982 research outputs found
A Low-Cost Unified Experimental FPGA Board for Cryptography Applications
This paper describes the evaluation of available
experimental boards, the comparison of their supported set
of experiments and other aspects. The second part of this
evaluation is focused on the design process of the PCB (Printed
Circuit Board) for an FPGA (Field Programmable Gate Array)
based cryptography environment suitable for evaluating the latest
trends in the IC (Integrated Circuit) security like SideâChannel
Attacks (SCA) or Physically Unclonable Function (PUF). It
leads to many criteria affecting the design process and also the
suitability for evaluating and measuring results of the attacks and
their countermeasures. The developed system should be open,
versatile and unrestricted by the U.S. law [1]
ProtoEXIST: Advanced Prototype CZT Coded Aperture Telescopes for EXIST
{\it ProtoEXIST1} is a pathfinder for the {\it EXIST-HET}, a coded aperture
hard X-ray telescope with a 4.5 m CZT detector plane a 9070 degree
field of view to be flown as the primary instrument on the {\it EXIST} mission
and is intended to monitor the full sky every 3 h in an effort to locate GRBs
and other high energy transients. {\it ProtoEXIST1} consists of a 256 cm
tiled CZT detector plane containing 4096 pixels composed of an 88 array
of individual 1.95 cm 1.95 cm 0.5 cm CZT detector modules
each with a 8 8 pixilated anode configured as a coded aperture
telescope with a fully coded field of view employing
passive side shielding and an active CsI anti-coincidence rear shield, recently
completed its maiden flight out of Ft. Sumner, NM on the 9th of October 2009.
During the duration of its 6 hour flight on-board calibration of the detector
plane was carried out utilizing a single tagged 198.8 nCi Am-241 source along
with the simultaneous measurement of the background spectrum and an observation
of Cygnus X-1. Here we recount the events of the flight and report on the
detector performance in a near space environment. We also briefly discuss {\it
ProtoEXIST2}: the next stage of detector development which employs the {\it
NuSTAR} ASIC enabling finer (3232) anode pixilation. When completed
{\it ProtoEXIST2} will consist of a 256 cm tiled array and be flown
simultaneously with the ProtoEXIST1 telescope
A double-sided silicon micro-strip super-module for the ATLAS inner detector upgrade in the high-luminosity LHC
The ATLAS experiment is a general purpose detector aiming to fully exploit the discovery potential of the Large Hadron Collider (LHC) at CERN. It is foreseen that after several years of successful data-taking, the LHC physics programme will be extended in the so-called High-Luminosity LHC, where the instantaneous luminosity will be increased up to 5 Ă 1034 cmâ2 sâ1. For ATLAS, an upgrade scenario will imply the complete replacement of its internal tracker, as the existing detector will not provide the required performance due to the cumulated radiation damage and the increase in the detector occupancy. The current baseline layout for the new ATLAS tracker is an all-silicon-based detector, with pixel sensors in the inner layers and silicon micro-strip detectors at intermediate and outer radii. The super-module is an integration concept proposed for the strip region of the future ATLAS tracker, where double-sided stereo silicon micro-strip modules are assembled into a low-mass local support structure. An electrical super-module prototype for eight double-sided strip modules has been constructed. The aim is to exercise the multi-module readout chain and to investigate the noise performance of such a system. In this paper, the main components of the current super-module prototype are described and its electrical performance is presented in detail
The ARIEL Instrument Control Unit design for the M4 Mission Selection Review of the ESA's Cosmic Vision Program
The Atmospheric Remote-sensing Infrared Exoplanet Large-survey mission
(ARIEL) is one of the three present candidates for the ESA M4 (the fourth
