SwePub
Sök i SwePub databas

  Utökad sökning

Träfflista för sökning "WFRF:(Marras A.) "

Sökning: WFRF:(Marras A.)

  • Resultat 1-50 av 54
Sortera/gruppera träfflistan
   
NumreringReferensOmslagsbildHitta
1.
  • Abelev, B., et al. (författare)
  • Upgrade of the ALICE Experiment Letter Of Intent
  • 2014
  • Ingår i: Journal of Physics G: Nuclear and Particle Physics. - : IOP Publishing. - 0954-3899 .- 1361-6471. ; 41:8
  • Tidskriftsartikel (refereegranskat)abstract
    • ALICE (A Large Ion Collider Experiment) is studying the physics of strongly interacting matter, and in particular the properties of the Quark–Gluon Plasma (QGP), using proton–proton, proton–nucleus and nucleus–nucleus collisions at the CERN LHC (Large Hadron Collider). The ALICE Collaboration is preparing a major upgrade of the experimental apparatus, planned for installation in the second long LHC shutdown in the years 2018–2019. These plans are presented in the ALICE Upgrade Letter of Intent, submitted to the LHCC (LHC experiments Committee) in September 2012. In order to fully exploit the physics reach of the LHC in this field, high-precision measurements of the heavy-flavour production, quarkonia, direct real and virtual photons, and jets are necessary. This will be achieved by an increase of the LHC Pb–Pb instant luminosity up to 6×1027 cm−2s−1 and running the ALICE detector with the continuous readout at the 50 kHz event rate. The physics performance accessible with the upgraded detector, together with the main detector modifications, are presented.
  •  
2.
  • Abelev, B., et al. (författare)
  • Technical Design Report for the Upgrade of the ALICE Inner Tracking System
  • 2014
  • Ingår i: Journal of Physics G: Nuclear and Particle Physics. - : IOP Publishing. - 0954-3899 .- 1361-6471. ; 41:8
  • Tidskriftsartikel (refereegranskat)abstract
    • LICE (A Large Ion Collider Experiment) is studying the physics of strongly interacting matter, and in particular the properties of the Quark–Gluon Plasma (QGP), using proton–proton, proton–nucleus and nucleus–nucleus collisions at the CERN LHC (Large Hadron Collider). The ALICE Collaboration is preparing a major upgrade of the experimental apparatus, planned for installation in the second long LHC shutdown in the years 2018–2019. A key element of the ALICE upgrade is the construction of a new, ultra-light, high-resolution Inner Tracking System (ITS) based on monolithic CMOS pixel detectors. The primary focus of the ITS upgrade is on improving the performance for detection of heavy-flavour hadrons, and of thermal photons and low-mass di-electrons emitted by the QGP. With respect to the current detector, the new Inner Tracking System will significantly enhance the determination of the distance of closest approach to the primary vertex, the tracking efficiency at low transverse momenta, and the read-out rate capabilities. This will be obtained by seven concentric detector layers based on a 50 μm thick CMOS pixel sensor with a pixel pitch of about 30×30 μm2. This document, submitted to the LHCC (LHC experiments Committee) in September 2013, presents the design goals, a summary of the R&D activities, with focus on the technical implementation of the main detector components, and the projected detector and physics performance.
  •  
3.
  • Aamodt, K., et al. (författare)
  • The ALICE experiment at the CERN LHC
  • 2008
  • Ingår i: Journal of Instrumentation. - 1748-0221. ; 3:S08002
  • Forskningsöversikt (refereegranskat)abstract
    • ALICE (A Large Ion Collider Experiment) is a general-purpose, heavy-ion detector at the CERN LHC which focuses on QCD, the strong-interaction sector of the Standard Model. It is designed to address the physics of strongly interacting matter and the quark-gluon plasma at extreme values of energy density and temperature in nucleus-nucleus collisions. Besides running with Pb ions, the physics programme includes collisions with lighter ions, lower energy running and dedicated proton-nucleus runs. ALICE will also take data with proton beams at the top LHC energy to collect reference data for the heavy-ion programme and to address several QCD topics for which ALICE is complementary to the other LHC detectors. The ALICE detector has been built by a collaboration including currently over 1000 physicists and engineers from 105 Institutes in 30 countries, Its overall dimensions are 16 x 16 x 26 m(3) with a total weight of approximately 10 000 t. The experiment consists of 18 different detector systems each with its own specific technology choice and design constraints, driven both by the physics requirements and the experimental conditions expected at LHC. The most stringent design constraint is to cope with the extreme particle multiplicity anticipated in central Pb-Pb collisions. The different subsystems were optimized to provide high-momentum resolution as well as excellent Particle Identification (PID) over a broad range in momentum, up to the highest multiplicities predicted for LHC. This will allow for comprehensive studies of hadrons, electrons, muons, and photons produced in the collision of heavy nuclei. Most detector systems are scheduled to be installed and ready for data taking by mid-2008 when the LHC is scheduled to start operation, with the exception of parts of the Photon Spectrometer (PHOS), Transition Radiation Detector (TRD) and Electro Magnetic Calorimeter (EMCal). These detectors will be completed for the high-luminosity ion run expected in 2010. This paper describes in detail the detector components as installed for the first data taking in the summer of 2008.
  •  
4.
  • Sanchez, Erlan, et al. (författare)
  • Association of plasma biomarkers with cognition, cognitive decline, and daily function across and within neurodegenerative diseases: Results from the Ontario Neurodegenerative Disease Research Initiative
  • 2024
  • Ingår i: Alzheimer's and Dementia. - 1552-5260 .- 1552-5279. ; 20:3, s. 1753-1770
  • Tidskriftsartikel (refereegranskat)abstract
    • INTRODUCTION: We investigated whether novel plasma biomarkers are associated with cognition, cognitive decline, and functional independence in activities of daily living across and within neurodegenerative diseases. METHODS: Glial fibrillary acidic protein (GFAP), neurofilament light chain (NfL), phosphorylated tau (p-tau)181 and amyloid beta (Aβ)42/40 were measured using ultra-sensitive Simoa immunoassays in 44 healthy controls and 480 participants diagnosed with Alzheimer's disease/mild cognitive impairment (AD/MCI), Parkinson's disease (PD), frontotemporal dementia (FTD) spectrum disorders, or cerebrovascular disease (CVD). RESULTS: GFAP, NfL, and/or p-tau181 were elevated among all diseases compared to controls, and were broadly associated with worse baseline cognitive performance, greater cognitive decline, and/or lower functional independence. While GFAP, NfL, and p-tau181 were highly predictive across diseases, p-tau181 was more specific to the AD/MCI cohort. Sparse associations were found in the FTD and CVD cohorts and for Aβ42/40. DISCUSSION: GFAP, NfL, and p-tau181 are valuable predictors of cognition and function across common neurodegenerative diseases, and may be useful in specialized clinics and clinical trials.
  •  
5.
  • Wunderer, C. B., et al. (författare)
  • Detector developments at DESY
  • 2016
  • Ingår i: Journal of Synchrotron Radiation. - 0909-0495 .- 1600-5775. ; 23, s. 111-117
  • Tidskriftsartikel (refereegranskat)abstract
    • With the increased brilliance of state-of-the-art synchrotron radiation sources and the advent of free-electron lasers (FELs) enabling revolutionary science with EUV to X-ray photons comes an urgent need for suitable photon imaging detectors. Requirements include high frame rates, very large dynamic range, single-photon sensitivity with low probability of false positives and (multi)-megapixels. At DESY, one ongoing development project-in collaboration with RAL/STFC, Elettra Sincrotrone Trieste, Diamond, and Pohang Accelerator Laboratory-is the CMOS-based soft X-ray imager PERCIVAL. PERCIVAL is a monolithic active-pixel sensor back-thinned to access its primary energy range of 250 eV to 1 keV with target efficiencies above 90%. According to preliminary specifications, the roughly 10 cm × 10 cm, 3.5k × 3.7k monolithic sensor will operate at frame rates up to 120 Hz (commensurate with most FELs) and use multiple gains within 27 μm pixels to measure 1 to ∼ 100000 (500 eV) simultaneously arriving photons. DESY is also leading the development of the AGIPD, a high-speed detector based on hybrid pixel technology intended for use at the European XFEL. This system is being developed in collaboration with PSI, University of Hamburg, and University of Bonn. The AGIPD allows singlepulse imaging at 4.5 MHz frame rate into a 352-frame buffer, with a dynamic range allowing single-photon detection and detection of more than 10000 photons at 12.4 keV in the same image. Modules of 65k pixels each are configured to make up (multi)megapixel cameras. This review describes the AGIPD and the PERCIVAL concepts and systems, including some recent results and a summary of their current status. It also gives a short overview over other FEL-relevant developments where the Photon Science Detector Group at DESY is involved. © 2016 International Union of Crystallography.
