Pulse Magnetization of Jointless Superconducting Loops for Magnetic Bearings Height Control

Superconductors can be used for applications such as magnetic levitation. The Maglev Cobra project, developed at the Universidade Federal do Rio de Janeiro, uses superconducting bulks, which are produced in a partially industrial process, which does not guarantee homogeneity, and operate passively, making height control impossible. Replacing these bulks with jointless 2G wires superconducting loops will guarantee a homogenous production and enables active control of levitation height through current pulse magnetization. In this work, superconducting loops were exposed to different values of current pulse width and intensity. The induced current in the tape was then measured. With this, the persistent current behavior in the superconductor could be observed, showing a correlation between the persistent current and the applied current pulse parameters. Saturation of the current in the superconductor was observed above certain values of applied current, due to the critical current value of the superconducting tape. Furthermore, as the width of the current pulse increases, the persistent current increment decreases. According to these results, an optimum point can be observed, in which the ratio between the persistent current and the energy used is maximized. To operate at the optimum point, the current pulse width must decrease as its intensity increases.