Beam Induced Electron Multipacting in the CERN Large Hadron Collider Accelerator LHC

Electron multiplication driven by the electric field of the proton bunches is expected to occur in the Large Hadron Collider (LHC), according to previous studies performed at CERN with two computer simulation codes. Electrons, secondary electrons and photo-electrons created by the beam will be accelerated in the electric field of the proton beam and will produce a large heat load at the surface, space charge in the chamber, coupling between the electrons and the beam and a pressure increase, which ultimately could cause the loss of the proton beam. It is, therefore, fundamental to study the phenomenon. The Ph.D. thesis work included studies and planning for the laboratory experimental setup to reproduce the electron multipacting induced by radio frequency, performing data aquisitionand analysis, modelization and simulations of the phenomenon, furthermore, to study the parameters influencing the effect, such as vacuum chamber material, cleaning, surface treatments, to better understand multipacting and determine the most effective ways to avoid this critical effect for the LHC accelerator.