Storage-ring Electron Cooler for Relativistic Ion Beams

TL;DR

This paper proposes a novel storage-ring electron cooler design with two sections at different energies, utilizing SRF technology to improve electron cooling efficiency for relativistic ion beams, and presents initial simulations and potential challenges.

Contribution

It introduces a dual-energy storage-ring electron cooler with an energy recovering SRF structure, enhancing cooling performance across a wider ion energy range.

Findings

Prototype linear optics developed and simulated

Initial tracking simulations conducted

Potential issues like CSR and BBU discussed

Abstract

Application of electron cooling at ion energies above a few GeV has been limited due to reduction of electron cooling efficiency with energy and difficulty in producing and accelerating a high-current high-quality electron beam. A high-current storage-ring electron cooler offers a solution to both of these problems by maintaining high cooling beam quality through naturally-occurring synchrotron radiation damping of the electron beam. However, the range of ion energies where storage-ring electron cooling can be used has been limited by low electron beam damping rates at low ion energies and high equilibrium electron energy spread at high ion energies. This paper reports a development of a storage ring based cooler consisting of two sections with significantly different energies: the cooling and damping sections. The electron energy and other parameters in the cooling section are adjusted for optimum cooling of a stored ion beam. The beam parameters in the damping section are adjusted for optimum damping of the electron beam. The necessary energy difference is provided by an energy recovering SRF structure. A prototype linear optics of such storage-ring cooler and initial tracking simulations are presented and some potential issues such as coherent synchrotron radiation and beam break up are discussed.