Channeling and Volume Reflection Based Crystal Collimation of Tevatron Circulating Beam Halo (T-980)

TL;DR

The T980 experiment at the Tevatron explores crystal channeling and volume reflection techniques to improve beam-halo collimation efficiency at high energies, with promising initial results and plans for hardware enhancements.

Contribution

This study demonstrates the application of crystal collimation techniques in a high-energy collider and reports on new experimental setups and initial promising results.

Findings

Channeled and volume-reflected beams observed as predicted

Comparison of crystal modes with amorphous collimators

Successful initial implementation of dual-plane crystal collimation

Abstract

The T980 crystal collimation experiment is underway at the Tevatron to determine if this technique could increase 980 GeV beam-halo collimation efficiency at high-energy hadron colliders such as the Tevatron and the LHC. T980 also studies various crystal types and parameters. The setup has been substantially enhanced during the Summer 2009 shutdown by installing a new O-shaped crystal in the horizontal goniometer, as well as adding a vertical goniometer with two alternating crystals (O-shaped and multi-strip) and additional beam diagnostics. First measurements with the new system are quite encouraging, with channeled and volume-reflected beams observed on the secondary collimators as predicted. Investigation of crystal collimation efficiencies with crystals in volume reflection and channeling modes are described in comparison with an amorphous primary collimator. Results on the system performance are presented for the end-of-store studies and for entire collider stores. The first investigation of colliding beam collimation simultaneously using crystals in both the vertical and horizontal plane has been made in the regime with horizontally channeled and vertically volume-reflected beams. Planning is underway for significant hardware improvements during the FY10 summer shutdown and for dedicated studies during the final year of Tevatron operation and also for a "post-collider beam physics running" period.