CRYM: A crystal channeling emulation program for the UA9 experiment

The UA9 CERN experiment concerns the future of beam collimation in modern accelerators, a fundamental task given the limits collimation poses on luminosity. UA9 will test an innovative approach based on the substitution of the amorphous first stage collimator (that spreads the halo over the whole solid angle) with a bent silicon crystal. The test will be performed in the CERN SPS, stimulating a 120 GeV de-bunched proton beam to create a halo. The crystal will deflect particles coherently outside the beam towards an absorber, increasing the collimation efficiency and releasing the requirements on the positioning of the absorber itself. Simulations will give a fundamental contribution to lead the experiment development and to interpret its results. The simulation should put together the accelerator behaviour with the crystal one. For this reason the emulation program CRYM has been developed. CRYM is a planar channeling crystal model based on the experimental data collected over the past two years. It is able to reproduce the different deflection effects, such as channeling and volume reflection, in single and multi-crystal systems. It is designed to be fast and easy to configure and integrate in an accelerator simulation.