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A constant gradient unilateral magnet for near-surface MRI profiling
Andrew E Marble1, Igor V Mastikhin, Bruce G Colpitts
1MRI Centre, Department of Physics, PO Box 4400, University of New Brunswick, Fredericton, New Brunswick, Canada E3B 5A3.
Journal of Magnetic Resonance (San Diego, Calif. : 1997)
|September 26, 2006
Summary
A new unilateral Nuclear Magnetic Resonance (NMR) magnet assembly enables near-surface 1D profiling of planar samples. This device offers a large spatial extent with moderate resolution for materials analysis.
Area of Science:
- Physics
- Materials Science
- Analytical Chemistry
Background:
- Nuclear Magnetic Resonance (NMR) is a powerful technique for materials characterization.
- Near-surface analysis requires specialized instrumentation for probing shallow depths.
Purpose of the Study:
- To design and construct a unilateral NMR (UMR) magnet assembly for near-surface 1D profiling.
- To enable frequency-encoded spin-echo experiments for planar sample analysis.
Main Methods:
- Utilized a single permanent magnet with a shaped iron pole cap.
- Analytically determined pole cap profile to shape the magnetic field.
- Employed a frequency-encoded spin-echo experiment for 1D profiling.
Main Results:
- Achieved a constant magnetic field gradient of 31 G/cm over an 8mm depth.
- Operated at a 1H frequency of 4.26 MHz with a probing spot of approximately 5 mm width.
- Magnetic field curvature limited resolution to hundreds of micrometers.
Conclusions:
- The UMR magnet assembly is suitable for 1D profiling of planar samples.
- The device is advantageous for applications requiring coarse resolution over a large spatial extent.
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