Design and operation of the wide angular-range chopper spectrometer ARCS at the Spallation Neutron Source

Journal Article · Sun Jan 15 00:00:00 EST 2012 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/1.3680104· OSTI ID:22066285

Abernathy, D L; Stone, M B; Loguillo, M J; Lucas, M S; Delaire, O ^[1]; Tang, X; Lin, J Y. Y.; Fultz, B ^[2]

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1. Neutron Scattering Sciences Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37831 (United States)
2. California Institute of Technology, W. M. Keck Laboratory 138-78, Pasadena, California 91125 (United States)

The wide angular-range chopper spectrometer ARCS at the Spallation Neutron Source (SNS) is optimized to provide a high neutron flux at the sample position with a large solid angle of detector coverage. The instrument incorporates modern neutron instrumentation, such as an elliptically focused neutron guide, high speed magnetic bearing choppers, and a massive array of {sup 3}He linear position sensitive detectors. Novel features of the spectrometer include the use of a large gate valve between the sample and detector vacuum chambers and the placement of the detectors within the vacuum, both of which provide a window-free final flight path to minimize background scattering while allowing rapid changing of the sample and sample environment equipment. ARCS views the SNS decoupled ambient temperature water moderator, using neutrons with incident energy typically in the range from 15 to 1500 meV. This range, coupled with the large detector coverage, allows a wide variety of studies of excitations in condensed matter, such as lattice dynamics and magnetism, in both powder and single-crystal samples. Comparisons of early results to both analytical and Monte Carlo simulation of the instrument performance demonstrate that the instrument is operating as expected and its neutronic performance is understood. ARCS is currently in the SNS user program and continues to improve its scientific productivity by incorporating new instrumentation to increase the range of science covered and improve its effectiveness in data collection.

• OSTI ID: 22066285
• Journal Information: Review of Scientific Instruments, Vol. 83, Issue 1; Other Information: (c) 2012 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0034-6748
• Country of Publication: United States
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
AMBIENT TEMPERATURE
ANALYTICAL SOLUTION
COMPARATIVE EVALUATIONS
DESIGN
EXCITATION
EXPERIMENTAL DATA
HE-3 COUNTERS
MAGNETIC BEARINGS
MEV RANGE
MONOCRYSTALS
MONTE CARLO METHOD
NEUTRON CHOPPERS
NEUTRON FLUX
NEUTRON GUIDES
NEUTRON SOURCES
NEUTRON SPECTROMETERS
POSITION SENSITIVE DETECTORS
SPALLATION