Monte Carlo modeling of crystal channeling at high energies

Channeling in bent crystals is becoming a reliable and efficient technique for collimating beams. At CERN, the installation of crystals in LHC is under scrutiny by the UA9 collaboration with the goal of investigating if they are a viable option for the collimation system upgrade. This paper describes a new model of channeling in bent crystals which has been developed from scratch in order to be implemented in the FLUKA Monte Carlo code simulating particle transport and interactions. Crystal channels are described through the concept of continuous potential taking into account thermal motion of atoms in crystal lattice. The energy of the particle transverse motion determines whether or not it is channeled while single scattering on lattice atoms can lead to dechanneling. Volume capture and reflection are also modeled, as well as crystal torsion and miscut angle. Data from experimental runs conducted at CERN was analyzed and is shown to be in good agreement with the simulation results.