medium mission) launch opportunity. The proposed Payload will perform a large
unbiased spectroscopic survey from space concerning the nature of exoplanets
atmospheres and their interiors to determine the key factors affecting the
formation and evolution of planetary systems. ARIEL will observe a large number
(>500) of warm and hot transiting gas giants, Neptunes and super-Earths around
a wide range of host star types, targeting planets hotter than 600 K to take
advantage of their well-mixed atmospheres. It will exploit primary and
secondary transits spectroscopy in the 1.2-8 um spectral range and broad-band
photometry in the optical and Near IR (NIR). The main instrument of the ARIEL
Payload is the IR Spectrometer (AIRS) providing low-resolution spectroscopy in
two IR channels: Channel 0 (CH0) for the 1.95-3.90 um band and Channel 1 (CH1)
for the 3.90-7.80 um range. It is located at the intermediate focal plane of
the telescope and common optical system and it hosts two IR sensors and two
cold front-end electronics (CFEE) for detectors readout, a well defined process
calibrated for the selected target brightness and driven by the Payload's
Instrument Control Unit (ICU).Comment: Experimental Astronomy, Special Issue on ARIEL, (2017
AttĂ©nuation des interactions Ă©lectromagnĂ©tiques entre le module de dĂ©tection LabPET II et lâIRM
Les scanners TEP/IRM simultanĂ©s offrent une occassion unique d'examiner en mĂȘme
temps les propriétés anatomiques et fonctionnelles des tissus malins, tout en évitant
l'incertitude des systÚmes séquentiels de TEP/IRM. Cependant, le couplage
électromagnétique entre les deux modalités constitue un défi important à relever. Ces
interférences électromagnétiques entravent les performances du scanner et altÚrent la
qualité d'image de chaque modalité.
Bien que les métaux possÚdent d'excellentes propriétés de blindage contre les
fréquences radioélectriques, ils ne constituent pas nécessairement une option de blindage
appropriée pour modifier les champs magnétiques induisant des courants de Foucault dans
les couches métalliques. En conséquence, il existe une demande considérable pour un
nouveau matériau de protection et une approche originale pour retirer les piÚces métalliques
du champ de vision IRM.
Lâobjectif de ce projet Ă©tait dâinitier les Ă©tudes en vue de la rĂ©alisation dâun scanner
TEP/IRM simultané basé sur des modules de détection LabPET II hautement pixélisés afin
dâobtenir une rĂ©solution spatiale millimĂ©trique pour le cerveau humain et le chien.
L'électronique LabPET II comprend des circuits intégrés à application spécifique dans
lesquels le signal est numérisé à proximité de la photodiode à avalanche et offre un
environnement moins sensible aux interférences électromagnétiques. Pour atteindre
l'objectif principal, premiÚrement, l'effet du matériau métallique des modules de détection
LabPET II sur les performances de la TEP et de l'IRM est examiné théoriquement. Les
résultats confirment que les composants métalliques du module de détection LabPET II
altÚrent le champ magnétique, génÚrent des courants de Foucault ce qui augmente leur
température. Ensuite, les performances électroniques des modules de détection LabPET II
sous lâinfluence de bobines dâIRM faites sur mesure sont examinĂ©es. La rĂ©solution en
énergie et la résolution temporelle se détériorent en présence de bobines RF et de bobines
à gradient en raison des perturbations électromagnétiques. Subséquemment, un module de
détection LabPET II blindé par une fine couche de composite cuivre-argent est étudié,
prouvant que le blindage contre les interférences électromagnétiques avec le composite
rétablit les performances en TEP, fournissant moins d'induction par courants de Foucault.
En outre, une nouvelle configuration de blindage basée sur un composite de couche flexible
de nanotubes de carbone a été fabriquée pour limiter les interférences électromagnétiques.
Les composites de nanotubes de carbone créent une couche hautement conductrice avec
des chemins conducteurs minimaux, ce qui permet de réduire les courants de Foucault.
