Conference

Review of Beam Dynamics and Instabilities in Linear Colliders

R. Wanzenberg

DESY, Hamburg, Germany

Abstract

An important issue for a next generation e⁺e^- high energy linear collider is the preservation of the high beam quality through the acceleration in the linac. Recent design studies at different laboratories adopt very flat beams at the collision point to minimize the beamstrahlung. Therefore most problems are related to the vertical single bunch dynamics which is determined by chromatic effects in the quadrupoles and wakefields effects in the accelerator structures due to the misalignment or vibrations of these linac components. Almost all linear collider designs consider multiple bunches in each rf pulse to raise the luminosity. The cumulative beam break-up instability due to long range wakefields (HOMs,higher order modes) is a severe problem for all multibunch schemes. Only the damping and detuning of the HOMs in the accelerator structures can reduce the long range wakefield effects.

This report reviews several topics with respect to the preservation of the longitudinal and transverse beam quality in a next generation linear collider. Single and multi bunch issues are covered.

sln 11 March 1996