Methods and apparatus to improve target life and deposition uniformity in PVD chambers are provided herein. In some embodiments, a magnetron assembly includes a shunt plate having a central axis, the shunt plate rotatable about the central axis, a first open loop magnetic pole arc coupled to the shunt plate at a first radius from the central axis, and a second open loop magnetic pole arc coupled the shunt plate at a first distance from the first open loop magnetic pole arc, wherein at least one of the first radius varies along the first open loop magnetic pole arc or the first distance varies along the second open loop magnetic pole arc. In some embodiments, a first polarity of the first open loop magnetic pole arc opposes a second polarity of the second open loop magnetic pole arc.