DYVACS (DYnamic VACuum Simulation) code: Calculation of gas density profiles in presence of electron cloud

The computation of residual gas density evolution in the LHC in the presence of proton beams was performed with a new simulation code called DYVACS (DYnamic VACuum Simulation). It is a modification of the VASCO code in order to take into account dynamic effects such as the electron cloud phenomenon leading to an increase of both the electron- and the ion-induced gas desorption. Results obtained with the DYVACS code is compared to pressure measurements recorded during a typical physics fill in the Vacuum Pilot Sector of the LHC. First results show a good agreement between the calculated pressure and the experimental values.