A geometrical calibration method for the PIXSCAN micro-CT scanner

Reconstruction in Cone-Beam Tomography can suffer from artifacts due to geometrical misalignments of the source-detector system. They can be avoided by a complete and precise description of the system. We present a high precision method for the geometric calibration for the PIXSCAN, a small animal X-ray CT scanner demonstrator based on hybrid pixel detectors (XPAD2). The specificities of the XPAD2 detectors (dead pixels, tilts and gaps between modules...) made the calibration of the PIXSCAN quite difficult. The method uses a calibration object consisting of a hollow cylinder of polycarbonate on which we positioned four metallic balls. It requires 360 X-ray images (1° increments). An analytic expression of the 3 image ellipses has been derived. It is used for a least square regression of the 13 alignment parameters after a correction of the internal XPAD2 geometry. Our method is fast and completely automated, achieving a precision of about 30 μm

3D electronics for hybrid pixel detectors – TWEPP-09

Future hybrid pixel detectors are asking for smaller pixels in order to improve spatial resolution and to deal with an increasing counting rate. Facing these requirements is foreseen to be done by microelectronics technology shrinking. However, this straightforward approach presents some disadvantages in term of performances and cost. New 3D technologies offer an alternative way with the advantage of technology mixing. For the upgrade of ATLAS pixel detector, a 3D conception of the read-out chip appeared as an interesting solution. Splitting the pixel functionalities into two separate levels will reduce pixel size and open the opportunity to take benefit of technology's mixing. Based on a previous prototype of the read-out chip FE-I4 (IBM 130nm), this paper presents the design of a hybrid pixel read-out chip using threedimensional Tezzaron-Chartered technology. In order to disentangle effects due to Chartered 130nm technology from effects involved by 3D architecture, a first translation of FEI4 prototype had been designed at the beginning of this year in Chartered 2D technology, and first test results will be presented in the last part of this paper

Euclid Near Infrared Spectro-Photometer: spatial considerations on H2RG detectors interpixel capacitance and IPC corrected conversion gain from on-ground characterization

International audienceEuclid is a major ESA mission scheduled for launch in 2023-2024 to map the geometry of the dark Universe using two primary probes, weak gravitational lensing and galaxy clustering. \Euclid's instruments, a visible imager (VIS) and an infrared spectrometer and photometer (NISP) have both been designed and built by Euclid Consortium teams. The NISP instrument will hold a large focal plane array of 16 near-infrared H2RG detectors, which are key elements to the performance of the NISP, and therefore to the science return of the mission. Euclid NISP H2RG flight detectors have been individually and thoroughly characterized at Centre de Physique des Particules de Marseille (CPPM) during a whole year with a view to producing a reference database of performance pixel maps. Analyses have been ongoing and have shown the relevance of taking into account spatial variations in deriving performance parameters. This paper will concentrate on interpixel capacitance (IPC) and conversion gain. First, per pixel IPC coefficient maps will be derived thanks to single pixel reset (SPR) measurements and a new IPC correction method will be defined and validated. Then, the paper will look into correlation effects of IPC and their impact on the derivation of per super-pixel IPC-free conversion gain maps. Eventually, several conversion gain values will be defined over clearly distinguishable regions

Evaluation de gains biologique et écologique associés à une réduction d'intrants polluants en milieu aquatique : un programme de recherche pluridisciplinaire

Les zones rurales à vocation viticole peuvent générer des flux polluants associés, en particulier, aux pratiques agricoles et aux produits de traitement phytosanitaires (herbicides, insecticides, fongicides). Ceux-ci peuvent entraîner des changements assez mal appréhendés de la qualité écologique des milieux aquatiques récepteurs. La zone du Beaujolais (France), est particulièrement concernée par cette problématique liée aux transferts de phytosanitaires vers les cours d'eau, qui, globalement, peuvent provoquer une dégradation écologique des zones aval et donc une perte de leur valeur touristique et patrimoniale. Le présent programme (2003-2005), se situe dans le cadre des objectifs définis par la Directive Cadre Européenne sur l'Eau, traitant de l'amélioration de l'état écologique des masses d'eau. Il a pour but d'évaluer les bénéfices écologiques et biologiques espérés dans un milieu aquatique, à la suite d'opérations de réduction des intrants polluants. En s'appuyant sur un site d'étude de terrain (cours d'eau d'ordre 1, typique de la région) plusieurs opérations de recherche, in situ et in vitro, associeront systématiquement des approches de chimie, de biologie, d'écotoxicologie sur le terrain ou en laboratoire et seront organisés en interaction en s'appuyant sur un large panel d'outils et de chimio- et bio-indicateurs. Ces opérations s'organisent selon 2 axes: - Relations entre pression chimique et état écologique en différent points du cours d'eau: caractérisation des polluants (nutriments, métaux et organiques, dans l'eau et les sédiments), dynamique des communautés d'invertébrés, des microorganismes du périphyton (diversité fonctionnelle et génétique des bactéries et microalgues), diversité des Diatomées, en traitant des questions de résistance et de résilience des communautés. Des tests de génotoxicité sur embryons de truites seront également réalisés. - Traitement et réduction des polluants phytosanitaires par des techniques physicochimiques (photodégradation, photocatalyse, oxydation catalytique voie humide) et biologiques (dégradation par consortium bactérien) et évaluation de gains biologiques associés à ces traitements (test Microtox, microcapteur enzymatique). Cette communication présentera la mise en place de ce programme

EUCLID detector system demonstrator model: a first demonstration of the NISP detection system

International audienceThe detector system (DS) of Euclid NISP’s instrument (Near-Infrared Spectro-Photometer) is a matrix of 16 H2RG infrared detectors acquired simultaneously. After their characterization done at CPPM (Centre de Physique des Particules de Marseille), these detectors are integrated into a mechanical structure designed at LAM (Laboratoire d'Astronomie de Marseille) and called NI-FPA (Focal Plane Array) Before delivering the full instrument to ESA several test models have to demonstrate the performances of the detector system. The first test model, the Demonstrator Model (DM), has been integrated and tested in dedicated facilities at LAM. The aim was to validate both the integration process and the simultaneous acquisition of the detectors. Dark, noise, self-compatibility and EMC performances are presented in this paper