  •  
6.
  • Allahgholi, A., et al. (författare)
  • AGIPD 1.0 : The high-speed high dynamic range readout ASIC for the adaptive gain integrating pixel detector at the European XFEL
  • 2014
  • Ingår i: 2014 IEEE Nuclear Science Symposium and Medical Imaging Conference, NSS/MIC 2014. - : Institute of Electrical and Electronics Engineers (IEEE). - 9781479960972
  • Konferensbidrag (refereegranskat)abstract
    • AGIPD is a hybrid pixel X-ray detector developed by a collaboration between Deutsches Elektronen-Synchrotron (DESY), Paul-Scherrer-Institute (PSI), University of Hamburg and the University of Bonn. The detector is designed to comply with the requirements of the European XFEL. The radiation tolerant Application Specific Integrated Circuit (ASIC) is designed with the following highlights: high dynamic range, spanning from single photon sensitivity up to 104 × 12.4 keV photons, achieved by the use of dynamic gain switching, auto-selecting one of 3 gains of the charge sensitive pre-amplifier. To cope with the unique features of the European XFEL source, image data is stored in 352 analogue memory cells per pixel. The selected gain is stored in the same way and depth, encoded as one of 3 voltage levels. These memories are operated in random-access mode at 4.5MHz frame rate. Data is read out on a row-by-row basis via multiplexers to the DAQ system for digitisation during the 99.4ms gap between the bunch trains of the European XFEL. The AGIPD 1.0 ASIC features 64×64 pixels with a pixel area of 200×200 μm2. It is bump-bonded to a 500 μm thick silicon sensor. The principles of the chip architecture were proven in different experiments and the ASIC characterization was performed with a series of development prototypes. The mechanical concept of the detector system was developed in close contact with the XFEL beamline scientists to ensure a seamless integration into the beamline setup and is currently being manufactured. The first single module system was successfully tested at APS1 the high dynamic range allows imaging of the direct synchrotron beam along with single photon sensitivity and burst imaging of 352 subsequent frames synchronized to the source.
  •  
7.
  • Allahgholi, A., et al. (författare)
  • AGIPD, a high dynamic range fast detector for the European XFEL
  • 2015
  • Ingår i: Journal of Instrumentation. - 1748-0221. ; 10:1
  • Tidskriftsartikel (refereegranskat)abstract
    • AGIPD-(Adaptive Gain Integrating Pixel Detector) is a hybrid pixel X-ray detector developed by a collaboration between Deutsches Elektronen-Synchrotron (DESY), Paul-Scherrer-Institut (PSI), University of Hamburg and the University of Bonn. The detector is designed to comply with the requirements of the European XFEL. The radiation tolerant Application Specific Integrated Circuit (ASIC) is designed with the following highlights: high dynamic range, spanning from single photon sensitivity up to 10(4) 12.5keV photons, achieved by the use of the dynamic gain switching technique using 3 possible gains of the charge sensitive preamplifier. In order to store the image data, the ASIC incorporates 352 analog memory cells per pixel, allowing also to store 3 voltage levels corresponding to the selected gain. It is operated in random-access mode at 4.5MHz frame rate. The data acquisition is done during the 99.4ms between the bunch trains. The AGIPD has a pixel area of 200 x 200 m m(2) and a 500 m m thick silicon sensor is used. The architecture principles were proven in different experiments and the ASIC characterization was done with a series of development prototypes. The mechanical concept was developed in the close contact with the XFEL beamline scientists and is now being manufactured. A first single module system was successfully tested at APS.
  •  
8.
  • Allahgholi, A., et al. (författare)
  • AGIPD, the electronics for a high speed X-ray imager at the Eu-XFEL
  • 2014
  • Ingår i: Proceedings of Science. - : Proceedings of Science (PoS).
  • Konferensbidrag (refereegranskat)abstract
    • The AGIPD (Adaptive Gain Integrated Pixel Detector) X-ray imaging camera will be operated at the X-ray Free Electron Laser, Eu-XFEL, under construction in Hamburg, Germany. Key parameters are 1 million 200 μm square pixels, single 12.4 keV photon detection and a dynamic range to 10 000/pixel/image. The developed sensors, ASICs, PCB-electronics and FPGA firmware acquire individual images per bunch at 27 000 bunches/s, packed into 10 bunch-trains/s with a bunch separation of 222 ns. Bunch-trains are handled by 352 analogue storage cells within each pixel of the ASIC and written during the 0.6msec train delivery. Therefore AGIPD can store 3520 images/s from the delivered 27 000 bunches/s. Random addressing provides reusability of each cell after an image has been declared as low-quality, so that good images can be selected. Digitization is performed between trains (99.4 msec). In the paper all functional blocks are introduced. The details concentrate on the DAQ-chain PCB-electronics and the slow control. A dense area of 1024 ADC-channels, each with a pickup-noise filtering and sampling of up to 50 MS/s/ADC and a serial output of 700 Mbit/s/ADC. FPGAs operate the ASICs synchronized to the bunch structure and collect the bit streams from 64 ADCs/FPGA. Pre-sorted data is transmitted on 10 GbE links out of the camera head using the time between trains. The control and monitoring of the camera with 600 A current consumption is based on a micro-controller and I2C bus with an addressing architecture allowing many devices and identical modules. The high currents require planned return paths at the system level. First experimental experience with the constructed components will be presented.
  •  
9.
  • Allahgholi, A., et al. (författare)
  • Front end ASIC for AGIPD, a high dynamic range fast detector for the European XFEL
  • 2016
  • Ingår i: Journal of Instrumentation. - 1748-0221. ; 11:1
  • Tidskriftsartikel (refereegranskat)abstract
    • The Adaptive Gain Integrating Pixel Detector (AGIPD) is a hybrid pixel X-ray detector for the European-XFEL. One of the detector's important parts is the radiation tolerant front end ASIC fulfilling the European-XFEL requirements: high dynamic range-from sensitivity to single 12.5keV-photons up to 104 photons. It is implemented using the dynamic gain switching technique with three possible gains of the charge sensitive preamplifier. Each pixel can store up to 352 images in memory operated in random-access mode at >= 4.5MHz frame rate. An external vetoing may be applied to overwrite unwanted frames.
  •  
10.
  • Allahgholi, A., et al. (författare)
  • The adaptive gain integrating pixel detector
  • 2016
  • Ingår i: Journal of Instrumentation. - 1748-0221. ; 11:2
  • Tidskriftsartikel (refereegranskat)abstract
    • The adaptive gain integrating pixel detector (AGIPD) is a development of a collaboration between Deustsches Elektronen-Synchrotron (DESY), the Paul-Scherrer-Institute (PSI), the University of Hamburg and the University of Bonn. The detector is designed to cope with the demanding challenges of the European XFEL. Therefore it comes along with an adaptive gain stage allowing a high dynamic range, spanning from single photon sensitivity to 10(4) x 12.4 keV photons and 352 analogue memory cells per pixel. The aim of this report is to briefly explain the concepts of the AGIPD electronics and mechanics and then present recent experiments demonstrating the functionality of its key features.
  •  
11.
