Abstract: A permanent magnet assembly for stably fixing a denture comprising a permanent magnet, a casing made of a corrosion-resistant, magnetic material having a cavity for receiving the permanent magnet, and a seal plate for covering an opening of the casing to prevent the permanent magnet from exposing outside, the seal plate consisting of a seal ring member made of a corrosion-resistant, non-magnetic material and a disc plate made of a corrosion-resistant, soft-magnetic material and having substantially the same outer diameter as the inner diameter of the seal ring member, the seal ring member and the disc plate being concentrically arranged in the same plane, the disc plate being welded to the seal ring member in their abutment, and the seal ring member being welded to the casing. Laser welding is utilized.

Abstract: A magnetic device for high-voltage pulse generating apparatuses including (a) at least one cylindrical conductor for defining a cavity, the cylindrical conductor being provided with input and output terminals and an inlet and an outlet for a coolant; (b) at least one sealing member fixed to the cylindrical conductor; (c) a plurality of wound magnetic cores each composed of a magnetic ribbon laminated with an insulating layer, the wound magnetic cores being fixed to the cylindrical conductor with such an interval as to provide a certain space between the adjacent wound magnetic cores; and (d) an outer ring member disposed between each of the magnetic cores and the cylindrical conductor and having at least one path for permitting the coolant to flow therethrough, whereby the coolant flows in a radial or circumferential direction of each wound magnetic core in each space between the adjacent wound magnetic cores.