Conveners
C1Po1E: Large Scale II: Cryogenic Moderators
- Li Wang (Lawrence Berkeley National Laboratory)
- Yi Jia (FermiLab)
The Spallation Neutron Source (SNS) incorporates a 20-K helium refrigeration system to cool three circuits supplying cold hydrogen to neutron moderators. The helium refrigeration system consists of a warm compressor, oil removal, purifier, 20-K cold box, and three helium-hydrogen heat exchangers. The hydrogen loops consist of a circulator, moderator, accumulator with expandable bellows, and...
The Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL) operates the Cryogenic Moderator System (CMS) which provides supercritical hydrogen cooling at 20K to three neutron moderators. A helium refrigerator provides 8 kW of cooling capacity to three parallel hydrogen circuits. Several projects have been completed to improve operational reliability CMS. The status of...
At the ESS target, high energy spallation neutrons are produced by impinging a 5 MW proton beam on the high-Z material, tungsten. The proton beam is pulsed with a repetition of 14 Hz and a pulse length of 2.86 ms. The moderator system consists of a water pre-moderator and two liquid hydrogen cold moderators, which are optimized to achieve a high cold neutron brightness. The neutronic...
The European Spallation Source (ESS) is a multi-disciplinary research facility based on the world’s most powerful neutron source. One key component of the target station is the cryogenic moderator system (CMS) which is designed and manufactured by the ZEA-1 of the Forschungszentrum Jülich. The cryostat of the CMS supplies liquid hydrogen in a closed loop at the temperature of around 18.5K and...
The National Institute of Standards and Technology (NIST) Center for Neutron Research (NCNR) houses an aging reactor that serves about 40% of all cold neutron research needs in the U.S. First critical in 1967, the National Bureau of Standards Reactor (NBSR) is now more than 50 years old. NCNR engineers have initiated a design effort for a replacement reactor – namely the NIST Neutron Source or...