  • Allahgholi, A., et al. (författare)
  • The AGIPD 1.0 ASIC : Random access high frame rate, high dynamic range X-ray camera readout for the European XFEL
  • 2015
  • Ingår i: 2015 IEEE Nuclear Science Symposium and Medical Imaging Conference, NSS/MIC 2015. - : Institute of Electrical and Electronics Engineers (IEEE). - 9781467398626
  • Konferensbidrag (refereegranskat)abstract
    • The European XFEL is an extremely brilliant Free Electron Laser Source with a very demanding pulse structure: trains of 2700 X-Ray pulses are repeated at 10 Hz. The pulses inside the train are spaced by 220 ns and each one contains up to 1012 photons of 12.4 keV, while being ≤ 100 fs in length. AGIPD (Adaptive Gain Integrating Pixel Detector) is a hybrid 1M-pixel detector developed by DESY, PSI, and the Universities of Bonn and Hamburg to cope with these properties. Thus the readout ASIC has to provide not only single photon sensitivity and a dynamic range ≳ 104 photons/pixel in the same image but also a memory for as many images of a pulse train as possible for delayed readout prior to the next train. The AGIPD 1.0 ASIC uses a 130 nm CMOS technology and radiation tolerant techniques to withstand the radiation damage incurred by the high impinging photon flux. Each ASIC contains 64 × 64 pixels of 200μmχ200μm. The circuit of each pixel contains a charge sensitive preamplifier with threefold switchable gain, a discriminator for an adaptive gain selection, and a correlated double sampling (CDS) stage to remove reset and low-frequency noise components. The output of the CDS, as well as the dynamically selected gain is sampled in a capacitor-based analogue memory for 352 samples, which occupies about 80% of a pixels area. For readout each pixel features a charge sensitive buffer. A control circuit with a command based interface provides random access to the memory and controls the row-wise readout of the data via multiplexers to four differential analogue ports. The AGIPD 1.0 full scale ASIC has been received back from the foundry in fall of 2013. Since then it has been extensively characterised also with a sensor as a single chip and in 2 × 8-chip modules for the AGIPD 1 Mpix detector. We present the design of the AGIPD 1.0 ASIC along with supporting results, also from beam tests at PETRA III and APS, and show changes incorporated in the recently taped out AGIPD 1.1 ASIC upgrade.
  •  
12.
  • Correa, J., et al. (författare)
  • On the Charge Collection Efficiency of the PERCIVAL Detector
  • 2016
  • Ingår i: Journal of Instrumentation. - : IOP. - 1748-0221. ; 11:12
  • Tidskriftsartikel (refereegranskat)abstract
    • The PERCIVAL soft X-ray imager is being developed by DESY, RAL, Elettra, DLS, and PAL to address the challenges at high brilliance Light Sources such as new-generation Synchrotrons and Free Electron Lasers. Typical requirements for detector systems at these sources are high frame rates, large dynamic range, single-photon counting capability with low probability of false positives, high quantum efficiency, and (multi)-mega-pixel arrangements. PERCIVAL is a monolithic active pixel sensor, based on CMOS technology. It is designed for the soft X-ray regime and, therefore, it is post-processed in order to achieve high quantum efficiency in its primary energy range (250 eV to 1 keV) . This work will report on the latest experimental results on charge collection efficiency obtained for multiple back-side-illuminated test sensors during two campaigns, at the P04 beam-line at PETRA III, and the CiPo beam-line at Elettra, spanning most of the primary energy range as well as testing the performance for photon-energies below 250 eV . In addition, XPS surface analysis was used to cross-check the obtained results.
  •  
13.
  • Marras, A., et al. (författare)
  • Vertically integrated circuits : Example of an application to an x-ray detector
  • 2014
  • Ingår i: 2014 21st IEEE International Conference on Electronics, Circuits and Systems, ICECS 2014. - 9781479942428 ; , s. 243-246
  • Konferensbidrag (refereegranskat)abstract
    • Replacing planar circuits with vertically integrated ones allows to increment circuit functionalities on a given silicon area, while avoiding some of the problems associated with aggressively scaled technology nodes. This is particularly true for applications likely to subject circuits to high doses of ionizing radiation (such of x-ray detectors to be used in synchrotron rings and Free Electron Lasers), since the degradation mechanisms of some of the innovative materials to be used in most recent nodes have not been fully characterized yet. In this paper, an evolution is presented for the readout ASIC of a pixelated x-ray detector to be used for such applications. The readout circuit is distributed in a stack of two vertically interconnected tiers, thus doubling the circuitry resident in each pixel without increasing the pixel pitch (and thus compromising spatial resolution of the detector). A first prototype has been designed and manufactured, using a commercial 130 nm CMOS technology. Design issues are discussed, along with preliminary characterization results. © 2014 IEEE.
  •  
14.
  • Mezza, D., et al. (författare)
  • Characterization of AGIPD1.0 : The full scale chip
  • 2016
  • Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 838, s. 39-46
  • Tidskriftsartikel (refereegranskat)abstract
    • The AGIPD (adaptive gain integrating pixel detector) detector is a high frame rate (4.5 MHz) and high dynamic range (up to 104 ·12.4 keV photons) detector with single photon resolution (down to 4 keV taking 5σ as limit and lowest noise settings) developed for the European XFEL (XFEL.EU). This work is focused on the characterization of AGIPD1.0, which is the first full scale version of the chip. The chip is 64×64 pixels and each pixel has a size of 200×200 μm2. Each pixel can store up to 352 images at a rate of 4.5 MHz (corresponding to 220 ns). A detailed characterization of the AGIPD1.0 chip has been performed in order to assess the main performance of the ASIC in terms of gain, noise, speed and dynamic range. From the measurements presented in this paper a good uniformity of the gain, a noise around 320 e− (rms) in standard mode and around 240 e− (rms) in high gain mode has been measured. Furthermore a detailed discussion about the non-linear behavior after the gain switching is presented with both experimental results and simulations.
  •  
15.
  • Mezza, D., et al. (författare)
  • Characterization of the AGIPD1.1 readout chip and improvements with respect to AGIPD1.0
  • 2019
  • Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 945
  • Tidskriftsartikel (refereegranskat)abstract
    • AGIPD, the Adaptive Gain Integrating Pixel Detector, is a hybrid detector with a frame rate of 4.5 MHz, a dynamic range up to 104⋅ 12.4 keV photons, as well as single photon resolution, developed for the European XFEL (Eu.XFEL). The final 1 Mpixel detector system consists of 16 tiled modules each one with 16 readout chips. The single ASIC is 64 x 64 pixels, each with a size of 200 x 200 μm2. Each pixel can store up to 352 images. This work is focused on the characterization of AGIPD1.1, the second version of the full scale ASIC, and the improvements with respect to AGIPD1.0. From the measurements presented in this paper we show that the flaws observed in AGIPD1.0 (i.e. ghosting, crosstalk, slow readout speed) have been fixed in AGIPD1.1. In addition the main performance parameters such as noise, dynamic range and so on were measured for the new version of the ASIC and will be summarized. 
  •  
16.
  • Mezza, D., et al. (författare)
  • New calibration circuitry and concept for AGIPD
  • 2016
  • Ingår i: Journal of Instrumentation. - 1748-0221. ; 11:11
  • Tidskriftsartikel (refereegranskat)abstract
    • AGIPD (adaptive gain integrating pixel detector) is a detector system developed for the European XFEL (XFEL.EU), which is currently being constructed in Hamburg, Germany. The XFEL.EU will operate with bunch trains at a repetition rate of 10 Hz. Each train consists of 2700 bunches with a temporal separation of 220 ns corresponding to a rate of 4.5 MHz. Each photon pulse has a duration of < 100 fs (rms) and contains up to 1012 photons in an energy range between 0.25 and 25 keV . In order to cope with the large dynamic range, the first stage of each bump-bonded AGIPD ASIC is a charge sensitive preamplifier with three different gain settings that are dynamically switched during the charge integration. Dynamic gain switching allows single photon resolution in the high gain stage and can cover a dynamic range of 104 × 12.4 keV photons in the low gain stage. The burst structure of the bunch trains forces to have an intermediate in-pixel storage of the signals. The full scale chip has 352 in-pixel storage cells inside the pixel area of 200 × 200 μm2. This contribution will report on the measurements done with the new calibration circuitry of the AGIPD1.1 chip (without sensor). These results will be compared with the old version of the chip (AGIPD1.0). A new calibration method (that is not AGIPD specific) will also be shown.
