A Mechanical Means of Producing Cold, Slow Beams of Molecules

This thesis reports on the combination of buffer-gas cooling with electric velocity filtering to produce a high-density guided beam of slow and internally cold polar molecules. In the continuous source, warm molecules are first cooled by collisions with a cryogenic helium buffer gas. Cold molecules are then extracted by means of an electric quadrupole guide. For formaldehyde the population of individual rotational states in the guide is monitored by depletion spectroscopy, resulting in single-state populations up to 82 %. This thesis also reports on a technique to produce pulses of slow guided molecules. The pulses exhibit a narrow velocity distribution around a tunable velocity.This thesis reports on the combination of buffer-gas cooling with electric velocity filtering to produce a high-density guided beam of slow and internally cold polar molecules. In the continuous source, warm molecules are first cooled by collisions with a cryogenic helium buffer gas. Cold molecules are then extracted by means of an electric quadrupole guide. For formaldehyde the population of individual rotational states in the guide is monitored by depletion spectroscopy, resulting in single-state populations up to 82 %. This thesis also reports on a technique to produce pulses of slow guided molecules. The pulses exhibit a narrow velocity distribution around a tunable velocity.

Jan 1, 20110 citations

Improved setup for producing slow beams of cold molecules using a rotating nozzle

M. Strebel, Frank Stienkemeier, Marcel Carto Constantin Mudrich

Intense beams of cold and slow molecules are produced by supersonic expansion out of a rapidly rotating nozzle, as first demonstrated by M. Gupta and D. Herschbach [J. Phys. Chem. A 103, 10670 (1999); 105, 1626 (2001)]. An improved setup is presented that is able to accelerate or decelerate cold atomic and molecular beams by up to 500 m/s. Technical improvements are discussed and beam parameters are characterized by detailed analysis of time-of-flight density distributions. The possibility of combining this beam source with electrostatic fields for guiding polar molecules is demonstrated.Intense beams of cold and slow molecules are produced by supersonic expansion out of a rapidly rotating nozzle, as first demonstrated by M. Gupta and D. Herschbach [J. Phys. Chem. A 103, 10670 (1999); 105, 1626 (2001)]. An improved setup is presented that is able to accelerate or decelerate cold atomic and molecular beams by up to 500 m/s. Technical improvements are discussed and beam parameters are characterized by detailed analysis of time-of-flight density distributions. The possibility of combining this beam source with electrostatic fields for guiding polar molecules is demonstrated.

arXiv:0910.3278Physical Review AMar 17, 201038 citations

Cold and Slow Molecular Beam

Aug 17, 20160 citations

Electrostatic Extraction of Cold Molecules from a Cryogenic Reservoir

L. D. van Buuren, Christian Sommer, M. Motsch +5 more

We present a method which delivers a continuous, high-density beam of slow and internally cold polar molecules. In our source, warm molecules are first cooled by collisions with a cryogenic helium buffer gas. Cold molecules are then extracted by means of an electrostatic quadrupole guide. For ${\mathrm{ND}}_{3}$ the source produces fluxes up to $(7{\ifmmode\pm\else\textpm\fi{}}_{4}^{7})\ifmmode\times\else\texttimes\fi{}{10}^{10}\text{ }\text{ }\mathrm{\text{molecules}}/\mathrm{s}$ with peak densities up to $(1.0{\ifmmode\pm\else\textpm\fi{}}_{0.6}^{1.0})\ifmmode\times\else\texttimes\fi{}{10}^{9}\text{ }\text{ }\mathrm{\text{molecules}}/{\mathrm{cm}}^{3}$. For ${\mathrm{H}}_{2}\mathrm{CO}$ the population of rovibrational states is monitored by depletion spectroscopy, resulting in single-state populations up to $(82\ifmmode\pm\else\textpm\fi{}10)%$.We present a method which delivers a continuous, high-density beam of slow and internally cold polar molecules. In our source, warm molecules are first cooled by collisions with a cryogenic helium buffer gas. Cold molecules are then extracted by means of an electrostatic quadrupole guide. For ${\mathrm{ND}}_{3}$ the source produces fluxes up to $(7{\ifmmode\pm\else\textpm\fi{}}_{4}^{7})\ifmmode\times\else\texttimes\fi{}{10}^{10}\text{ }\text{ }\mathrm{\text{molecules}}/\mathrm{s}$ with peak densities up to $(1.0{\ifmmode\pm\else\textpm\fi{}}_{0.6}^{1.0})\ifmmode\times\else\texttimes\fi{}{10}^{9}\text{ }\text{ }\mathrm{\text{molecules}}/{\mathrm{cm}}^{3}$. For ${\mathrm{H}}_{2}\mathrm{CO}$ the population of rovibrational states is monitored by depletion spectroscopy, resulting in single-state populations up to $(82\ifmmode\pm\else\textpm\fi{}10)%$.

arXiv:0806.2523Physical Review LettersJan 21, 200993 citations

Slow beams of massive molecules

Sarayut Deachapunya, P. J. FAGAN, Andras Major +5 more

arXiv:0708.1449The European Physical Journal DOct 23, 200741 citations

{\mathrm{ND}}_{3}

the source produces fluxes up to $(7{\ifmmode\pm\else\textpm\fi{}}_{4}^{7})\ifmmode\times\else\texttimes\fi{}{10}^{10}\text{ }\text{ }\mathrm{\text{molecules}}/\mathrm{s}$ with peak densities up to $(1.0{\ifmmode\pm\else\textpm\fi{}}_{0.6}^{1.0})\ifmmode\times\else\texttimes\fi{}{10}^{9}\text{ }\text{ }\mathrm{\text{molecules}}/{\mathrm{cm}}^{3}$. For

{\mathrm{H}}_{2}\mathrm{CO}

the population of rovibrational states is monitored by depletion spectroscopy, resulting in single-state populations up to $(82\ifmmode\pm\else\textpm\fi{}10)%$.