Speaker
Description
The Spallation Neutron Source (SNS) at Oak Ridge National Laboratory is a world-leading pulsed neutron facility supporting a broad range of research in materials science, chemistry, biology, and engineering. To address emerging scientific challenges and expand the capabilities available to the neutron science community, the Second Target Station (STS) project is developing a next-generation neutron source optimized for high-brightness cold neutrons which will be constructed at the existing SNS site. The recent Proton Power Upgrade project at SNS upgraded the SNS accelerator capabilities to be able to deliver 1.3 Gev protons with an average power output of 2.8 MW. The STS will complement the existing first target station by diverting one quarter (15 out of 60 pulses per second) of the SNS accelerator beam to a new target system where neutrons are produced via spallation and moderated to long wavelengths suitable for experiments requiring high sensitivity, small sample volumes, or extended length scales. These capabilities will support research in soft matter, biological systems, quantum materials, and energy technologies.
The Ring-To-Second-Target (RTST) beam transport line will extract proton pulses from the existing First Target Station (FTS) beamline with a repetition rate of 15 Hz and transport them to the new Second Target Station. The key requirements for the RTST system are: (1) transport a 1.3 GeV proton beam to the STS target while meeting beam position tolerances and nominal spot size specifications at the target; (2) maintain uncontrolled beam loss below 1 W/m throughout the transport line for serviceability; (3) operate without degradation of existing FTS capabilities; (4) support 5000 hours of STS operation per year; and (5) wherever practical utilize scaled implementations of existing SNS design concepts and components while implementing lessons learned from ~20 years of SNS operations.
The design of the RTST is currently in its final stage. The STS project is preparing for a combined CD-2/3 DOE Office of Science review to establish the project baseline and obtain approval to execute construction. Equipment procurement is planned to begin in early 2027.
This paper provides an overview of the design of the RTST.