  •  
17.
  • Singer, A., et al. (författare)
  • Intensity Interferometry of Single X-Ray Pulses from a Synchrotron Storage Ring
  • 2014
  • Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 113:6, s. Art. no. 064801-
  • Tidskriftsartikel (refereegranskat)abstract
    • We report on measurements of second-order intensity correlations at the high-brilliance storage ring PETRA III using a prototype of the newly developed adaptive gain integrating pixel detector. The detector records individual synchrotron radiation pulses with an x-ray photon energy of 14.4 keV and repetition rate of about 5 MHz. The second-order intensity correlation function is measured simultaneously at different spatial separations, which allows us to determine the transverse coherence length at these x-ray energies. The measured values are in a good agreement with theoretical simulations based on the Gaussian Schell model.
  •  
18.
  • Trunk, Ulrich, et al. (författare)
  • AGIPD : A multi megapixel, multi megahertz X-ray camera for the European XFEL
  • 2017
  • Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE - International Society for Optical Engineering. - 9781510611009
  • Konferensbidrag (refereegranskat)abstract
    • AGIPD is a hybrid pixel detector developed by DESY, PSI, and the Universities of Bonn and Hamburg. It is targeted for use at the European XFEL, a source with unique properties: a train of up to 2700 pulses is repeated at 10 Hz rate. The pulses inside a train are ≤100fs long and separated by 220 ns, containing up to 1012 photons of 12.4 keV each. The readout ASICs with 64 x 64 pixels each have to cope with these properties: Single photon sensitivity and a dynamic range up to 104 photons/pixel in the same image as well as storage for as many as possible images of a pulse train for delayed readout, prior to the next train. The high impinging photon flux also requires a very radiation hard design of sensor and ASIC, which uses 130 nm CMOS technology and radiation tolerant techniques. The signal path inside a pixel of the ASIC consists of a charge sensitive preamplifier with 3 individual gains, adaptively selected by a subsequent discriminator. The preamp also feeds to a correlated double sampling stage, which writes to an analogue memory to record 352 frames. It is random-access, so it can be used most efficiently by overwriting bad or empty images. Encoded gain information is stored to a similar memory. Readout of these memories is via a common charge sensitive amplifier in each pixel, and multiplexers on four differential ports. Operation of the ASIC is controlled via a command interface, using 3 LVDS lines. It also serves to configure the chip's operational parameters and timings.
  •  
19.
  • Graafsma, Heinz, et al. (författare)
  • Detector developments for photon science at DESY
  • 2023
  • Ingår i: Frontiers in Physics. - : Frontiers Media SA. - 2296-424X. ; 11
  • Tidskriftsartikel (refereegranskat)abstract
    • The past, current and planned future developments of X-ray imagers in the Photon-Science Detector Group at DESY-Hamburg is presented. the X-ray imagers are custom developed and tailored to the different X-ray sources in Hamburg, including the storage ring PETRA III/IV; the VUV-soft X-ray free electron laser FLASH, and the European Free-Electron Laser. Each source puts different requirements on the X-ray detectors, which is described in detail, together with the technical solutions implemented. 
  •  
20.
  • Greiffenberg, D., et al. (författare)
  • Towards AGIPD1.0 : Optimization of the dynamic range and investigation of a pixel input protection
  • 2014
  • Ingår i: Journal of Instrumentation. - 1748-0221. ; 9:6, s. Art. no. P06001-
  • Tidskriftsartikel (refereegranskat)abstract
    • AGIPD is a charge integrating, hybrid pixel readout ASIC, which is under development for the European XFEL [1,2]. A dynamic gain switching logic at the output of the preamplifier (preamp) is used to provide single photon resolution as well as covering a dynamic range of at least 104·12.4 keV photons [3,4]. Moreover, at each point of the dynamic range the electronics noise should be lower than the Poisson fluctuations, which is especially challenging at the points of gain switching. This paper reports on the progress of the chip design on the way to the first full-scale chip AGIPD1.0, focusing on the optimization of the dynamic range and the implementation of protection circuits at the preamplifier input to avoid pixel destruction due to high intense spots. © 2014 IOP Publishing Ltd and Sissa Medialab srl.
  •  
21.
  • Mezza, D., et al. (författare)
  • Calibration methods for charge integrating detectors
  • 2022
  • Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 1024
  • Tidskriftsartikel (refereegranskat)abstract
    • Since the introduction of the extremely intense X-ray free electron lasers, the need for low noise, high dynamic range and potentially fast charge integrating detectors has increased significantly. Among all the problems that research and development groups have to face in the development of such detectors, their calibration represents one of the most challenging and the collaboration between the detector development and user groups is of fundamental importance. The main challenge is to develop a calibration suite that is capable to test the detector over a wide dynamic range, with a high granularity and a very high linearity, together with a certain radiation tolerance and the possibility to well define the timings and the synchronization with the detector. Practical considerations have also to be made like the possibility to calibrate the detector in a reasonable time, the availability of the calibration source at the experimental place and so on. Such a calibration test suite is often not represented by a single source but by several sources that can cover different parts of the dynamic range and that need to be cross calibrated to have a final calibration curve. In this respect an essential part of the calibration is also to develop a mathematical model that allows calibrating the entire dynamic range, taking into account features that are calibration source and/or detector specific. The aim of this contribution is to compare the calibration for the AGIPD detector using several calibration sources such as internal current source, backside pulsing, IR pulsed laser, LED light and mono-energetic protons. The mathematical procedure used to calibrate the different sources will be discussed in great detail showing how to take into account a few shortcomings (like pixel coupling) that are common for many charge integrating detectors. This work has been carried out in the frame of the AGIPD project for the European X-ray Free Electron Laser. 
  •  
22.
  • Becker, J., et al. (författare)
  • Architecture and design of the AGIPD detector for the European XFEL
  • 2012
  • Konferensbidrag (refereegranskat)abstract
    • AGIPD is a hybrid pixel detector developed by DESY, PSI, the University of Bonn and the University of Hamburg. The detector is targeted for use at the European XFEL, a source with unique properties: a bunch train of 2700 pulses with > 1012 photons of 12 keV each, only 100 fs long and with a 220 ns spacing, is repeated at a 10Hz rate. This puts up very demanding requirements: dynamic range has to cover the detection of single photons and extend up to > 104 photons/pixel in the same image, and as many images, as possible have to be recorded in the pixel to be read out between pulse trains. The high photon flux impinging on the detector also calls for a very radiation hard design of sensor and ASIC. The detector will consist of 16 Sensor modules arranged around a central hole for the direct beam. Each made of a single sensor bump-bonded to 2 × 8 readout chips of 64 × 64 pixels in a grid of 200 μm pitch. Each pixel of these ASICs contains a charge sensitive preamplifier featuring adaptive gain switching, changing sensitivity in three ranges, and a buffer to provide correlated double sampling (in the highest sensitivity mode). Most of the pixel area, albeit, is used for an analogue memory to record 352 frames. It is operated in random-access mode: data containing bad frames can be overwritten and the memory can be used in the most efficient way. The readout between two bunch trains is arranged via 4 ports: Data from pixels of one row is read in parallel and serialised by 4 multiplexers at the end of the pixel columns and driven off-chip as differential signals. The operation of the ASIC is controlled via a three-line serial interface, using a command based protocol. It is also used to configure the chip's operational parameters and internal timings. © 2012 IEEE.
  •  
23.
