Electropermanent magnets for variable-field NMR.
Related Articles Electropermanent magnets for variable-field NMR.
J Magn Reson. 2019 Apr 23;303:82-90
Authors: Ropp C, Chen C, Greer M, Glickstein J, Mair L, Hale O, Ariando D, Jafari S, Hevaganinge A, Mandal S, Weinberg IN
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.
PMID: 31026669 [PubMed - as supplied by publisher]
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