NMR apparatus with spatially distributed receive antennae

A magnetic resonance measurement apparatus that is subject to relative motion between the apparatus and a specimen (e.g. an earth formation) along a path includes a plurality of spatially distributed receive antennae 52 along the path, and a magnet 54 which polarises the specimen. Because of the spatial distribution of the antennae, each antenna corresponds to a different polarisation time (wait time) for the magnetic resonance measurements. This allows faster acquisition and determination of both longitudinal and transverse relaxation times for the specimen. The distribution of antennae along the path may be varied depending upon the experiments being performed (see figures 3 and 4). Mutual inductance between the antenna coils may be reduced by incorporating a loop (205, see figure 20) into each coil. In a specific embodiment, the apparatus is used for well-logging, and measurement while drilling is also possible.