Evaluation of motion of a high-T-c superconducting thin film in microgravity experiments

Motion of a high-T-c superconducting (HTS) thin film was observed in microg ravity experiments with a free fall drop shaft facility. The field-cooled t hin film was suspended under a permanent magnet in the free fall experiment s. When the magnet was rotated in microgravity, the thin film moved to a st able position where centrifugal force was balanced to restoring force cause d by pinning of superconductor. The motion of the HTS thin film is numerica lly evaluated by using the frozen field model, which is based on an assumpt ion that fluxoids are fixed at pinning points on the surface of the superco nductor. The numerical evaluation is useful to explain the experimental res ults. (C) 1999 Elsevier Science B.V. All rights reserved.