The extraction system of a cyclotron guides an ion beam from a spiral acceleration orbit, through an extraction trajectory, into a high energy transport line. The two methods commonly used to direct an ion into the extraction path are deflection, by the electric field of an electrostatic deflector, and ion stripping, by a thin carbon foil. Compared to the electrostatic deflector system, the stripping extraction provides a fast and easy change of the extracted ion energy and is easier to manufacture operate, and maintain. However, the extraction trajectory and dynamics of an ion beam after stripping are highly dependant on the ion energy and specific charge. Thus, when a multipurpose machine such as the VINCY Cyclotron is concerned, it is far from easy to deliver a variety of ion beams into the same high energy transport line and at the same time preserve a reasonable compactness of the extraction system. The front side stripping extraction system of the VINCY Cyclotron provides high (~70 MeV) and mid (~30 MeV) energy protons, as well as a number of heavy ions in broad energy ranges. The back side stripping extraction system extracts low energy protons (~18 MeV) and enables their simultaneous use with high energy protons at the front side of the machine

In an isochronous relativistic cyclotron, axial defocusing of a beam caused by the radial growth of the isochronous magnetic field is compensated by the azimuthal field gradient introduced by sectors. The focusing capabilities of sectors set the maximum ion energy obtainable from the machine. Usually, the focusing limit of a machine is determined by using the criterion for axial beam instability evolving from the equations of betatron oscillations. The obtained value of the focusing limit is approximate because the equations of betatron oscillations it originates from are approximate as well. The accurate value of the focusing limit is obtained by simulating accelerated beam dynamics in the extraction region. It is shown that the focusing limit of a cyclotron resulting from the two methods could differ for more than 9%. The suggested third method for focusing limit computation relies on the beam dynamics simulation along the critical equilibrium orbit rather than the acceleration orbit and thus it is less time consuming although equally accurate

In an accelerating region of a cyclotron, an ion makes a large number of turns; thus, its n the Runge-Kutta method of the fourth order with the adaptive time step has been developed. The accuracy requirement is simultaneously set on position and momentum calculation. Magnetic fields used as inputs, have been evaluated in terms of the radial fluctuations of the orbital frequency, i.e. their isochronisms. Ion trajectory tracking has been performed for the following four test beams: H-, H+3, 4He+, He+, and 40Ar6+

The VINCY Cyclotron is the main part of the TESLA Accelerator Installation at the Vinča Institute of Nuclear Sciences in Belgrade. It is an isochroous cyclotron for the acceleration of both light and heavy ions. The pole of its magnet has the diameter of 2000 mm; its bending limit is 134 MeV, while its focusing limit is 73 MeV. This paper describes the magnetic field measurement system that has been used for the shimming of the VINCY Cyclotron magnet i.e., for precise shaping of its sectors and plugs. It is an automatic measurement system based on the Hall-probe that moves in the median plane between the poles of the magnet. We have used this system to obtain precise maps of the magnetic field for different operating regimes of the cyclotron needed in the process of shimming. The overall measurement uncertainty was estimated to be in the range of ±0.02%

In an accelerating region of a cyclotron an ion makes a large number of turns; thus its tracking requires fast as well as highly accurate computation. Computer code, based on the adaptive time step fourth order Runge Kutta method, has been developed. Accuracy requirement is set simultaneously on the position and momentum calculation. Magnetic fields used as input, have been evaluated in terms of the radial fluctuations of the orbital frequency, i.e. their isochronism. Ion trajectory tracking has been performed for the four test beams: H-, H2 +, 4He+, and 40Ar6+