The Cold Neutron Chopper Spectrometer is a multi-chopper spectrometer designed to provide both high energy and Q resolution at low incident energies (2-50 meV). These capabilities will allow the instrument to address a broad variety of scientific problems in areas as diverse as biomaterials, polymers, cements, magnetic system, geological systems, and quantum liquids. These topics are at the forefront in many different areas such as condensed matter physics, materials science, chemistry, biology and environmental science. The flux on CNCS, which is expected to be two orders of magnitude greater than current state-of-the-art instruments, will allow it to address many exciting and technology relevant problems not possible at present. In addition, the energy resolution and momentum transfers of the CNCS are complimentary to the planned Backscattering and Fermi chopper instruments, providing the SNS with an initial suite of instruments that spans a broad spectrum of the inelastic scattering plane.

New CNCS Building Design.                           Old CNCS Building Design.

The CNCS will be located 35 m from the source on a cold-neutron guide at beam line 5. Two high-resolution choppers, one to shape the neutron pulse from the moderator and a second to provide final energy selection, will provide adjustable energy resolutions between 10 and 100 meV. The final flight path, with a length of 3-4 m, will have a highly pixilated detector covering scattering angles between +140o in the scattering plane and +30o perpendicular to the scattering plane. This will allow the instrument to simultaneously cover a large range of momentum transfer with excellent Q resolution.

The instrument will be designed and constructed by an Instrument Development Team (IDT), one of the first for a SNS instrument. The IDT is lead by Paul Sokol (Physics - The Pennsylvania State University) and has over 30 members from universities and national laboratories. An executive committee has been formed consisting of Sokol (chair), Meigan Aronson (Physics - University of Michigan), Sow-Hsin Chen (Nuclear Engineering - Massachusetts Institute of Technology), Robert Dimeo (NCNR NIST), Herbert Strauss (Chemistry - Berkeley) and Haskell Taub (Physics - University of Missouri). The IDT has received funding from the DOE to pursue the construction of the CNCS. Additional information can be obtained by contacting the Principal Investigator, Paul Sokol (

This project is funded by DOE.