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arXiv · 1801.10586

Optimized cell geometry for buffer-gas-cooled molecular-beam sources

Vijay Singh·Amit K. Samanta·Nils Roth·Daniel Gusa·Tim Ossenbrüggen·Igor Rubinsky·Daniel A. Horke·Jochen Küpper
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Abstract

We have designed, constructed, and commissioned a cryogenic helium buffer-gas source for producing a cryogenially-cooled molecular beam and evaluated the effect of different cell geometries on the intensity of the produced molecular beam, using ammonia as a test molecule. Planar and conical entrance and exit geometries are tested. We observe a three fold enhancement in the NH$_3$ signal for a cell with planar-entrance and conical-exit geometry, compared to that for a typically used `box'-like geometry with planar entrance and exit. These observations are rationalized by flow-field simulations for the different buffer-gas cell geometries. The full thermalization of molecules with the helium buffer-gas is confirmed through rotationally-resolved REMPI spectra yielding a rotational temperature of 5 K.

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Vijay Singh, Amit K. Samanta, Nils Roth, Daniel Gusa, Tim Ossenbrüggen, Igor Rubinsky, Daniel A. Horke, Jochen Küpper. 2018-01-31. Optimized cell geometry for buffer-gas-cooled molecular-beam sources. https://doi.org/10.1103/physreva.97.032704

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