Speaker
Description
A software tool has been designed which allows us to make isochronous cyclotron field maps. The rotational symmetry number, the center field, the particle properties, the maximum radius and the sector spiraling angle as function of radius can be freely chosen. Out of four radius-dependent parameters (flutter, hill-field, valley-field and sector azimuthal extent), the user can define two of them freely and the tool will then calculate the complementary two; from that the full isochronous map is calculated. The azimuthal field profiles are defined by the hill field and the valley field which are connected by user defined transition zones. These zones may have a double-quadratic or cubic form factor. For the average isochronous field, a precise theoretical formula is used. The tool, in combination with a closed orbit code, may be used for exploring the parameter space of new cyclotrons to be designed. This may predict optical properties such as tunes and structural resonances. The author designed the tool in order to validate a theoretical model that predicts the energy limit of isochronous cyclotrons (as presented in the previous cyclotron conference). Equations are derived and the fundamentals of the tool are explained. Good precision of isochronism is confirmed by closed-orbit integrations for a wide range of the field map parameters introduced above.
