Search for dissertations about: "positron range"

Showing result 1 - 5 of 37 swedish dissertations containing the words positron range.

2. 1. Investigation of Nuclear Materials with Positron Measurements

   Author : Petty Bernitt Cartemo; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; depth profiling; positron beam; nuclear materials; radiation damage; positron lifetime measurements;

   Abstract : Positron Annihilation Lifetime Spectroscopy can be used to characterize radia- tion-induced material defects to subsequently optimize nuclear materials with respect to radiation damage. Nuclear Systems of the future such as Generation IV and fusion concepts demand high performance from structural materials, comprising a material's stability in highly-radiative and hot environments. READ MORE

4. 2. Novel computational methods for image analysis and quantification using position sensitive radiation detectors

   Author : Alejandro Sanchez Crespo; Stig A. Larsson; Magnus Dahlbom; Stockholms universitet; []
   Keywords : LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; SPET; PET; CMOS; spatial resolution; photon depth of interaction; positron annihilation; positron range; non-collinearity; scatter; attenuation; lung ventilation; lung perfusion; breast tumour; Medicine; Medicin;

   Abstract : The major advantage of position sensitive radiation detector systems lies in their ability to non invasively map the regional distribution of the emitted radiation in real-time. Three of such detector systems were studied in this thesis, gamma-cameras, positron cameras and CMOS image sensors. READ MORE

5. 3. Modelling of radiation damage and positron annihilation in metallic materials

   Author : Qigui Yang; Pär Olsson; Bernardo Barbiellini; KTH; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Radiation damage; First-principles; Positron annihilation spectroscopy; Cu precipitation; Two-component density functional theory; Tungsten; Transition metals; Kärnenergiteknik; Nuclear Engineering; Physics; Fysik;

   Abstract : The radiation damage is one of the key concerns in the research of materials used in radiation environments. In this thesis, we theoretically investigate the radiation damage phenomenon by focusing on two important topics: the defect production and evolution, and the defect characterization. The first part aims at two aspects. READ MORE

6. 4. Evaluation of Regularized Image Reconstruction for Clinical Positron Emission Tomography

   Author : Elin Lindström; Mark Lubberink; Jens Sörensen; Anders Sundin; Anne Larsson Strömvall; Uppsala universitet; []
   Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Positron emission tomography; PET CT; molecular imaging; image reconstruction; regularized reconstruction; quantification; oncology; neurology; cardiology; Medicinsk radiofysik; Medical Radiophysics;

   Abstract : Positron emission tomography (PET) combined with computed tomography (CT) is a widely used noninvasive molecular imaging modality with a broad range of clinical applications in oncology, neurology, and cardiology. Producing imperative image quality and accurate quantification are important driving forces behind the technological advances within PET image reconstruction and system development. READ MORE

7. 5. Development of in vitro and ex vivo positron-emitting tracer techniques and their application to neurotrauma

   Author : Sven Sihver; Uppsala universitet; []
   Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Neurosciences; Short-lived radionuclides; in vitro receptor binding; in vitro and ex vivo autoradiography; positron emission tomography; benzodiazepine; muscarinic acetylcholine; and NMDA receptors in CNS; experimental neurotrauma; Neurovetenskap; Neurology; Neurologi; medicinsk farmakologi; Medical Pharmacology;

   Abstract : The use of positron-emitting tracers has been extended beyond tomographic facilities in the last few years, giving rise to a general positron-emitting tracing technique. The methodological part of the present thesis involved the evaluation of the performance of storage phosphor (SP) plates, with tracers labeled with high-energy, short-lived, positron-emitting radionuclides, using homogenized tissue specimens and autoradiography with frozen brain sections. READ MORE