Optimized cell geometry for buffer-gas-cooled molecular-beam sources
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 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.
Cite
@article{arxiv.1801.10586,
title = {Optimized cell geometry for buffer-gas-cooled molecular-beam sources},
author = {Vijay Singh and Amit K. Samanta and Nils Roth and Daniel Gusa and Tim Ossenbrüggen and Igor Rubinsky and Daniel A. Horke and Jochen Küpper},
journal= {arXiv preprint arXiv:1801.10586},
year = {2018}
}