DA-PHI-NE BROAD-BAND BUTTON ELECTRODES

We describe the DA Phi NE broad-band button electrodes used to measure the individual time and transverse bunch offset, on a bunch-by-bunch basis, i.e. without ''memory'' of the preceding bunches in the feedbac k systems and for general purpose diagnostics. We give analytical esti mates of the transfer and coupling impedances. The numerical simulatio ns and laboratory measurements are in good agreement with the analytic al results. The button transfer impedance is reasonably high, flat and free of narrow-band resonances in the frequency range of utilization. The coupling impedance and parasitic losses are found to be within th e acceptable values.