Proton–nucleus scattering approximations and implications for LHC crystal collimation

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 phase space distribution and particle loss. Simple approximations for nuclear scattering processes causing limited energy loss to high-energy protons traversing matter are developed, which are suitable for rapid estimates and reduced-description Monte Carlo simulations. The implications for proton loss in the CERN Large Hadron Collider, due to nuclear scattering on collimation crystals are discussed.