PURPOSE: To obtain a magnet formed by a wire rod having excellent characteristics extending over the longitudinal direction by removing one part of a copper pipe after the working of the reduction of a cross section and exposing compression-molded powder.
CONSTITUTION: The inside of a copper or copper alloy pipe is filled with the powder of a ceramic superconductor or mixed powder composed of a component forming the ceramic superconductor through heat treatment. The powder is molded to a wire rod through area reducing working. One part of the surface of the wire rod is exposed, and a masking tape is positioned longitudinally near or wound on the surface of the wire rod. The outer circumference of the masking tape is covered with a porous insulating material. An exposed section is melted and removed chemically. Consequently, the wire rod acquired is wound on a spool, thus shaping a coil. The coil is thermally treated in an oxidizing atmosphere, and impregnated with a cured resin. Accordingly, a magnet formed by the wire rod having excellent characteristics extending over the longitudinal direction is obtained.
NAKAMURA SHUNZABURO
UCHIYAMA TAKESHI
MIYAKE SEIICHI
ODA YUICHIRO
