The beam conditions on the target and its operational impacts on beam intercepting devices at European Spallation Source

A large flux of spallation neutrons will be produced at the European Spallation Source (ESS) by impinging high power proton beam on the tungsten target. Until the 5 MW proton beam is stopped by the spallation target, it travels through a number of beam intercepting devices (BIDs), which include the proton beam window, a multi-wire beam profile monitor, an aperture monitor, the beam entrance window, spallation material and the target shroud. The beam-induced thermo-mechanical loads and the damage dose rate in the BIDs are largely determined by the beam energy and the beam current density. At ESS, the proton beam energy will be commissioned step-wisely, from 571 MeV towards 2 GeV. The beam current density on the BIDs in the target station is uniformly painted by raster beam optics. The ESS Linac and its beam optics will create rectangular beam profiles on the target with varying beam intensities. In this paper, we study the impact of different plausible beam intensities and beam energies on the thermo-mechanical loads and radiation damage rates in the BIDs at the ESS target station.