Speaker
Ms
Mahboobe Hoseini
(Shahid Beheshti University)
Description
Hybrid pixel detectors that convert X-ray photons directly into electrical signal have become very powerful tools at synchrotrons. Recent developments continue to improve their performance, especially for higher spatial resolution at higher count rates. In this work, the spatial resolution and the count rate of a GaAs pixel detector for application to digital mammography with synchrotron radiation is investigated. In order to evaluate the proposed detector, GEANT4 has been used to simulate the X-ray photon transport in the sensor material and Finite Element Method (FEM) Multiphysics COMSOL software has been used to simulate the behavior of signal charge carriers in GaAs. The two simulations were then combined in order to evaluate the response of the detector. The Modulation Transfer Function (MTF) and charge collection time is calculated as characteristic for the description of the spatial resolution and the count rate respectively. Finally, the results were then benchmarked with measurement data taken by Elias Hamann (2013). The results represented a high spatial resolution (12 lp/mm at 30%MTF) and a high count rate ((10^12 ph)/(s.cm^2 )) which is suitable for low contrast objects detection in mammography with synchrotron radiation.
Author
Ms
Mahboobe Hoseini
(Shahid Beheshti University)
Co-authors
Dr
Sanaz Hariri Tabrizi
(Shahid Beheshti University)
Prof.
Seyed Mahmoud Reza Aghamiri
(Shahid Beheshti University)
Dr
Shahyar Saramad
(Amirkabir University of Technology)
