On the theory of coherent instabilities due to coupling between a dense cooled beam and charged particles from the residual gas

The authors discuss intensity limitations due to ions trapped in the p-beam and assess antidotes which have recently been applied in the Antiproton Accumulator (AA) at CERN. They reexamine the theory and analyze Landau damping of dipole and quadrupole modes, stabilization by the appropriate choice of the working point, and ion clearing by shaking of the p-beam.<>