Search for dissertations about: "photon counting"

Showing result 1 - 5 of 36 swedish dissertations containing the words photon counting.

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

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

    Abstract : 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. READ MORE

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

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

    Abstract : 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. READ MORE

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

    Author : Börje Norlin; Christer Fröjdh; Hans-Erik Nilsson; Sherwood Parker; Mittuniversitetet; []
    Keywords : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; 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;

    Abstract : 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. READ MORE

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

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

    Abstract : 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. READ MORE

  5. 5. Digital Mammography with a Photon Counting Detector in a Scanned Multislit Geometry

    Author : Magnus Åslund; Mats Danielsson; Ehsan Samei; KTH; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; mammography; digital; photon counting; scanning; detective quantum effciency; scattered radiation; automatic exposure control; Physics; Fysik;

    Abstract : Mammography screening aims to reduce the number of breast cancer deaths by early detection of the disease, which is one of the leading causes of deaths for middle aged women in the western world. The risk from the x-ray radiation in mammography is relatively low but still a factor in the benefit-risk ratio of screening. READ MORE