Molway, Michael J., Liana Bales-Shaffer, Kaili Ranta, James Ball, Eleanor Sparling, Mia Prince, Daniel Cocking, et al. “Dramatic Improvement in the ‘Bulk’ Hyperpolarization of 131Xe via Spin Exchange Optical Pumping Probed Using in Situ Low-Field NMR.” Journal of Magnetic Resonance 354 (September 1, 2023): 107521.
https://doi.org/10.1016/j.jmr.2023.107521.
We report on hyperpolarization of quadrupolar (I=3/2) 131Xe via spin-exchange optical pumping. Observations of the 131Xe polarization dynamics via in situ low-field NMR show that the estimated alkali-metal/131Xe spin-exchange rates can be large enough to compete with 131Xe spin relaxation. 131Xe polarization up to 7.6±1.5% was achieved in ∼8.5×1020 spins—a ∼100-fold improvement in the total spin angular momentum—potentially enabling various applications, including: measurement of spin-dependent neutron-131Xe s-wave scattering; sensitive searches for time-reversal violation in neutron-131Xe interactions beyond the Standard Model; and surface-sensitive pulmonary MRI.