  • Becker, J., et al. (författare)
  • High speed cameras for X-rays : AGIPD and others
  • 2013
  • Ingår i: Journal of Instrumentation. - 1748-0221. ; 8:1, s. Art. no. C01042-
  • Tidskriftsartikel (refereegranskat)abstract
    • Experiments at high pulse rate Free Electron Laser (FEL) facilities require new cameras capable of acquiring 2D images at high rates, handling large signal dynamic ranges and resolving images from individual pulses. The Adaptive Gain Integrated Pixel Detector (AGIPD) will operated with pulse rates and separations of 27000/s and 220 ns, respectively at European XFEL. Si-sensors, ASICs, PCBs, and FPGA logic are developed for a 1 Mega-pixel camera with 200 μm square pixels with per-pulse occupancies 104. Data from 3520 images/s will be transferred with 80 Gbits/s to a DAQ-system. The electronics have been adapted for use in other synchrotron light source detectors. 
  •  
24.
  • Becker, J., et al. (författare)
  • The high speed, high dynamic range camera AGIPD
  • 2013
  • Ingår i: IEEE Nuclear Science Symposium Conference Record. - : IEEE conference proceedings. - 9781479905348 ; , s. Art. no. 6829504-
  • Konferensbidrag (refereegranskat)abstract
    • The European X-Ray Free Electron Laser (XFEL) will provide ultra short, highly coherent X-ray pulses which will revolutionize scientific experiments in a variety of disciplines spanning physics, chemistry, materials science, and biology. One of the differences between the European XFEL and other free electron laser sources is the high pulse frequency of 4.5 MHz. The European XFEL will provide pulse trains, consisting of up to 2700 pulses separated by 220 ns (600 μs in total) followed by an idle time of 99.4 ms, resulting in a supercycle of 10 Hz. Dedicated fast 2D detectors are being developed, one of which is the Adaptive Gain Integrating Pixel Detector (AGIPD). AGIPD is based on the hybrid pixel technology. The design goals of the recently produced, radiation hard Application Specific Integrated Circuit (ASIC) with dynamic gain switching amplifiers are (for each pixel) a dynamic range of more than 10 4 12.4 keV photons in the lowest gain, single photon sensitivity in the highest gain, an analog memory capable of storing 352 images, and operation at 4.5 MHz frame rate. A vetoing scheme allows to maximize the number of useful images that are acquired by providing the possibility to overwrite any previously recorded image during the pulse train. The AGIPD will feature a pixel size of (200 μm)2 and a silicon sensor with a thickness of 500 μm. The image data is read out and digitized between pulse trains. © 2013 IEEE.
  •  
25.
  • Bianco, L., et al. (författare)
  • The AGIPD System for the European XFEL
  • 2013
  • Ingår i: ADVANCES IN X-RAY FREE-ELECTRON LASERS II. - : SPIE. - 9780819495808 ; , s. Art. no. UNSP 87780V-
  • Konferensbidrag (refereegranskat)abstract
    • The European XFEL will generate extremely brilliant pulses of X-rays organized in pulse trains consisting of 2700 pulses <100 fs long, with >10(12) photons, and with a 220 ns spacing. The pulse trains are running at a 10Hz repetition rate. The detector to be used under these conditions will have to face several challenges: the dynamic range has to cover the detection of single photons and extend up to >10(4) photons/pixel/pulse in the same image, framing rates of 4.5 MHz (220 ns) are required in order to record one image per pulse, and as many images as possible have to be recorded during the pulse trains. Due to the high flux, the detector will have to withstand a dose up to 1GGy integrated over 3 years. To meet these challenges a consortium, consisting of Deutsches Elektronensynchrotron (DESY), Paul-Scherrer-Institut (PSI), University of Hamburg and University of Bonn, is developing the Adaptive Gain Integrating Pixel Detector (AGIPD). It is a hybrid-pixel detector, featuring a charge integrating amplifier with dynamic gain switching to cope with the extended dynamic range, and an analogue on-pixel memory for image storage at the required 4.5 MHz frame rate. The readout chip consists of 64x64 pixels of (200 mu m)(2), 8x2 of these readout chips are bump-bonded to a monolithic silicon sensor to form the basic module with 512 x 128 pixels. 4 of these modules are stacked to form a quadrant of the 1k x 1k detector system. Each quadrant is independently moveable in order to adjust a central hole, needed for the direct beam to pass through. Special designs are employed for both the sensor and the readout chip to withstand the integrated dose for 3 years.
  •  
26.
  • Greiffenberg, D., et al. (författare)
  • Optimization of the noise performance of the AGIPD prototype chips
  • 2013
  • Ingår i: Journal of Instrumentation. - 1748-0221. ; 8:10, s. Art. no. P10022-
  • Tidskriftsartikel (refereegranskat)abstract
    • The charge integrating readout electronics AGIPD (adaptive gain integrating pixel detector) is a hybrid detector system developed for the European XFEL. It features a threefold dynamic gain switching to be able to resolve single photons and to cover a dynamic range of 104·12.4 keV photons. As a result of dynamic gain switching, single photon resolution will be achieved in the high gain stage, while the maximum dynamic range will be reached in the low gain stage. The specification to resolve single photons requires a signal-over-noise ratio of at least 10 for a single incoming photon with an energy of 12.4 keV. When using a silicon sensor, that translates to an equivalent noise charge of less than 343 e-. Several AGIPD prototype chips have been designed and characterized, particularly focusing on the noise performance. During the testing phase, the dominant noise sources were identified and the corresponding circuit blocks were improved in the subsequent ASICs. This paper reports on the procedures to identify the dominating noise sources, the optimization process of the circuit blocks and discusses the effect of the optimization on the noise performance.© 2013 IOP Publishing Ltd and Sissa Medialab srl.
  •  
27.
  • Khromova, A., et al. (författare)
  • Report on recent results of the PERCIVAL soft X-ray imager
  • 2016
  • Ingår i: Journal of Instrumentation. - : IOP. - 1748-0221. ; 11:November
  • Tidskriftsartikel (refereegranskat)abstract
    • The PERCIVAL (Pixelated Energy Resolving CMOS Imager, Versatile And Large) soft X-ray 2D imaging detector is based on stitched, wafer-scale sensors possessing a thick epi-layer, which together with back-thinning and back-side illumination yields elevated quantum efficiency in the photon energy range of 125–1000 eV. Main application fields of PERCIVAL are foreseen in photon science with FELs and synchrotron radiation. This requires high dynamic range up to 105 ph @ 250 eV paired with single photon sensitivity with high confidence at moderate frame rates in the range of 10–120 Hz. These figures imply the availability of dynamic gain switching on a pixel-by-pixel basis and a highly parallel, low noise analog and digital readout, which has been realized in the PERCIVAL sensor layout. Different aspects of the detector performance have been assessed using prototype sensors with different pixel and ADC types. This work will report on the recent test results performed on the newest chip prototypes with the improved pixel and ADC architecture. For the target frame rates in the 10–120 Hz range an average noise floor of 14e− has been determined, indicating the ability of detecting single photons with energies above 250 eV. Owing to the successfully implemented adaptive 3-stage multiple-gain switching, the integrated charge level exceeds 4 centerdot 106 e− or 57000 X-ray photons at 250 eV per frame at 120 Hz. For all gains the noise level remains below the Poisson limit also in high-flux conditions. Additionally, a short overview over the updates on an oncoming 2 Mpixel (P2M) detector system (expected at the end of 2016) will be reported.
  •  
28.
