Ultra-Short-Z Linear Collider Parameters

TL;DR

This paper explores the potential of ultra-short electron bunches (<100nm) in future linear colliders, aiming to achieve high luminosity with lower power and improved quality through advanced compression techniques.

Contribution

It proposes a new set of collision parameters for linear colliders utilizing ultra-short, low charge, round electron beams based on FACET-II experience.

Findings

Potential to match existing luminosities with lower RF power

Possibility of improved luminosity quality near energy peak

Requires further R&D on bunch compression systems

Abstract

Interest in highly-compressed electron beams has been increasing in recent times, driven by the study of non-linear and even non-perturbative aspects of QED [2]. The FACET-II [7] facility at SLAC is currently (at the time of writing) being constructed and has been predicted to be able to deliver unprecedented peak beam intensities (>200 kA). We consider here what might be possible in pushing the bunch length compression to its limits at a future Linear Collider facility based on experience at FACET and ongoing photo-injector designs. We present an alternative electron-electron collision parameter table for ILC and CLIC colliders in which low charge, round beams with very short (<100nm) bunches are collided. The parameters shown present the possiblility to provide identical luminosities to the existing designs but with lower rf power requirements and/or with improved luminosity quality (fraction of luminosity close to energy peak). Achieving these beam parameters requires further R&D on the bunch compression and beam delivery systems associated with the Linear Colliders, which is discussed.