Magnetic field amplifier employing high-Tc bulk superconductor

We propose a new device built from a bulk superconductor to enhance the magnetic flux density within a high-field superconducting magnet. The high-temperature superconductor (HTS) bulk application, named the magnetic field amplifier, was constructed from four pieces of Gd–Ba–Cu–O superconductor. The field amplifier has a unique configuration of the bulk superconductor, which suppresses the current on the periphery of the bulk induced by external field variation. We experimentally demonstrated that the field was effectively amplified at the center of the HTS bulk device. By increasing the background field from 12 to 13 T in field-cooling mode, a magnetic flux density of 14.76 T was obtained at the center of the amplifier. The observed multiplication factor was 2.76, corresponding to external field variation. A configuration to further improve efficiency and reduce size is also presented.