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

Laser induced polarization properties of a neon three-level system

Birger Stahlberg, Peter Jungner, Tomas Fellman +2 more

Optics CommunicationsJun 1, 19906 citations

Spin polarization of photoelectrons in bichromatic extreme-ultraviolet atomic ionization

Грызлова Елена Владимировна, Maria M. Popova, Alexei N. Grum-Grzhimailo

Spin polarization of photoelectrons is considered in the ionization of atoms by a laser field and its second harmonic, concentrating on the effects of interference between the two ionization paths. The possibility for a crucial increase of the spin polarization by manipulating the relative phase of the harmonics is demonstrated. Observation of these effects, exemplified by the ionization of neon atoms, is accessible by modern free-electron lasers working in the extreme-ultraviolet wavelength regime.Spin polarization of photoelectrons is considered in the ionization of atoms by a laser field and its second harmonic, concentrating on the effects of interference between the two ionization paths. The possibility for a crucial increase of the spin polarization by manipulating the relative phase of the harmonics is demonstrated. Observation of these effects, exemplified by the ionization of neon atoms, is accessible by modern free-electron lasers working in the extreme-ultraviolet wavelength regime.

Physical Review ANov 25, 20208 citations

Limit on suppression of ionization in metastable neon traps due to long-range anisotropy

M. R. Doery, Edgar J. D. Vredenbregt, S. S. Op de Beek +2 more

This paper investigates the possibility of suppressing the ionization rate in a magnetostatic trap of metastable neon atoms by spin-polarizing the atoms. Suppression of the ionization is critical for the possibility of reaching Bose-Einstein condensation with such atoms. We estimate the relevant long-range interactions for the system, consisting of electric quadrupole-quadrupole and dipole-induced dipole terms, and develop short-range potentials based on the ${\mathrm{Na}}_{2}$ singlet and triplet potentials. The autoionization widths of the system are also calculated. With these ingredients we calculate the ionization rate for spin-polarized and for spin-isotropic samples, caused by anisotropy of the long-range interactions. We find that spin polarization may allow for four orders of magnitude suppression of the ionization rate for Ne. The results depend sensitively on a precise knowledge of the interaction potentials, however, pointing out the need for experimental input. The same model gives a suppression ratio close to unity for metastable xenon in accordance with experimental results, due to a much increased anisotropy in this case.This paper investigates the possibility of suppressing the ionization rate in a magnetostatic trap of metastable neon atoms by spin-polarizing the atoms. Suppression of the ionization is critical for the possibility of reaching Bose-Einstein condensation with such atoms. We estimate the relevant long-range interactions for the system, consisting of electric quadrupole-quadrupole and dipole-induced dipole terms, and develop short-range potentials based on the ${\mathrm{Na}}_{2}$ singlet and triplet potentials. The autoionization widths of the system are also calculated. With these ingredients we calculate the ionization rate for spin-polarized and for spin-isotropic samples, caused by anisotropy of the long-range interactions. We find that spin polarization may allow for four orders of magnitude suppression of the ionization rate for Ne. The results depend sensitively on a precise knowledge of the interaction potentials, however, pointing out the need for experimental input. The same model gives a suppression ratio close to unity for metastable xenon in accordance with experimental results, due to a much increased anisotropy in this case.

arXiv:physics/9806018Physical Review ANov 1, 199823 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{Na}}_{2}

singlet and triplet potentials. The autoionization widths of the system are also calculated. With these ingredients we calculate the ionization rate for spin-polarized and for spin-isotropic samples, caused by anisotropy of the long-range interactions. We find that spin polarization may allow for four orders of magnitude suppression of the ionization rate for Ne. The results depend sensitively on a precise knowledge of the interaction potentials, however, pointing out the need for experimental input. The same model gives a suppression ratio close to unity for metastable xenon in accordance with experimental results, due to a much increased anisotropy in this case.