Tuning methods for the SPIRAL facility
Résumé
In the SPIRAL facility we will accelerate radioactive ion beams with intensities as small as a few pps mixed with possibly much more abundant unwanted species. Such low currents and the mixing of several species imply special tuning methods and associated diagnostics. The beam lines and the cyclotron will be pretuned with a stable analogue beam close to the radioactive one in terms of charge-to-mass ratio. This difference in charge-to-mass ratio implies a shift towards the correct tuning in order to accelerate the required species. Several methods are possible depending on this difference. We can act either on the magnetic field or on the RF or both. Consequences are different for the beam lines and the cyclotron. Constraints on the source extraction voltage and on the injection phase have to be taken into account.