Measurement of double differential cross-section of light water at high temperature and pressure to generate S(α,β)
A series of double differential inelastic scattering cross-section measurements were performed on light water at several temperatures and pressures using high resolution time-of-flight inelastic spectrometers, namely the IN4c and the IN6 at the Institut Laue-Langevin (ILL), Grenoble, France to investigate the impact of temperature and pressure on S( q ,ω) and thus on the S(α, β) thermal scattering kernel. The present work aims at extending previous measurements with light water at room temperature and pressure to more realistic operating conditions in connection with nuclear power reactors.
The thermal neutron time-of-flight spectrometer IN4C
Abstract The IN4C spectrometer has been constructed by ILL in collaboration with the Italian Istituto Nazionale Fisica della Materia, INFM. The instrument was designed in order to have a high counting rate and signal-to-noise ratio with optimised resolution performance. The main ingredients for attaining these objectives are the focusing optics, the efficient background suppression by the chopper system, and the large detector area. In our contribution we shall present the results on the first operational tests.
Evaluation of the neutron scattering cross-section for light water by molecular dynamics
Abstract The neutron scattering cross-section for light water is evaluated by means of molecular dynamics (MD) simulation for incident neutron energies from 1 μ eV to 10 eV at six temperatures between 293.6 and 800 K. In the evaluation, the velocity autocorrelation functions for hydrogen and oxygen are calculated from trajectory data and used for the reconstruction of the double differential scattering cross-section. Typical results on differential and total cross-sections are presented together with experimental data. As compared with ENDF/B-VII, better agreement with experiments is found on the total cross-section below several meV. Hence, the present MD-based approach can serve for the new method of generating the thermal neutron scattering cross-section library for light water.