Methods and apparatus for a magnetron assembly are provided herein. In some embodiments, a magnetron assembly includes a first plate having a first central axis, the first plate rotatable about the first central axis, a first open loop magnetic pole coupled to the first plate, a second plate having a second central axis, the second plate rotatable about the second central axis, and a second open loop magnetic pole coupled to the second plate, wherein the first open loop magnetic pole and the second open loop magnetic pole form a closed loop magnetic pole when the first and second open loop magnetic poles are aligned.