82 research outputs found
Studies and application of bent crystals for beam steering at 70-GeV IHEP accelerator
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).Comment: 12 pages, 14 figure
Radiation of photons in process of charge particle volume reflection in bent single crystal
New type of radiation in crystals is predicted and investigated in computer
simulation. It is shown that process of volume reflection of electrons and
positrons in bent crystals is accomplished with high-power radiation of
photons. Volume reflection radiation has intensity comparable with known
channeling radiation, but it is less sensitive to entrance angle and sign of
charge of a particle. Simulated spectra of radiation power are presented for 10
GeV and 200GeV particles.Comment: Latex, 8 pages, 4 fig
Channeling and Volume Reflection Based Crystal Collimation of Tevatron Circulating Beam Halo (T-980)
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.Comment: 3 pp. 1st International Particle Accelerator Conference: IPAC'10,
23-28 May 2010: Kyoto, Japa
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