Abstract: A repeller assembly mounts in an arc chamber of an ion implanter. The repeller assembly contains a repeller, a tubular insert, first and second insulators, a contact member, and a lock member. The repeller has a knob-shaped body placed on an inner side of the arc chamber opposite to a cathode assembly. A repeller shaft is arranged extending through an opening of a wall of the arc chamber to an outer side. The repeller shaft has a step narrowing down the repeller shaft. The tubular insert is mounted concentrically to the repeller shaft. The first insulator has a collar shape and is attached to the tubular insert so that an inner shoulder of the first insulator is pressed against an outer side of the wall of the arc chamber. The second insulator is cap-nut shaped and is attached to the first insulator with an outer flange thereof.

Abstract: A cathode holding assembly to be mounted on an arc chamber support of an ion implanter includes a cathode holding plate, an insulator block, and a shield cap. The cathode holding plate has a protruding outer rib towards the shield cap and an opening with a protruding inner rib. A protrusion of the insulator block passes through the opening of the cathode holding plate. The insulator block abuts the protruding inner rib of the opening of the cathode holding plate at an edge of the insulator block to precisely fit the insulator block into the opening of the cathode holding plate. The shield cap is arranged to a side of the insulator block opposing the protrusion. A gap extends between the cathode holding plate and the shield cap, then between the cathode holding plate and the insulator block where it ends.