Analysis of the influence structural defects on the critical current of the HTc superconducting tapes.

In the paper it is theoretically analysed the influence on the critical current phenomena of the HTc superconducting tapes, of the structural defects created in HTc superconductors, especially during the heavy ions irradiation arising at the work of the superconducting magnets in the modern nuclear accelerators but also at the mechanical bending strain process. The losses generated then during the pulsed current flow through the superconducting current leads, supplying accelerators are calculated as the function of the time and current. Attention will be devoted here to the analysis of the hysteresis effects. The influence of the nano-sized structural defects on the current-voltage characteristics of the HTc superconducting materials is investigated basing on the model of interaction magnetic pancake type vortices with nano-sized defects as the function of the strength of this interaction, leading to various depths of vortices anchoring in the initial state.