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The Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL) in Tennessee is a pulsed neutron source that the U.S. Department of Energy (DOE) Office of Science operates as a user facility. If you are a researcher, a research administrator or a grants officer weighing neutron scattering for a project, this guide explains what the machine does and where its user program is documented, so you know what to look up before you plan a proposal.
What the Spallation Neutron Source is
SNS produces neutrons by spallation: a linear accelerator delivers short, microsecond-long proton pulses to a steel target filled with liquid mercury, and the impacts release neutrons that are directed to instruments (ORNL Neutron Sciences, checked 2026-11-07). The Proton Power Upgrade doubled the power capability of the SNS linear accelerator from 1.4 to 2.8 megawatts. Researchers use the neutrons to study materials through techniques such as diffraction, spectroscopy, reflectometry and imaging; see what crystallography is and what materials science covers for research areas that rely on this kind of probe.
Who runs it and what it covers
ORNL describes SNS and the High Flux Isotope Reactor (HFIR) as DOE Office of Science User Facilities. Per ORNL, SNS delivered its first beam to target on April 28, 2006, and DOE’s Deputy Secretary certified completion of the SNS project on June 5, 2006, at a total project cost of $1,411.7 million (DOE Office of Science news archive, 2006).
The ORNL SNS page lists 20 instruments, each on a numbered beam line. A selection, with the titles ORNL gives them (CORELLI and FNPB complete the 20 on the page):
| Instrument | Beam line | ORNL description |
|---|---|---|
| ARCS | BL-18 | Wide Angular-Range Chopper Spectrometer |
| BASIS | BL-2 | Backscattering Spectrometer |
| CNCS | BL-5 | Cold Neutron Chopper Spectrometer |
| EQ-SANS | BL-6 | Extended Q-Range Small-Angle Neutron Scattering Diffractometer |
| HYSPEC | BL-14 | Hybrid Spectrometer |
| LIQREF | BL-4B | Liquids Reflectometer |
| MAGREF | BL-4A | Magnetism Reflectometer |
| MANDI | BL-11B | Macromolecular Neutron Diffractometer |
| NOMAD | BL-1B | Nanoscale-Ordered Materials Diffractometer |
| NSE | BL-15 | Neutron Spin Echo Spectrometer |
| POWGEN | BL-11A | Powder Diffractometer |
| SEQUOIA | BL-17 | Fine-Resolution Fermi Chopper Spectrometer |
| SNAP | BL-3 | Spallation Neutrons and Pressure Diffractometer |
| TOPAZ | BL-12 | Single-Crystal Diffractometer |
| USANS | BL-1A | Ultra Small-Angle Neutron Scattering Instrument |
| VENUS | BL-10 | Versatile Neutron Imaging Instrument |
| VISION | BL-16B | Vibrational Spectrometer |
| VULCAN | BL-7 | Engineering Materials Diffractometer |
How the user program is organized
ORNL states that both scientists and non-scientists can access its research facilities through the DOE User Program, and that submitted proposals are reviewed by independent scientists from within the neutron scattering community. The ORNL neutron user-facilities site is the place to start. Its “Become a User” page is organized under these sections:
- Proposal Calls
- Integrated Proposal Tracking System (IPTS)
- How to Submit a Proposal
- Proposal Review Process, including the Scientific Review Committee and Proposal Review Statistics
- Proposal Types, including Mail-in Proposals
- Proposal Writing Tips
- New User Beamtime (NUBe) Program
The site also has “User Guide” and “User & Instrument Support” areas, and the SNS-HFIR User Group (SHUG) represents users. Deadlines, eligibility details and any costs are set out on those pages and are updated by the facility, so take them from the live pages rather than from a summary.
Strengths and limits
- Strength: a national user facility open to scientists and non-scientists through the DOE User Program, with 20 listed instruments covering several scattering techniques.
- Strength: review by independent scientists from the neutron scattering community, so access follows the proposal’s scientific case.
- Limit: beam time is requested through the proposal process rather than purchased on demand, so build proposal calls and review into a project timeline.
Related facility at ORNL
| Facility | What ORNL states |
|---|---|
| Spallation Neutron Source (SNS) | Pulsed proton beam on a liquid-mercury target; 1.4 to 2.8 MW linac power capability; DOE Office of Science User Facility |
| High Flux Isotope Reactor (HFIR) | DOE Office of Science User Facility at ORNL; shares the SNS-HFIR User Group |
For grants and research administrators
Beam-time access and research funding are separate steps. Time on a DOE user facility is requested through the facility’s proposal process, while the costs of your own project are funded through your own grants. See writing a DOE Office of Science grant proposal narrative for the funding side, and what nuclear engineering covers for the neighbouring field.
FAQ
What does a spallation neutron source do?
It produces neutrons by firing pulses of accelerated protons at a heavy-metal target. At SNS the target is a steel vessel filled with liquid mercury.
Where is the Spallation Neutron Source?
At Oak Ridge National Laboratory in Tennessee, as a DOE Office of Science User Facility.
Who can use SNS?
ORNL says scientists and non-scientists can access its facilities through the DOE User Program, with proposals reviewed by independent scientists.
When did SNS start operating?
It delivered its first beam to target on April 28, 2006, per ORNL.
Sources
- ORNL Neutron Sciences, Spallation Neutron Source (checked 2026-11-07)
- ORNL Neutron Sciences, Become a User (checked 2026-11-07)
- ORNL, SNS celebrates 15 years (checked 2026-11-07)
- DOE Office of Science, June 5, 2006 news item (checked 2026-11-07)
