First Direct Observations of Gear-Changing In A Collider

TL;DR

This paper presents the first experimental demonstration of gear-changing in a collider, showcasing synchronization of different harmonic bunch configurations using DESIREE, and providing insights into control mechanisms for such systems.

Contribution

First real-world demonstration of gear-changing in a collider, validating theoretical models with experimental data and exploring control strategies.

Findings

Gear-changing system demonstrated with 4 on 3 and 5 on 4 bunch configurations.

System remains stable for at least 37,500 turns.

New control insights developed for gear-changing colliders.

Abstract

In this work we perform the first ever demonstration of gear-changing in a real world collider. Gear-changing refers to a collision scheme where each ring of a collider stores a different harmonic number of bunches. These bunches are kept synchronized using different velocities. Such a system has been theorized, but has now been demonstrated using the Double ElectroStatic Ion Ring ExpEriment (DESIREE) in Stockholm Sweden. The experiment was able to demonstrate a gear-changing system, with both four on three bunches and five on four bunches. We determined a measurable parameter that shows a gear-changing system out to $37500$ turns of the slow beam. We also developed new insights into how to control this type of system, opening up new possibilities for research.