ESS European Spallation Source. The ESS reflector concept

In the present report the concept of the reflectors for both target stations will be described. We mainly focus on the development status of the mechanical structure and the problems of cooling the reflector. The purpose of the reflector of a spallation source is to scatter back those fast neutrinos released from the target, which have not been directly intercepted by the moderators. In order to achieve this, materials with a high macroscopic scattering cross section such as beryllium, nickel, lead or aluminium are commonly used. For the ESS reflectors lead has been proposed. The cooling requirements are particularly demanding due to the high density of deposited energy and the complex geometrical details of the reflector. (orig.)