Comparative Results on Collimation of the SPS Beam of Protons and Pb Ions with Bent Crystals
Abstract
New experiments on crystal assisted collimation have been carried out at the CERN SPS with stored beams of 120 GeV/c protons and Pb ions. Bent silicon crystals of 2 mm long with about 170 {mu}rad bend angle and a small residual torsion were used as primary collimators. In channeling conditions, the beam loss rate induced by inelastic interactions of particles with the crystal nuclei is minimal. The loss reduction was about 6 for protons and about 3 for Pb ions. Lower reduction value for Pb ions can be explained by their considerably larger ionization losses in the crystal. In one of the crystals, the measured fraction of the Pb ion beam halo deflected in channeling conditions was 74%, a value very close to that for protons. The intensity of the off-momentum halo leaking out from the collimation station was measured in the first high dispersion area downstream. The particle population in the shadow of the secondary collimator-absorber was considerably smaller in channeling conditions than for amorphous orientations of the crystal. The corresponding reduction was in the range of 2-5 for both protons and Pb ions.
- Authors:
- more »
- Publication Date:
- Research Org.:
- SLAC National Accelerator Lab., Menlo Park, CA (United States)
- Sponsoring Org.:
- USDOE
- OSTI Identifier:
- 1039546
- Report Number(s):
- SLAC-REPRINT-2012-069
Journal ID: ISSN 0370-2693; PYLBAJ; TRN: US1202170
- DOE Contract Number:
- AC02-76SF00515
- Resource Type:
- Journal Article
- Resource Relation:
- Journal Name: Physics Letters, (Section) B; Journal Volume: 703; Journal Issue: 5
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; CERN; CHANNELING; COLLIMATORS; ION BEAMS; IONIZATION; NUCLEI; PROTONS; SILICON; TORSION; Accelerators,ACCSYS
Citation Formats
Scandale, W., /CERN /Orsay, LAL /INFN, Rome, Arduini, G., /CERN, Assmann, R., /CERN, Bracco, C., /CERN, Cerutti, F., /CERN, Christiansen, J., /CERN, Gilardoni, S., /CERN, Laface, E., /CERN, Losito, R., /CERN, Masi, A., /CERN, Metral, E., /CERN, Mirarchi, D., /CERN, Montesano, S., /CERN, Previtali, V., /CERN, Redaelli, S., /CERN, Valentino, G., /CERN, Schoofs, P., /CERN, Smirnov, G., /CERN, Tlustos, L., /CERN, Bagli, E., /INFN, Ferrara /Ferrara U., Baricordi, S., and /INFN, Ferrara /Ferrara U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /Ferrara U. /Frascati /Frascati /INFN, Legnaro /INFN, Legnaro /INFN, Legnaro /INFN, Legnaro /INFN, Legnaro /INFN, Legnaro /INFN, Rome /INFN, Rome /INFN, Rome /INFN, Rome /INFN, Naples /Serpukhov, IHEP /Serpukhov, IHEP /Serpukhov, IHEP /Serpukhov, IHEP /Serpukhov, IHEP /Dubna, JINR /Dubna, JINR /Dubna, JINR /St. Petersburg, INP /St. Petersburg, INP /St. Petersburg, INP /St. Petersburg, INP /Imperial Coll., London /Imperial Coll., London /Imperial Coll., London /Imperial Coll., London /Imperial Coll., London /Imperial Coll., London /Imperial Coll., London /Imperial Coll., London /Brookhaven /SLAC /SLAC /SLAC. Comparative Results on Collimation of the SPS Beam of Protons and Pb Ions with Bent Crystals. United States: N. p., 2012.
Web.
Scandale, W., /CERN /Orsay, LAL /INFN, Rome, Arduini, G., /CERN, Assmann, R., /CERN, Bracco, C., /CERN, Cerutti, F., /CERN, Christiansen, J., /CERN, Gilardoni, S., /CERN, Laface, E., /CERN, Losito, R., /CERN, Masi, A., /CERN, Metral, E., /CERN, Mirarchi, D., /CERN, Montesano, S., /CERN, Previtali, V., /CERN, Redaelli, S., /CERN, Valentino, G., /CERN, Schoofs, P., /CERN, Smirnov, G., /CERN, Tlustos, L., /CERN, Bagli, E., /INFN, Ferrara /Ferrara U., Baricordi, S., & /INFN, Ferrara /Ferrara U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /Ferrara U. /Frascati /Frascati /INFN, Legnaro /INFN, Legnaro /INFN, Legnaro /INFN, Legnaro /INFN, Legnaro /INFN, Legnaro /INFN, Rome /INFN, Rome /INFN, Rome /INFN, Rome /INFN, Naples /Serpukhov, IHEP /Serpukhov, IHEP /Serpukhov, IHEP /Serpukhov, IHEP /Serpukhov, IHEP /Dubna, JINR /Dubna, JINR /Dubna, JINR /St. Petersburg, INP /St. Petersburg, INP /St. Petersburg, INP /St. Petersburg, INP /Imperial Coll., London /Imperial Coll., London /Imperial Coll., London /Imperial Coll., London /Imperial Coll., London /Imperial Coll., London /Imperial Coll., London /Imperial Coll., London /Brookhaven /SLAC /SLAC /SLAC. Comparative Results on Collimation of the SPS Beam of Protons and Pb Ions with Bent Crystals. United States.
