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Getting the elastic scattering length by observing inelastic collisions in ultracold metastable helium atoms

Signe Seidelin·Rodolphe Hoppeler·Olivier Sirjean·Denis Boiron·Alain Aspect·Christoph I. Westbrook·Jose Viana Gomes
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Abstract

We report an experiment measuring simultaneously the temperatureand the flux of ions produced by a cloud of triplet metastablehelium atoms at the Bose-Einstein critical temperature. The onsetof condensation is revealed by a sharp increase of the ion fluxduring evaporative cooling. Combining our measurements withprevious measurements of ionization in a pure BEC,we extract an improved value of the scattering length$a=11.3^{+2}_{-1}$ nm. The analysis includes corrections takinginto accountthe effect of atomic interactions on the criticaltemperature, and thus an independent measurement of the scatteringlength would allow a new test of these calculations.

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Signe Seidelin, Rodolphe Hoppeler, Olivier Sirjean, Denis Boiron, Alain Aspect, Christoph I. Westbrook, Jose Viana Gomes. 2004-08-31. Getting the elastic scattering length by observing inelastic collisions in ultracold metastable helium atoms. https://doi.org/10.1103/physrevlett.93.090409

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