TY - JOUR AU - Beßler, Yannick AU - Natour, Ghaleb TI - Cryogenic hydrogen Moderator infrastructure at ESS JO - Journal of neutron research VL - 24 IS - 2 SN - 1023-8166 CY - Amsterdam PB - IOS Press M1 - FZJ-2023-01672 SP - 239 - 246 PY - 2023 AB - The European Spallation Source (ESS) in Lund, Sweden, is designed to become the most powerful spallation neutron source in theworld. As one subsystem of the Target Station, which was developed and built at Central Institute of Engineering, Electronics and Analytics –Engineering and Technology (ZEA-1) of Forschungszentrum Juelich, the cold Moderator slows down high-energy neutrons from the spallationprocess. To gain maximum neutron flux intensities along with high system availability for condensed and soft matter research, an optimizedliquid hydrogen Moderator circuit has been developed. Hydrogen with a pressure around 1 MPa, a temperature around 20 K, and a para-hydrogen fraction of at least 0.995 will be utilized to interact with neutrons in a unique cold Moderator vessel arrangement. Hydrogen conversionfrom ortho- to para-hydrogen will be controlled using a catalyst. Two turbo pumps are arranged in series and circulate the cryogen. A heliumrefrigerator, the Target Moderator Cryoplant (TMCP), continuously recools the hydrogen mass flow. Pressure stabilization is achieved by apressure control buffer. The individual ESS Cryogenic Moderator System (CMS) components, the first and second generation of hydrogenModerators (BF1 and BF2) and a first draft of a deuterium Moderator upgrade are presented LB - PUB:(DE-HGF)16 UR - <Go to ISI:>//WOS:000910540500014 DO - DOI:10.3233/JNR-220033 UR - https://juser.fz-juelich.de/record/1006438 ER -