Automatic Isochronisation and Computer Aided Centering in the VICKSI Cyclotron

Starting from precalculated settings for the trim coils the magnetic field is automatically isochronized via a measurement of the beam phase history with the ten capacitive phase probes in the extraction-valley (see fig. 1) and an online computer routine which uses a calculated correction matrix. The beam centering is done with a radially localized first harmonic field bump and observed via measurement with the two radial differential probes. Programs for automatically finding the turn positions and calculating the amplitude and phase of the harmonic bump are developed.