Scandale, W., /CERN /Orsay, LAL /INFN, Rome, Arduini, G., /CERN, Assmann, R., /CERN, Bracco, C., /CERN, Cerutti, F., /CERN, Christiansen, J., /CERN, Gilardoni, S., /CERN, Laface, E., /CERN, Losito, R., /CERN, Masi, A., /CERN, Metral, E., /CERN, Mirarchi, D., /CERN, Montesano, S., /CERN, Previtali, V., /CERN, Redaelli, S., /CERN, Valentino, G., /CERN, Schoofs, P., /CERN, Smirnov, G., /CERN, Tlustos, L., /CERN, Bagli, E., /INFN, Ferrara /Ferrara U., Baricordi, S., and /INFN, Ferrara /Ferrara U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /Ferrara U. /Frascati /Frascati /INFN, Legnaro /INFN, Legnaro /INFN, Legnaro /INFN, Legnaro /INFN, Legnaro /INFN, Legnaro /INFN, Rome /INFN, Rome /INFN, Rome /INFN, Rome /INFN, Naples /Serpukhov, IHEP /Serpukhov, IHEP /Serpukhov, IHEP /Serpukhov, IHEP /Serpukhov, IHEP /Dubna, JINR /Dubna, JINR /Dubna, JINR /St. Petersburg, INP /St. Petersburg, INP /St. Petersburg, INP /St. Petersburg, INP /Imperial Coll., London /Imperial Coll., London /Imperial Coll., London /Imperial Coll., London /Imperial Coll., London /Imperial Coll., London /Imperial Coll., London /Imperial Coll., London /Brookhaven /SLAC /SLAC /SLAC. Mon .
"Comparative Results on Collimation of the SPS Beam of Protons and Pb Ions with Bent Crystals". United States.
doi:.
@article{osti_1039546,
title = {Comparative Results on Collimation of the SPS Beam of Protons and Pb Ions with Bent Crystals},
author = {Scandale, W. and /CERN /Orsay, LAL /INFN, Rome and Arduini, G. and /CERN and Assmann, R. and /CERN and Bracco, C. and /CERN and Cerutti, F. and /CERN and Christiansen, J. and /CERN and Gilardoni, S. and /CERN and Laface, E. and /CERN and Losito, R. and /CERN and Masi, A. and /CERN and Metral, E. and /CERN and Mirarchi, D. and /CERN and Montesano, S. and /CERN and Previtali, V. and /CERN and Redaelli, S. and /CERN and Valentino, G. and /CERN and Schoofs, P. and /CERN and Smirnov, G. and /CERN and Tlustos, L. and /CERN and Bagli, E. and /INFN, Ferrara /Ferrara U. and Baricordi, S. and /INFN, Ferrara /Ferrara U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /Ferrara U. /Frascati /Frascati /INFN, Legnaro /INFN, Legnaro /INFN, Legnaro /INFN, Legnaro /INFN, Legnaro /INFN, Legnaro /INFN, Rome /INFN, Rome /INFN, Rome /INFN, Rome /INFN, Naples /Serpukhov, IHEP /Serpukhov, IHEP /Serpukhov, IHEP /Serpukhov, IHEP /Serpukhov, IHEP /Dubna, JINR /Dubna, JINR /Dubna, JINR /St. Petersburg, INP /St. Petersburg, INP /St. Petersburg, INP /St. Petersburg, INP /Imperial Coll., London /Imperial Coll., London /Imperial Coll., London /Imperial Coll., London /Imperial Coll., London /Imperial Coll., London /Imperial Coll., London /Imperial Coll., London /Brookhaven /SLAC /SLAC /SLAC},
abstractNote = {New experiments on crystal assisted collimation have been carried out at the CERN SPS with stored beams of 120 GeV/c protons and Pb ions. Bent silicon crystals of 2 mm long with about 170 {mu}rad bend angle and a small residual torsion were used as primary collimators. In channeling conditions, the beam loss rate induced by inelastic interactions of particles with the crystal nuclei is minimal. The loss reduction was about 6 for protons and about 3 for Pb ions. Lower reduction value for Pb ions can be explained by their considerably larger ionization losses in the crystal. In one of the crystals, the measured fraction of the Pb ion beam halo deflected in channeling conditions was 74%, a value very close to that for protons. The intensity of the off-momentum halo leaking out from the collimation station was measured in the first high dispersion area downstream. The particle population in the shadow of the secondary collimator-absorber was considerably smaller in channeling conditions than for amorphous orientations of the crystal. The corresponding reduction was in the range of 2-5 for both protons and Pb ions.},
doi = {},
journal = {Physics Letters, (Section) B},
number = 5,
volume = 703,
place = {United States},
year = {Mon Apr 30 00:00:00 EDT 2012},
month = {Mon Apr 30 00:00:00 EDT 2012}
}
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First results on the SPS beam collimation with bent crystals
Experiments were performed at the CERN SPS with 120 GeV/c stored proton beams to assess the possibility of beam halo collimation assisted by bent crystals. A bent crystal was used to deflect horizontally by an angle of about 170 {micro}rad the beam halo protons in channeling states directing them into a 60 cm long tungsten absorber. The halo loss rate due to nuclear inelastic interactions of protons in the aligned crystal was up to five times smaller than for its amorphous orientation. Channeled fractions, (75 {+-} 4)% and (85 {+-} 5)% for the two tested silicon crystals, were measured bymore » -
High-Efficiency Beam Extraction and Collimation Using Channeling in Very Short Bent Crystals
A silicon crystal was used to channel and extract 70GeV protons from the U-70 accelerator with an efficiency of 85.3{+-}2.8% , as measured for a beam of {approx}10{sup 12} protons directed towards crystals of {approx}2 mm length in spills of {approx}2 s duration. The experimental data follow very well the prediction of Monte Carlo simulations. This demonstration is important in devising a more efficient use of the U-70 accelerator in Protvino and provides crucial support for implementing crystal-assisted slow extraction and collimation in other machines, such as the Tevatron, RHIC, the AGS, the SNS, COSY, and the LHC.