Electron Scattering Based on Spin-Exchange Optical Pumping

A spin-exchange optical-pumping experiment to study the temperature dependence of the electron-rubidium spin-exchange cross section is reported. In this experiment, electrons were polarized in a weak magnetic field by spin-exchange collisions with optically pumped Rb atoms. The electron-Rb collisions were the principal source of the electron-spin-resonance linewidth, and they also produced a shift in the resonance frequency. The magnitudes of the linewidth and frequency shift are functions of the electron-Rb-scattering phase shifts. The electron linewidth at fixed Rb density was essentially constant over the temperature range 200-840 \ifmmode^\circ\else\textdegree\fi{}K indicating the spin-exchange cross section is well approximated by a $\frac{1}{v}$ velocity dependence. The ratio of the frequency shift to linewidth was 0.075\ifmmode\pm\else\textpm\fi{}0.005 at 300 \ifmmode^\circ\else\textdegree\fi{}K with an estimated Rb polarization of (20\ifmmode\pm\else\textpm\fi{}10)%, and the ratio was 0.027\ifmmode\pm\else\textpm\fi{}0.007 at 600 \ifmmode^\circ\else\textdegree\fi{}K with a Rb polarization of (10\ifmmode\pm\else\textpm\fi{}5)%.A spin-exchange optical-pumping experiment to study the temperature dependence of the electron-rubidium spin-exchange cross section is reported. In this experiment, electrons were polarized in a weak magnetic field by spin-exchange collisions with optically pumped Rb atoms. The electron-Rb collisions were the principal source of the electron-spin-resonance linewidth, and they also produced a shift in the resonance frequency. The magnitudes of the linewidth and frequency shift are functions of the electron-Rb-scattering phase shifts. The electron linewidth at fixed Rb density was essentially constant over the temperature range 200-840 \ifmmode^\circ\else\textdegree\fi{}K indicating the spin-exchange cross section is well approximated by a $\frac{1}{v}$ velocity dependence. The ratio of the frequency shift to linewidth was 0.075\ifmmode\pm\else\textpm\fi{}0.005 at 300 \ifmmode^\circ\else\textdegree\fi{}K with an estimated Rb polarization of (20\ifmmode\pm\else\textpm\fi{}10)%, and the ratio was 0.027\ifmmode\pm\else\textpm\fi{}0.007 at 600 \ifmmode^\circ\else\textdegree\fi{}K with a Rb polarization of (10\ifmmode\pm\else\textpm\fi{}5)%.

Physical Review AOct 1, 19726 citations

Sodium-Electron Spin-Exchange Collisions

L. C. Balling

A spin-exchange optical pumping experiment to study collisions between sodium atoms and free electrons is reported. In this experiment, electrons in a weak magnetic field were polarized by spin-exchange collisions with optically pumped sodium atoms. The sodium-electron collisions were the principal source of the electron resonance linewidth, and they also produced a shift in the electron resonance frequency. The magnitudes of the linewidth and the frequency shift depend upon the scattering amplitude for sodium-electron collisions, the sodium polarization, and the sodium atom density. The ratio of the frequency shift to the linewidth was 0.03. The sodium polarization was approximately 30%. The electron resonance frequency was lower when the sodium polarization was positive. The measurements of the electron linewidth and the frequency shift agree with theoretical values of the linewidth and frequency shift obtained from the sodium-electron scattering phase shifts which have been recently calculated by Garrett.A spin-exchange optical pumping experiment to study collisions between sodium atoms and free electrons is reported. In this experiment, electrons in a weak magnetic field were polarized by spin-exchange collisions with optically pumped sodium atoms. The sodium-electron collisions were the principal source of the electron resonance linewidth, and they also produced a shift in the electron resonance frequency. The magnitudes of the linewidth and the frequency shift depend upon the scattering amplitude for sodium-electron collisions, the sodium polarization, and the sodium atom density. The ratio of the frequency shift to the linewidth was 0.03. The sodium polarization was approximately 30%. The electron resonance frequency was lower when the sodium polarization was positive. The measurements of the electron linewidth and the frequency shift agree with theoretical values of the linewidth and frequency shift obtained from the sodium-electron scattering phase shifts which have been recently calculated by Garrett.

Physical ReviewNov 4, 196619 citations

Physics of practical spin-exchange optical pumping

Ian A. Nelson

Oct 1, 200112 citations

\frac{1}{v}

velocity dependence. The ratio of the frequency shift to linewidth was 0.075\ifmmode\pm\else\textpm\fi{}0.005 at 300 \ifmmode^\circ\else\textdegree\fi{}K with an estimated Rb polarization of (20\ifmmode\pm\else\textpm\fi{}10)%, and the ratio was 0.027\ifmmode\pm\else\textpm\fi{}0.007 at 600 \ifmmode^\circ\else\textdegree\fi{}K with a Rb polarization of (10\ifmmode\pm\else\textpm\fi{}5)%.