Spallation Neutron Source Closes for Upgrade Work
On Thursday, the Spallation Neutron Source user facility at Oak Ridge National Lab will start a shutdown lasting until July of next year to install equipment for its Proton Power Upgrade project. The facility will add new superconducting radio-frequency accelerating structures to its proton beam, replace some of the magnets in its accumulator ring, and upgrade its proton beam target to accommodate higher beam power.
Following the upgrade’s first phases, SNS has already reached a new world-record power level of 1.7 megawatts, and after resuming operations it will ramp up to 2.0 megawatts by late 2026. In tandem with a larger follow-on project to build a Second Target Station at the facility, the beam power will eventually reach 2.8 megawatts. The Proton Power Upgrade is set to receive the last installment of its total $272 million budget in fiscal year 2024.
The upgrade and the Second Target Station project will keep SNS at the global vanguard for its type of facility. That status will be challenged when the European Spallation Source in Sweden begins operations, currently scheduled for late 2027, with an initial beam power of 2.0 megawatts.
In the immediate future, the SNS shutdown will place a new burden on the U.S. community of neutron scattering researchers, who have been grappling for years with a shortage of domestic research capacity.
Exacerbating that shortage, the National Institute of Standards and Technology’s Center for Neutron Research has been closed for two and a half years following a radiation incident and it is currently operating at low power as it works toward resuming normal science operations.
Aside from SNS and the NIST facility, the only other major national neutron-scattering user facility in the U.S. is Oak Ridge’s High Flux Isotope Reactor.