Particle orbits in cyclotrons

The physical problem of particle motion in cyclotrons is briefly explained and the mathematical description of the process introduced with special reference to synchro-cyclotrons. It is shown how a design study may be broken into three distinct parts: injection, acceleration and extraction, each of which needs special computer programmes for its treatment. It is demonstrated by examples how a design study can be carried out in many steps starting with approximate and ending with exact results. Examples are given from the CERN 600 MeV Synchro- Cyclotron Improvement study. Some auxiliary activities such as magnet shimming and measurements also requiring computer aid are briefly mentioned.