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Author Simeoni, G. G. ♦ Valicu, R. G. ♦ Borchert, G. ♦ Böni, P. ♦ Rasmussen, N. G. ♦ Yang, F. ♦ Kordel, T. ♦ Holland-Moritz, D. ♦ Kargl, F. ♦ Meyer, A.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS ♦ BEAMS ♦ EFFICIENCY ♦ FEDERAL REPUBLIC OF GERMANY ♦ FOCUSING ♦ FRM-II REACTOR ♦ NEUTRON CHOPPERS ♦ NEUTRON FLUX ♦ NEUTRON GUIDES ♦ NEUTRON SOURCES ♦ NEUTRON SPECTROMETERS ♦ NEUTRON SPECTROSCOPY ♦ OPTICS ♦ PHYSICAL PROPERTIES ♦ SCATTERING ♦ SIGNALS ♦ SIMULATION ♦ SYMMETRY ♦ TIME-OF-FLIGHT METHOD
Abstract Neutron Spectroscopy employing extreme-conditions sample environments is nowadays a crucial tool for the understanding of fundamental scientific questions as well as for the investigation of materials and chemical-physical properties. For all these kinds of studies, an increased neutron flux over a small sample area is needed. The prototype of a focusing neutron guide component, developed and produced completely at the neutron source FRM II in Garching (Germany), has been installed at the time-of-flight (TOF) disc-chopper neutron spectrometer TOFTOF and came into routine-operation. The design is based on the compressed Archimedes' mirror concept for finite-size divergent sources. It represents a unique device combining the supermirror technology with Adaptive Optics, suitable for broad-bandwidth thermal-cold TOF neutron spectroscopy (here optimized for 1.4–10 Å). It is able to squeeze the beam cross section down to a square centimeter, with a more than doubled signal-to-background ratio, increased efficiency at high scattering angles, and improved symmetry of the elastic resolution function. We present a comparison between the simulated and measured beam cross sections, as well as the performance of the instrument within real experiments. This work intends to show the unprecedented opportunities achievable at already existing instruments, along with useful guidelines for the design and construction of next-generation neutron spectrometers.
ISSN 00036951
Educational Use Research
Learning Resource Type Article
Publisher Date 2015-12-14
Publisher Place United States
Journal Applied Physics Letters
Volume Number 107
Issue Number 24


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