Spatially resolved measurements of critical parameters in superconducting filaments by laser scanning technique

We present an experimental study of local transport properties of supercond ucting filaments by means of low temperature scanning laser microscopy ( LT SLM). A novel theoretical model that treats the laser-beam- induced voltage response is proposed and applied to analyze the measured data. The method of LTSLM allows to visualize the local inhomogeneities In individual filame nts extracted from (Bi,Pb)(2)Sr2Ca2Cu3O10+x/Ag tapes. Using the proposed th eoretical analysis we extract the spatial distributions of the critical cur rents and critical temperatures over the sample. The data obtained by LTLSM show good agreement with standard non-local transport measurements, Using autocorrelation analysis of the voltage response, the characteristic length of the critical current variation is retrieved for filaments that belong t o different parts of the tape.