Comparing the behavior of simulated proton synchrotron radiation in the arcs of the LHC with measurements

In previous work it was shown that at high proton-beam
energies, synchrotron radiation is an important source of
beam-screen heating, of beam-related vacuum pressure in-
crease, and of primary photoelectrons, which can contribute
to electron-cloud formation. We have used the Synrad3D
code developed at Cornell to simulate the photon distribu-
tions in the arcs of the LHC, HL-LHC, and FCC-hh. In par-
ticular, for the LHC we studied the effect of the ‘sawtooth’
chamber. In this paper, specific results of the Synrad3D
simulations are compared with simulations by another code,
Synrad+, developed at CERN, and with experimental data
from a synchrotron-light beam line at BESSY II for actual
LHC vacuum-chamber samples.