We measure the rates of elastic and inelastic two-body collisions of cold spin-polarized neon atoms in the metastable $^{3}P_{2}$ state for $^{20}\mathrm{Ne}$ and $^{22}\mathrm{Ne}$ in a magnetic trap. From particle loss, we determine the loss parameter of inelastic collisions $\ensuremath{\beta}=6.5(18)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}12}\text{ }\text{ }{\mathrm{cm}}^{3}\text{ }{\mathrm{s}}^{\ensuremath{-}1}$ for $^{20}\mathrm{Ne}$ and $\ensuremath{\beta}=1.2(3)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}11}\text{ }\text{ }{\mathrm{cm}}^{3}\text{ }{\mathrm{s}}^{\ensuremath{-}1}$ for $^{22}\mathrm{Ne}$ . These losses are caused by ionizing (i.e., Penning) collisions and occur less frequently than for unpolarized atoms. This proves the suppression of Penning ionization due to spin polarization. From cross-dimensional relaxation measurements, we obtain elastic scattering lengths of $a=\ensuremath{-}180(40){a}_{0}$ for $^{20}\mathrm{Ne}$ and $a=+{150}_{\ensuremath{-}50}^{+80}{a}_{0}$ for $^{22}\mathrm{Ne}$ , where ${a}_{0}=0.0529\text{ }\text{ }\mathrm{nm}$ .We measure the rates of elastic and inelastic two-body collisions of cold spin-polarized neon atoms in the metastable $^{3}P_{2}$ state for $^{20}\mathrm{Ne}$ and $^{22}\mathrm{Ne}$ in a magnetic trap. From particle loss, we determine the loss parameter of inelastic collisions $\ensuremath{\beta}=6.5(18)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}12}\text{ }\text{ }{\mathrm{cm}}^{3}\text{ }{\mathrm{s}}^{\ensuremath{-}1}$ for $^{20}\mathrm{Ne}$ and $\ensuremath{\beta}=1.2(3)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}11}\text{ }\text{ }{\mathrm{cm}}^{3}\text{ }{\mathrm{s}}^{\ensuremath{-}1}$ for $^{22}\mathrm{Ne}$. These losses are caused by ionizing (i.e., Penning) collisions and occur less frequently than for unpolarized atoms. This proves the suppression of Penning ionization due to spin polarization. From cross-dimensional relaxation measurements, we obtain elastic scattering lengths of $a=\ensuremath{-}180(40){a}_{0}$ for $^{20}\mathrm{Ne}$ and $a=+{150}_{\ensuremath{-}50}^{+80}{a}_{0}$ for $^{22}\mathrm{Ne}$, where ${a}_{0}=0.0529\text{ }\text{ }\mathrm{nm}$.

arXiv:quant-ph/0502020Physical Review LettersJun 7, 200525 citations

The Theory of Atomic Collisions

F. W. Sohon

ThoughtJan 1, 193693 citations

Cold N+NH Collisions in a Magnetic Trap

Matthew T. Hummon, Timur V. Tscherbul, Jacek A. Kłos +5 more

We present an experimental and theoretical study of atom-molecule collisions in a mixture of cold, trapped N atoms and NH molecules at a temperature of $\ensuremath{\sim}600\text{ }\text{ }\mathrm{mK}$. We measure a small $\mathrm{N}+\mathrm{NH}$ trap loss rate coefficient of ${k}_{\mathrm{loss}}^{(\mathrm{N}+\mathrm{NH})}=9(5)(3)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}13}\text{ }\text{ }{\mathrm{cm}}^{3}\text{ }{\mathrm{s}}^{\ensuremath{-}1}$. Accurate quantum scattering calculations based on ab initio interaction potentials are in agreement with experiment and indicate the magnetic dipole interaction to be the dominant loss mechanism. Our theory further indicates the ratio of $\mathrm{N}+\mathrm{NH}$ elastic-to-inelastic collisions remains large ( $>100$ ) into the mK regime.We present an experimental and theoretical study of atom-molecule collisions in a mixture of cold, trapped N atoms and NH molecules at a temperature of $\ensuremath{\sim}600\text{ }\text{ }\mathrm{mK}$. We measure a small $\mathrm{N}+\mathrm{NH}$ trap loss rate coefficient of ${k}_{\mathrm{loss}}^{(\mathrm{N}+\mathrm{NH})}=9(5)(3)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}13}\text{ }\text{ }{\mathrm{cm}}^{3}\text{ }{\mathrm{s}}^{\ensuremath{-}1}$. Accurate quantum scattering calculations based on ab initio interaction potentials are in agreement with experiment and indicate the magnetic dipole interaction to be the dominant loss mechanism. Our theory further indicates the ratio of $\mathrm{N}+\mathrm{NH}$ elastic-to-inelastic collisions remains large ($>100$) into the mK regime.

