We discuss the relaxation of a spin-polarized alkali-metal vapor due to the electric-quadrupole interaction in ${}^{1}{\ensuremath{\Sigma}}_{g}^{+}$ dimers, and present a model that accurately describes the measured relaxation rates under a wide variety of conditions. We use the model along with experimental results to deduce the quadrupole interaction strength, atom-dimer chemical-exchange reaction rate, and the rate of reorientation of singlet dimers due to collisions with the buffer gas.We discuss the relaxation of a spin-polarized alkali-metal vapor due to the electric-quadrupole interaction in ${}^{1}{\ensuremath{\Sigma}}_{g}^{+}$ dimers, and present a model that accurately describes the measured relaxation rates under a wide variety of conditions. We use the model along with experimental results to deduce the quadrupole interaction strength, atom-dimer chemical-exchange reaction rate, and the rate of reorientation of singlet dimers due to collisions with the buffer gas.

Physical Review AOct 15, 200111 citations

Spin relaxation in alkali vapors

Stephen J. Kadlecek

Nov 1, 19994 citations

Spin Relaxation of Atoms in Molecular Buffer Gases

Howard C. Berg

The Journal of Chemical PhysicsSep 1, 19655 citations

Spin-exchange cross sections for hydrogen-atom–alkali-metal-atom collisions

H. R. Cole, R. E. Olson

The pseudopotential molecular-structure method has been used to calculate the ${X}^{1}$ \ensuremath{\Sigma} and ${a}^{3}$ \ensuremath{\Sigma} interaction potentials for the alkali-metal-atom--hydrogen-atom systems. These potentials were then used in a quantum-mechanical calculation to determine the spin-exchange cross sections in the energy range from 2.5\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}4}$ eV to 2.5 eV. The cross sections follow the general form ${Q}^{1/2}$ =a-b lnv. However, abundant structure on the cross sections is present due to orbiting resonances induced by the deeply bound well of the ${X}^{1}$ \ensuremath{\Sigma} molecular state. The spin-exchange cross sections range from 17\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}16}$ to 25\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}16}$ ${\mathrm{cm}}^{2}$ at room temperature for H(F=1) transferring to H(F=0) in collision with unpolarized lithium and cesium, respectively.The pseudopotential molecular-structure method has been used to calculate the ${X}^{1}$\ensuremath{\Sigma} and ${a}^{3}$\ensuremath{\Sigma} interaction potentials for the alkali-metal-atom--hydrogen-atom systems. These potentials were then used in a quantum-mechanical calculation to determine the spin-exchange cross sections in the energy range from 2.5\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}4}$ eV to 2.5 eV. The cross sections follow the general form ${Q}^{1/2}$=a-b lnv. However, abundant structure on the cross sections is present due to orbiting resonances induced by the deeply bound well of the ${X}^{1}$\ensuremath{\Sigma} molecular state. The spin-exchange cross sections range from 17\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}16}$ to 25\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}16}$ ${\mathrm{cm}}^{2}$ at room temperature for H(F=1) transferring to H(F=0) in collision with unpolarized lithium and cesium, respectively.

Physical Review AApr 1, 198525 citations

The pseudopotential molecular-structure method has been used to calculate the

{X}^{1}

\ensuremath{\Sigma} and

{a}^{3}

\ensuremath{\Sigma} interaction potentials for the alkali-metal-atom--hydrogen-atom systems. These potentials were then used in a quantum-mechanical calculation to determine the spin-exchange cross sections in the energy range from 2.5\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}4}$ eV to 2.5 eV. The cross sections follow the general form

{Q}^{1/2}

=a-b lnv. However, abundant structure on the cross sections is present due to orbiting resonances induced by the deeply bound well of the

{X}^{1}

\ensuremath{\Sigma} molecular state. The spin-exchange cross sections range from 17\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}16}$ to 25\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}16}$

{\mathrm{cm}}^{2}

at room temperature for H(F=1) transferring to H(F=0) in collision with unpolarized lithium and cesium, respectively.