We have measured the binary spin-exchange rate coefficient for collisions between Rb and ${}^{129}\mathrm{Xe}$ atoms at a magnetic field $B=9.4\mathrm{T}$ and in the temperature range $160<T<200\ifmmode^\circ\else\textdegree\fi{}\mathrm{C}.$ The longitudinal spin-relaxation rate ${1/T}_{1}$ of ${}^{129}\mathrm{Xe}$ is dominated by ${}^{129}\mathrm{Xe}\ensuremath{-}\mathrm{Rb}$ binary collisions. We measured ${1/T}_{1}$ using the methods of conventional nuclear magnetic resonance, with no spin enhancement by optical pumping. At the high magnetic field and large gas pressures used in this work, the contribution of ${}^{129}\mathrm{Xe}\ensuremath{-}\mathrm{Rb}$ molecules to the spin-exchange rate was less than 0.1% of the binary-collision rate. The Rb atomic number density [Rb] was measured directly from the large Faraday rotation of the polarization of near-resonant light passing through the sample cells. The rate coefficient is $\ensuremath{\kappa}{=d(1/T}_{1})/d[\mathrm{Rb}]=(1.75\ifmmode\pm\else\textpm\fi{}0.12)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}16}{\mathrm{cm}}^{3}/\mathrm{s}.$We have measured the binary spin-exchange rate coefficient for collisions between Rb and ${}^{129}\mathrm{Xe}$ atoms at a magnetic field $B=9.4\mathrm{T}$ and in the temperature range $160<T<200\ifmmode^\circ\else\textdegree\fi{}\mathrm{C}.$ The longitudinal spin-relaxation rate ${1/T}_{1}$ of ${}^{129}\mathrm{Xe}$ is dominated by ${}^{129}\mathrm{Xe}\ensuremath{-}\mathrm{Rb}$ binary collisions. We measured ${1/T}_{1}$ using the methods of conventional nuclear magnetic resonance, with no spin enhancement by optical pumping. At the high magnetic field and large gas pressures used in this work, the contribution of ${}^{129}\mathrm{Xe}\ensuremath{-}\mathrm{Rb}$ molecules to the spin-exchange rate was less than 0.1% of the binary-collision rate. The Rb atomic number density [Rb] was measured directly from the large Faraday rotation of the polarization of near-resonant light passing through the sample cells. The rate coefficient is $\ensuremath{\kappa}{=d(1/T}_{1})/d[\mathrm{Rb}]=(1.75\ifmmode\pm\else\textpm\fi{}0.12)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}16}{\mathrm{cm}}^{3}/\mathrm{s}.$

Physical Review ANov 15, 200240 citations

Spin Exchange in Slow Atomic Collisions

A. P. Blinov

Russian Physics JournalSep 1, 20050 citations

Optical pumping of Rb in the presence of high-pressure He3 buffer gas

B. Larson, O. Häusser, P. P. J. Delheij +2 more

A cryogenic technique has been used to produce polarized $^{3}\mathrm{He}$ targets of up to relative density p=12 atm (\ensuremath{\approxeq}3\ifmmode\times\else\texttimes\fi{} ${10}^{20}$ $^{3}\mathrm{He}$ atoms/ ${\mathrm{cm}}^{3}$ ; p=1 atm corresponds to 760 Torr or 101.3 kPa pressure at 273 K). In these targets $^{3}\mathrm{He}$ nuclei are polarized by spin-exchange collisions with optically pumped rubidium atoms. From transmission measurements at wavelengths of 790--800 nm, we have determined pressure shifts, linewidths, and line-shape asymmetries for the Rb 5 ${\mathit{S}}_{1/2}$ \ensuremath{\rightarrow}5 ${\mathit{P}}_{1/2}$ D1 transition. The Rb spin-destruction rate was found to exhibit a quadratic increase versus $^{3}\mathrm{He}$ pressure, which indicates the importance of Rb${\mathrm{\ensuremath{-}}}^{3}$He${\mathrm{\ensuremath{-}}}^{3}$He collision processes. The transmission results for circularly polarized light are well described by a model that predicts the dependence of the average Rb polarization on Rb density, $^{3}\mathrm{He}$ pressure, light intensity, and cell geometry. The Rb${\mathrm{\ensuremath{-}}}^{3}$He spin-exchange cross section, 〈${\mathrm{\ensuremath{\sigma}}}_{\mathrm{SE}}$v〉=6.1\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}20}$ ${\mathrm{cm}}^{3}$ ${\mathrm{s}}^{\mathrm{\ensuremath{-}}1}$, was found to be independent of $^{3}\mathrm{He}$ pressure up to p=12.1 atm. Maximum $^{3}\mathrm{He}$ polarizations of 72--79% were observed with cells of 17 ${\mathrm{cm}}^{3}$ volume that contained $^{3}\mathrm{He}$ at p=6--9 atm.A cryogenic technique has been used to produce polarized $^{3}\mathrm{He}$ targets of up to relative density p=12 atm (\ensuremath{\approxeq}3\ifmmode\times\else\texttimes\fi{}${10}^{20}$ $^{3}\mathrm{He}$ atoms/${\mathrm{cm}}^{3}$; p=1 atm corresponds to 760 Torr or 101.3 kPa pressure at 273 K). In these targets $^{3}\mathrm{He}$ nuclei are polarized by spin-exchange collisions with optically pumped rubidium atoms. From transmission measurements at wavelengths of 790--800 nm, we have determined pressure shifts, linewidths, and line-shape asymmetries for the Rb 5${\mathit{S}}_{1/2}$\ensuremath{\rightarrow}5${\mathit{P}}_{1/2}$ D1 transition. The Rb spin-destruction rate was found to exhibit a quadratic increase versus $^{3}\mathrm{He}$ pressure, which indicates the importance of Rb${\mathrm{\ensuremath{-}}}^{3}$He${\mathrm{\ensuremath{-}}}^{3}$He collision processes. The transmission results for circularly polarized light are well described by a model that predicts the dependence of the average Rb polarization on Rb density, $^{3}\mathrm{He}$ pressure, light intensity, and cell geometry. The Rb${\mathrm{\ensuremath{-}}}^{3}$He spin-exchange cross section, 〈${\mathrm{\ensuremath{\sigma}}}_{\mathrm{SE}}$v〉=6.1\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}20}$ ${\mathrm{cm}}^{3}$ ${\mathrm{s}}^{\mathrm{\ensuremath{-}}1}$, was found to be independent of $^{3}\mathrm{He}$ pressure up to p=12.1 atm. Maximum $^{3}\mathrm{He}$ polarizations of 72--79% were observed with cells of 17 ${\mathrm{cm}}^{3}$ volume that contained $^{3}\mathrm{He}$ at p=6--9 atm.

