Spallation Neutron Source Project Officially Completed

On June 5, 2006, Deputy Secretary of Energy Clay Sell formally certified the successful completion of the Spallation Neutron Source (SNS) project, located at Oak Ridge National Laboratory (ORNL). During the ceremony where the Deputy Secretary signed the project’s Critical Decision 4, Associate Director of Science for Basic Energy Sciences Dr. Patricia Dehmer noted that the $1,411.7 million SNS project has exceeded its baseline objectives, delivering significantly more technical performance capability than promised, one month ahead of schedule, and slightly under budget. In addition, the project achieved an outstanding safety record with no lost workday injuries in over 4.2 million construction work hours.

The SNS project was executed over a period of about 10 years by a DOE multi-laboratory partnership led by the SNS Project Office at ORNL. The other partners were Argonne National Laboratory, Brookhaven National Laboratory, Lawrence Berkeley National Laboratory, Los Alamos National Laboratory, and Thomas Jefferson National Accelerator Facility.

The SNS will become the world’s leading research facility for study of the structure and dynamics of materials using neutrons. It will operate as a user facility that will enable researchers from the United States and abroad to study the science of materials that forms the basis for new technologies in telecommunications, manufacturing, transportation, information technology, biotechnology and health.

Briefly, the SNS facility consists of: (1) a Front End System, where a pulsed beam of negative hydrogen ions is produced; (2) a Linear Accelerator or Linac System, where the beam is accelerated to an energy of 1 billion electron volts; (3) a Ring and Transfer System, where the negative ions are converted into protons and then stored in very short, high intensity pulses and then directed onto; (4) a liquid mercury Target System, where neutrons are generated by spallation reactions and then moderated to lower energies; (5) Instrument Systems, which receive the neutrons through beam guides and where experiments are conducted; and (6) Conventional Facilities and site infrastructure, including a Central Laboratory and Office Building.

In May 2006, the first neutrons generated at SNS were used in a spectrometer instrument to study the molecular structure of a material sample. During the months ahead, the facility’s proton beam power will be steadily increased, and by 2008, the design power level of 1.4 megawatts onto the target will be reached. At the same time, the facility’s availability to scientific users will also increase to full capacity.

For additional information about the SNS, please visit