Hall Probe Based System for Study of AC Transport Current Distribution in YBCO Coated Conductors at Frequencies Up to 700 Hz

The distributions of dc transport current in a copper stabilized mono-core YBCO coated conductor sample were compared with that of sinusoidal ac transport current, i(t) = I₀ldrsin(omegat), with frequencies up to 700 Hz. The current distribution was determined from the measurement of the magnetic field produced by the transport current using a small active area Hall probe. The ac magnetic field component perpendicular to the surface of the tape was measured to determine its variation across the tape. A triggering data acquisition (DAQ) system, which had a capability of sampling frequency of up to 200 kHz, based on DAQ measuring cards was used. The current distribution at various phases within one ac transport current cycle for different frequency was studied. The change in frequency from ~0 Hz up to 40 Hz had only a minor effect on the current distribution at any of the studied phases and the current distribution is practically the same as the one in dc regime.