Speaker
Description
The Spallation Neutron Source (SNS) at the Oak Ridge National Laboratory currently operates up to 2 MW and 1.3 GeV at the First Targe Station. With the power increase from the Proton Power Upgrade project realized, future performance improvements will increasingly depend on advances beyond the accelerator, including optimization and novel developments in moderator design and operation. The future Second Target Station, also located at SNS, will establish a new benchmark for moderator brightness at a short-pulse neutron facility. Together, the two target stations will provide complementary capabilities that expand the scientific reach of the SNS user program.
Moderators are often cryogenic, hydrogenous vessels positioned adjacent to neutron-producing targets that tailor neutron energy distributions for the instrument suites they serve. Many moderators also incorporate neutron poisons, such as cadmium or gadolinium, to further shape the temporal characteristics of the neutron pulse. Moderator geometry, materials, operating media, and thermal conditions all have a significant influence on the brightness, pulse shape, and overall performance of the neutron beam delivered to scientific instruments.
At SNS, moderators are integrated within the Inner Reflector Plug (IRP), a complex assembly that is typically replaced only once every five years. The development, qualification, and integration of updated moderator designs begin many years before installation, leaving limited opportunities to validate new concepts under representative operating conditions. Because moderator performance cannot be readily adjusted after installation, reducing technical risk through prototype testing is essential.
The Moderator Test Station (MTS) at SNS is being developed to provide a dedicated platform for the evaluation and optimization of next-generation moderator technologies. Numerous promising moderator concepts have the potential to significantly improve neutron brightness and pulse characteristics but require experimental validation prior to deployment in an operating target station. By providing an on-site test facility, MTS will accelerate the maturation of new moderator designs for both the First and Second Target Stations while reducing implementation risk. The MTS project has completed final design, including supporting development activities, and has entered the procurement phase. This presentation will provide an overview of the completed design, summarize the key development and testing efforts that informed it, along with lessons learned, and discuss the upcoming installation activities that will enable accelerated development of future moderator technologies at SNS.
Key Words
Moderator Test Station, Final Design, Lessons Learned, Project Management