Stray field imaging by magnetic field sweep

A novel variant on nuclear magnetic resonance stray field imaging (STRAFI) is presented in which an additional magnetic field sweep coil is used to sweep the region of resonant frequency through a stationary sample. Variants on this technique using an integral superconducting field sweep coil as part of a spectroscopy magnet and a room temperature field sweep coil mounted inside an imaging magnet are detailed. One-dimensional profiles of "Perspex" and polytetrafluoroethylene samples are presented. The results from both superconducting and room temperature field sweep coils compare favorably with "conventional" STRAFI. (C) 1998 Academic Press.