In the vicinity of an end on the side of a large diameter portion of a deflection device, a pair of first permanent magnets for converging three electron beams in an X-axis direction and a pair of second permanent magnets for diverging them in the X-axis direction are provided. When a conserve setting is selected, a flow of oxygen travels through an oxygen regulating valve that has an open state and a closed state. Each of the first and second grids allows the user to filter each grid by typing in the search criteria and forwarding the criteria to the server. A plug, formed preferably of a soft metal, is pressed as a hydraulic seal into the bore.