An integrated end piece for an MRI magnet vacuum container

摘要

An end piece for an MRI magnet vacuum container comprises a thin metal plate 42 for welding to the inner 14 and outer 12 cylinders of the vacuum container, a decorative GRP shell 44 and a solid foam filling 46 bonded to the GRP shell and the metal plate to form an integrated end piece. The integrated structure permits the decorative shell 44 and the metal plate 42 to be made thinner so that the overall magnet length is reduced. The end piece may be made less massive while retaining stiffness. The foam layer may comprise regions of high-density foam and regions of low-density foam. The foam may be cut and shaped before bonding, or expanding foam may be used. The reduced thickness of the metal plate lessens eddy currents induced by the gradient fields and so reduces noise.