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1. PURPOSE
This probe tests resolution limits of FT STRAFI (Stray Field Imaging) technique at the high field and high stray
gradient 833 MHz magnet,
allowing the 1D imaging of thin solid samples at increased spatial resolution. The FT method studies the samples
thin enough to be completely excited with a single RF pulse. Thus the probe can be stationary avoiding the necessity
of small step sizes in the translational STRAFI method and the complications of vibration during the motion.
This FT probe was designed with a precision leveling platform to help overcome the deleterious effects of
sample misalignment. Platform tilt resolution of 0.01 degrees provides very accurate leveling of the phantom in the
horizontal plane, at right angles to the vertical field and gradient direction.
2. EXAMPLE
A profile of a sandwiched phantom with 6 micron PTFE film in the middle is shown in figure below.
The proton containing tape was attached to the PTFE film with its adhesive side.
The absence of signal from the glass plates (approx. 70 micron) and the PTFE film can be clearly seen.
In the proton region one can distinguish the polymer and glue portions of the tape.
The dip due to the PTFE can be resolved to about half-way to the base line,
so the achieved spatial resolution is 6 micron in formal terms.
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