Inductively coupled NMR probe for versatile dynamic nuclear polarization operation at 7 T: Observation of 61 ± 2% 1H polarization at 4 K

► Our low power (<70 mW), diode-based, DNP instrument at 7 T was further optimized. ► An inductively coupled Alderman-Grant coil was used for solid state 1H DNP at 7 T. ► Record high 1H nuclear polarization of 61 ± 2% was recorded at 4 K and 7 T. ► Enhanced DNP can be expected with optimized radicals and higher microwave powers.