Assessment of the Impact of Static Field Inhomogeneity on the Performance of Miniaturized NMR Devices

Abstract

Miniaturized nuclear magnetic resonance (NMR) devices are a trend in the industry because they allow flexible use within a range of applications that would be otherwise not feasible with standard NMR equipment. However, one of the main obstacles in the development of miniaturized NMR systems is the availability of a static magnetic field <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$B_{0}$ </tex-math></inline-formula> with enough homogeneity. It is of the utmost interest to be able to evaluate upfront the quality of the static magnetic field of the miniaturized system in order to assess its impact on the NMR spectrum resolution, and its usability for the targeted application. This article proposes an efficient simulator that can compute the deformation of an ideal NMR spectrum due to any <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$B_{0}$ </tex-math></inline-formula> field inhomogeneity using a coarse discretization of the sample volume. Its validation is performed by comparing the spectrum deformation it provides with the one obtained from an intensive numerical simulation using a high-density discretization of the sample volume. Such intensive simulation is only practical on small sample volumes. Finally, the simulator is applied on a real spectrum and its applicability as well as some improvements are discussed.