Transport current saturated HTS magnets

An HTS magnet system comprising:

• an HTS field coil comprising:
• a plurality of turns comprising HTS material;
• a resistive material electrically connecting the turns, such that current can be shared radially between turns via the resistive material;
• a temperature control system comprising a cooling system configured to keep the temperature of the HTS field coil below a self-field critical temperature of the HTS material;
• a power supply configured to supply current to the HTS field coil;
• and
• a controller configured to:
• cause the power supply to provide current sufficiently high to saturate the HTS material in the coil so that it all operates at its critical current;
• reduce the magnetic field generated by the HTS field coil by increasing the current supplied by the power supply, and increase the magnetic field generated by the HTS field coil by decreasing the current supplied by the power supply.

A high temperature superconducting, HTS, magnet system comprising:

• a plurality of HTS field coils, each comprising:
• a plurality of turns comprising HTS material;
• a resistive material electrically connecting the turns, such that current can be shared radially between turns via the resistive material;
• a temperature control system configured to control the temperature of each coil, the temperature control system comprising at least a cryogenic cool system configured to keep each coil below a self-field critical temperature of the HTS material;
• a power supply configured to supply current to the HTS field coil;
• a controller configured to:
• cause the power supply to provide a current to each field coil such that a transport current of each HTS field coil is greater than a critical current of all of the HTS material in the HTS field coil;
• cause the temperature control system to adjust the temperature of each HTS coil and thereby adjust the contribution of each HTS coil to the magnetic field.