Filamentary YBCO conductors for AC applications

High current density YBCO conductors as they are presently conceived for use at liquid nitrogen temperatures are in the form of tapes, usually the order of a centimeter in width and suitable only for de use. Possibilities for developing similar YBCO conductors for ac applications are discussed, and the ac loss expected from such conductors is computed. The conversion from a de to an ac conductor requires breaking up a wide-tape de conductor into narrow strip-like filaments which spiral about the conductor axis. Various ways of producing this pattern are proposed.