Comprehensive study of beam focusing by crystal devices

Abstract

International audienceThis paper is devoted to an experimental study of focusing and defocusing positively charged particle beams with the help of specially bent single crystals. Four crystals have been fabricated for this purpose. The studies have been performed at the CERN SPS in 400 GeV/c proton and 180 GeV/c pion beams. The results of measurements of beam envelopes are presented. The rms size of the horizontal profile at the focus was 5–8 times smaller than at the exit of the crystals. The measured focal lengths were 4–21 m. The results of measurements are in good agreement with calculations. Possible applications of focusing crystals in present and future high energy accelerators are discussed

Studies of various physics effects on an on-axis LHCD experiment using numerical tools

“…Tests have also been performed with lead beam at injection and top energies (2. (see also [120]). Let us also stress that the crystal degradation due to radiation, once thought to be an issue, is negligible as demonstrated by tests [121] with the HiRadMat facility of the SPS.…”

A fixed-target programme at the LHC: Physics case and projected performances for heavy-ion, hadron, spin and astroparticle studies

“…Tests have also been performed with lead beam at injection and top energies (2.5 TeV) at the end of 2016. They clearly demonstrated the feasibility of crystalassisted collimation and, in turn, gave a new momentum in the plans for crystal-assisted extraction (see also [136]). Let us also stress that the crystal degradation due to radiation, once thought to be an issue, is negligible as demonstrated by tests [137] with the HiRadMat facility of the SPS.…”

Reduction of multiple scattering of high-energy positively charged particles during channeling in single crystals

“…The first measurements of the beam focusing effect were performed in the 1990s [18]. Since then the focusing devices have been significantly improved [5,19]. Fig.…”

“…In this paper we investigate the multiple scattering of particles during their channeling within silicon crystals. The investigation is based on measurements of interactions of high energy (180 and 400 GeV/c) positively charged particles with focusing bent silicon crystals (with (111) planar orientation ) [5]. We compare these results with those for non-channeled particles.…”