Nonlinear dynamics of proton beams with hollow electron lens in the CERN high-luminosity LHC

• Published in: European physical journal plus Vol. 137; no. 1; p. 7
• Main Authors: Mirarchi, D., Appleby, R. B., Bruce, R., Giovannozzi, M., Mereghetti, A., Redaelli, S., Stancari, G.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-01-2022; Springer Nature B.V; Springer
• Subjects: Active control; Applications; Applied and Technical Physics; Atomic; CERN; Challenges; Collimators; Complex Systems; Condensed Matter Physics; Diffusion rate; Electron beams; Electrons; Energy; Focus Point on High-Energy Accelerators: Advances; Internal energy; Large Hadron Collider; Luminosity; Mathematical and Computational Physics; Molecular; Nonlinear dynamics; Optical and Plasma Physics; Particle beams; Physics; Physics and Astronomy; PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; Proton beams; Regular Article; Theoretical
• ISSN: 2190-5444; 2190-5444
• DOI: 10.1140/epjp/s13360-021-02201-5

The design stored beam energy in the CERN high-luminosity large hadron collider (HL-LHC) upgrade is about 700 MJ, with about 36 MJ in the beam tails, according to estimates based on scaling considerations from measurements at the LHC. Such a large amount of stored energy in the beam tails poses serious challenges on its control and safe disposal. In particular, orbit jitters can cause significant losses on primary collimators, which can lead to accidental beam dumps, magnet quenches, or even permanent damage to collimators and other accelerator elements. Thus, active control of the diffusion speed of halo particles is necessary and the use of hollow electron lenses (HELs) represents the most promising approach to handle overpopulated tails at the HL-LHC. HEL is a very powerful and advanced tool that can be used for controlled depletion of beam tails, thus enhancing the performance of beam halo collimation. For these reasons, HELs have been recently included in the HL-LHC baseline. In this paper, we present detailed beam dynamics calculations performed with the goal of defining HEL specifications and operational scenarios for HL-LHC. The prospects for effective halo control in HL-LHC are presented.