Crystals Application in the Totem Experiment to Increase the Acceptance of a Roman Pot∗

Bent crystal may enhance the physics reach of a nearbeam physics detector in the CERN-LHC, by increasing the acceptance of scattered protons in low transverse momentum reactions. As an example we present simulations demonstrating the increase of the Roman Pot acceptance in the TOTEM apparatus. Starting from the MadX v6.5 collision optics, a crystal is placed at different longitudinal and transversal positions: for each scheme a gaussian beam of protons with different kinematic variables is created and tracked along the optical line with crystal. The number of protons with transversal coordinates greater than 10 σ + 0.5 mm, that is inside the Roman Pot, is compared with the total number of protons. The possible gain in acceptance is around 15− 20%.