ARCS

A wide Angular-Range Chopper Spectrometer at the SNS

ARCS will be a wide Angular-Range, direct-geometry, time-of-flight Chopper Spectrometer at the Spallation Neutron Source. It will be optimized to provide a high neutron flux at the sample, and a large solid angle of detector coverage.

ARCS will advance the science of dynamical processes in materials. It is designed to measure excitations in materials and condensed matter having energies from a few meV to several hundred meV, with an efficiency better than any existing high-energy chopper spectrometer. Research topics include: (i) studies of vibrational excitations and their relationship to phase diagrams and equations of state of materials, including materials with correlated electrons, and (ii) studies of spin correlations in magnets, superconductors, and materials close to metal-insulator transitions.

To date, inelastic neutron scattering experiments have been constrained by low neutron flux, forcing experimental compromises in energy resolution, momentum resolution, and in the number of spectra that can be measured. With its high detection efficiency and its location at the high-power target station of the SNS, ARCS will free experimenters from many restrictions caused by low flux. The uncompromising hardware and advanced software of ARCS will enable new experiments with a sophistication not yet achieved with chopper spectrometers.

Here is a general interest news report about ARCS, which appeared in the Jan. 2002 issue of Engineering and Science, an official publication of the California Institute of Technology. It was written by Doug Smith of Caltech, who has a unique sense of humor. Nevertheless, there is no such thing as bad publicity.

Hot and Cold Running Neutrons

Here is the ARCS proposal as submitted to the Department of Energy in Adobe Acrobat .pdf format.

Main Text of ARCS Proposal

Appendix (P.I. info, cost profile)

Here is a link to the 1.0 release for the ARCS software:

ARCS 1.0 release {arcs-1.0}

Here is a link to the beta release for the ARCS software:

ARCS beta release {arcs-beta}

Additional Reference Material in Adobe Acrobat .pdf format:

Fermi Chopper Slit Package Options

Cryogenic Goniometer User's Manual by Markus Hehlen

ARCS Project Execution Plan 2004