Homonuclear ionizing collisions of laser-cooled metastable helium atoms

R. J. W. Stas·J. M. McNamara·W. Hogervorst·W. Vassen
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Abstract

We present a theoretical and experimental investigation of homonuclear ionizing collisions of laser-cooled metastable helium atoms, considering both the fermionic He-3 and bosonic He-4 isotope. The theoretical description combines quantum threshold behavior, Wigner's spin-conservation rule and quantum statistical symmetry requirements in a single-channel model, complementing a more complete close-coupling theory that has been reported for collisions of metastable He-4 atoms. The model is supported with measurements (in the absence of light fields) of ionization rates in magneto-optically trapped samples, that contain about 3*10^8 atoms of a single isotope. The ionization rates are determined from measurements of trap loss due to light-assisted collisions combined with comparative measurements of the ion production rate in the absence and presence of trapping light. Theory and experiment show good agreement.

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R. J. W. Stas, J. M. McNamara, W. Hogervorst, W. Vassen. 2006-01-18. Homonuclear ionizing collisions of laser-cooled metastable helium atoms. https://doi.org/10.1103/physreva.73.032713

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