FIRST VAMAS USA INTERLABORATORY COMPARISON OF HIGH-TEMPERATURE SUPERCONDUCTOR CRITICAL-CURRENT MEASUREMENTS

We conducted an interlaboratory comparison of critical current (I-c) measurements on Bi2Sr2Ca2Cu3O10 tapes (2223). This study includes measurements from six participating US laboratories, with NIST as the central, organizing laboratory. A number of specimens were prepared with different degrees of instrumentation to isolate sources of variability, Most of the specimens were pre-measured by NIST to reduce uncertainties due to sample variability. Different specimen routing patterns among the laboratories were implemented to isolate sources of variability due to the specimen's measurement history. This study is similar to other VAMAS intercomparisons being performed in Japan and Europe and is the first internationally cooperative interlaboratory comparison of HTS (High Temperature Superconductors) I-c measurements. These are the first steps towards developing standard measurement procedures for HTS.