Sökning: "photon counting"

Visar resultat 16 - 20 av 44 avhandlingar innehållade orden photon counting.

1. 16. Architecture and circuit design of photon counting readout for X-ray imaging sensors

   Författare :Suliman A Abdalla; Bengt Oelmann; Kenway Smith; Mittuniversitetet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electrical engineering; electronics and photonics; Elektroteknik; elektronik och fotonik;

   Sammanfattning : Hybrid pixel array detectors for X-ray imaging are based on different technologies for sensor and readout electronics. The readout electronics are based on standard CMOS technologies that are experiencing continuously rapid improvements by means of down-scaling the feature sizes, which in turn lead to higher transistor densities, lower power consumption, and faster circuits. LÄS MER

3. 17. Characterization and Energy Calibration of a Silicon-Strip Detector for Photon-Counting Spectral Computed Tomography

   Författare :Xuejin Liu; Mats Danielsson; Sarah E Bohndiek; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Medical Technology; Medicinsk teknologi;

   Sammanfattning : Multibin photon-counting x-ray detectors are promising candidates to be applied in next generation computed tomography (CT), whereby energy information from a broad x-ray spectrum can be extracted and properly used for improving image quality and correspondingly reducing radiation dose. A silicon-strip detector has been developed for spectral CT, which operates in photon-counting mode and allows pulse-height discrimination with 8 adjustable energy bins. LÄS MER

4. 18. Electronic Energy Transfer within Asymmetric Pairs of Fluorophores: Partial Donor-Donor Energy Migration (PDDEM)

   Författare :Stanislav Kalinin; Lennart B.-Å. Johansson; Helge Lemmetyinen; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physical chemistry; fluorescence resonance energy transfer FRET ; donor-donor energy migration DDEM ; homotransfer; fluorescence relaxation; lifetimes; time-resolved fluorescence anisotropy; time-correlated single photon counting; distance measurements; protein structure; Fysikalisk kemi; Physical chemistry; Fysikalisk kemi; Physical Chemistry; fysikalisk kemi;

   Sammanfattning : A kinetic model of electronic energy migration within pairs of photophysically non-identical fluorophores has been developed. The model applies to fluorescent groups that exhibit different photophysical and spectral properties when attached to different positions in a macromolecule. LÄS MER

5. 19. Extended Förster Theory of Electronic Energy Transport within Pairs of Reorienting Chromophoric Molecules

   Författare :Nils Norlin; Lennart B.-Å. Johansson; Yehudi K. Levine; Umeå universitet; []
   Nyckelord :electronic energy migration transfer; extended Förster theory; orientation factor; DDEM; PDDEM; time-resolved fluorescence anisotropy; time-correlated single photon counting; Brownian dynamics; fysikalisk kemi; Physical Chemistry;

   Sammanfattning : An extended Förster theory (EFT), previously derived (L. B.-Å. Johansson et al. LÄS MER

7. 20. Design and characterization of 64K pixels chips working in single photon processing mode

   Författare :Xavier Llopart Cudié; Christer Fröjdh; Michael Campbell; Mittuniversitetet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electronics; Elektronik;

   Sammanfattning : Progress in CMOS technology and in fine pitch bump bonding has made possible the development of high granularity single photon counting detectors for X-ray imaging. This thesis studies the design and characterization of three pulse processing chips with 65536 square pixels of 55 μm x 55 μm designed in a commercial 0. LÄS MER