Levitation force measurement on a switchable track for superconducting levitation systems. (26th October 2018)

• Record Type: Journal Article
• Authors: Espenhahn, Tilo; Berger, Dietmar; Schultz, Ludwig; Nielsch, Kornelius; Hühne, Ruben
• Is Part Of: Superconductor science & technology. Volume 31:Number 12(2018:Dec.)
• Publication Date: 2018-10-26
• Subjects: large scale application -- superconducting levitation -- track design -- force measurement; Superconductivity -- Periodicals; Superconductors -- Periodicals; 537.623
• DOI: 10.1088/1361-6668/aae45f
• Languages: English
• ISSNs: 0953-2048

Abstract

Abstract: Whereas current superconducting levitation systems typically use permanent magnetic tracks, additional switchable components are required to realize fast turnouts or crossings. Therefore, a prototype for a switchable track segment was realized by a combination of permanent magnets with a superconducting coil, which enables switching of the magnetic field above the track from active (magnetic field is present) to inactive (significantly reduced magnetic field) and back. Previous studies of the magnetic flux density distribution above both track types showed only a small mismatch between the standard permanent magnetic setup and the new switchable design. Here, we present measurements of the levitation as well as of the lateral forces for both track types. The results show that the active switchable track leads to comparable force values as for the standard track. The differences lead only to a slight reduction of the levitation height above the switchable track. In contrast, the measured forces are significantly reduced, if the track is switched in the inactive mode, i.e. the values are no longer sufficient to maintain a stable levitation. Furthermore, a typical hysteresis for the force values was observed for both systems. The lateral asymmetry of the measured force values was traced back to inhomogeneities of the used superconductors.