Abstract: A present invention relates to improvements in electric arc vapor deposition chambers. A first improvement involves the utilization of a heat shield disposed between a source and a substrate to decrease heat energy radiating from the source directly to the substrate. In a preferred embodiment, the heat shield is cooled by a liquid cooling system which acts to remove heat energy from the chamber. An improved source mounting assembly of the present invention provides for enhanced cooling of the source material. It includes the utilization of a back surface of the source material as a wall of a coolant chamber within the source mounting assembly. An O-ring seal is disposed at the rearward face of the source material to provide a cool temperature environment for the O-ring seal while it prevents coolant leakage into the chamber.