The GANIL injector design

The GANIL injector is a small flat pole tip cyclotron which has to be operated on high harmonic numbers (h=4 and 8). Preliminary orbit computations made with a uniform electric field in the gaps for the radial motion and a thin lens approximation for the vertical motion, had shown that the beam qualities required for injection into SSC1 could be obtained from such a cyclotron. In order to get an evaluation of the intensity limitation due to the injector acceptance and of space charge effects, it was decided to modify the CERN model of the SC central region into a fixed-frequency (8 MHz) model of the injector, excluding the extraction system, and to perform a series of measurements on the 5 first revolutions of an N/sup 3+/ beam (h=4) and on Ar/sup 3+/ (h=8). At the same time, more accurate computations were made using potential maps obtained with an electrolytic tank. (1 refs) .