Study of the effective temperatures of two neutron moderating materials: Ethane and triphenylmethane

Abstract

We studied the effective temperatures of hydrogen and carbon in solid ethane at 80 K and triphenylmethane at 22 K at the VESUVIO spectrometer (ISIS Neutron and Muon Source, Rutherford Appleton Laboratory, UK), using the Deep Inelastic Neutron Scattering (DINS) and Neutron Transmission techniques. The systems are of potential application as moderators for the design of cold neutron sources. We discuss in detail the process of data analysis and parameter fitting, in which we introduced improved algorithms. The results were compared with density functional theory calculations, which yield compatible results. The importance of these determinations for their applications to Nuclear Engineering calculations is highlighted. The results of the effective temperatures obtained are supported by comparisons with the total cross sections measured simultaneously with DINS in this experiment.