Stability condition for the drive bunch in a collinear wakefield accelerator

TL;DR

This paper analyzes the beam breakup instability in collinear wakefield accelerators and proposes a stability condition that guides the design of focusing and energy chirp strategies to ensure stable drive bunch operation.

Contribution

It introduces a new stability condition for the drive bunch, incorporating focusing channel design and energy chirp management to prevent beam breakup instability.

Findings

Derived a stability condition limiting the accelerating field.

Proposed a focusing channel design for stability.

Outlined energy chirp application to maintain stability.

Abstract

The beam breakup instability of the drive bunch in the structure-based collinear wakefield accel- erator is considered and a stabilizing method is proposed. The method includes using the specially designed beam focusing channel, applying the energy chirp along the electron bunch, and keeping energy chirp constant during the drive bunch deceleration. A stability condition is derived that defines the limit on the accelerating field for the witness bunch.