© 2026 Aqora Quantum S.A.S.

Terms Privacy Legal Notice

arXiv:0708.1743 · Physical Review A

Production of long-lived atomic vapor inside high-density buffer gas

Alexander O. Sushkov, Dmitry Budker

Published Apr 9, 2008• 25 citations

Abstract

Atomic vapor of four different paramagnetic species: gold, silver, lithium, and rubidium, is produced and studied inside several buffer gases: helium, nitrogen, neon, and argon. The paramagnetic atoms are injected into the buffer gas using laser ablation. Wires with diameters 25, 50, and $100\text{ }\ensuremath{\mu}\text{m}$ are used as ablation targets for gold and silver; bulk targets are used for lithium and rubidium. The buffer gas cools and confines the ablated atoms, slowing down their transport to the cell walls. Buffer gas temperatures between 20 and 295 K and densities between ${10}^{16}\text{ }{\text{cm}}^{\ensuremath{-}3}$ and $2\ifmmode\times\else\texttimes\fi{}{10}^{19}\text{ }{\text{cm}}^{\ensuremath{-}3}$ are explored. Peak paramagnetic atom densities of ${10}^{11}\text{ }{\text{cm}}^{\ensuremath{-}3}$ are routinely achieved. The longest observed paramagnetic vapor density decay times are 110 ms for silver at 20 K and 4 ms for lithium at 120 K. The candidates for the principal paramagnetic-atom loss mechanism are impurities in the buffer gas, dimer formation, and atom loss on sputtered clusters.

DOI: 10.1103/physreva.77.042707

Related papers

Cold, optically dense gases of atomic rubidium

Sofia Magkiriadou, David Patterson, T Nicolas +1 more

Cold and optically dense gases of atomic rubidium are produced using buffer gas cooling in combination with rapid, high-flow vapor injection. The observed rubidium density is 3 × 10 12 cm −3 at a gas temperature of ∼20 K, leading to an optical density of the order of 200.

New Journal of Physics•Feb 3, 2011•8 citations

Properties of Alkali Atoms Confined in a Cold Helium Gas

A. Hatakeyama, Katsunari Enomoto, T. Yabuzaki

Properties of alkali atoms (mainly rubidium and cesium) in a cold helium gas have been extensively studied. Experiments are performed at temperatures down to 1.2 K using alkali-metal vapor cells containing a helium buffer gas, with alkali atoms driven from the cell walls by one of three loading methods: laser ablation, light-induced atom desorption, and spark discharge. For alkali atoms loaded into the cold helium gas, we have found that the relaxation time of the electronic spin of optically polarized rubidium atoms in the ground state is about a minute, much longer than that achieved in conventional vapor cells at room temperature and above. We have also spectroscopically investigated the interactions of excited alkali atoms with helium atoms, especially the formation of alkali–He exciplexes.

Physica Scripta•Jan 1, 2004•7 citations

Magnetic Trapping of Silver and Copper, and Anomalous Spin Relaxation in the Ag-He System

Nathan Brahms, Bonna K. Newman, Cort Johnson +3 more

We have trapped large numbers of copper (Cu) and silver (Ag) atoms using buffer-gas cooling. Up to $3\ifmmode\times\else\texttimes\fi{}{10}^{12}\text{ }\text{ }\mathrm{Cu}$ atoms and $4\ifmmode\times\else\texttimes\fi{}{10}^{13}\text{ }\text{ }\mathrm{Ag}$ atoms are trapped. Lifetimes are as long as 5 s, limited by collisions with the buffer gas. Ratios of elastic to inelastic collision rates with He are $\ensuremath{\gtrsim}{10}^{6}$, suggesting Cu and Ag are favorable for use in ultracold applications. The temperature dependence of the $\mathrm{Ag}\mathrm{\text{\ensuremath{-}}}^{3}\mathrm{He}$ collision rate varies as ${T}^{5.8\ifmmode\pm\else\textpm\fi{}0.4}$. We find that this temperature dependence is inconsistent with the behavior predicted for relaxation arising from the spin-rotation interaction, and conclude that the $\mathrm{Ag}\mathrm{\text{\ensuremath{-}}}^{3}\mathrm{He}$ system displays anomalous collisional behavior in the multiple-partial wave regime. Gold (Au) was ablated into $^{3}\mathrm{He}$ buffer gas, however, atomic Au lifetimes were observed to be too short to permit trapping.

