Design of a nuclear magnetic resonance sensor working in inhomogeneous magnetic field

Nuclear magnetic resonance (NMR) in inhomogeneous magnetic fields has been developed in the last decade for portable applications. High resolution NMR spectrometry is possible in non homogeneous magnetic fields, if the static and the radiofrequency (RF) magnetic field are perpendicular and correlated on the measurement volume. An analytic solution is proposed: using the easy-axis rotation theorem and the Amperian current model, it is possible to exactly match two magnetic fields in two-dimensional systems. We derive a basic probe element based on this principle. From this, a portable NMR probe has been designed. The static and RF magnetic fields of this probe are matched on a large volume. A single-sided NMR was constructed. Its dimensions are 75 x 30 x 15 mm and the probe weights 210 g. Preliminary results has been obtained in inhomogeneous magnetic field.