Cryogenic Cooling of the Cold Neutron Source at ESS

The European Spallation Source (ESS) project currently being designed will be built outside of Lund, Sweden. The ESS design includes three He cryogenic plants, providing cryogenic cooling for the proton accelerator superconducting cavities, for the target cold neutron source, and for the ESS instrument suite. Supercritical H2 circulates through and cools the target cold neutron source, and is in turn cooled from the target He cryogenic plant. This report describes the unique cooling requirements for the supercritical H2 cooling system, defines the operating parameters for the target He cryogenic plant based on expected heat loads, and explores design options for the target cryogenic plant to optimize its performance.