Electropermanent magnets for variable-field NMR
 

Electropermanent magnets for variable-field NMR

Publication date: June 2019

Source: Journal of Magnetic Resonance, Volume 303

Author(s): Chad Ropp, Cheng Chen, Mason Greer, Jarred Glickstein, Lamar Mair, Olivia Hale, David Ariando, Sahar Jafari, Anjana Hevaganinge, Soumyajit Mandal, Irving N. Weinberg

Abstract

In this work, a dynamically tunable B0 field is used to perform variable-field NMR. The system consists of an array of electropermanent AlNiCo-5 magnets whose magnetizations are individually programmed using pulse-power control. This design allows the field strength to be varied for field-dispersion measurements. An ultra-broadband front-end is utilized that maintains efficient power transmission over a broad range of frequencies for robust operation without probe tuning. We perform T1-T2 correlation measurements at various B0 field strengths (0.5–2 MHz) and demonstrate discrimination of different dairy products. We observe variation in the frequency dependence of the proton spin–lattice relaxation for the different products as a function of the degree of protein hydration. This variable-field technique provides a low-cost alternative to fast field-cycling NMR and could open possibilities for novel contrast measurements and spatial encoding in magnetic resonance imaging.



Graphical abstract

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