Three-field NMR to preserve hyperpolarized proton magnetization as long-lived states in moderate magnetic fields

►Molecules are hyperpolarized at BDNP = 3.35 T by dynamic nuclear polarization (DNP). ► Long Lived States (LLS) are prepared via a suitable initial condition at high field (BNMR = 7 T). ► Sample is adiabatically shuttled to 'low' magnetic fields (0.002 T ⩽ Blow ⩽ 7 T). ► Without applying any rf irradiation, the hyperpolarized magnetization has a lifetime TLLS ≫ T1 in low fields.