Magnetic levitation on a type-I superconductor as a practical demonstration experiment for students

Abstract

Abstract. We describe and discuss an experimental set-up which allows undergraduate and graduate students to view and study magnetic levitation on a type-I superconductor. The demonstration can be repeated many times using one readily available 25 liter liquid helium dewar. We study the equilibrium position of a magnet that levitates over a lead bowl immersed in a liquid hand-held helium cryostat. We combine the measurement of the position of the magnet with simple analytical calculations. This provides a vivid visualization of magnetic levitation from the balance between pure flux expulsion and gravitation. The experiment contrasts and illustrates the case of magnetic levitation with high temperature type-II superconductors using liquid nitrogen, where levitation results from partial flux expulsion and vortex physics.

Materials for teaching the rotational motion of magnetically levitating bodies with a video camera

“…Various motions of levitating bodies can be performed by devising the magnetic field distribution. Such interesting motions are not only enjoyable to watch but also have the potential to be used in physics education [11][12][13][14]. In particular, the educational use of superconductors has been actively carried out [15][16][17][18][19][20][21][22].…”