skip to main content

DOE PAGESDOE PAGES

This content will become publicly available on June 14, 2017

Title: Demonstration of a Single-Crystal Reflector-Filter for Enhancing Slow Neutron Beams

The cold polycrystalline beryllium reflector-filter concept has been used to enhance the cold neutron emission of cryogenic hydrogen moderators, while suppressing the intermediate wavelength and fast neutron emission at the same time. While suppressing the fast neutron emission is often desired, the suppression of intermediate wavelength neutrons is often unwelcome. It has been hypothesized that replacing the polycrystalline reflector-filter concept with a single-crystal reflector-filter concept would overcome the suppression of intermediate wavelength neutrons and thereby extend the usability of the reflector-filter concept to shorter but still important wavelengths. In this paper we present the first experimental data on a single-crystal reflector-filter and compare experimental results with hypothesized performance. We find that a single-crystal reflector-filter retains the long-wavelength benefit of the polycrystalline reflector-filter, without suffering the same loss of important intermediate wavelength neutrons. Ultimately, this finding extends the applicability of the reflector-filter concept to intermediate wavelengths, and furthermore indicates that the reflector-filter benefits arise from its interaction with fast (background) neutrons, not with intermediate wavelength neutrons of potential interest in many types of neutron scattering.
Authors:
 [1] ;  [2] ;  [3] ;  [4] ;  [5] ;  [3] ;  [3] ;  [2]
  1. European Spallation Source (ESS), Lund (Sweden); Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Los Alamos Neutron Science Center (LANSCE)
  2. Technical Univ. of Denmark, Roskilde (Denmark); European Spallation Source (ESS), Lund (Sweden)
  3. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS)
  4. Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Los Alamos Neutron Science Center (LANSCE)
  5. Indiana Univ., Bloomington, IN (United States). Center for Exploration of Energy and Matter
Publication Date:
OSTI Identifier:
1295104
Grant/Contract Number:
AC05-00OR22725;DMR-0220560; DMR-0320627; AC52-06NA25396
Type:
Accepted Manuscript
Journal Name:
Nuclear Instruments and Methods in Physics Research. Section A, Accelerators, Spectrometers, Detectors and Associated Equipment
Additional Journal Information:
Journal Volume: 830; Journal ID: ISSN 0168-9002
Publisher:
Elsevier
Research Org:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). High Flux Isotope Reactor (HFIR); Spallation Neutron Source
Sponsoring Org:
USDOE National Nuclear Security Administration (NNSA); USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY Moderator; Neutron; Beam; Reflector-filter