Patent ID: 6348792
Filing Date: 2002-02-19
Classification: G01N,G01V

Abstract:
A Nuclear Magnetic Resonance (NMR) sensing apparatus comprising:(a) at least one primary (first) magnet to generate a static magnetic field in a volume containing materials sought to be analyzed, said at least one primary magnet having a longitudinal axis and being magnetized in a magnetization direction substantially perpendicular to said longitudinal axis, said magnetic field of said first magnet substantially that of an equivalent dipole magnet; (b) a radio frequency (RF) antenna for inducing a RF magnetic field in said volume and exciting nuclei therein and receiving signals from said excited nuclei, said RF magnetic field substantially that of a RF dipole orthogonal to the equivalent dipole magnet and displaced laterally therefrom; and (c) a second magnet having a magnetization substantially parallel to the magnetization of the at least one primary magnet, said second magnet disposed from the at least one primary magnet and the RF antenna for shaping said static magnetic field thereby defining an arcuate region of investigation in said volume wherein said static magnetic field has a field strength within predetermined limits and wherein said RF magnetic field has a substantially uniform field strength component orthogonal to the shaped static magnetic field.