Abstract: A rotary cathode for a magnetron sputtering apparatus is disclosed. The rotary cathode comprises a rotatable target cylinder, and a non-rotatable interior structure in the target cylinder. The interior structure has an outer surface and an inner passageway. An outer passageway is defined between an inner surface of the target cylinder and the outer surface of the interior structure. An end cap is affixed at a distal end of the target cylinder. A rotating aperture is adjacent to an inner surface of the target cylinder at the distal end thereof, with the rotating aperture configured to direct a fluid toward the inner surface at the distal end. A fluid pathway is at least partially defined by the end cap, with the pathway providing fluid communication between the outer passageway and the inner passageway through the rotating aperture.