Sökning: "Photon counting"

Visar resultat 1 - 5 av 44 avhandlingar innehållade orden Photon counting.

  1. 1. Counting Calories : Studies of Energy Loss in a Segmented Calorimeter

    Författare :Sara Bergenius Gavler; Per Carlson; Oscar Adriani; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physics; Fysik;

    Sammanfattning : The Gamma-ray Large Area Space Telescope (GLAST) is a space mission with anticipated launch in 2007. The aim is to study the gamma-ray sky in the energy range 10 keV – 300 GeV. The GLAST electromagnetic calorimeter is 8.6X0 deep and has a total of 1536 CsI(Tl) crystals each measuring 32. LÄS MER

  3. 2. Spectral Computed Tomography with a Photon-Counting Silicon-Strip Detector

    Författare :Mats Persson; Mats Danielsson; Hans Bornefalk; Jiang Hsieh; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Photon-counting; silicon-strip detector; spectral computed tomography; ring artifacts; fluence rate; basis material decomposition; sub-pixel information; Fysik; Physics;

    Sammanfattning : Computed tomography (CT) is a widely used medical imaging modality. By rotating an x-ray tube and an x-ray detector around the patient, a CT scanner is able to measure the x-ray transmission from all directions and form an image of the patient’s interior. LÄS MER

  4. 3. Characterisation and application of photon counting X-ray detector systems

    Författare :Börje Norlin; Christer Fröjdh; Hans-Erik Nilsson; Sherwood Parker; Mittuniversitetet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Monte Carlo simulation; Three-dimensional; X-ray flouriscence; Charge transport; Semiconductor materials; Image sensors; CdTe; Photon counting; Synchrotron radiation; Material recognition; X-ray; Pixel Detector; Silicon; Charge sharing; Imaging; Medipix; Spectroscopy; Dental diagnosis; Image quality; Energy weighting; Electronics; Elektronik;

    Sammanfattning : This thesis concerns the development and characterisation of X-ray imaging systems based on single photon processing. “Colour” X-ray imaging opens up new perspectives within the fields of medical X-ray diagnosis and also in industrial X-ray quality control. LÄS MER

  5. 4. A Segmented Silicon Strip Detector for Photon-Counting Spectral Computed Tomography

    Författare :Cheng Xu; Hans Bornefalk; Mats Danielsson; Ami Altman; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; photon counting; spectral computed tomography; silicon strip detector; ASIC; energy resolution; cadmium telluride; charge sharing; Monte Carlo simulation; synchrotron;

    Sammanfattning : Spectral computed tomography with energy-resolving detectors has a potential to improve the detectability of images and correspondingly reduce the radiation dose to patients by extracting and properly using the energy information in the broad x-ray spectrum. A silicon photon-counting detector has been developed for spectral CT and it has successfully solved the problem of high photon flux in clinical CT applications by adopting the segmented detector structure and operating the detector in edge-on geometry. LÄS MER

  7. 5. Spectral Photon-Counting Computed Tomography with Silicon Detectors: New Models and Applications

    Författare :Fredrik Grönberg; Mats Danielsson; Mats Persson; Amir Pourmorteza; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; photon-counting; spectral computed tomography; material decomposition; pulse pileup; Compton scatter; image formation; fotonräknande; spektral datortomografi; materialbasupdelning; pulsöverlagring; Comptonspridning; bildbildning; Physics; Fysik;

    Sammanfattning : X-ray computed tomography (CT) is a widely used imaging modality that enables visualization of nearly every part of the human body. It is used for diagnosis of disease and injury as well as medical treatment planning. LÄS MER