Abstract: A method of constructing a superconducting coil. The method includes embedding a plurality of heater elements throughout a superconducting coil. The heater elements are positioned according to a predetermined distribution and substantially in thermal contact with the coil for heating the coil in response to a quench condition. Other aspects of the invention involve an active protection circuit and a high temperature superconductor magnet that includes such an active protection circuit for internally dissipating stored magnetic energy in the event of a quench.

Abstract: An actively shielded superconducting magnet having a dipole shim coil for adjusting and fine-tuning an external or far fringe magnetic field produced by a main coil of the magnet. An active shield coil is coupled to the main coil in reverse polarity and produces a magnetic field when energized that opposes the far fringe field to substantially reduce the far fringe field. The dipole shim coil is electrically isolated from the active shield and main coils of superconducting magnet, and produces a magnetic field when energized that provides for the fine adjustment of any residual far fringe field.