Conventional Collimation System Research Articles

Collimation with Hollow Electron Beams

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.

A Microchannel Plate X-Ray Collimator

A simple and compact X-ray collimator utilizing a microchannel plate, which is a bundle of small tubes, was considered and tested using X-rays from an X-ray tube. The collimation performance has confirmed that the beam divergence is limited by the geometrical opening of a channel pore and its length (about 6 mrad in this study). Some other properties of a channel plate collimator (CPC) have been demonstrated; for instance, the CPC can transfer the source image and has a large aperture. The throughput of the CPC system has been estimated and is compared with a conventional collimation system.