  • Pallanti, S., et al. (författare)
  • Manifesto for an ECNP Neuromodulation Thematic Working Group (TWG): Non-invasive brain stimulation as a new Super-subspecialty
  • 2021
  • Ingår i: European Neuropsychopharmacology. - : Elsevier BV. - 0924-977X. ; 52, s. 72-83
  • Tidskriftsartikel (refereegranskat)abstract
    • Non-Invasive Brain Stimulation (NIBS) techniques and in particular, repetitive Transcranial Magnetic Stimulation (rTMS), are developing beyond mere clinical application. Although originally purposed for the treatment of resistant neuropsychiatric disorders, NIBS is also contributing to a deeper understanding of psychiatric disorders. rTMS is also changing the model of the disorder itself, from “mental” to one of neural connectivity. TMS allows the assessment of brain circuit excitability and eventually, of plastic changes affecting these circuits. While a clinical translational approach is, at the present time, the most adequate to meet the dimensional-circuit base model of the disorder, it refines the standard categorical classification of psychiatric disorders. The discovery of the fundamental importance of the balance between neuroplasticity and inflammation is also now explored through neuro-modulation findings consistently with the evidence of anti-inflammatory actions of the magnetic pulses. rTMS may activate, inhibit, or otherwise interfere with the activity of neuronal cortical networks, depending on stimulus frequency and intensity of brain-induced electric field. Of particular interest, yet still unclear, is how the relatively unspecific nature of TMS stimulation may lead to specific neuronal reorganization, as well as a definition of the TMS-triggered reorganization of functional brain modules, raising attention on the importance of the active participation of the patient to the treatment. Configuration and state of consciousness of the subject have made subjective experience under treatment regain importance in the neuro-scientific Psychiatry based on the requirement of United States National Institute of Health (NIH) and the substantial importance of the consciousness state in the efficacy of the TMS treatment. By focusing on the subjective experience, a renaissance of the phenomenology offers Psychiatry an opportunity to become proficient and to distinguish itself from other disciplines. For all these reasons, TMS should be included in the cluster of the sub-specialties as a new “Super-Specialty” and an appropriate training course has to be inaugurated. Psychiatrists are nowadays multi-specialists, moving from a specialty to another, vs super-specialist. The cultivation of a properly trained cohort of TMS psychiatrists will better meet the challenges of treatment-resistant psychiatric conditions (disorders of connectivity), through appropriate and ethical practice, meanwhile facilitating an informed development and integration of additional emerging neuro-modulation techniques. The aim of this consensus paper is to underline the interdisciplinary nature of NIBS, that also encompasses the subjective experience and to point out the necessity of a neuroscience-applied approach to NIBS in the context of the European College of Neuro-psychopharmacology (ECNP). © 2021
  •  
29.
  • Becker, J., et al. (författare)
  • Performance tests of an AGIPD 0.4 assembly at the beamline P10 of PETRA III
  • 2013
  • Ingår i: Journal of Instrumentation. - 1748-0221. ; 8:6, s. Art. no. P06007-
  • Tidskriftsartikel (refereegranskat)abstract
    • The Adaptive Gain Integrating Pixel Detector (AGIPD) is a novel detector system, currently under development by a collaboration of DESY, the Paul Scherrer Institute in Switzerland, the University of Hamburg and the University of Bonn, and is primarily designed for use at the European XFEL. To verify key features of this detector, an AGIPD 0.4 test chip assembly was tested at the P10 beamline of the PETRA III synchrotron at DESY. The test chip successfully imaged both the direct synchrotron beam and single 7.05 keV photons at the same time, demonstrating the large dynamic range required for XFEL experiments. X-ray scattering measurements from a test sample agree with standard measurements and show the chip's capability of observing dynamics at the microsecond time scale.
  •  
30.
  • Correa, J., et al. (författare)
  • The PERCIVAL detector : first user experiments
  • 2023
  • Ingår i: Journal of Synchrotron Radiation. - 0909-0495 .- 1600-5775. ; 30, s. 242-250
  • Tidskriftsartikel (refereegranskat)abstract
    • The PERCIVAL detector is a CMOS imager designed for the soft X-ray regime at photon sources. Although still in its final development phase, it has recently seen its first user experiments: ptychography at a free-electron laser, holographic imaging at a storage ring and preliminary tests on X-ray photon correlation spectroscopy. The detector performed remarkably well in terms of spatial resolution achievable in the sample plane, owing to its small pixel size, large active area and very large dynamic range; but also in terms of its frame rate, which is significantly faster than traditional CCDs. In particular, it is the combination of these features which makes PERCIVAL an attractive option for soft X-ray science.
  •  
31.
  • Correa, J., et al. (författare)
  • The PERCIVAL soft X-ray Detector
  • 2018
  • Ingår i: 2018 IEEE Nuclear Science Symposium and Medical Imaging Conference, NSS/MIC 2018 - Proceedings. - : Institute of Electrical and Electronics Engineers (IEEE). - 9781538684948
  • Konferensbidrag (refereegranskat)abstract
    • The PERCIVAL collaboration to develop a soft X-ray imager able to address the challenges of high brilliance light sources, such as new-generation synchrotrons and Free Electron Lasers, has reached one of its major milestones: a full 2-MegaPixel (P2M) system (uninterrupted 4 × 4 cm2 active area) has already seen its first light.Smaller prototypes of the device, a monolithic active pixel sensor based on CMOS technology, have already been fully characterised, and have demonstrated high frame rate, large dynamic range, and relatively high quantum efficiency.The PERCIVAL modular layout allows for clover-leaf like arrangement of up to four P2M systems. Moreover, it will be post-processed in order to achieve a high quantum efficiency in its primary energy range (250 eV to 1 keV).We will present the P2M system, its status and newest results, bring these in context with achieved prototype performance, and outline future steps. 
  •  
32.
  •  
33.
  • Kalia, Lorraine V, et al. (författare)
  • Clinical Correlations With Lewy Body Pathology in LRRK2-Related Parkinson Disease.
  • 2015
  • Ingår i: JAMA Neurology. - : American Medical Association (AMA). - 2168-6157 .- 2168-6149. ; 72:1, s. 100-105
  • Tidskriftsartikel (refereegranskat)abstract
    • Mutations in leucine-rich repeat kinase 2 (LRRK2) are the most common cause of genetic Parkinson disease (PD) known to date. The clinical features of manifesting LRRK2 mutation carriers are generally indistinguishable from those of patients with sporadic PD. However, some PD cases associated with LRRK2 mutations lack Lewy bodies (LBs), a neuropathological hallmark of PD. We investigated whether the presence or absence of LBs correlates with different clinical features in LRRK2-related PD.
  •  
34.
  •  
35.
  • Marras, A., et al. (författare)
  • Development of CoRDIA : An Imaging Detector for next-generation Synchrotron Rings and Free Electron Lasers
  • 2022
  • Ingår i: Journal of Physics. - : Institute of Physics (IOP).
  • Konferensbidrag (refereegranskat)abstract
    • An x-ray imager is being developed for use in diffraction-limited synchrotron rings and continuous wave free electron lasers. The imager is named CoRDIA (COntinuous Readout Digitising Imager Array) and aims at achieving continuous operation at a frame rate in excess of 100kHz. Other goals include single-photon sensitivity at 12 keV (or below), a full well in excess of 10k photon/pixel/image, and a 100μm pixel pitch. The detector ASIC will be compatible with multiple sensor materials to cover different energy ranges. Exploratory prototypes of the readout ASIC (basic circuital blocks) have been manufactured in TSMC 65nm technology: they are presently under test. 
  •  
36.
  • Marras, A., et al. (författare)
  • Development of the Continuous Readout Digitising Imager Array detector
  • 2024
  • Ingår i: Journal of Instrumentation. - : IOP Publishing. - 1748-0221. ; 19:3
  • Tidskriftsartikel (refereegranskat)abstract
    • The CoRDIA project aims to develop an X-ray imager capable of continuous operation in excess of 100 kframe/s. The goal is to provide a suitable instrument for Photon Science experiments at diffraction-limited Synchrotron Rings and Free Electron Lasers considering Continuous Wave operation. Several chip prototypes were designed in a 65 nm process: in this paper we will present an overview of the challenges and solutions adopted in the ASIC design. 
  •  
37.
