The European Spallation Source ESS will use cryogenics in at least three different parts of the machine, namely the linac, the target and the experiments including instruments. Additionally, cryogenics might be used in test stands, workshops and laboratories. Each of these systems presents its own special challenges linked to the nature of the client. The common challenges faced by all systems include (i) energy efficiency (ii) CAPEX (investment costs), (iii) OPEX (running costs) and (iv) availability/reliability/operational stability.
Energy efficiency, although closely linked to OPEX, has its own very high importance, as the ESS is held to stringent energy consumption limits as part of its commitment to sustainability. This report explains the basic setup of the ESS cryogenic system and includes a rough heat load analysis based on earlier reports. This report does not deal with energy efficiency or detailed cryogenic process design.