| 摘要 |
PURPOSE:To reduce a leakage magnetic film without increasing the weight and size of a title magnet by forming a high temperature superconductor thin film on one layer of a thermal radiation shield. CONSTITUTION:Once a high temperature semiconductor thin film 6 which gets a superconducting state depending upon the temperatures of thermal radiation shields 4 is formed on the thermal radiation shield 4, the high temperature superconductor thin film 6 serves to counteract a magnetic field generated by a superconductivity coil 1 by a Meissner effect surrounding the external diameter side of the superconducting coil 1 to confine a leakage magnetic field in a space between the high temperature superconductor thin film 6 and the superconducting coil 1. Since the high temperature superconductor thin film 6 is thin, the size of the superconducting magnet is reduced with its weight likewise reduced. Hereby, any leakage magnetic flux is reduced even if its size and weight are the same as those of prior art ones. |
