Normal zone acceleration in superconductor with changing current
Abstract
The quench propagation in superconductors with changing current I(t) and/or placed into varying magnetic field B(t) is studied. The perturbations induced by the first derivative of T with respect to time, the first derivative of B with respect to time, may result in the thermomagnetical instability at quench current I(sub q)(the first derivative of T with respect to time, the first derivative of B with respect to time) less than I(sub s), where I(sub s) is the critical current. It is shown that the interaction between the instability and the propagating normal zone leads to the acceleration of normal zone. The quench propagation velocity v increases sharply and the quench energy e(sub c) tends to zero at I to approx. I(sub q) or with increase of the first derivative of T with respect to time, the first derivative of B with respect to time. The effects of current sharing and the nonuniformities of superconductor on quench process are discussed. Analytical dependencies of v and e(sub c) on the first derivative of T with respect to time, first derivative of B with respect to time are found and compared with the experiments.
 Publication:

IEEE Transactions on Magnetics
 Pub Date:
 July 1994
 DOI:
 10.1109/20.305657
 Bibcode:
 1994ITM....30.1994B
 Keywords:

 Electric Current;
 Heat Transfer;
 Magnetic Fields;
 Perturbation;
 Quenching;
 Superconductors (Materials);
 Thermal Stability;
 Transition Temperature;
 Electric Fields;
 Electrical Resistance;
 Propagation Velocity;
 Specific Heat;
 Electronics and Electrical Engineering