The Spallation Neutron Source project

The SNS is a “joint-venture” project of five DOE National Laboratories, aimed at building the world´s most powerful accelerator-based pulse spallation source. At its planned 2 MW operation, it will produce neutron fluxes at least a factor of ten greater than Rutherford Appleton Laboratory´s ISIS, currently the world´s leading spallation source. The current design of the SNS calls for 600 ns pulses of 1 GeV protons striking a liquid mercury target at a 60 Hz rate. Room-temperature and cryogenic moderators produce beams of slow neutrons suitable for materials research. Responsibility for system components is as follows: LBNL will provide the high-brightness H^- ion source, transport structures and a 2.5-MeV RFQ accelerator; Los Alamos will build linacs to bring the beam to the full energy of 1 GeV; Brookhaven will build the accumulator ring to compress the 1 ms linac pulse into the sharp pulse delivered to the target; ≈1200 turns will be injected, storing 2×10¹⁴ protons in the ring, which are extracted in a single turn; Oak Ridge will provide the mercury target systems and all conventional facilities; and Argonne and Oak Ridge are coordinating the design of at least 10 neutron-scattering instruments to be provided as the initial suite of experiment stations. The project is formally underway, having been approved and funded by DOE and the US Congress for a construction start in FY99. Neutron beams will be available for users in FY06