|
Pulsed-Field-Gradient (PFG) NMR has proved to be a powerful tool
to characterize molecular motion in a non-invasive fashion. A
large family of PFG sequences have been developed for different
applications, but they have been always implemented and tested
in the homogeneous field of conventional magnets. These magnets
offer limited volume for housing the flow setup restricting the
application field of this technique.
In this work a modified stimulated spin-echo (SSE) sequence was
implement on a single-sided sensor to encode displacement along
the pulsed gradient direction. The sequence effectively reduces
the signal attenuation due to diffusion under the strong static
gradient of the unilateral magnet, and removes distortions
introduced by the off-resonance excitation. The method was
combined with imaging techniques to spatially resolved velocity
distributions for different pipe geometries. Thanks to the
implementation of a novel multi-echo acquisition the
experimental times were drastically reduced. |
