0000000000223545
AUTHOR
María José Rodríguez-álvarez
Detector blockbased on arrays of 144 SiPMs and monolithic scintillators: A performane study
[EN] We have developed a detector block composed by a monolithic LYSO scintillator coupled to a custom made 12 12 SiPMs array. The design is mainly focused to applications such as Positron Emission Tomography. The readout electronics is based on 3 identical and scalable Application Specific Integrated Circuits (ASIC). We have determined the main performance of the detector block namely spatial, energy, and time resolution but also the system capability to determine the photon depth of interaction, for different crystal surface treatments. Intrinsic detector spatial resolution values as good as 1.7 mm FWHM and energies of 15% for black painted crystals were measured. & 2014 Elsevier B.V. All…
QR-Factorization Algorithm for Computed Tomography (CT): Comparison With FDK and Conjugate Gradient (CG) Algorithms
[EN] Even though QR-factorization of the system matrix for tomographic devices has been already used for medical imaging, to date, no satisfactory solution has been found for solving large linear systems, such as those used in computed tomography (CT) (in the order of 106 equations). In CT, the Feldkamp, Davis, and Kress back projection algorithm (FDK) and iterative methods like conjugate gradient (CG) are the standard methods used for image reconstruction. As the image reconstruction problem can be modeled by a large linear system of equations, QR-factorization of the system matrix could be used to solve this system. Current advances in computer science enable the use of direct methods for…
Determination of IBIS mask transmission matrix
The high-angular resolution imager IBIS is one of the two main instruments aboard the ESA INTEGRAL satellite launched in October 2002. IBIS uses coded aperture mask technique in order to provide the required imaging capabilities for energies between 15 and 10 MeV.The precise knowledge of the coded mask response function critically determine the IBIS imaging performances. In this paper, we present a general description of the IBIS coded mask design together with its main features. Transparency and homogeneity values of the IBIS mask flight model from our laboratory measurements are presented with indication of the instrumental set-up used and accuracy achieved. Mask transmission as a functio…
Background in low Earth orbits measured by LEGRI telescope – short and long term variability
Abstract In this paper we present the first Low Energy Gamma Ray Imager (LEGRI) background measurements which were carried out in the earlier nominal operation activities of LEGRI Instrument on board MINISAT-01, after initial spacecraft and instrument check-up procedures. Short term (daily) and expected long term background variability is presented. A background model is also discussed in order to be used for celestial γ-ray emitters observations.