Pulsed Magnetization of a Short-Circuited HTSC Coil

Resumo

We have studied trapped magnetic fields and their relaxation during pulsed magnetization of a 20-turn short-circuited coil made of a stabilized HTSC-2G tape at liquid nitrogen temperature. The highest trapped field is close to the value obtained during field cooling (FC process) and varies insignificantly upon a five-fold increase of the magnetizing pulse amplitude. Copper coating of the tape considerably suppresses pulsed heating effects. Current relaxation at the initial segment is determined by the current passing between superconducting and normal layers and by the form of the current–voltage characteristic. Over long time intervals (t > 100 s), relaxation is determined by the contact resistance of the soldered junction.