| 摘要 |
PURPOSE:To prevent effects of the past excitation history at a low cost by providing a detachable magnetic body for bypassing magnetic flux in a gap forming a magnetic circuit in series with an electromagnet iron core so as to eliminate a remaining magnetic field in the gap to zero. CONSTITUTION:A magnetic body 4 is provided in a gap of an electromagnet consisting of an iron core 2 having an excitation coil 3 applied for bypassing a magnetic flux. By detaching the magnetic body 4 while excitation of the electromagnet, a need of deflecting charged particles is eliminated, and if an exciting power source for the electromagnet is disconnected, a remaining magnetic field is produced by hysteresis phenomenon of the iron core 2. By inserting the magnetic body 4 into the gap then, remaining magnetic flux passes the magnetic body 4 to eliminate the remaining magnetic field in the gap to zero. Effects of hysteresis phenomenon of the iron core can thus be eliminated at a low cost without providing a power source for demagnetizing separately. |
