Performance of Trapped Magnetic Field in Superconducting Bulk Magnets Activated by Pulsed Field Magnetization

摘要

Melt-textured large grain high temperature superconducting materials have a characteristic feature so as to trap the magnetic fields applied from outside, and act as quasi- permanent magnets yielding intense magnetic fields which reach values of several T in the open space above the sample surface. The performance of the magnets has been precisely investigated when intense pulsed magnetic fields generated by feeding currents up to 9.12 kA to the pulse coil settled around a cylindrical bulk magnet. In the experiment a condenser bank with large capacitances of 40–120 mF has been adapted to apply the magnetic fields up to 8.44 T to the Gd-Ba-Cu-O-based bulk magnet with the size of 30 mm in diameter. The trapped field has reached 3.28 T on the sample surface. The magnetic fields successively penetrating the sample in the process called the IMRA method have been investigated with respect to the behavior of the magnetic flux in the sample.