Cryogenic magnetic field sensing to compensate for magnetic field fluctuations in magnetic resonance imaging magnets

摘要

The superconducting magnet includes superconducting magnet coils C1, C2, C3, C4, C5, C6, S1, and S2 arranged inside the magnet cryostat 12. The superconducting magnet coil generates a static magnetic field (B0) when current flows through the superconducting magnet coil. A superconducting B0 compensation circuit 30, 60, 70 is further disposed within the magnet cryostat and coupled to the superconducting magnet coil to passively reduce the temporal variation of the B0 magnetic field generated by the superconducting magnet coil. Is done. A current sensor 40 is further disposed within the magnet cryostat and connected to measure the current flowing through the superconducting B0 compensation circuit. An active B0 compensation component 50 is operatively connected to the current sensor to receive a measurement of the current flowing through the superconducting B0 compensation circuit and to perform active B0 magnetic field compensation based on the measured current.