DETECTION OF WEAK POINTS IN HIGH-TEMPERATURE SUPERCONDUCTOR TAPES BY STATISTICAL METHODOLOGIES

Specimens of 2223-BSCCO tapes were subjected to mechanical degradation , measuring, after and before degradation, the voltage-current (V-I) c haracteristic. The tmo-parameter Weibull function was used to fit the cumulative and density probability distributions (obtained from V-I da ta by numerical-analytical differentiation). It is shown that Weibull- function parameter values are sensitive to weak points generated in th e tapes by mechanical stress, thus providing clear evidence of the pre sence of defects. In particular, attention is focused to the answer of diagnostic procedures resorting to the Weibull distribution to weak p oints which can be encountered in a HTSC tape typically used for high- voltage cables. These defects can arise due to aging or be already pre sent in the new tape, thus the proposed procedure has both diagnostic and quality control features.