Stripper foil mechanism for the K1200 superconducting cyclotron

The Coupled Cyclotron Facility at MSU comprises two superconducting cyclotrons, the K500 (injector) and the K1200 (booster). Both cyclotrons are of the compact design with three hills and three dees in the valleys. The beam from the K500 is injected in the K1200 and stripped to a high charge state inside one of the dees of the cyclotron. The stripper mechanism consists of 31 foil holders attached to a bicycle chain, mounted on a moving platter. A complicated design was necessary to fit all the hardware necessary to do foil exchange in the tight space inside the dee. Five different hydraulic cylinders move the foil to the stripping position, exchange foils within the stripper chain, and position the foils in the loading position. We describe in the paper the mechanical design as well as the control programs developed for it.