Measuring the enhancement factor of the hyperpolarized Xe in nuclear magnetic resonance gyroscopes

Abstract

In atomic gyroscopes, measuring the effective noble-gas magnetic field enables the determination of the noble-gas polarization. The enhancement factor is introduced to relate the effective magnetic field and the polarization in a certain magnetic-field environment. Earlier experiments concentrate on the strong magnetic-field environment for measuring the spin-exchange cross section precisely, so the results on the enhancement factor in the weak magnetic field are still insufficient. In our nuclear magnetic resonance gyroscope based on Cs-$^{129}\mathrm{Xe}$ and -$^{131}\mathrm{Xe}$, the magnetic field is usually set to 1--10 $\ensuremath{\mu}\mathrm{T}$. In this paper, we measure the effective magnetic field and the polarization of Xe atoms to estimate the Cs-Xe enhancement factor in the weak magnetic field of 2.5 $\ensuremath{\mu}\mathrm{T}$ and give the estimation of the Cs-$^{129}\mathrm{Xe}$ enhancement factor of $(1.60\ifmmode\pm\else\textpm\fi{}0.06)\ifmmode\times\else\texttimes\fi{}{10}^{4}$.