arXiv:0804.0766•Physical Review Letters•Sep 4, 2008•36 citations

Hyperfine Relaxation of Optically Pumped Rb87 Atoms in Buffer Gases

Maurice Arditi, T. R. Carver

The hyperfine relaxation of a population difference, produced by optical pumping, between the $F=1$ ${m}_{F}=0$ and $F=2$ ${m}_{F}=0$ energy levels of the ground state of ${\mathrm{Rb}}^{87}$, has been studied in cells containing neon, argon, helium, or krypton as a buffer gas. The relaxation times ${T}_{1}$ and ${T}_{2}$ have been measured as a function of the rubidium vapor pressure in the cell. The relaxation rate due to spin exchange in ${\mathrm{Rb}}^{87}$-${\mathrm{Rb}}^{87}$ collisions has been found equal to 65 ${\mathrm{sec}}^{\ensuremath{-}1}$ at 44\ifmmode^\circ\else\textdegree\fi{}C, and the diffusion coefficients of ${\mathrm{Rb}}^{87}$ atoms in He, Ne, and Ar evaluated as 0.6, 0.31, and 0.22 ${\mathrm{cm}}^{2}$ ${\mathrm{sec}}^{\ensuremath{-}1}$, respectively. The cross section for ${\mathrm{Rb}}^{87}$-Ne and ${\mathrm{Rb}}^{87}$-Ar collisions are found to be 1.6\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}22}$ ${\mathrm{cm}}^{2}$ and 9\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}22}$ ${\mathrm{cm}}^{2}$. These values are in general agreement with values previously obtained by other methods. The extrapolated values of $\frac{1}{{T}_{2}}$ for zero vapor pressure of rubidium are 185, 237, and 318 ${\mathrm{sec}}^{\ensuremath{-}1}$ for Ne, He, or Ar, respectively. Relaxations by the pumping light or by the magnetic field inhomogeneities are also discussed.

Physical Review•Nov 2, 1964•38 citations

Magnetic trapping of NH molecules with 20 s lifetimes

Edem Tsikata, Wesley C. Campbell, Matthew T. Hummon +2 more

Buffer gas cooling is used to trap NH molecules with 1/ e lifetimes exceeding 20 s. Helium vapor generated by laser desorption of a helium film is employed to thermalize 10 5 molecules at a temperature of 500 mK in a 3.9 T magnetic trap. Long molecule trapping times are attained through rapid pumpout of residual buffer gas. Molecules experience a helium background gas density below 1 × 10 12 cm −3 .

New Journal of Physics•Jun 28, 2010•40 citations

Room temperature buffer gas beam of metastable state titanium atoms

Jackson Schrott, Scott Eustice, Dan Stamper-Kurn

We produce beams of neutral titanium (Ti) atoms in their metastable 3d3(F4)4sa5F5 state by laser ablation into He, N2, and Ar buffer gases. The high temperatures associated with the ablation process populate the a5F5 level without the need for optical pumping. Remarkably, we observe that Ti atoms in the a5F5 state survive thousands of collisions with He and Ar buffer gas atoms without being quenched to lower-energy states. We study the yield of Ti atoms when ablated into buffer gases of varying species and pressure, quantify quenching rates and diffusion cross sections based on simple models, and provide insight into optimal design parameters for an ablation cell. Using a 3.3 cm ablation cell with interchangeable exit apertures, we produce metastable atom beams and quantify their brilliance and velocity distributions as functions of buffer gas pressure.

arXiv:2410.02876•Review of Scientific Instruments•Apr 1, 2025•1 citation

Atomic vapor of four different paramagnetic species: gold, silver, lithium, and rubidium, is produced and studied inside several buffer gases: helium, nitrogen, neon, and argon. The paramagnetic atoms are injected into the buffer gas using laser ablation. Wires with diameters 25, 50, and

100\text{ }\ensuremath{\mu}\text{m}

are used as ablation targets for gold and silver; bulk targets are used for lithium and rubidium. The buffer gas cools and confines the ablated atoms, slowing down their transport to the cell walls. Buffer gas temperatures between 20 and 295 K and densities between

{10}^{16}\text{ }{\text{cm}}^{\ensuremath{-}3}

and

2\ifmmode\times\else\texttimes\fi{}{10}^{19}\text{ }{\text{cm}}^{\ensuremath{-}3}

are explored. Peak paramagnetic atom densities of

{10}^{11}\text{ }{\text{cm}}^{\ensuremath{-}3}

are routinely achieved. The longest observed paramagnetic vapor density decay times are 110 ms for silver at 20 K and 4 ms for lithium at 120 K. The candidates for the principal paramagnetic-atom loss mechanism are impurities in the buffer gas, dimer formation, and atom loss on sputtered clusters.

