Electron-Cloud Build-Up Simulations and Experiments at CERN

We benchmark the predictions of electron-cloud buildup simulations against measurements at the CERN SPS. Specifically we compare the electron flux at the wall, electron-energy spectra, heat loads and the spatial distribution of the electrons for two different bunch spacings, with variable magnetic fields, and for several chamber temperatures and associated surface conditions. The simulations employ a modified, improved version of the ECLOUD code. The main changes are briefly described. We finally present updated simulation results for the heat load in the cold LHC arcs.