SUPERCONDUCTING BIRDCAGE COILS

摘要

Superconducting birdcage coil with low-pass and high-pass coil configurations are formed by using strips each with an elongated sapphire substrate with a layer of a high temperature superconductor (HTS) material grown in a wavy pattern over its entire length on one of its main surfaces. A low-pass coil is formed with a pair of ring elements made of an electrically conductive metal and a plurality of such strips arranged parallel to one another and interconnecting these ring elements at junctions which are spaced peripherally along each of the rings. At each of the junctions, the ring element and the HTS layer form a capacitance. A high-pass coil is formed by a plurality of such strips each with electrodes of the HTS material also grown at two end positions separated from each other on the other main surface of its sapphire substrates. These strips are arranged parallel to each other and sequentially around a central axis, each lying in a plane which includes the center axis. The electrodes and the HTS layers on mutually adjacent pairs of strips are closely in face-to-face relationship so as to serve as the ring part of a birdcage configuration containing capacitors.