1. Главная
  2. Ресурсы
  3. Библиотечный поиск
Effect of detectorgeometry and surfacefinish on Cerenkovbased time estimationin monolithic BGOdetectors Jens MaebeStefaan Vandenberghe2022 год

Effect of detector geometry and surface finish on Cerenkov based time estimation in monolithic BGO detectors
статья из журнала

Полный текстСтраница публикацииПубликация в OpenAlex
Аннотация: Abstract Objective. Time-of-flight positron emission tomography based on bismuth germanate (BGO) detectors is made possible due to fast emission of Cerenkov light. Only around 17 Cerenkov photons are produced per 511 keV photoelectric event, making high photon collection efficiency crucial for obtaining good time-of-flight capabilities. In this study, we investigate how different lateral and back surface finishes affect the photon collection efficiency and Cerenkov based timing performance in monolithic BGO. Approach. The study is performed using GATE for gamma and optical photon modeling, with surface reflections of photons simulated by the LUT Davis model. We compare for different detector configurations (regarding size and surface finishes) the photon collection efficiency, detection delays of the first few optical photons and coincidence time resolution estimations obtained by modeling the SiPM signals and performing leading edge discrimination. An additional comparison is made to LYSO scintillators and pixelated detectors. Main results. Although Cerenkov photon emission is directional, many high incidence angle Cerenkov photons are emitted due to electron scattering in the crystal. Substituting a polished back (photodetector side) surface for a rough surface increases the collection efficiency of these high angle of incidence photons. Results show that for a monolithic 50 × 50 × 12 mm 3 BGO detector with reflective side surfaces, this leads to an overall increase in photon collection efficiency of 34%. Cerenkov photon collection efficiency is also improved, resulting in a reduction of the photon detection delays (and the variation therein) of the first few optical photons. This leads to a better coincidence time resolution, primarily achieved by a shortening of the tails in the time-of-flight kernel, with an 18% reduction in full width at tenth maximum. Significance. This study shows the importance of the photon collection efficiency for timing performance in Cerenkov based monolithic detectors, and how it can be improved with different surface finishes.
Год издания: 2022
Авторы: Jens Maebe, Stefaan Vandenberghe
Издательство: IOP Publishing
Источник: Physics in Medicine and Biology
Ключевые слова: Radiation Detection and Scintillator Technologies, Medical Imaging Techniques and Applications, Particle Detector Development and Performance
Другие ссылки: Physics in Medicine and Biology (HTML)
Ghent University Academic Bibliography (Ghent University) (PDF)
Ghent University Academic Bibliography (Ghent University) (HTML)
PubMed (HTML)