  We have fabricated prototype Bi,Pb(2223)/Ag superconduting multifilamentary
wires with a square cross-section. The AC losses of these wires were measured,
compared with those of tapes and also compared with the theory. Wires show
largely reduced AC magnetic field losses at 47 Hz, compared to those of tapes
in a perpendicular magnetic field. The effects of the twist pitch and of the
use of the high resisitive barriers were also investigated. The results show
that the use of a twist pitch of about 10 mm is sufficient for decoupling the
filaments, and that the use of very short twist pitches does not further reduce
the absolute value of the AC losses. The losses in the wires are still higher
than those of tapes in a parallel magnetic field, but the results show that the
square or round configurations are interesting for applications where a
perpendicular component of the magnetic field cannot be avoided, or for
applications in rotating magnetic fields.