  • Marras, A., et al. (författare)
  • Experimental characterization of the PERCIVAL soft X-ray detector
  • 2016
  • Ingår i: 2015 IEEE Nuclear Science Symposium and Medical Imaging Conference, NSS/MIC 2015. - : Institute of Electrical and Electronics Engineers (IEEE). - 9781467398626
  • Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
    • Considerable interest has been manifested for the use of high-brilliance X-ray synchrotron sources and X-ray Free-Electron Lasers for the investigation of samples.
  •  
38.
  • Marras, A., et al. (författare)
  • Front end electronics for European XFEL sensor : The AGIPD project
  • 2013
  • Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 731, s. 79-82
  • Tidskriftsartikel (refereegranskat)abstract
    • The AGIPD (Adaptive Gain Integrating Pixel Detector) is a detector under development, to be used in the European X-ray Free-Electron Laser (XFEL). The constraints imposed by the XFEL source are discussed, and the solutions implemented to cope with them are explained. The present status of the project is reported, along with results achieved in terms of noise, memory depth, and radiation tolerance. © 2013 Elsevier B.V.
  •  
39.
  • Marras, A., et al. (författare)
  • Percival P2M-FSI detector : First test at a Synchrotron Ring beamline with tender x-ray photons
  • 2019
  • Ingår i: 2019 IEEE Nuclear Science Symposium and Medical Imaging Conference, NSS/MIC 2019. - : IEEE. - 9781728141640
  • Konferensbidrag (refereegranskat)abstract
    • In this paper, we are presenting the results of the first test of the Percival P2M-FSI detector with tender x-rays photons at a synchrotron beamline. Percival is a monolithic CMOS Imager for detection of x-rays in Synchrotron Rings and Free Electron Lasers: the Front-Side-Illuminated (FSI) version of the detector has been proven able to successfully distinguish tender (2keV) x-ray single photons. 
  •  
40.
  •  
41.
  • Pinaroli, G., et al. (författare)
  • PERCIVAL : Possible applications in X-ray micro-tomography
  • 2020
  • Ingår i: Journal of Instrumentation. - 1748-0221. ; 15:2
  • Tidskriftsartikel (refereegranskat)abstract
    • X-ray computed micro-tomography (μCT) is one of the most advanced and common non-destructive techniques in the field of medical imaging and material science. It allows recreating virtual models (3D models), without destroying the original objects, by measuring three-dimensional X-ray attenuation coefficient maps of samples on the (sub) micrometer scale. The quality of the images obtained using μCT is strongly dependent on the performance of the associated X-ray detector i.e. to the acquisition of information of the X-ray beam traversing the patient/sample being precise and accurate. Detectors for μCT have to meet the requirements of the specific tomography procedure in which they are going to be used. In general, the key parameters are high spatial resolution, high dynamic range, uniformity of response, high contrast sensitivity, fast acquisition readout and support of high frame rates. At present the detection devices in commercial μCT scanners are dominated by charge-coupled devices (CCD), photodiode arrays, CMOS acquisition circuits and more recently by hybrid pixel detectors. Monolithic CMOS imaging sensors, which offer reduced pixel sizes and low electronic noise, are certainly excellent candidates for μCT and may be used for the development of novel high-resolution imaging applications. The uses of monolithic CMOS based detectors such as the PERCIVAL detector are being recently explored for synchrotron and FEL applications. PERCIVAL was developed to operate in synchrotron and FEL facilities in the soft X-ray regime from 250 eV to 1 keV and it could offer all the aforementioned technical requirements needed in μCT experiments. In order to adapt the system for a typical tomography application, a scintillator is required, to convert incoming X-ray radiation (∼ tens of KeV) into visible light which may be detected with high efficiency. Such a taper-based scintillator was developed and mounted in front of the sensitive area of the PERCIVAL imager. In this presentation we will report the setup of the detector system and preliminary results of first μCTs of reference objects, which were performed in the TomoLab at ELETTRA. 
  •  
42.
  • Sedgwick, I., et al. (författare)
  • P2M : First Optical Characterisation Results of a 2MPixel CMOS Image Sensor for Soft X-Ray Detection
  • 2019
  • Ingår i: 2019 IEEE NUCLEAR SCIENCE SYMPOSIUM AND MEDICAL IMAGING CONFERENCE (NSS/MIC). - : IEEE. - 9781728141640
  • Konferensbidrag (refereegranskat)abstract
    • High brilliance synchrotrons and FELs require high performing detector systems to realise their full potential. High dynamic range, low noise and high frame rate are all of great importance. In this paper we present first optical characterization results of the P2M CMOS sensor, designed for soft X-ray detection at such facilities. Previous work is summarised and an overview of the sensor is presented. Test results for the sensor's column-parallel ADC and readout chain are presented, and first test results for the pixel acquired using the Photon Transfer Curve (PTC) method are shown. Finally, an outline of future work is provided.
  •  
43.
  • Viti, M., et al. (författare)
  • Spatial resolution studies for the PERCIVAL sensor
  • 2015
  • Ingår i: Journal of Instrumentation. - 1748-0221. ; 10
  • Tidskriftsartikel (refereegranskat)abstract
    • The PERCIVAL ("Pixelated Energy Resolving CMOS Imager, Versatile and Large") is a collaboration of DESY, RAL/STFC, ELETTRA, and DLS to develop a monolithic active pixel sensor (MAPS) to provide a suitable detector for photon science for the photon energy regime between 250 eV and 1 keV. An important performance parameter is the spatial resolution which can be inferred from the Modulation Transfer Function (MTF). The MTF measures in optical systems the relative contrast of a pattern in function of the spatial frequency. With a back-thinned and back- illuminated PERCIVAL prototype chip, dedicated MTF evaluation data were taken at Elettra's TwinMic Beamline in March 2014 at a photon energy of 535 eV. We will present our MTF derivation approaches together with MTF results for 3 pixel types of the irradiated test sensor.
  •  
44.
  • Wunderer, C. B., et al. (författare)
  • The Percival 2-Megapixel monolithic active pixel imager
  • 2019
  • Ingår i: Journal of Instrumentation. - 1748-0221. ; 14:1
  • Tidskriftsartikel (refereegranskat)abstract
    • The peak brilliance reached by today's Free-Electron Laser and Synchrotron light sources requires photon detectors matching their output intensity and other characteristics in order to fully realize the sources' potential. The Pixellated Energy Resolving CMOS Imager, Versatile And Large (Percival) is a dedicated soft X-ray imager (0.25-1 keV) developed for this purpose by a collaboration of DESY, Rutherford Appleton Laboratory/STFC, Elettra Sincrotrone Trieste, Diamond Light Source, and Pohang Accelerator Laboratory. Following several generations of prototypes, the Percival "P2M" 2-Megapixel imager - a 4.5x5 cm monolithic, stitched sensor with an uninterrupted imaging area of 4x4 cm(2) (1408x1484 pixels of 27x27 mu m - was produced and has demonstrated basic functionality with a first-light image using visible light. It is currently being brought to full operation in a front-illuminated configuration. The readout system being commissioned in parallel has been developed specifically for this imager which will produce - at full 300 Hz frame rate - data at 20 Gbit/s. A first wafer with eight Percival P2M chips has undergone backthinning to enable soft X-ray detection. It has been diced and chips are currently being wirebonded. We summarize here the P2M system, the project status, and show the P2M sensor's first response to visible light.
  •  
45.
