Measurements of Coherent Damping and Tune Shifts with Amplitude at LEP

The coherent damping offers the possibility to study various machine parameters such as head-tail damping, radiation damping and the horizontal detuning with amplitude. At the LEP electron-positron co llider the beam orbit system is able to store the beam positions over 1000 turns following a deflection by a horizontal kicker. A precise analysis of such data for many beam position monitors was used to study the dependance of head-tail damping on beam parameters. The tune dependance on the horizontal amplitude was determined during the decay of the beam oscillation for various LEP optics. This pa rameter turned out to be an important issue for the LEP high energy optics