Bornet, A.l., S. Jannin, and G. Bodenhausen, Three-field NMR to preserve hyperpolarized proton magnetization as long-lived states in moderate magnetic fields. Chem. Phys. Lett., 2011. 512(4–6): p. 151-154.
http://dx.doi.org/10.1016/j.cplett.2011.07.015
This communication describes a three-field experiment where inequivalent scalar coupled spin pairs are hyperpolarized at 3.35T and 1.2K by dynamic nuclear polarization (DNP), rapidly transferred to high field (7T) to prepare a suitable initial condition that is converted adiabatically into a long-lived state (LLS) by shuttling to a ’low’ magnetic field (2mT - 7T). Even without applying any rf irradiation to sustain the LLS, it has a lifetime TLLS»T1 in low fields. Finally, the sample is shuttled back to high field for observation under high-resolution conditions.