Development of the magnet design and choice of the magnetic structure of the isochronous cyclotron for H- ion acceleration to 80 MeV

An approach to designing the magnet and selecting the magnetic structure of an isochronous cyclotron is described. The approach is based on magnetic field calculations according to a two-dimensional POISSON program with subsequent testings and examinations using models with minor and major sectors. Optimization of magnetic circuit is realized at the second stage. Calculated and experimental data on flutter, mean field as well as the selected profile and shape of the cyclotron sectors are presented. 4 refs.; 6 figs