Studies and application of bent crystals for beam steering at 70-GeV IHEP accelerator

TL;DR

This paper reviews two decades of research on bent crystals at the U70 proton synchrotron, focusing on their use for beam extraction and halo collimation, including recent advances like the volume reflection effect.

Contribution

It provides experimental confirmation of high-efficiency beam extraction using bent crystals and explores new applications such as halo collimation with the volume reflection effect.

Findings

Beam extraction efficiency of around 85% with bent crystals.

Successful application of bent crystals for halo collimation.

Discovery of the volume reflection effect in high-energy accelerators.

Abstract

This report overviews studies accomplished in the U70 proton synchrotron of IHEP-Protvino during the recent two decades. Major attention is paid to a routine application of bent crystals for beam extraction from the machine. It has been confirmed experimentally that efficiency of beam extraction with a crystal deflector of around 85% is well feasible for a proton beam with intensity up to 1012 protons per cycle. Another trend is to use bent crystals for halo collimation in a high energy collider. New promising options emerge for, say, LHC and ILC based on the "volume reflection" effect, which has been discovered recently in machine study runs at U70 of IHEP (50 GeV) and SPS of CERN (400 GeV).