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.
@article{arxiv.1105.3256,
title = {Collimation with hollow electron beams},
author = {G. Stancari and A. Valishev and G. Annala and G. Kuznetsov and V. Shiltsev and D. A. Still and L. G. Vorobiev},
journal= {arXiv preprint arXiv:1105.3256},
year = {2015}
}