A Systematic Approach to the Design, Fabrication and Testing of Permanent Magnets Applied to Single‐Sided NMR

In this paper, we discuss the application of a systematic approach to magnet design to single‐sided magnets [1]. This approach, based on analytical expressions of the spherical harmonic expansion terms for basic magnet blocks allows to compute exact geometry parameters for structures optimized in homogeneity and field strength for a given amount of material. The case of homogeneous fields and a controlled strong gradients are treated separately. This method can be applied to both in situ and ex situ configurations. We present a possible single‐sided structure generating a strong gradient at a remote distance. This structure adopt an axial symmetry and is magnetized along its axis, generating a field along that axis. A prototype of this model has been fabricated and we report its initial performances. This magnet has been integrated with an optimized planar coil for single‐sided excitation and detection. Initial images of thin olive oil layers are also presented.