METHOD FOR MANUFACTURING MAGNET FOR ELECTRON-BEAM CONTROL SYSTEM, AND THE MAGNET FOR THE ELECTRON-BEAM CONTROL SYSTEM AND ELECTRON BEAM CONTROL SYSTEM MANUFACTURED BY THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a ring magnet which is hard to be demagnetized by external magnetic field, even through alnico magnetic particle is used. SOLUTION: A method for manufacturing a magnet for an electron-beam control system molded by a material including an alnico magnetic particle comprises the steps of setting a primary magnetization to 140 to 250% of final magnetization and forming a magnetic pole of 100% final magnetization, on an inner peripheral surface of the ring magnet after demagnetization process. The number of magnetic poles formed on the internal circumference of the ring magnet produced is one among 2, 4, or 6.