arXiv:1009.2513Physical Review LettersFeb 2, 201191 citations

Slow atom collisions: A review

Paul S. Julienne

AIP conference proceedingsJan 1, 19950 citations

Collisions between laser-cooled atoms and molecules

Sarunas Jurgilas

This thesis describes an experiment to produce the first laser cooled mixtures of atoms and polar molecules in magneto-optical and magnetic quadrupole traps. Inelastic collision processes between CaF molecules and Rb atoms are studied in both trapping arrangements. When molecules occupy the first rotationally excited state it is found that loss from either trap occurs at near the universal rate due to collisions with co-trapped atoms. When the molecular sample is transferred to the ground rotational state the loss rate is suppressed by at least an order of magnitude. The experimental results are compared to a quantum scattering model based on quantum defect theory and the results seem to be encouraging for observing a high ratio of elastic to inelastic collision rates in this system. In addition, improvements to the experimental apparatus are presented which led to the first measurements of the elastic cross-section for collisions between CaF and Rb. Although at the currently attainable number densities no thermalization is observed, an upper bound on the value of the cross section is placed.This thesis describes an experiment to produce the first laser cooled mixtures of atoms and polar molecules in magneto-optical and magnetic quadrupole traps. Inelastic collision processes between CaF molecules and Rb atoms are studied in both trapping arrangements. When molecules occupy the first rotationally excited state it is found that loss from either trap occurs at near the universal rate due to collisions with co-trapped atoms. When the molecular sample is transferred to the ground rotational state the loss rate is suppressed by at least an order of magnitude. The experimental results are compared to a quantum scattering model based on quantum defect theory and the results seem to be encouraging for observing a high ratio of elastic to inelastic collision rates in this system. In addition, improvements to the experimental apparatus are presented which led to the first measurements of the elastic cross-section for collisions between CaF and Rb. Although at the currently attainable number densities no thermalization is observed, an upper bound on the value of the cross section is placed.

Bulletin of the American Physical SocietyJul 1, 20210 citations

Effect of Atomic Collisions

D. V. Skobelʹt︠s︡yn

Nonlinear OpticsJan 1, 19700 citations

We measure the rates of elastic and inelastic two-body collisions of cold spin-polarized neon atoms in the metastable

^{3}P_{2}

state for

^{20}\mathrm{Ne}

and

^{22}\mathrm{Ne}

in a magnetic trap. From particle loss, we determine the loss parameter of inelastic collisions $\ensuremath{\beta}=6.5(18)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}12}\text{ }\text{ }{\mathrm{cm}}^{3}\text{ }{\mathrm{s}}^{\ensuremath{-}1}$ for

^{20}\mathrm{Ne}

and $\ensuremath{\beta}=1.2(3)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}11}\text{ }\text{ }{\mathrm{cm}}^{3}\text{ }{\mathrm{s}}^{\ensuremath{-}1}$ for

^{22}\mathrm{Ne}

. These losses are caused by ionizing (i.e., Penning) collisions and occur less frequently than for unpolarized atoms. This proves the suppression of Penning ionization due to spin polarization. From cross-dimensional relaxation measurements, we obtain elastic scattering lengths of $a=\ensuremath{-}180(40){a}_{0}$ for

^{20}\mathrm{Ne}

and $a=+{150}_{\ensuremath{-}50}^{+80}{a}_{0}$ for

^{22}\mathrm{Ne}

, where

{a}_{0}=0.0529\text{ }\text{ }\mathrm{nm}

\mathrm{N}+\mathrm{NH}

trap loss rate coefficient of ${k}_{\mathrm{loss}}^{(\mathrm{N}+\mathrm{NH})}=9(5)(3)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}13}\text{ }\text{ }{\mathrm{cm}}^{3}\text{ }{\mathrm{s}}^{\ensuremath{-}1}$. Accurate quantum scattering calculations based on ab initio interaction potentials are in agreement with experiment and indicate the magnetic dipole interaction to be the dominant loss mechanism. Our theory further indicates the ratio of

\mathrm{N}+\mathrm{NH}

elastic-to-inelastic collisions remains large (

>100

) into the mK regime.