Beam-Beam Interaction in a Dielectric Laser Accelerator Electron-Positron Collider

TL;DR

This paper investigates beam-beam interactions in a dielectric laser accelerator-based electron-positron collider, analyzing luminosity, energy loss, and beamstrahlung effects through numerical modeling.

Contribution

It derives a time-dependent envelope equation including radiation reaction force for multiple bunches in a DLA collider scenario, providing new insights into beam dynamics and efficiency.

Findings

Luminosity peaks with the number of bunches for Gaussian trains.

Energy loss is about 1.75%, reduced to 0.35% with nonlinear force considerations.

Average beamstrahlung parameter is 0.075, indicating manageable radiation losses.

Abstract

We examine through numerical calculation the collision of counter-propagating trains of optically spaced electron/positron microbunches in a 1 TeV collider scenario for a dielectric laser accelerator (DLA). A time-dependent envelope equation is derived for arbitrary number of bunches in the classical limit, with inclusion of the radiation reaction force (RRF). Example parameters are examined based on a constrained luminosity relation that takes into account the bunch charge for optimal efficiency, material damage limits, and power constraints. We find that for initially identical counter-propagating Gaussian bunch trains the periodic temporal structure leads to a peak in luminosity with number of bunches. For longer bunch trains, the enhancement then decreases inversely with number of bunches. The corresponding fractional energy loss of the beam is found to be of order 1.75\%, which is reduced to 0.35\% when the nonlinear radial dependence of the transverse force is included, with an average beamstrahlung parameter of 0.075, an important result considering that beamstrahlung losses are a critical concern for future TeV colliders.