Topologically Optimized Magnetic Lens for MR Applications

Abstract. Improvements to the signal-to-noise ratio of magnetic resonance detection leads to a strong reduction in measurement time, yet as a sole optimization goal for resonator design it would be an oversimplification of the problem at hand. Multiple constraints, for example for field homogeneity, and sample shape, suggests the use of numerical optimization to obtain resonator designs that delivers the intended improvement. Here we consider the 2D Lenz lens as a sufficiently broad-band flux transforming interposer between the sample and an RF circuit, as a flexible and an easily manufacturable device family with which to mediate different design requirements. We report on a method to apply topology optimization to determine the optimal layout of a Lenz lens, and demonstrate realisations for both low (45 MHz), and high frequency (500 MHz) NMR.