Magnetic field generating assembly

摘要

A magnetic field generating assembly for use in NMR apparatus comprises a pair of first magnets arranged coaxially with like poles facing each other and axially spaced apart. At least one second magnet is positioned between the first magnets and with its axis coaxial with the first magnets. The axial positions and strengths of the magnets are arranged such that a working region is defined radially spaced from the magnets and extending substantially parallel with the axis of the magnets. The magnetic field within the working region is suitable for obtaining NMR information from material in the working region and exhibits a radial gradient which is substantially uniform in the axial direction.