Physical Review A

Evaporative cooling of magnetically trapped atomic molybdenum

Cindy Hancox, Matthew T. Hummon, Scott V. Nguyen, John M. Doyle

Published Mar 11, 2005• 14 citations

Abstract

We have magnetically trapped and evaporatively cooled atomic molybdenum. Using a cryogenic helium buffer gas, $2\ifmmode\times\else\texttimes\fi{}{10}^{10}$ molybdenum atoms are loaded into a magnetic trap at an initial temperature of 500 mK. The molybdenum atoms undergo two-body decay with a measured inelastic rate constant of ${g}_{\mathrm{in}}=(1.2\ifmmode\pm\else\textpm\fi{}0.6)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}12}\phantom{\rule{0.3em}{0ex}}{\mathrm{cm}}^{3}\phantom{\rule{0.2em}{0ex}}{\mathrm{s}}^{\ensuremath{-}1}$ for the initial conditions after loading. The molybdenum atoms are cooled by adiabatic expansion and forced evaporation to 200 mK.

DOI: 10.1103/physreva.71.031402

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Evaporative cooling of atomic chromium

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Physical Review AJan 4, 200252 citations

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Physical Review A

Evaporative cooling of magnetically trapped atomic molybdenum

Cindy Hancox, Matthew T. Hummon, Scott V. Nguyen, John M. Doyle

Published Mar 11, 2005• 14 citations

Publisher

Abstract

We have magnetically trapped and evaporatively cooled atomic molybdenum. Using a cryogenic helium buffer gas,

2\ifmmode\times\else\texttimes\fi{}{10}^{10}

molybdenum atoms are loaded into a magnetic trap at an initial temperature of 500 mK. The molybdenum atoms undergo two-body decay with a measured inelastic rate constant of

{g}_{\mathrm{in}}=(1.2\ifmmode\pm\else\textpm\fi{}0.6)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}12}\phantom{\rule{0.3em}{0ex}}{\mathrm{cm}}^{3}\phantom{\rule{0.2em}{0ex}}{\mathrm{s}}^{\ensuremath{-}1}

for the initial conditions after loading. The molybdenum atoms are cooled by adiabatic expansion and forced evaporation to 200 mK.

DOI: 10.1103/physreva.71.031402

Related papers

Evaporative cooling of atomic chromium

Jonathan D. Weinstein, Robert deCarvalho, Cindy Hancox +1 more

We report the magnetic trapping and evaporative cooling of bosonic and fermionic isotopes of atomic chromium. Using a cryogenic helium buffer gas, ${10}^{12}$ chromium atoms are trapped at an initial temperature of \ensuremath{\sim}1 K. The chromium atoms are then cooled adiabatically and evaporatively to temperatures as low as \ensuremath{\sim}10 mK. Elastic and inelastic ${}^{52}\mathrm{Cr}$ collisional cross sections are measured over this temperature range. Prospects for simultaneously creating a ${}^{52}\mathrm{Cr}$ Bose-Einstein condensate and ${}^{53}\mathrm{Cr}$ Fermi degenerate gas will be discussed.We report the magnetic trapping and evaporative cooling of bosonic and fermionic isotopes of atomic chromium. Using a cryogenic helium buffer gas, ${10}^{12}$ chromium atoms are trapped at an initial temperature of \ensuremath{\sim}1 K. The chromium atoms are then cooled adiabatically and evaporatively to temperatures as low as \ensuremath{\sim}10 mK. Elastic and inelastic ${}^{52}\mathrm{Cr}$ collisional cross sections are measured over this temperature range. Prospects for simultaneously creating a ${}^{52}\mathrm{Cr}$ Bose-Einstein condensate and ${}^{53}\mathrm{Cr}$ Fermi degenerate gas will be discussed.

