Accommodation of Pulsed Field Gradients with Cascade Field Regulation in Powered Magnets.

Proc IEEE Conf Decis Control

National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310.

Published: December 2021

High magnetic fields significantly improve the resolution and sensitivity of nuclear magnetic resonance (NMR) spectroscopy measurements, which presents exciting research opportunities in areas of chemistry, biology, and material science. Powered magnets can provide much higher magnetic fields than persistent mode superconducting magnets but suffer from temporal magnetic field fluctuations due to power supply ripple and variations in cooling water temperature and flow rate which make powered magnets non-viable for high resolution NMR experiments. Previous work has demonstrated that a multi-rate sampled data cascade control system may be used to improve the resolution of NMR experiments in powered magnets. Despite these advances in reducing temporal magnetic field fluctuations, the field regulation design does not accommodate the use of pulsed field gradients, which are necessary in many NMR experiments. This work presents a control topology which accommodates the use of pulsed field gradient signals with the field regulation system. This control approach is verified using NMR measurements.

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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC10900990PMC
http://dx.doi.org/10.1109/cdc45484.2021.9683312DOI Listing

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