We have created an atomic beam source of lithium atoms for use in a cryogenic environment. \nThis beam source is expected to provide a \nflux of 10 to the 18 atoms/s. The main features of this source \nare a reservoir chamber of solid lithium heated with heater wire, creating a lithium gas that \ntravels down an ohmically heated tube and exits as an effusive beam. That beam is directed at \na cold supersonic jet of helium. As lithium atoms enter the helium gas they rapidly thermalize \nand become entrained. The design challenges faced included directing the heat load away from \nthe cold elements of the cryogenic chamber, obtaining the correct temperatures to provide the \ndesired \nflux, and measuring the beam as it exited the reservoir. Through the use of laser induced fluorescence, we believe we have observed capture of lithium by the helium jet. Such a beam source \ncan be used to form an intense cold atom source with the potential future application of serving \nas a pump source for an atom laser.We have created an atomic beam source of lithium atoms for use in a cryogenic environment. \nThis beam source is expected to provide a \nflux of 10 to the 18 atoms/s. The main features of this source \nare a reservoir chamber of solid lithium heated with heater wire, creating a lithium gas that \ntravels down an ohmically heated tube and exits as an effusive beam. That beam is directed at \na cold supersonic jet of helium. As lithium atoms enter the helium gas they rapidly thermalize \nand become entrained. The design challenges faced included directing the heat load away from \nthe cold elements of the cryogenic chamber, obtaining the correct temperatures to provide the \ndesired \nflux, and measuring the beam as it exited the reservoir. Through the use of laser induced fluorescence, we believe we have observed capture of lithium by the helium jet. Such a beam source \ncan be used to form an intense cold atom source with the potential future application of serving \nas a pump source for an atom laser.

Jan 1, 20170 citations

Pulsed supersonic beam of cold hydrogen atoms

A. S. Belov, S.A. Kubalov, V.E. Kuzik +1 more

Technical Physics LettersAug 1, 19840 citations

Entrainment of lithium atoms into a supersonic beam and magnetic deceleration

Yu Wei Lu, Lukas Gerhard Georg Gradl, Li-Chung Ha +5 more

Bulletin of the American Physical SocietyJun 8, 20170 citations

Monte Carlo simulations of the capture and cooling of alkali-metal atoms by a supersonic helium jet

Jeremy J. Glick, William Huntington, Michael Borysow +4 more

We present three-dimensional Monte Carlo simulations of the capture of 1000 K $^{7}\mathrm{Li}$ or 500 K $^{87}\mathrm{Rb}$ atoms by a continuous supersonic $^{4}\mathrm{He}$ jet and show that intense, cold alkali-metal beams form. The simulations use differential cross sections obtained from quantum scattering calculations of $^{7}\mathrm{Li}$ or $^{87}\mathrm{Rb}$ atoms with $^{4}\mathrm{He}$ atoms for relative collision energies between $k\ifmmode\times\else\texttimes\fi{}1$ mK and $k\ifmmode\times\else\texttimes\fi{}3000$ K, where $k$ is the Boltzmann constant. For collision energies higher than approximately $k\ifmmode\times\else\texttimes\fi{}4$ K the collisions favor forward scattering, deflecting the $^{7}\mathrm{Li}$ or $^{87}\mathrm{Rb}$ atoms by no more than a few degrees. From the simulations, we find that about 1% of the lithium atoms are seeded into the $^{4}\mathrm{He}$ jet, resulting in a lithium beam with a most probable velocity of about $210\phantom{\rule{0.28em}{0ex}}\mathrm{m}/\mathrm{s}$ and number densities on the order of ${10}^{8}\phantom{\rule{4pt}{0ex}}{\mathrm{cm}}^{\ensuremath{-}3}$. Simulations predict narrow yet asymmetric velocity distributions which are verified by comparing to fluorescence measurements of the seeded $^{7}\mathrm{Li}$ atoms. We find agreement between simulated and experimentally measured seeded $^{7}\mathrm{Li}$ densities to be better than 50% across a range of $^{4}\mathrm{He}$ flow rates. We make predictions for seeding efficiency and cooling of $^{87}\mathrm{Rb}$ by a supersonic $^{4}\mathrm{He}$ jet. The seeding efficiency for $^{87}\mathrm{Rb}$ is expected to be similar to $^{7}\mathrm{Li}$ .We present three-dimensional Monte Carlo simulations of the capture of 1000 K $^{7}\mathrm{Li}$ or 500 K $^{87}\mathrm{Rb}$ atoms by a continuous supersonic $^{4}\mathrm{He}$ jet and show that intense, cold alkali-metal beams form. The simulations use differential cross sections obtained from quantum scattering calculations of $^{7}\mathrm{Li}$ or $^{87}\mathrm{Rb}$ atoms with $^{4}\mathrm{He}$ atoms for relative collision energies between $k\ifmmode\times\else\texttimes\fi{}1$ mK and $k\ifmmode\times\else\texttimes\fi{}3000$ K, where $k$ is the Boltzmann constant. For collision energies higher than approximately $k\ifmmode\times\else\texttimes\fi{}4$ K the collisions favor forward scattering, deflecting the $^{7}\mathrm{Li}$ or $^{87}\mathrm{Rb}$ atoms by no more than a few degrees. From the simulations, we find that about 1% of the lithium atoms are seeded into the $^{4}\mathrm{He}$ jet, resulting in a lithium beam with a most probable velocity of about $210\phantom{\rule{0.28em}{0ex}}\mathrm{m}/\mathrm{s}$ and number densities on the order of ${10}^{8}\phantom{\rule{4pt}{0ex}}{\mathrm{cm}}^{\ensuremath{-}3}$. Simulations predict narrow yet asymmetric velocity distributions which are verified by comparing to fluorescence measurements of the seeded $^{7}\mathrm{Li}$ atoms. We find agreement between simulated and experimentally measured seeded $^{7}\mathrm{Li}$ densities to be better than 50% across a range of $^{4}\mathrm{He}$ flow rates. We make predictions for seeding efficiency and cooling of $^{87}\mathrm{Rb}$ by a supersonic $^{4}\mathrm{He}$ jet. The seeding efficiency for $^{87}\mathrm{Rb}$ is expected to be similar to $^{7}\mathrm{Li}$.

