Magnetic field simulation in the central region of the VINCY Cyclotron

The VINCY Cyclotron is under construction at the Vinc∨ a Institute of Nuclear Sciences, Laboratory of Physics (Belgrade, Serbia and Montenegro) [5]. In the VINCY Cyclotron, as in any multipurpose isochronous machine, the magnetic field must be provided for all ion beams within the cyclotron operating range. One of the most difficult problems to solve is the magnetic field shaping in the central region of the machine in a wide range of field levels. Concerning this region (R < 10 cm), one has to mention the following facts: sectors are absent or very reduced, and the small gap between the sectors restricts remarkably the possibilities to produce a field bump. Therefore, the design of these elements is the most critical one. Optimization of the central plug gap affects both the vertical sparking probability and the beam dynamics. The possibility of producing a required magnetic field in the region of the initial beam turns is considered in the present paper.