Analytical models of probe dynamics effects on NMR measurements

Mason Greer; David Ariando; Martin Hurlimann; Yi-Qiao Song; Soumyajit Mandal

doi:10.1016/j.jmr.2021.106975

Analytical models of probe dynamics effects on NMR measurements

J Magn Reson. 2021 Jun:327:106975. doi: 10.1016/j.jmr.2021.106975. Epub 2021 Mar 27.

Authors

Mason Greer¹, David Ariando², Martin Hurlimann³, Yi-Qiao Song⁴, Soumyajit Mandal⁵

Affiliations

¹ Case Western Reserve University, 10900 Euclid Ave, Cleveland, OH 44106, USA. Electronic address: mkg53@case.edu.
² University of Florida, 1064 Center Drive, Gainesville, FL 32611, USA. Electronic address: dariando@ufl.edu.
³ Schlumberger-Doll Research, Cambridge, MA 02139, USA.
⁴ Massachusetts General Hospital, Charlestown, MA 02129, USA. Electronic address: ysong5@mgh.harvard.edu.
⁵ University of Florida, 1064 Center Drive, Gainesville, FL 32611, USA. Electronic address: soumyajit@ece.ufl.edu.

PMID: 33873092
DOI: 10.1016/j.jmr.2021.106975

Abstract

This paper provides a detailed analysis of three common NMR probe circuits (untuned, tuned, and impedance-matched) and studies their effects on multi-pulse experiments, such as those based on the Carr-Purcell-Meiboom-Gill (CPMG) pulse sequence. The magnitude of probe dynamics effects on broadband refocusing pulses are studied as a function of normalized RF bandwidth. Finally, the probe circuit models are integrated with spin dynamics simulations to design hardware-specific RF excitation and refocusing pulses for optimizing user-specified metrics such as signal-to-noise ratio (SNR) in grossly inhomogeneous fields. Preliminary experimental results on untuned probes are also presented.

Keywords: LOW-field NMR; Optimal control theory; Probe circuits; Pulse design; Spin dynamics.

Published by Elsevier Inc.