Plasma-accelerator-based linear beam cooling system*

Plasma-based accelerators enable compact acceleration of beams to high energy and are considered a promising technology for future colliders.  Conventional colliders require damping rings to generate the required beam emittance for high-energy physics applications.  We propose and discuss a plasma-based linear damping system that allows cooling of ultrashort bunches compatible with plasma-based accelerators, removing the need for bunch compression.  Ultra-high plasma accelerating gradients allow for linear damping systems, and there is a trade-off between system length and the achievable emittance reduction.  Final asymptotic beam emittance is shown to be independent of beam energy.