Experiments on YBCO tape type high temperature superconductor junctions

This paper is concerned with the study of electrical contacts between the components used in building key parts of high temperature superconducting (HTS) electromagnets, e.g., HTS coils, HTS current leads, etc. Some preliminary tests on two types of junctions are presented, Cu - HTS and HTS - HTS, and some details of their manufacturing process are shown. Experimental and numerical results on the electrical resistances of these junctions may provide for a basis analysis of selection for appropriate solutions under specific working circumstances. Of particular concern is the experimental setup used to measure the electrical resistances of the junctions. A Gifford - McMahon Cryo-Cooler (GM-CC) conditioned cryo-environment provides adequate experimental conditions to the study. The paper presents numerical simulation results of the electrokinetic model for the electrical current flow within the junctions too, aiming at computing their electrical resistances, the magnetic field produced by the current flowing through the junctions with the aim to asses the background magnetic field that might affect the measurements, and the heat transfer to the ambient, to ascertain the efficiency of the cryo-system used in the experiments.