Abstract: An ion implanter has a source arc chamber including a conductive end wall at a repeller end of the arc chamber, the end wall having a central portion surrounding an opening. A ceramic insulator is secured to an outer surface of the end wall, such as by peripheral screw threads engaging mating threads at the periphery of a recessed area of the end wall. A conductive repeller has a narrow shaft secured to the insulator and extending through the end wall opening, and a body disposed within the source arc chamber adjacent to the end wall. The end wall, insulator and repeller are configured to form a continuous vacuum gap between the central portion of the end wall and (i) the repeller body, (ii) the repeller shaft, and (iii) the insulator. The insulator interior surface can have a ridged cross section.

Abstract: A cathode system having a cathode element configured to extend through an aperture in a wall of an arc chamber of an ion implanter system. A gas flow through a spacing between the cathode element and the aperture is restricted by a restriction member. A method of ionizing a source gas and a cathode element incorporating the restriction member are also provided.