Collimation with hollow electron beams

TL;DR

This paper introduces a novel hollow electron beam technique for controlled halo removal in high-energy storage rings, enhancing collimation efficiency without disturbing the beam core, demonstrated experimentally at Fermilab.

Contribution

It presents a new method using a pulsed hollow electron beam for halo control, extending collimation capabilities in high-energy accelerators.

Findings

Successful experimental demonstration at Fermilab Tevatron

Effective halo removal without core disturbance

Potential to surpass conventional collimation limits

Abstract

A novel concept of controlled halo removal for intense high-energy beams in storage rings and colliders is presented. It is based on the interaction of the circulating beam with a 5-keV, magnetically confined, pulsed hollow electron beam in a 2-m-long section of the ring. The electrons enclose the circulating beam, kicking halo particles transversely and leaving the beam core unperturbed. By acting as a tunable diffusion enhancer and not as a hard aperture limitation, the hollow electron beam collimator extends conventional collimation systems beyond the intensity limits imposed by tolerable losses. The concept was tested experimentally at the Fermilab Tevatron proton-antiproton collider. The first results on the collimation of 980-GeV antiprotons are presented.