The Recent Trends of High Temperature Superconductors. IV. Present Status of High Temperature Superconducting Current Limiters.

Status of High Temperature Superconducting Magnet Development

Since the discovery of high temperature superconductors more than 2 decades ago, there has been interest in their use for future fusion machines. Lack of performance of commercially available materials, however, dampened the initial optimism. However, recent advances in HTS materials, mostly second-generation tapes, open attractive topologies. In addition to reduced cryogenic loads and increase...

Thermal Behaviour and Refrigeration of High-Temperature Superconducting Fault Current Limiters and Microlimiters

Transition temperature and a spatial dependence of the superconducting gap for multilayer high-temperature superconductors.

We derive the expressions for the transition temperature (Tc), and the spatial dependence of the superconducting gap for a multilayer high-Tc superconductor composed of groups of tightly spaced planes separated by a larger distance. The results are compared with experiment and provide a strong support for an interlayer hopping as the driving force of the large Tc enhancement in multilayered com...

Kiloampere, Variable-Temperature, Critical-Current Measurements of High-Field Superconductors

We review variable-temperature, transport critical-current (I c) measurements made on commercial superconductors over a range of critical currents from less than 0.1 A to about 1 kA. We have developed and used a number of systems to make these measurements over the last 15 years. Two exemplary variable-temperature systems with coil sample geometries will be described: a probe that is only varia...

Pairing Symmetry of the High Temperature Superconductors

A review of relevant experiments that favour an unconventional pairing symmetry in high temperature cuprates is made. Results of magnitude sensitive techniques are discussed and then tests which probe directly the phase of the order parameter are presented in more detail. Josephson eeect and its relevance to this problem is described. Consensus resulting from compelling arguments for a d x 2 ?y...