Inductance calculation system for superconducting circuits

A method for calculating the inductance of complicated three-dimensional superconducting circuits is described. The current distribution is obtained by assuming that the edge currents satisfy both Maxwell´s and London´s equations. Inductance is calculated from the magnetic energy resulting from the current. Extrapolations are used to reduce the computational requirements and to increase the accuracy of the results. Using the method, a CAD (computer-aided design) system was developed for superconducting circuits. The inductance of 3-D superconducting circuits, which was unattainable except by experiments, can be easily calculated by this system. The coupling inductance of a DC SQUID (superconducting quantum interference device) is calculated using the CAD system. Agreement between experiment and the computation is good