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Evaporative cooling of atomic chromium

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Chirped magneto-optical trap of molybdenum

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Metastable helium is buffer gas cooled, magnetically trapped, and evaporatively cooled in large numbers. ${10}^{11}$ $^{4}\mathrm{He}^{*}$ atoms are trapped at an initial temperature of $400\phantom{\rule{0.3em}{0ex}}\mathrm{mK}$ and evaporatively cooled into the ultracold regime, resulting in a cloud of $2\ifmmode\pm\else\textpm\fi{}0.5\ifmmode\times\else\texttimes\fi{}{10}^{9}$ atoms at $1.4\ifmmode\pm\else\textpm\fi{}0.2\phantom{\rule{0.3em}{0ex}}\mathrm{mK}$. Efficient evaporation indicates low collisional loss for $^{4}\mathrm{He}^{*}$ in both the ultracold and multi-partial-wave regime, in agreement with theory.Metastable helium is buffer gas cooled, magnetically trapped, and evaporatively cooled in large numbers. ${10}^{11}$ $^{4}\mathrm{He}^{*}$ atoms are trapped at an initial temperature of $400\phantom{\rule{0.3em}{0ex}}\mathrm{mK}$ and evaporatively cooled into the ultracold regime, resulting in a cloud of $2\ifmmode\pm\else\textpm\fi{}0.5\ifmmode\times\else\texttimes\fi{}{10}^{9}$ atoms at $1.4\ifmmode\pm\else\textpm\fi{}0.2\phantom{\rule{0.3em}{0ex}}\mathrm{mK}$. Efficient evaporation indicates low collisional loss for $^{4}\mathrm{He}^{*}$ in both the ultracold and multi-partial-wave regime, in agreement with theory.

Physical Review ADec 29, 200512 citations

Magnetic trapping of an atomic Mn55−Cr52 mixture

Scott V. Nguyen, Joel S. Helton, Kenneth Maussang +2 more

Atomic manganese $^{55}\mathrm{Mn}$ and chromium $^{52}\mathrm{Cr}$ are simultaneously loaded and confined in a magnetic trap. Using a cryogenic $^{3}\mathrm{He}$ buffer gas, ${10}^{11}$ manganese and ${10}^{12}$ chromium atoms are trapped at an initial temperature of 600 mK. The buffer gas is then pumped away, thermally isolating the sample. The Mn-Cr interspecies inelastic rate constant is measured to be ${\ensuremath{\Gamma}}_{\mathrm{Mn},\mathrm{Cr}}=1.5(\ifmmode\pm\else\textpm\fi{}0.2)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}13}\phantom{\rule{0.2em}{0ex}}{\mathrm{cm}}^{3}∕\mathrm{s}$.Atomic manganese $^{55}\mathrm{Mn}$ and chromium $^{52}\mathrm{Cr}$ are simultaneously loaded and confined in a magnetic trap. Using a cryogenic $^{3}\mathrm{He}$ buffer gas, ${10}^{11}$ manganese and ${10}^{12}$ chromium atoms are trapped at an initial temperature of 600 mK. The buffer gas is then pumped away, thermally isolating the sample. The Mn-Cr interspecies inelastic rate constant is measured to be ${\ensuremath{\Gamma}}_{\mathrm{Mn},\mathrm{Cr}}=1.5(\ifmmode\pm\else\textpm\fi{}0.2)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}13}\phantom{\rule{0.2em}{0ex}}{\mathrm{cm}}^{3}∕\mathrm{s}$.

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Buffer-gas loading of atoms and molecules into a magnetic trap

John M. Doyle, Břetislav Friedrich, Jinha Kim +1 more

We describe a method for loading paramagnetic atoms or molecules into a magnetic trap. A $^{3}\mathrm{He}$ buffer gas is employed to thermalize atoms or molecules to a temperature of approximately 240 mK, lower than the depth of the trap. A model is described that indicates an initial loading density of approximately ${10}^{13}$ ${\mathrm{cm}}^{\ensuremath{-}3}$. Once loading has taken place the buffer gas is removed by cryopumping. Evaporative cooling can then be applied to further lower the temperature and increase the density of the trapped sample.We describe a method for loading paramagnetic atoms or molecules into a magnetic trap. A $^{3}\mathrm{He}$ buffer gas is employed to thermalize atoms or molecules to a temperature of approximately 240 mK, lower than the depth of the trap. A model is described that indicates an initial loading density of approximately ${10}^{13}$ ${\mathrm{cm}}^{\ensuremath{-}3}$. Once loading has taken place the buffer gas is removed by cryopumping. Evaporative cooling can then be applied to further lower the temperature and increase the density of the trapped sample.

