Method and Apparatus for Continuous $I_{\rm c}$ Examination of HTS Tape Using Magnetic Circuit

A new method based on the principle of magnetic circuits is proposed and realized for continuous I_c examination of HTS tapes. The greatest advantages of the new method are that it first eliminates all the noise caused by mechanical fluctuations, and thus makes high speed and high stability measurement possible, and second has a natural ability to measure HTS tape with a magnetic substrate. The principle of the method is introduced with the help of Finite Element Analysis. An apparatus for examination of kilometer long tapes has been constructed, by which continuous I_c examination for a YBa₂Cu₃O_7-x tape with and without a magnetic substrate and a Bi₂Si₂Ca₂Cu₃Ox multi-filamentary tape is reported.