Initial study on the shape optimisation of the CLIC crab cavity

TL;DR

This paper explores the shape optimization of a novel travelling wave crab cavity for CLIC, aiming to improve amplitude and phase stability crucial for collision precision.

Contribution

It introduces a high group velocity TW cavity design that differs from previous structures, focusing on geometry optimization for better control.

Findings

High group velocity reduces error propagation time.

Optimized cavity geometry enhances amplitude and phase stability.

Design implications for cavity parameters are analyzed.

Abstract

The compact linear collider (CLIC) requires a crab cavity to align bunches prior to collision. The bunch structure demands tight amplitude and phase tolerances of the RF fields inside the cavity, for the minimal luminosity loss. Beam loading effects require special attention as it is one potential sources of field errors in the cavity. In order to assist the amplitude and phase control, we propose a travelling wave (TW) structure with a high group velocity allowing rapid propagation of errors out of the system. Such a design makes the cavity structure significantly different from previous ones. This paper will look at the implications of this on other cavity parameters and the optimisation of the cavity geometry.