Physical Review AOct 1, 1995257 citations

We have magnetically trapped and evaporatively cooled atomic molybdenum. Using a cryogenic helium buffer gas,

2\ifmmode\times\else\texttimes\fi{}{10}^{10}

molybdenum atoms are loaded into a magnetic trap at an initial temperature of 500 mK. The molybdenum atoms undergo two-body decay with a measured inelastic rate constant of

{g}_{\mathrm{in}}=(1.2\ifmmode\pm\else\textpm\fi{}0.6)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}12}\phantom{\rule{0.3em}{0ex}}{\mathrm{cm}}^{3}\phantom{\rule{0.2em}{0ex}}{\mathrm{s}}^{\ensuremath{-}1}

for the initial conditions after loading. The molybdenum atoms are cooled by adiabatic expansion and forced evaporation to 200 mK.

We report the magnetic trapping and evaporative cooling of bosonic and fermionic isotopes of atomic chromium. Using a cryogenic helium buffer gas,

{10}^{12}

chromium atoms are trapped at an initial temperature of \ensuremath{\sim}1 K. The chromium atoms are then cooled adiabatically and evaporatively to temperatures as low as \ensuremath{\sim}10 mK. Elastic and inelastic

{}^{52}\mathrm{Cr}

collisional cross sections are measured over this temperature range. Prospects for simultaneously creating a

{}^{52}\mathrm{Cr}

Bose-Einstein condensate and

{}^{53}\mathrm{Cr}

Fermi degenerate gas will be discussed.

Metastable helium is buffer gas cooled, magnetically trapped, and evaporatively cooled in large numbers.

{10}^{11}

^{4}\mathrm{He}^{*}

atoms are trapped at an initial temperature of

400\phantom{\rule{0.3em}{0ex}}\mathrm{mK}

and evaporatively cooled into the ultracold regime, resulting in a cloud of $2\ifmmode\pm\else\textpm\fi{}0.5\ifmmode\times\else\texttimes\fi{}{10}^{9}$ atoms at $1.4\ifmmode\pm\else\textpm\fi{}0.2\phantom{\rule{0.3em}{0ex}}\mathrm{mK}$. Efficient evaporation indicates low collisional loss for

^{4}\mathrm{He}^{*}

in both the ultracold and multi-partial-wave regime, in agreement with theory.

Atomic manganese

^{55}\mathrm{Mn}

and chromium

^{52}\mathrm{Cr}

are simultaneously loaded and confined in a magnetic trap. Using a cryogenic

^{3}\mathrm{He}

buffer gas,

{10}^{11}

manganese and

{10}^{12}

chromium atoms are trapped at an initial temperature of 600 mK. The buffer gas is then pumped away, thermally isolating the sample. The Mn-Cr interspecies inelastic rate constant is measured to be ${\ensuremath{\Gamma}}_{\mathrm{Mn},\mathrm{Cr}}=1.5(\ifmmode\pm\else\textpm\fi{}0.2)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}13}\phantom{\rule{0.2em}{0ex}}{\mathrm{cm}}^{3}∕\mathrm{s}$.

We describe a method for loading paramagnetic atoms or molecules into a magnetic trap. A

^{3}\mathrm{He}

buffer gas is employed to thermalize atoms or molecules to a temperature of approximately 240 mK, lower than the depth of the trap. A model is described that indicates an initial loading density of approximately

{10}^{13}

${\mathrm{cm}}^{\ensuremath{-}3}$. Once loading has taken place the buffer gas is removed by cryopumping. Evaporative cooling can then be applied to further lower the temperature and increase the density of the trapped sample.