Patent ID: 8482369

Claim:
A superconducting magnet assembly comprising: a superconducting magnet coil assembly positioned within a vessel and comprising a plurality of magnet coils connected in series, the plurality of magnet coils being arranged to form symmetric coil pairs such that the magnet coils corresponding to each respective symmetric coil pair are positioned on opposite sides of a center point of the superconducting magnet coil assembly; a power supply selectively coupled to the superconducting magnet coil assembly to supply power to the plurality of magnet coils so as to cause the superconducting magnet coil assembly to generate a magnetic field; and a magnet protection system disposed within the vessel and electrically coupled to the plurality of magnet coils to form a closed loop circuit, the magnet protection system comprising: a single superconducting switch connected between ends of the closed loop circuit to selectively connect the power supply to the superconducting magnet coil assembly; a plurality of dump resistors arranged to form a resistor ladder circuit, wherein each of the plurality of dump resistors is connected between magnet coils forming a respective symmetric coil pair; and a heater network connected between ends of the closed loop circuit and to the superconducting magnet coil assembly, the heater network being configured to perform a quench-back operation to protect the plurality of magnet coils during quench; wherein the heater network is driven by a partial-magnet coil voltage generated in a magnet coil in the plurality of magnet coils upon initiation of a quench condition in the magnet coil.