Properties of alkali atoms (mainly rubidium and cesium) in a cold helium gas have been extensively studied. Experiments are performed at temperatures down to 1.2 K using alkali-metal vapor cells containing a helium buffer gas, with alkali atoms driven from the cell walls by one of three loading methods: laser ablation, light-induced atom desorption, and spark discharge. For alkali atoms loaded into the cold helium gas, we have found that the relaxation time of the electronic spin of optically polarized rubidium atoms in the ground state is about a minute, much longer than that achieved in conventional vapor cells at room temperature and above. We have also spectroscopically investigated the interactions of excited alkali atoms with helium atoms, especially the formation of alkali–He exciplexes.

We have trapped large numbers of copper (Cu) and silver (Ag) atoms using buffer-gas cooling. Up to $3\ifmmode\times\else\texttimes\fi{}{10}^{12}\text{ }\text{ }\mathrm{Cu}$ atoms and $4\ifmmode\times\else\texttimes\fi{}{10}^{13}\text{ }\text{ }\mathrm{Ag}$ atoms are trapped. Lifetimes are as long as 5 s, limited by collisions with the buffer gas. Ratios of elastic to inelastic collision rates with He are $\ensuremath{\gtrsim}{10}^{6}$, suggesting Cu and Ag are favorable for use in ultracold applications. The temperature dependence of the $\mathrm{Ag}\mathrm{\text{\ensuremath{-}}}^{3}\mathrm{He}$ collision rate varies as ${T}^{5.8\ifmmode\pm\else\textpm\fi{}0.4}$. We find that this temperature dependence is inconsistent with the behavior predicted for relaxation arising from the spin-rotation interaction, and conclude that the $\mathrm{Ag}\mathrm{\text{\ensuremath{-}}}^{3}\mathrm{He}$ system displays anomalous collisional behavior in the multiple-partial wave regime. Gold (Au) was ablated into

^{3}\mathrm{He}

buffer gas, however, atomic Au lifetimes were observed to be too short to permit trapping.

The hyperfine relaxation of a population difference, produced by optical pumping, between the

F=1

{m}_{F}=0

and

F=2

{m}_{F}=0

energy levels of the ground state of

{\mathrm{Rb}}^{87}

, has been studied in cells containing neon, argon, helium, or krypton as a buffer gas. The relaxation times

{T}_{1}

and

{T}_{2}

have been measured as a function of the rubidium vapor pressure in the cell. The relaxation rate due to spin exchange in

{\mathrm{Rb}}^{87}

-

{\mathrm{Rb}}^{87}

collisions has been found equal to 65 ${\mathrm{sec}}^{\ensuremath{-}1}$ at 44\ifmmode^\circ\else\textdegree\fi{}C, and the diffusion coefficients of

{\mathrm{Rb}}^{87}

atoms in He, Ne, and Ar evaluated as 0.6, 0.31, and 0.22

{\mathrm{cm}}^{2}

${\mathrm{sec}}^{\ensuremath{-}1}$, respectively. The cross section for

{\mathrm{Rb}}^{87}

-Ne and

{\mathrm{Rb}}^{87}

-Ar collisions are found to be 1.6\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}22}$

{\mathrm{cm}}^{2}

and 9\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}22}$

{\mathrm{cm}}^{2}

. These values are in general agreement with values previously obtained by other methods. The extrapolated values of

\frac{1}{{T}_{2}}

for zero vapor pressure of rubidium are 185, 237, and 318 ${\mathrm{sec}}^{\ensuremath{-}1}$ for Ne, He, or Ar, respectively. Relaxations by the pumping light or by the magnetic field inhomogeneities are also discussed.

We produce beams of neutral titanium (Ti) atoms in their metastable 3d3(F4)4sa5F5 state by laser ablation into He, N2, and Ar buffer gases. The high temperatures associated with the ablation process populate the a5F5 level without the need for optical pumping. Remarkably, we observe that Ti atoms in the a5F5 state survive thousands of collisions with He and Ar buffer gas atoms without being quenched to lower-energy states. We study the yield of Ti atoms when ablated into buffer gases of varying species and pressure, quantify quenching rates and diffusion cross sections based on simple models, and provide insight into optimal design parameters for an ablation cell. Using a 3.3 cm ablation cell with interchangeable exit apertures, we produce metastable atom beams and quantify their brilliance and velocity distributions as functions of buffer gas pressure.