Cryogenics for the new European Spallation Source

The European Spallation Source (ESS) will be part of the future European research infrastructure providing experimental possibilities for research from both academia and industry. A proton accelerator is under development at the ESS. The ESS collects expertise from 17 participating countries. The ESS goal is to complete an accelerator with capability of providing 5 MW proton beam with acceptable environment and to commission the beam up to the target by 2019. The pre-construction phase aims at identifying the requested cryogens to operate the accelerator using superconducting materials, the rotating tungsten target and necessary cryogenic systems. Liquid helium, liquid nitrogen and liquid hydrogen are considered for those purposes. This paper describes the conceptual cryogenic design of the system involved in the construction. (author)