REDUCTION OF PROTON LOSSES IN HERA BY COMPENSATING THE TUNE MODULATION IN THE PROTON-BEAM

The combined effect of a tune modulation with more than one frequency component and the nonlinear fields due to the beam-beam interaction du ring luminosity operation leads to increased background rates and part icle losses. The following work describes a new method of controlling the proton losses in HERA by compensating for fast modulation frequenc ies in the machine. The method allows a direct control of the particle diffusion in the brain halo without interfering with the normal lumin osity operation. The work summarises experimental results of two exper iments in the proton storage ring at DESY.