Sökning: "neutron transmission methods"

Visar resultat 1 - 5 av 9 avhandlingar innehållade orden neutron transmission methods.

1. 1. Fast-Neutron Tomography using a Mobile Neutron Generator for Assessment of Steam-Water Distributions in Two-Phase Flows

   Författare :Peter Andersson; Staffan Jacobsson Svärd; Henrik Sjöstrand; Stephan Pomp; Ane Håkansson; Michael Österlund; Bernhard Ludewigt; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Void distribution; neutron tomography; plastic scintillator; transmission measurements; neutron detection; Applied Nuclear Physics; Tillämpad kärnfysik;

   Sammanfattning : This thesis describes the measurement technique of fast-neutron tomography for assessing spatial distributions of steam and water in two-phase flows. This so-called void distribution is of importance both for safe operation and for efficient use of the fuel in light water reactors, which compose the majority of the world’s commercial nuclear reactors. LÄS MER

3. 2. Influence of Composition and Pore Geometry on Immiscible Fluid Flow through Greensands: Development of Neutron Transmission Methods and Image Analysis

   Författare :Mikael Solymar; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; pore geometry; image analysis; fluid flow; petrography; greensand; porosity; glauconite; permeability; neutron transmission methods; fluid saturation;

   Sammanfattning : The effect of the mineralogical composition and pore geometry of sediments on the distribution as well as the flow of immiscible fluids are of importance when evaluating petroleum reservoirs. Greensand containing the clay mineral glauconite is a complex reservoir rock type. LÄS MER

4. 3. 3D Electron Microscopy Methods and Applications : Structures from Atomic Scale to Mesoscale

   Författare :Taimin Yang; Xiaodong Zou; Grüne Tim; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; 3D Electron microscopy; continuous rotation electron diffraction; structure determination; data quality; electron tomography; mesoporous materials; zeolites; Inorganic Chemistry; oorganisk kemi;

   Sammanfattning : The crystal structure determines the physical properties of a material. The structure can be analysed at different levels, from atomic level, mesoscale level, all the way up to the macroscale level. LÄS MER

5. 4. Enhanced Polarizing Neutron Optics with 11B4C Incorporation : SLD Tunability, Interface Refinement, and Elimination of Magnetic Coercivity

   Författare :Anton Zubayer; Fredrik Eriksson; Jens Birch; Naureen Ghafoor; Linköpings universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : This thesis explores novel strategies for improving Fe-based polarizing neutron optics, a critical part for improving neutron scattering methods to study materials science, physics, biology, medicine, chemistry and cultural heritage. Polarization analysis is important in uncovering data on magnetic domains, protein structures, molecular composition and orientation in biological systems, and ion-diffusion mechanisms that would otherwise be inaccessible. LÄS MER

7. 5. Mixed Beam Dosimetry - From Reactor Core to BNCT Patient

   Författare :Per Munck af Rosenschöld; Lund Medicinsk strålningsfysik; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; BNCT; dosimetry; radiotherapy; mixed beam; quality assurance; in vivo dosimetry; Monte Carlo; ionization chamber; foil activation; MCNP; beam quality correction factor; photon transmission.; Nukleärmedicin; radiobiology; Nuclear medicine; radiobiologi; Radiofarmaceutisk teknik; Radiopharmaceutical technology;

   Sammanfattning : Accurate radiation dosimetry is of paramount importance in order to ensure safe delivery of radiotherapy, and for the possibility of meaningful evaluation of clinical trials, as the radiation absorbed dose is correlated to tissue response. The aim of the studies described in this thesis was to investigate and devise novel approaches to mixed beam dosimetry in boron neutron capture therapy (BNCT). LÄS MER