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Updated: Nov 30, 2025
07:01
Frequency Mixing Magnetic Detection Scanner for Imaging Magnetic Particles in Planar Samples
Published on: June 9, 2016
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Ultra-low frequency EPR using longitudinal detection and fictitious-field modulation.
Xueyan Tang1, Steven Suddarth1, Guhan Qian1
1Center for Magnetic Resonance Research and Department of Radiology, University of Minnesota, 2021 6(th) Street SE, Minneapolis, MN 55455, USA.
Journal of Magnetic Resonance (San Diego, Calif. : 1997)
|November 13, 2020
Summary
Researchers demonstrated electron paramagnetic resonance (EPR) spectroscopy and imaging using a novel ultra-low frequency system. This method detects electron spins with short relaxation times by modulating radiofrequency fields.
Area of Science:
- Physics
- Spectroscopy
- Magnetic Resonance
Background:
- Radiofrequency (RF) fields in a rotating frame appear as a longitudinal fictitious field.
- Modulating this fictitious field allows for the measurement of longitudinal magnetization patterns.
Purpose of the Study:
- To demonstrate Electron Paramagnetic Resonance (EPR) spectroscopy and 1D imaging using fictitious-field modulation.
- To detect electron spins with short relaxation times (~nanoseconds) at ultra-low frequencies (24 MHz).
Main Methods:
- Utilized a custom-built longitudinal detection system.
- Employed fictitious-field modulation combined with longitudinal detection.
- Achieved simultaneous transmit and receive with high transmitter isolation (~80 dB).
Main Results:
- Successfully demonstrated EPR spectroscopy and 1D imaging at 24 MHz.
- Enabled detection of electron spins with short relaxation times.
- Showcased simultaneous transmit and receive capabilities.
Conclusions:
- Fictitious-field modulation and longitudinal detection offer a viable approach for ultra-low frequency EPR.
- This technique is suitable for studying electron spins with rapid relaxation.
- The developed system supports advanced EPR applications including imaging.
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