Emittance Dilution in 1 and 5 TeV 30 GHz Linear Colliders

In this paper, we describe the single and multi-bunch sources of emittance dilution in the linacs of both 1 and 5 TeV center-of-mass energy linear colliders. The linacs operate at high rf accelerating gradients with a frequency around 30 GHz. At this high accelerating frequency, the wakefields are very strong and we discuss the BNS damping and correction procedures as well as the alignment and construction tolerances that are required to preserve the transverse emittance. Finally, because the collider must operate with long bunch trains, we consider the multi-bunch emittance dilution for a few cases where either the long-range transverse wakefield is damped or it is decreased by a combination of weak damping and detuning