Proton therapy tuning apparatus and method of use thereof

A method for tuning a positively charged particle beam path in a gap of a charged particle beam system used to treat a tumor of a patient with positively charged particles, comprising the steps of:

• positioning a first two-dimensional charged particle detector in a beam line downstream from a first upstream magnet pair of a cancer therapy system, said beam line running at least from an injector, through a synchrotron, and along a beam transport line to a patient position;
• operating windings of said first upstream magnet pair at a first power level to generate a first magnetic field across the gap;
• measuring a beam position with said first two-dimensional charged particle detector;
• adjusting a correction magnetic field by driving voltage of a correction coil at a second power level, said second power level less than five percent of said first power level, wherein the first magnetic field and the correction magnetic field combine to yield an operational magnetic field during use;
• and
• said steps of measuring and adjusting the correction magnetic field changing the operational magnetic field to adjust a measured beam position toward a target beam position.