bw7 CONTROLLING MULTIBUNCH BEAM BREAKUP IN TEV LINEAR COLLIDERS*

To obtain luminosities near @%m’2sec- ’ in a TeV linear collider, it will probably be essential to accelera.%e many bunches per RF fill in order to increase the energy transfer efficiency. In this paper we study the transverse dynamics of multiple bunches in a linac, and we examine the effects of several methods of con-trolling the beam blow-up that would otherwise be induced by transverse dipole wake fields. The methods we study are: (1) damping the transverse modes, (2) ad-justing the frequency of the dominant transverse mode so that bunches may be placed near zero-crossings of the transverse wake, and (3) bunch-to-bunch varia-tion of the transverse focusing. We study the utility of these cures in the main linacs of an example of a TeV collider