Magnetização de laços supercondutores 2G com pulsos curtos de corrente

Abstract

Superconducting materials are able to trap magnetic field in their interior, which allows them to be used for magnetic levitation. As far as field entrapment is concerned, 2G loops, made from segments of second generation superconducting tapes, work similarly to superconducting bulks, generating currents that partially cancel out the external magnetic field. When exposed to magnetic field pulses, 2G loops are capable of carrying high current densities persistently. This work has as its theme the study of the magnetization of 2G loops through the application of short current pulses in the primary of a transformer. Throughout the work, experimental results are presented, obtained during magnetization tests of the 2G loop, in which the width and intensity of the pulse are varied to verify the influence of these parameters on the energy transferred to the loop and the persistent current. The results of the electric field and current measured in these tests are confronted with a proposed model of the system, which is used to explain the transient of the magnetization phenomenon. Finally, the results of the short pulse tests are compared to tests with pulses whose duration is two orders of magnitude higher. The differences in both the transient behaviour and the final values of persistent current and energy are analysed.