Physical Review ASep 1, 199180 citations

Spin-exchange and spin-relaxation in ultracold Rb-Sr

^+

collisions

We have measured the binary spin-exchange rate coefficient for collisions between Rb and

{}^{129}\mathrm{Xe}

atoms at a magnetic field

B=9.4\mathrm{T}

and in the temperature range $160<T<200\ifmmode^\circ\else\textdegree\fi{}\mathrm{C}.$ The longitudinal spin-relaxation rate

{1/T}_{1}

{}^{129}\mathrm{Xe}

is dominated by ${}^{129}\mathrm{Xe}\ensuremath{-}\mathrm{Rb}$ binary collisions. We measured

{1/T}_{1}

using the methods of conventional nuclear magnetic resonance, with no spin enhancement by optical pumping. At the high magnetic field and large gas pressures used in this work, the contribution of ${}^{129}\mathrm{Xe}\ensuremath{-}\mathrm{Rb}$ molecules to the spin-exchange rate was less than 0.1% of the binary-collision rate. The Rb atomic number density [Rb] was measured directly from the large Faraday rotation of the polarization of near-resonant light passing through the sample cells. The rate coefficient is $\ensuremath{\kappa}{=d(1/T}_{1})/d[\mathrm{Rb}]=(1.75\ifmmode\pm\else\textpm\fi{}0.12)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}16}{\mathrm{cm}}^{3}/\mathrm{s}.$

A cryogenic technique has been used to produce polarized

^{3}\mathrm{He}

targets of up to relative density p=12 atm (\ensuremath{\approxeq}3\ifmmode\times\else\texttimes\fi{}

{10}^{20}

^{3}\mathrm{He}

atoms/

{\mathrm{cm}}^{3}

; p=1 atm corresponds to 760 Torr or 101.3 kPa pressure at 273 K). In these targets

^{3}\mathrm{He}

nuclei are polarized by spin-exchange collisions with optically pumped rubidium atoms. From transmission measurements at wavelengths of 790--800 nm, we have determined pressure shifts, linewidths, and line-shape asymmetries for the Rb 5

{\mathit{S}}_{1/2}

\ensuremath{\rightarrow}5

{\mathit{P}}_{1/2}

D1 transition. The Rb spin-destruction rate was found to exhibit a quadratic increase versus

^{3}\mathrm{He}

pressure, which indicates the importance of Rb${\mathrm{\ensuremath{-}}}^{3}$He${\mathrm{\ensuremath{-}}}^{3}$He collision processes. The transmission results for circularly polarized light are well described by a model that predicts the dependence of the average Rb polarization on Rb density,

^{3}\mathrm{He}

pressure, light intensity, and cell geometry. The Rb${\mathrm{\ensuremath{-}}}^{3}$He spin-exchange cross section, 〈${\mathrm{\ensuremath{\sigma}}}_{\mathrm{SE}}$v〉=6.1\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}20}$

{\mathrm{cm}}^{3}

${\mathrm{s}}^{\mathrm{\ensuremath{-}}1}$, was found to be independent of

^{3}\mathrm{He}

pressure up to p=12.1 atm. Maximum

^{3}\mathrm{He}

polarizations of 72--79% were observed with cells of 17

{\mathrm{cm}}^{3}

volume that contained

^{3}\mathrm{He}

at p=6--9 atm.