Le principal rĂ©sultat scientifique de ce projet est que le blindage composite empĂȘche
les interférences de basses et hautes fréquences et réduit l'induction de courants de
Foucault, offrant ainsi la flexibilité nécessaire pour acquérir une séquence rapide de
commutation de gradients. D'un point de vue technique, le module de détection LabPET II
ainsi blindé présente une excellente performance dans un environnement de type IRM, ce
qui permet de concevoir un insert TEP basé sur la technologie LabPET II.Abstract: Simultaneous PET/ MRI scanners provide a unique opportunity to investigate anatomical and functional properties of malignant tissues at the same time while avoiding the uncertainty of a sequential PET/MRI systems. However, electromagnetic coupling between the two modalities is a significant challenge that needs to be addressed. These electromagnetic interferences (EMI) hinder the performance of both scanners and distort the image quality of each modality. Although metals have excellent radio-frequency shielding properties, they are not necessarily an appropriate shielding option for altering magnetic fields that induce eddy currents in any metallic layer. Thus, there is a considerable demand for a new shielding material and an original approach to remove metallic parts from the MRI field of view. The objective of this project was to initiate the realization of a simultaneous PET/MRI scanner based on highly pixelated LabPET II detection modules to achieve millimeter spatial resolution for the human brain and dogs. The LabPET II electronics include application specific integrated circuits where the signal is digitized near the avalanche photodiode and offers an environment less susceptible to EMI. To fulfill the main aim, for the first time, the effect of the metallic material of LabPET II on PET and MRI performance was theoretically examined. Results confirm that metallic components of the LabPET II detection modules distort the magnetic field, generate eddy currents, and increase temperature. Then, the LabPET II electronics performance under the influence of custom-made MRI coils was investigated. Its energy and timing resolutions deteriorate in the presence of both RF and gradient signals because of EMIs. Thus, a LabPET II detection module shielded by a thin layer of the copper-silver composite was investigated, proving that shielding EMIs with the composite restores the PET performance, with less eddy current induction. Besides, a new shielding configuration based on a flexible layer of carbon nanotube (CNT) composite was fabricated to limit the EMIs. The CNT composite creates a highly conductive layer with minimal conductive paths that allows eddy currents to be decreased. The primary scientific outcome of this project is that the novel composite shielding rejects both low and high-frequency interferences and reduces eddy current induction, offering the flexibility to acquire a fast gradient switching sequence. From a technical point of view, the shielded LabPET II detection module demonstrates an excellent performance in an MRI-like environment supporting the feasibility of designing a PET-insert based on LabPET II technology
Design and construction of a Cherenkov imager for charge measurement of nuclear cosmic rays
A proximity focusing Cherenkov imager called CHERCAM, has been built for the
charge measurement of nuclear cosmic rays with the CREAM instrument. It
consists of a silica aerogel radiator plane across from a detector plane
equipped with 1,600 1" diameter photomultipliers. The two planes are separated
by a ring expansion gap. The Cherenkov light yield is proportional to the
charge squared of the incident particle. The expected relative light collection
accuracy is in the few percents range. It leads to an expected single element
separation over the range of nuclear charge Z of main interest 1 < Z < 26.
CHERCAM is designed to fly with the CREAM balloon experiment. The design of the
instrument and the implemented technical solutions allowing its safe operation
in high altitude conditions (radiations, low pressure, cold) are presented.Comment: 24 pages, 19 figure
The ABC130 barrel module prototyping programme for the ATLAS strip tracker
For the Phase-II Upgrade of the ATLAS Detector, its Inner Detector,
consisting of silicon pixel, silicon strip and transition radiation
sub-detectors, will be replaced with an all new 100 % silicon tracker, composed
of a pixel tracker at inner radii and a strip tracker at outer radii. The
future ATLAS strip tracker will include 11,000 silicon sensor modules in the
central region (barrel) and 7,000 modules in the forward region (end-caps),
which are foreseen to be constructed over a period of 3.5 years. The
construction of each module consists of a series of assembly and quality
control steps, which were engineered to be identical for all production sites.
In order to develop the tooling and procedures for assembly and testing of
these modules, two series of major prototyping programs were conducted: an
early program using readout chips designed using a 250 nm fabrication process
(ABCN-25) and a subsequent program using a follow-up chip set made using 130 nm
processing (ABC130 and HCC130 chips). This second generation of readout chips
was used for an extensive prototyping program that produced around 100
barrel-type modules and contributed significantly to the development of the
final module layout. This paper gives an overview of the components used in
ABC130 barrel modules, their assembly procedure and findings resulting from
their tests.Comment: 82 pages, 66 figure
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