Introducing Hyperpolarized Xenon-131 Directly Detected by NMR Spectroscopy

Previously, high-field NMR and MRI applications of hyperpolarized (hp) noble gasses focused on the isotopes helium-3 (spin I = 1/2), xenon-129 (spin I = 1/2) [1], and more recently krypton-83 (spin I = 9/2) [2]. In this contribution, hp xenon-131 (spin I = 3/2) was generated by spin-exchange optical pumping and separated from the rubidium vapor for high field NMR detection at 14.1 T field strength. Xenon-131 is of particular interest because of its quadrupolar nature that can be utilized for the study of surfaces [3] and for the investigation of high magnetic field effects on the electronic structure of the noble gas atom [4]. In addition, this isotope is a useful probe for quadrupolar processes during gas transfer and during NMR/MRI detection. Experiments with xenon-131, including multiple quantum filtered NMR spectroscopy [3], provides insights into similar processes present in krypton-83 and its more complicated spin system [5]. [1] D. Raftery \textit{Ann. Rep. NMR Spec.}, \textbf{57}, 208 (2006). [2] G. Pavlovskaya, \textit{et al}., \textit{Pro. Natl. Acad. Sci. U.S.A.} \textbf{102}, 18275 (2005). [3] T. Meersmann \textit{et al.}, \textit{Phys. Rev. Lett. }\textbf{80}, 1398 (1998). [4] T. Meersmann and M. Haake, \textit{Phys. Rev. Lett.} \textbf{81}, 1211 (1998). [5] Z. Cleveland, \textit{et al.}, \textit{J. Chem. Phys.}\textbf{124}, 044312 (2006).