Methods and apparatus for processing substrates with a multi-cathode chamber. The multi-cathode chamber includes a shield with a plurality of holes and a plurality of shunts. The shield is rotatable to orient the holes and shunts with a plurality of cathodes located above the shield. The shunts interact with magnets from the cathodes to prevent interference during processing. The shield can be raised and lowered to adjust gapping between a target of a cathode and a hole to provide a dark space during processing.