Proton–nucleus scattering approximations and implications for LHC crystal collimation

Abstract

In particle accelerators, scattered protons with energies close to the incident particles may travel considerable distances with the beam before impacting on accelerator components downstream. To analyze such problems, angular deflection and energy loss of scattered particles are the main quantities to be simulated since these lead to changes in the beam's phase space distribution and particle loss. Simple approximations for nuclear scattering processes causing limited energy loss to highenergy protons traversing matter are developed which are suitable for rapid estimates and reduced-description Monte Carlo simulations. The implications for proton loss in the Large Hadron Collider due to nuclear scattering on collimation crystals are discussed.

Channeling through Bent Crystals

“…The main tool used for analysis of positively charged particles passing through a bent crystal was the FORTRAN code CRY AP written by Igor Yazynin and modified by Robert J. Noble [4]. The code uses a truncated Monte Carlo method for determining the position and angle of the particle as it exits the crystal.…”

“…The CRY AP code written in Fortran by Igor Yazynin and modified by Robert J. Noble [4] provides the baseline for the study of the bent crystal. The effects of volume reflection, volume capture, channeling and dechanneling were investigated with a beam of positively charged particles passing through the crystal.…”