Search for dissertations about: "gamma-ray spectrometry"

Found 5 swedish dissertations containing the words gamma-ray spectrometry.

  2. 1. Improving accuracy of in situ gamma-ray spectrometry

    Author : Jonas Boson; Christer Samuelsson; Umeå universitet; []
    Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; gamma-ray spectrometry; in situ measurement; HPGe detector; 137Cs; Monte Carlo; efficiency calibration; measurement uncertainty; Radiological physics; Radiofysik;

    Abstract : Gamma-ray spectrometry measurements performed on site, or “in situ”, is a widely used and powerful method that can be employed both to identify and quantify ground deposited radionuclides. The purpose of this thesis is to improve the calibration of high purity germanium (HPGe) detectors for in situ measurements, and calculate the combined uncertainty and potential systematic effects. READ MORE

  4. 2. Orphan source detection in mobile gamma-ray spectrometry - Improved techniques for background assessment

    Author : Peder Kock; Malmö Medicinsk strålningsfysik; []
    Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Gamma spectrometry; airborne; car-borne; radioactive; orphan sources; hypothesis testing; background radiation;

    Abstract : Hazardous radioactive sources out of regulatory control are referred to as orphan sources. Focussing on gamma-emitting orphan sources, this thesis describes methods that can be used in mobile gamma-ray spectrometry to perform real-time discrimination between an actual source signal and the signal due to the natural radiation background. READ MORE

  5. 3. In situ measurements of radionuclide concentration in soil : An investigation into detector properties and methods

    Author : Johan Kastlander; Christoph Bargholtz; Mats Isaksson; Stockholms universitet; []
    Keywords : In situ gamma-ray spectrometry; LaBr3; CdTe; Cs-137; soil samples; fysik; Physics;

    Abstract : In case of a release of radioactive nuclides into the environment it is necessary to  have reliable methods to estimate the potential effect on people and the ecosystem. In this context the total activity deposited, the elemental composition and the depth distribution are of importance. READ MORE

  6. 4. Development of methods for in situ measurements of radioactivity in the enviroment

    Author : Johan Kastlander; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; In situ gamma ray spectrometry; CdTe; HPGe; Low energy physics; Lågenergifysik;

    Abstract : In case of a release of radioactive nuclides into the environment it is necessary to have reliable methods to estimate the potential effect on population and ecosystem. In this context the total activity deposited, the elemental composition and its depth distribution are of importance. READ MORE

  7. 5. Fluorine mass balance in wildlife and consumer products : How much organofluorine are we missing?

    Author : Lara Schultes; Jonathan P. Benskin; Michael McLachlan; Jörg Feldmann; Elsie M. Sunderland; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; PFASs; PFOS; fluorine mass balance; organofluorine; EOF; TF; wildlife; consumer products; combustion ion chromatography; high resolution mass spectrometry; suspect screening; Applied Environmental Science; tillämpad miljövetenskap;

    Abstract : Per- and polyfluoroalkyl substances (PFASs) are a class of anthropogenic pollutants. Many PFASs are highly persistent and have been linked to adverse effects in humans. According to latest estimates, there are more than 4700 PFASs in global commerce, which poses immense challenges for environmental monitoring. READ MORE