Xe129-Cs (D1,D2) versusXe129-Rb (D1) spin-exchange optical pumping at high xenon densities using high-power laser diode arrays

Abstract

We investigate $^{129}\mathrm{Xe}$-Cs (${D}_{1},{D}_{2}$) spin exchange optical pumping (SEOP) at high Xe densities ($~$0.12--2.44 amagat) using newly available high-power ($>$40 W) laser diode arrays and compare with $^{129}\mathrm{Xe}$-Rb ${D}_{1}$ SEOP under similar conditions. At elevated Xe densities, the spin-exchange rate (per alkali-metal atom, ${\ensuremath{\gamma}}^{\ensuremath{'}}$) for Cs-$^{129}\mathrm{Xe}$ is $~$1.5-fold greater than that for Rb-$^{129}\mathrm{Xe}$. Higher spin-exchange rates and lower $^{129}\mathrm{Xe}$ spin-destruction rates for Cs-$^{129}\mathrm{Xe}$ versus Rb-$^{129}\mathrm{Xe}$ contribute to $~$twofold improvement in $^{129}\mathrm{Xe}$ nuclear spin polarization measured at 9.4 T---with the largest gains observed at the highest Xe densities.