The impact of fill patterns on the fast ion instability in the ILC damping ring

TL;DR

This paper investigates how different fill patterns in the ILC damping ring influence the fast ion instability, demonstrating that mini train fill patterns can significantly mitigate this issue.

Contribution

It provides a simulation-based analysis of fill pattern effects on ion instability, highlighting the effectiveness of mini train patterns in reducing instability growth.

Findings

Mini train fill patterns reduce ion instability growth.

Fill pattern choice impacts beam stability in ILC.

Simulations confirm mitigation strategies for ion effects.

Abstract

The ions produced via collisional ionization of the residual gas molecules in vacuum pipe with the circulating electron beam have deleterious effect on the beam properties and may become a limiting factor for the machine's performance. For the electron damping ring of the International Linear Collider (ILC), the ion instability is noticeable due to the ultra-low beam emittance with many bunches operation. In this paper, the different beam fill patterns are investigated and their effects on the fast ion instability are discussed. The simulations show that the mini train fill patterns can reduce the growth of the fast ion instability significantly.