  The LHC crystal-based collimation system is mainly addressed. A CRYSTAL
simulation code for particle tracking in crystals is introduced. Its essence
consists in both adequate and fast sampling of proton trajectories in crystals
which is crucial for both correct description of experiments and quantitative
prediction of new effects. The H8 single-pass experiment at the CERN SPS as
well as 7 TeV proton deflection by a bent crystal at the LHC are simulated. We
predict the existence of dechanneling peaks corresponding to the planar
channeling oscillations as well as describe the possibility of their
observation at high energies, specifically in the LHC crystal-assisted
collimation experiment planned on 2015. An effect of excess over the amorphous
level of ionization losses in the channeling mode was also found for the LHC
energy. In addition, the LHC crystal-based collimation system is simulated as
well as its possible improved layouts with application of a crystal with the
cut and multiple volume reflection in one bent crystal.
