Sökning: "neutron scintillator"

Visar resultat 1 - 5 av 24 avhandlingar innehållade orden neutron scintillator.

1. 1. Neutron Spectroscopy : Instrumentation and Methods for Fusion Plasmas

   Författare :Henrik Sjöstrand; Göran Ericsson; Johan Frenje; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Neutron spectroscopy; plasma diagnostics; fusion power; fusion; plasma heating; MPRu; JET; triton burn-up; ITER; neutron yield; calibration; Fusion; Fusion;

   Sammanfattning : When the heavy hydrogen isotopes deuterium (D) and tritium (T) undergo nuclear fusion large amounts of energy are released. At the Joint European Torus (JET) research is performed on how to harvest this energy. Two of the most important fusion reactions, d+d→3He+n (En = 2.5 MeV) and d+t→4He+n (En = 14 MeV), produce neutrons. LÄS MER

3. 2. A Fast Pixelated Thermal-Neutron Detector

   Författare :Emil Rofors; Kärnfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; SoNDe; thermal-neutron detector; GS20 scintillator; Li-glass; H12700A MAPMT; position-dependent response; alpha-particle; proton; deuteron; neutron; ESS; SKADI;

   Sammanfattning : This thesis presents the study of a position-sensitive scintillation-based detector called the Solid-State Neutron Detector (SoNDe). SoNDe is being developed for cold- and thermal-neutron detection at the small-angle neutron scattering (SANS) instrument SKADI at the European Spallation Source (ESS), currently under construction in Lund, Sweden. LÄS MER

4. 3. Neutron Irradiation Techniques

   Författare :Julius Scherzinger; Kärnfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; actinide Be; fast-neutrons; NE-213 liquid scintillator; He-4 scintillators; pulse-shape discrimination; Cf-252; absolute detection efficiency; neutron irradiation; Fysicumarkivet A:2016:Scherzinger;

   Sammanfattning : The He-3 “crisis” has become a fact in the last decade and large scale neutron detectors based on He-3 technologies have become unaffordable. This new He-3 reality has resulted in a major effort worldwide to develop replacement neutron-detector technologies. LÄS MER

5. 4. Characterisation of the Neutron Wall and of Neutron Interactions in Germanium-Detector Systems

   Författare :Joa Ljungvall; Johan Nyberg; Andres Gadea; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Nuclear physics; High-purity Ge detectors; Liquid scintillator detectors; Neutron scattering; Digital electronics; Time-of-flight technique; Pulse-shape simulation and analysis; Monte Carlo simulations; Geant4; Gamma-ray tracking; AGATA; Neutron Wall; Kärnfysik; Nuclear physics; Kärnfysik;

   Sammanfattning : A Monte Carlo simulation of the Neutron Wall detector system has been performed using Geant4, in order to define optimum conditions for the detection and identification of multiple neutrons. Emphasis was put on studying the scattering of neutrons between different detectors, which is the main source of the apparent increase of the number of detected neutrons. LÄS MER

7. 5. 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