skip to main content

SciTech ConnectSciTech Connect

Title: Focusing adaptive-optics for neutron spectroscopy at extreme conditions

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 ofmore » next-generation neutron spectrometers.« less
Authors:
 [1] ;  [2] ;  [1] ;  [2] ;  [2] ;  [1] ;  [3] ;  [4] ; ; ; ; ;  [5]
  1. Heinz Maier-Leibnitz Zentrum (MLZ), FRM II, Technical University of Munich, D-85748 Garching (Germany)
  2. (Germany)
  3. Physics Department E21, Technical University of Munich, D-85748 Garching (Germany)
  4. Nanoscience Center, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen (Denmark)
  5. Institut für Materialphysik im Weltraum, Deutsches Zentrum für Luft- und Raumfahrt, D-51170 Köln (Germany)
Publication Date:
OSTI Identifier:
22486250
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 107; Journal Issue: 24; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 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