First Studies of Ion Collimation for the LHC Using BDSIM

At the Large Hadron Collider (LHC) at CERN ion physics runs are performed in addition to proton physics runs. In ion operation the cleaning efficiency of the collimation system is lower than in the case of protons and the ion showering process is more complicated and produces a larger variety of secondary particles. In particular, lighter ion species can be produced as fragmentation products in the collimation system and specialised physics lists are required to simulate their production and propagation in matter. The Geant4 toolkit offers comprehensive physics process lists that extend to the case of arbitrary ion species at high energies. First results from a study of ion collimation for the LHC using the Geant4 physics library in BDSIM are presented here. These include simulations of a full ring loss map and particle spectra for collimator leakage for a Pb beam at injection energy in the LHC.