  • Wunderer, C. B., et al. (författare)
  • The PERCIVAL soft X-ray imager
  • 2015
  • Ingår i: Journal of Instrumentation. - 1748-0221. ; 10:2
  • Tidskriftsartikel (refereegranskat)abstract
    • With the increased brilliance of state-of-the-art Synchrotron radiation sources and the advent of Free Electron Lasers enabling revolutionary science on atomic length and time scales with EUV to X-ray photons comes an urgent need for suitable photon imaging detectors. Requirements include high frame rates, very large dynamic range, single-photon counting capability with low probability of false positives, and (multi)-megapixels. PERCIVAL ("Pixelated Energy Resolving CMOS Imager, Versatile And Large") is currently being developed by a collaboration of DESY, RAL, Elettra, DLS and Pohang to address this need for the soft X-ray regime. PERCIVAL is a monolithic active pixel sensor (MAPS), i.e. based on CMOS technology. It will be back-thinned to access its primary energy range of 250 eV to 1 keV with target efficiencies above 90%. According to its preliminary specifications, the roughly 10 × 10 cm2, 3.5k × 3.7k monolithic "PERCIVAL13M" sensor will operate at frame rates up to 120 Hz (commensurate with most FELs) and use multiple gains within its 27 μm pixels to measure 1 to ∼ 105 (500 eV) simultaneously-arriving photons. A smaller "PERCIVAL2M" with ∼ 1.4k × 1.5k pixels is also planned. Currently, small-scale back-illuminated prototype systems (160 × 210 pixels of 25 μm pitch) are undergoing detailed testing with X-rays and optical photons. In March 2014, a prototype sensor was tested at 350 eV-2 keV at Elettra's TwinMic beamline. The data recorded include diffraction patterns at 350 eV and 400 eV, knife edge and sub-pixel pinhole illuminations, and comparisons of different pixel types. Another prototype chip will be submitted in fall 2014, first larger sensors could be in hand in late 2015.
  •  
46.
  • Cancelliere, Carol, et al. (författare)
  • Protocol for a systematic review of prognosis after mild traumatic brain injury : an update of the WHO Collaborating Centre Task Force findings
  • 2012
  • Ingår i: Systematic Reviews. - : Springer Science and Business Media LLC. - 2046-4053. ; :1, s. 17-
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Mild traumatic brain injury (MTBI) is a major public-health concern and represents 70-90% of all treated traumatic brain injuries. The last best-evidence synthesis, conducted by the WHO Collaborating Centre for Neurotrauma, Prevention, Management and Rehabilitation in 2002, found few quality studies on prognosis. The objective of this review is to update these findings. Specifically, we aim to describe the course, identify modifiable prognostic factors, determine long-term sequelae, and identify effects of interventions for MTBI. Finally, we will identify gaps in the literature, and make recommendations for future research.Methods: The databases MEDLINE, PsychINFO, Embase, CINAHL and SPORTDiscus were systematically searched (2001 to date). The search terms included 'traumatic brain injury', 'craniocerebral trauma', 'prognosis', and 'recovery of function'. Reference lists of eligible papers were also searched. Studies were screened according to pre-defined inclusion and exclusion criteria. Inclusion criteria included original, published peer-reviewed research reports in English, French, Swedish, Norwegian, Danish and Spanish, and human participants of all ages with an accepted definition of MTBI. Exclusion criteria included publication types other than systematic reviews, meta-analyses, randomized controlled trials, cohort studies, and case-control studies; as well as cadaveric, biomechanical, and laboratory studies. All eligible papers were critically appraised using a modification of the Scottish Intercollegiate Guidelines Network (SIGN) criteria. Two reviewers performed independent, in-depth reviews of each eligible study, and a third reviewer was consulted for disagreements. Data from accepted papers were extracted into evidence tables, and the evidence was synthesized according to the modified SIGN criteria.Conclusion: The results of this study form the basis for a better understanding of recovery after MTBI, and will allow development of prediction tools and recommendation of interventions, as well as informing health policy and setting a future research agenda.
  •  
47.
  • Correa, J., et al. (författare)
  • Characterisation of a PERCIVAL monolithic active pixel prototype using synchrotron radiation
  • 2016
  • Ingår i: Journal of Instrumentation. - : IOP. - 1748-0221. ; 11:2
  • Tidskriftsartikel (refereegranskat)abstract
    • PERCIVAL ("Pixelated Energy Resolving CMOS Imager, Versatile And Large") is a monolithic active pixel sensor (MAPS) based on CMOS technology. Is being developed by DESY, RAL/STFC, Elettra, DLS, and PAL to address the various requirements of detectors at synchrotron radiation sources and Free Electron Lasers (FELs) in the soft X-ray regime. These requirements include high frame rates and FELs base-rate compatibility, large dynamic range, single-photon counting capability with low probability of false positives, high quantum efficiency (QE), and (multi-)megapixel arrangements with good spatial resolution. Small-scale back-side-illuminated (BSI) prototype systems are undergoing detailed testing with X-rays and optical photons, in preparation of submission of a larger sensor. A first BSI processed prototype was tested in 2014 and a preliminary result—first detection of 350eV photons with some pixel types of PERCIVAL—reported at this meeting a year ago. Subsequent more detailed analysis revealed a very low QE and pointed to contamination as a possible cause. In the past year, BSI-processed chips on two more wafers were tested and their response to soft X-ray evaluated. We report here the improved charge collection efficiency (CCE) of different PERCIVAL pixel types for 400eV soft X-rays together with Airy patterns, response to a flat field, and noise performance for such a newly BSI-processed prototype sensor.
  •  
48.
  • de Roos, Paul, et al. (författare)
  • A Consensus Set of Outcomes for Parkinson's Disease from the International Consortium for Health Outcomes Measurement
  • 2017
  • Ingår i: Journal of Parkinson's Disease. - : IOS Press. - 1877-7171 .- 1877-718X. ; 7:3, s. 533-543
  • Tidskriftsartikel (refereegranskat)abstract
    • BACKGROUND: Parkinson's disease (PD) is a progressive neurodegenerative condition that is expected to double in prevalence due to demographic shifts. Value-based healthcare is a proposed strategy to improve outcomes and decrease costs. To move towards an actual value-based health care system, condition-specific outcomes that are meaningful to patients are essential.OBJECTIVE: Propose a global consensus standard set of outcome measures for PD.METHODS: Established methods for outcome measure development were applied, as outlined and used previously by the International Consortium for Health Outcomes Measurement (ICHOM). An international group, representing both patients and experts from the fields of neurology, psychiatry, nursing, and existing outcome measurement efforts, was convened. The group participated in six teleconferences over a six-month period, reviewed existing data and practices, and ultimately proposed a standard set of measures by which patients should be tracked, and how often data should be collected.RESULTS: The standard set applies to all cases of idiopathic PD, and includes assessments of motor and non-motor symptoms, ability to work, PD-related health status, and hospital admissions. Baseline demographic and clinical variables are included to enable case mix adjustment.CONCLUSIONS: The Standard Set is now ready for use and pilot testing in the clinical setting. Ultimately, we believe that using the set of outcomes proposed here will allow clinicians and scientists across the world to document, report, and compare PD-related outcomes in a standardized fashion. Such international benchmarks will improve our understanding of the disease course and allow for identification of 'best practices', ultimately leading to better informed treatment decisions.
  •  
49.
  • Domenici, P., et al. (författare)
  • How sailfish use their bills to capture schooling prey
  • 2014
  • Ingår i: Proceedings of the Royal Society of London. Biological Sciences. - : The Royal Society. - 0962-8452 .- 1471-2954. ; 281:1784, s. 20140444-
  • Tidskriftsartikel (refereegranskat)abstract
    • The istiophorid family of billfishes is characterized by an extended rostrum or 'bill'. While various functions (e.g. foraging and hydrodynamic benefits) have been proposed for this structure, until now no study has directly investigated the mechanisms by which billfishes use their rostrum to feed on prey. Here, we present the first unequivocal evidence of how the bill is used by Atlantic sailfish (Istiophorus albicans) to attack schooling sardines in the open ocean. Using high-speed video-analysis, we show that (i) sailfish manage to insert their bill into sardine schools without eliciting an evasive response and (ii) subsequently use their bill to either tap on individual prey targets or to slash through the school with powerful lateral motions characterized by one of the highest accelerations ever recorded in an aquatic vertebrate. Our results demonstrate that the combination of stealth and rapid motion make the sailfish bill an extremely effective feeding adaptation for capturing schooling prey.
  •  
50.
  •  
Skapa referenser, mejla, bekava och länka
  • Resultat 1-50 av 54

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

 
pil uppåt Stäng

Kopiera och spara länken för att återkomma till aktuell vy