Protection of Large Insulated React and Wind HTS Solenoids and Toroidal Coils

High temperature superconductor (HTS) conductors have low quench velocities compared to low temperature superconductor (LTS) conductors. An HTS conductor with very little copper has a low value of the integral of j²dt between the magnet operating temperature and 300 K. Adding copper to an HTS conductor reduces the quench propagation velocity and increases the time for the maximum hot spot temperature to be reached, but copper makes quench detection harder. To safely quench any large HTS magnet, one must reduce the current in the conductor rapidly and, ideally, one must heat up the coil to quench it. This paper explains how this can be done for large HTS solenoids or toroidal coils. These methods could permit one to wind solenoids and toroidal coils with higher energy densities per unit mass.