Validated scattering kernels for triphenylmethane at cryogenic temperatures

Cold neutrons are widely used in different fields of research such as the study of the structure and dynamics of solids and liquids, the investigation of magnetic materials, biological systems, polymer science, and a rapidly growing area of industrial applications. In a pulsed neutron source where the pulse width is an important parameter to be considered, hydrogenated materials are often used because of their high energy transfer in each collision. The preliminary scattering kernel for triphenylmethane, a material of great potential interest for cold neutron production, had been presented at the ND2016 conference. Here, a new model for the generation of the scattering kernels for this material, together with experimental results on its total cross section measured at the VESUVIO instrument (ISIS Neutron and Muon Source, United Kingdom) is presented. The thermal scattering kernel was generated by means of the NJOY Nuclear Data Processing system, using as input the vibrational modes obtained by density functional theory techniques (DFT). The agreement between measurements and our model validates the scattering kernel construction and the cross section library generated in ENDF and ACE formats.</jats:p

Validated scattering kernels for triphenylmethane at cryogenic temperatures

Cold neutrons are widely used in different fields of research such as the study of the structure and dynamics of solids and liquids, the investigation of magnetic materials, biological systems, polymer science, and a rapidly growing area of industrial applications. In a pulsed neutron source where the pulse width is an important parameter to be considered, hydrogenated materials are often used because of their high energy transfer in each collision. The preliminary scattering kernel for triphenylmethane, a material of great potential interest for cold neutron production, had been presented at the ND2016 conference. Here, a new model for the generation of the scattering kernels for this material, together with experimental results on its total cross section measured at the VESUVIO instrument (ISIS Neutron and Muon Source, United Kingdom) is presented. The thermal scattering kernel was generated by means of the NJOY Nuclear Data Processing system, using as input the vibrational modes obtained by density functional theory techniques (DFT). The agreement between measurements and our model validates the scattering kernel construction and the cross section library generated in ENDF and ACE formats

Validated scattering kernels for triphenylmethane at cryogenic temperatures

Cold neutrons are widely used in different fields of research such as the study of the structure and dynamics of solids and liquids, the investigation of magnetic materials, biological systems, polymer science, and a rapidly growing area of industrial applications. In a pulsed neutron source where the pulse width is an important parameter to be considered, hydrogenated materials are often used because of their high energy transfer in each collision. The preliminary scattering kernel for triphenylmethane, a material of great potential interest for cold neutron production, had been presented at the ND2016 conference. Here, a new model for the generation of the scattering kernels for this material, together with experimental results on its total cross section measured at the VESUVIO instrument (ISIS Neutron and Muon Source, United Kingdom) is presented. The thermal scattering kernel was generated by means of the NJOY Nuclear Data Processing system, using as input the vibrational modes obtained by density functional theory techniques (DFT). The agreement between measurements and our model validates the scattering kernel construction and the cross section library generated in ENDF and ACE formats

Modeling and analysis of single-molecule experiments

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 2005.Vita.Includes bibliographical references (p. 281-311).Single molecule experiments offer a unique window into the molecular world. This window allows us to distinguish the behaviors of individual molecules from the behavior of bulk by observing rare events and heterogeneity in the dynamics. This thesis discusses both models for single molecule experiments, including the stretching of DNA in hydrodynamic flows and the diffusion of tracer particles in heterogeneous environments, and methods to analyze single molecule data to allow determination of properties and models for single molecule experiments. These methods of analysis are based on combining information theory and Bayesian methods with physical insight and are applied to several experimental situations.by James B. Witkoskie.Ph.D