IEEE Transactions on Applied Superconductivity

Taking advantage of the recent development of very low AC loss superconducting composites, the realization of AC current limiters is now possible. This device, without conventional equivalence, is based on the ultrafast transition from the superconducting (nonresistive) state to the normal (resistive) state by overstepping the critical current density. This paper first proposes an original device ... View full abstract»

This paper describes the tests conducted to characterize the performance of the 200 kA conductor used in the Bechtel Team's SMES (superconducting magnetic energy storage) design. The CICC-type conductor was tested at operating temperature (1.8 K) and field by placing the sample in the bore of a dipole magnet and simultaneously ramping the current and the background field to simulate operation alon... View full abstract»

An important issue for electrodynamic maglev operation is quenching of the superconducting magnets induced by interactions with the guideway. Such quenching limited the velocity of the MLU002 maglev in Japan. Here we study one of the mechanisms by which the SCM-ground coil interactions affect the thermal stability of maglev SCM's. The time-varying forces are determined from the SCM-ground coil int... View full abstract»

Levitation force between permanent magnets and high-T/sub c/ superconductors (HTSC's) is evaluated numerically based on the critical state model. The bulk HTSC is approximated to a thin plate multilayer model from its anisotropic structure. The thin plate eddy current code with the finite element method is applied to the analysis of the HTSC flywheel, where ring magnets and the HTSC are arranged i... View full abstract»

This paper describes engineering analysis and simulation results for a device intended to transfer current among parallel superconducting branches in a meshed superconducting dc system. Meshed superconducting dc systems offer unique problems of current distribution between parallel paths due to the lack of resistance. Neither resistances nor steady-state impedances can be relied upon to equalize t... View full abstract»

An optical input/output interface system for a Josephson junction integrated circuit is fabricated and tested. The system consists of a superconducting optical detector, a dc powered Josephson circuit, a dc powered Josephson high voltage circuit, a liquid-He-cooled semiconductor amplifier, and a liquid-He-cooled semiconductor laser. Features of the system are use of an ultrathin NbN film for the o... View full abstract»

We describe results of a study comparing the magnetic field sensitivities of variable thickness bridge (VTB) arrays fabricated in TBCCO, BSCCO, and YBCO thin films. Identical structures were patterned in a variety of films, and the bridges were thinned by four different methods. Analysis of the data yields experimental evidence as to the suitability of these types of films for devices such as the ... View full abstract»