Reflection of photons and azimuthal distribution of photoelectrons in a cylindrical beam pipe

In a cryogenic proton accelerator, such as the LHC, the creation of an elec tron cloud and generated heat loads resulting from electron bombardment are strongly dependent on the azimuthal distribution of created photoelectrons . In this context, photon reflection and photoelectron yield measurements h ave been performed using a beam line on the VEPP-2M storage ring. Six elect rodes, covering the complete vacuum chamber perimeter, were mounted such th at they could be suitably biased, and while one electrode was irradiated wi th synchrotron radiation the resulting electron current of all the others c ould be measured. A detailed description of the experimental apparatus and the results of the measurements of photon reflection and the azimuthal dist ribution of generated photoelectrons are presented. (C) 2000 Published by E lsevier Science B.V. All rights reserved.