The invention comprises a patient specific tray insert removably inserted into a tray frame to form a beam control tray assembly, which is removably inserted into a slot of a tray receiver assembly proximate a gantry nozzle of a charged particle cancer treatment system. Optionally, multiple tray inserts, each used to control a different beam state parameter, are inserted into corresponding slots of the tray receiver assembly where the multiple inserts are used to control beam intensity, shape, focus, and/or energy. The beam control tray assembling includes an identifier, such as an electromechanical identifier, of the particular insert type, which is communicated to a main controller, such as via the tray receiver assembly along with slot position and/or patient information.