Transverse-field losses in aluminum-stabilized superconducting conductors

The frequency characteristics of ac losses in aluminum-stabilized superconducting conductors are investigated in order to elucidate their loss mechanism under changing transverse magnetic field. AC loss measurement is carried out for the short and straight sample conductor for the helical coil system of the Large Helical Device. The sample of about 50 cm in length is subjected to an ac ripple field with a frequency range from 0.05 to 337 Hz superimposed on the bias field. The experimental results show that the loss feature much depends both on direction of the transverse magnetic field and location of the stabilizer relative to the strand bundle. These results are quantitatively explained by the theoretical analysis.