Position and Magnetic Field Angle Dependent Ic for Long-Length Coated Conductors

To measure the critical current of a long coated conductor tape as a function of angle, I_c(thetas), where thetas is the angle between the magnetic field B and the c-axis direction, we have solved the problems of measurement system geometry, size, and cost by developing a cryogenic rotator containing permanent magnets to change the angle of the applied field. Central magnetic fields of 0.3 T and 0.53 T have been generated. For position dependent measurements, a device, similar in design to a large audio cassette, translates the superconductor tape through the magnetic field region. To demonstrate the usefulness of this device, we present results on the position-dependent critical current anisotropy at 75 K for a 5 m long YBCO coated conductor.