th  - 1988 - 51st ENC Conference

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[I'IED 8:30 I
REMOVAL OF EXTRANEOUS LINE BROADENING FOR SOLID STATE
IMAGING: HOW MUCH IS ENOUGH, J. B. Miller and A. N. Garroway*,
Naval Research Laboratory, Code 6122, Washington D. C. 20375-5000
There are questions in materials science which can be
addressed by NMR imaging. Under some circumstances, there is
sufficient molecular motion within the specimen so that the now
familiar techniques of medical NMR imaging (MRI) can be applied
almost directly. However, the more general case requires methods
specifically for imaging rigid solids.
In this talk we present a number of solid state imaging
approaches. Homonuclear line narrowing sequences are appended to
the usual Fourier transform imaging procedure to produce two-
dimensional images of solids. Even rare sDin imaging is tenable,
as other workers have shown. Though the 13C signal is weaker
than that of IH, heteronuclear decoupling is generally more
efficient than homonuclear decoupling in organic polymers. But
reducing only the dipolar contribution to the linewidth may not
be sufficient for best spatial resolution. We demonstrate the
removal of chemical shift-like broadening (isotropic and
anisotropic chemical shifts, susceptibility, static field
inhomogeneity) for both abundant (~H) and rare spin (13C) solid
state imaging. We also present line narrowing methods and the
first results for solid state imaging with a surface coil.
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