A double-crystal fixed-target experiment is planned for installation in CERN’s Large Hadron Collider (LHC). This experiment features a 7 cm-long bent silicon crystal, with 7 mrad bend-angle to deflect particles produced by proton interactions with a target. As this crystal is more than an order of magnitude longer than any other installed in the LHC, it requires specific characterization, alignment, and testing. Testing will begin using the LHC’s proton beam at different beam energies, before considering studies of interactions with particles out scattered from a target. Using a particle tracking program, we simulate the expected signals from the angular alignment of this unique crystal with multi-turn halo particles of the circulating LHC proton beam. A range of beam energies is considered to evaluate the performance, as particles with a spread of energies are anticipated downstream of the target following the interactions of the 7 TeV proton beams in the final experiment. The simulation results predict the crystal’s multi-turn efficiency as a function of energy and serve as a benchmark for the commissioning process to integrate this long crystal into the LHC.

A novel double-crystal experiment is being considered for installation in CERN’s Large Hadron Collider (LHC) to measure precession properties of short-lived baryons such as the Λc+. The experiment utilises a first bent silicon crystal of 50 µrad to deflect halo particles away from the circulating proton beam. Further downstream, a second crystal is installed, which produces a significantly greater bending angle of 7 mrad. While the former is well understood in simulations and measurements, the latter presents a new challenge for existing simulation tools. Using particle tracking programs, SixTrack and the newly developed Xsuite, we simulate a single pass experiment to calculate the expected channelling efficiency of these crystals. The results serve as a prediction for the performance of prototype crystals recently tested in CERN’s North Experimental Area at 180 GeV, and that are planned to be installed in the LHC in 2025 for use in the multi-TeV energy range.

An important upgrade programme is planned for the collimation system of Large Hadron Collider (LHC) for lead–ion beams that will already reach their high-luminosity target intensity upgrade in the LHC Run 3 (2022-2025). While certain effects like e-cloud, beam-beam, impedance, inject and dump protection are relaxed with ion beams, halo collimation becomes a challenge, as the conventional multi-stage collimation system is about two orders of magnitude less efficient than for proton beams. Ion fragments scattered out of the collimators in the betatron cleaning insertion risk to quench cold dipole magnets downstream and may represent performance limitations. Planar channeling in bent crystals has been proven effective for high energy heavy ions and is now considered as baseline solution for collimation at High-Luminosity LHC (HL-LHC). In this paper, simulation and measurement results, demonstrating the observation of channeling of heavy-ion beams and improvement of collimation cleaning in the multi-TeV energy regime, and the efficiency of the collimation scheme foreseen for HL-LHC are presented.