Author: Filges, U.
Paper Title Page
THPWO084 Optimization of a Bi-spectral Boxed Side-by-Side Moderator for the Target-Moderator-Reflector System of the ESS 3957
  • T. Reiss, U. Filges, V. Talanov, M. Wohlmuther
    PSI, Villigen PSI, Switzerland
  • F. X. Gallmeier
    ORNL, Oak Ridge, Tennessee, USA
  Providing bi-spectral neutron beams is one of the main neutronics design criteria for the target-moderator-reflector (TMR) system of the European Spallation Source, to be built in Lund (Sweden). As a first step, the requirements of neutronics instruments regarding the neutron spectrum are formulated, a figure of merit is defined. In order to maximize the moderator performance to obtain bi-spectral neutron extraction, a parametrized model of the TMR system is developed and used with a MCNPX-based optimization framework. This model is then used to study and optimize the moderator performance, especially in the thermal and cold parts of the spectrum. Results obtained with an optimized moderator setup are dicussed and compared with the requirements of the instruments.