Improvement of characteristic of critical current density in Bi-2223 superconductor

测量了Bi-2223超导体的凝聚能密度，它决定了临界电流的性质，并讨论了超导体的可能性。发现Bi-2223超导体在低温下具有与实用稀土-123超导体相当的电势。此外，还制作了液氮超导磁体，并成功地产生了1.3T的磁场。

The condensation energy density of Bi-2223 superconductor, which determined the property of the critical current, was measured and the possibility of superconductor was discussed. It was found that Bi-2223 superconductor had potential equal to the practical rare earth-123 superconductor at low temperatures. In addition, the superconducting magnet working at liquid nitrogen was fabricated and magnetic field of 1.3T was successfully generated.