High-Resolution Magnetic Field Mapping System With an NMR Probe.

Area of Science:

• Physics
• Electrical Engineering
• Materials Science

Background:

• Nuclear Magnetic Resonance (NMR) magnets require precise magnetic field characterization for optimal performance.
• Accurate spatial magnetic field mapping is crucial for evaluating NMR magnet homogeneity.

Purpose of the Study:

• To present a novel high-resolution magnetic field mapping system for NMR magnets.
• To detail the design and implementation of an NMR probe and associated electronic systems for magnetic field measurement.

Main Methods:

• Development of a 5.73 MHz NMR probe with a Q-factor of ~191.
• Utilization of an RF continuous-wave technique with magnetic field modulation to detect water molecule power dispersion.
• Implementation of an embedded system with a numerically controlled digital oscillator for precise frequency sweeping (0.02 Hz steps).
• Design of an RF preamplifier and bidirectional coupler for power delivery and signal reflection detection.

Main Results:

• The system successfully collects spatial magnetic field data.
• The zero-crossing frequency of the NMR dispersion signal accurately corresponds to the magnetic field at the sample's center.
• The system demonstrates high precision, with frequency steps equivalent to 4.7 e-7 mT for hydrogen atoms.

Conclusions:

• The developed system provides high-resolution magnetic field mapping capabilities for NMR magnets.
• The system's precision and methodology enable effective determination of NMR magnet homogeneity.
• This technology contributes to advancements in NMR magnet quality control and characterization.