Main beam diagnostics at GANIL

The main diagnostics designed at GANIL are: 1) a probe in 3 yokes of each SSC (The pick-up probe consists of differential interceptive targets for the measurement of the vertical and radial beam positions and a semi-interceptive wire target, using secondary electron emission, for the measurement of the time-length of the bunches. The pick-up probe is supported by a tube which moves through the yoke; it covers a 2.5 m range). 2) central phase diagnostics (15 couples of 50 ohm capacitive probes are located in one valley of each SSC. They mainly allow to adjust the isochronism by measuring the central phase of the beam. 8 high impedance capacitive probes are located in the beam line. They measure the beam phase in order to control the RF phase of the accelerating and bunching voltages. The phase measurement is made on the second harmonic of the beam signal with an analogic multiplier between the beam signal and the pilot. Amplifier gain, fundamental rejection filters, noise rejection and other parameters are microprocessor controlled according to the magnitude of the picked-up signal and the working frequency). 3) profile monitors (The GANIL extracted beam is going to be tuned with the help of secondary emission monitors. They are multiwire chambers operating in the beam line vacuum. They provide two simultaneous beam profiles in the vertical and horizontal planes. The profiles are displayed on a scope or processed by a Camac-unit. They give informations on the location, width, emittance and intensity of the beam. The number of monitors for the whole GANIL is about 80). These diagnostics have been tested at GANIL (ion soure, that means to very low energy beams, and injector extracted beam), at ALICE and at ISN cyclotron