Electron-Cloud Energy and Angular Distributions

We discuss simulated energy and angular spectra of electrons lost to the vacuum chamber wall during beam-induced multipacting in SPS and LHC. Our simulations demonstrate that electron energies and impact angles are strongly correlated, and that the angular distribution can be modified by the beam magnetic field. The energy spectrum is found to be remarkably sensitive to changes in the bunch length or, to a lesser extent, in the transverse beam size, which may open new possibilities for beam diagnostics. From our simulation results, we estimate the energy and angular acceptance required for future as well as the electron impact rate.