Distributed phase RF coil

摘要

Apparatus for generating and detecting magnetic field components oscillating at a radio frequency in a direction transverse to a static magnetic field in a nuclear-magnetic-resonance (NMR) system. The apparatus has a plurality of conductive elements spaced from one another and from the axis along which the static magnetic field is directed. The relative amplitudes of alternating currents in the conductive elements are controlled to generate a spatially uniform field. A preferred embodiment uses a standing wave in a coil assembly to control relative current amplitudes, which takes advantage of the current-phase characteristics of such waves. Detection of RF magnetic fields results from an EMF generated in the coil assembly in response to the time-varying magnetic field; the high Q of the coil assembly enhances detection properties.