arXiv:2401.13895Physical Review AAug 27, 20241 citation

Intense continuous cold-atom source

William Huntington, Jeremy Glick, Michael Borysow +1 more

The authors demonstrate an intense, continuous cold atomic beam generated via postnozzle seeding of a supersonic ${}^{4}$ He jet with ${}^{7}$ Li atoms, which is comparable to the highest flux sources based on laser cooling. The technique could potentially be widely applicable to any paramagnetic atom or molecule.The authors demonstrate an intense, continuous cold atomic beam generated via postnozzle seeding of a supersonic ${}^{4}$He jet with ${}^{7}$Li atoms, which is comparable to the highest flux sources based on laser cooling. The technique could potentially be widely applicable to any paramagnetic atom or molecule.

Physical Review AJan 6, 20239 citations

We present three-dimensional Monte Carlo simulations of the capture of 1000 K

^{7}\mathrm{Li}

or 500 K

^{87}\mathrm{Rb}

atoms by a continuous supersonic

^{4}\mathrm{He}

jet and show that intense, cold alkali-metal beams form. The simulations use differential cross sections obtained from quantum scattering calculations of

^{7}\mathrm{Li}

^{87}\mathrm{Rb}

atoms with

^{4}\mathrm{He}

atoms for relative collision energies between $k\ifmmode\times\else\texttimes\fi{}1$ mK and $k\ifmmode\times\else\texttimes\fi{}3000$ K, where

k

is the Boltzmann constant. For collision energies higher than approximately $k\ifmmode\times\else\texttimes\fi{}4$ K the collisions favor forward scattering, deflecting the

^{7}\mathrm{Li}

^{87}\mathrm{Rb}

atoms by no more than a few degrees. From the simulations, we find that about 1% of the lithium atoms are seeded into the

^{4}\mathrm{He}

jet, resulting in a lithium beam with a most probable velocity of about

210\phantom{\rule{0.28em}{0ex}}\mathrm{m}/\mathrm{s}

and number densities on the order of ${10}^{8}\phantom{\rule{4pt}{0ex}}{\mathrm{cm}}^{\ensuremath{-}3}$. Simulations predict narrow yet asymmetric velocity distributions which are verified by comparing to fluorescence measurements of the seeded

^{7}\mathrm{Li}

atoms. We find agreement between simulated and experimentally measured seeded

^{7}\mathrm{Li}

densities to be better than 50% across a range of

^{4}\mathrm{He}

flow rates. We make predictions for seeding efficiency and cooling of

^{87}\mathrm{Rb}

by a supersonic

^{4}\mathrm{He}

jet. The seeding efficiency for

^{87}\mathrm{Rb}

is expected to be similar to

^{7}\mathrm{Li}

The authors demonstrate an intense, continuous cold atomic beam generated via postnozzle seeding of a supersonic

{}^{4}

He jet with

{}^{7}

Li atoms, which is comparable to the highest flux sources based on laser cooling. The technique could potentially be widely applicable to any paramagnetic atom or molecule.