326 research outputs found
A Survey on FPGA-Based Heterogeneous Clusters Architectures
In recent years, the most powerful supercomputers have already reached megawatt power consumption levels, an important issue that challenges sustainability and shows the impossibility of maintaining this trend. To this date, the prevalent approach to supercomputing is dominated by CPUs and GPUs. Given their fixed architectures with generic instruction sets, they have been favored with lots of tools and mature workflows which led to mass adoption and further growth. However, reconfigurable hardware such as FPGAs has repeatedly proven that it offers substantial advantages over this supercomputing approach concerning performance and power consumption. In this survey, we review the most relevant works that advanced the field of heterogeneous supercomputing using FPGAs focusing on their architectural characteristics. Each work was divided into three main parts: network, hardware, and software tools. All implementations face challenges that involve all three parts. These dependencies result in compromises that designers must take into account. The advantages and limitations of each approach are discussed and compared in detail. The classification and study of the architectures illustrate the trade-offs of the solutions and help identify open problems and research lines
A Simple Method for Detecting Periodic Signals in Sparse Astronomical Event Data
We present a simple method to detect periodic signals in sparse astronomical event data. The method is particularly appropriate for gamma-ray astronomy where the number of available photons is sparse in time and Poissonian noise dominates the statistics. It is based on an autocorrelation function, which provides phase independence. We have implemented and successfully applied this method on simulated data. This paper presents some numerical results and a description of the model used to generate the synthetic data along with a formal definition of the signal-to-noise ratio in the generated time series
Gamma/neutron classification with SiPM CLYC detectors using frequency-domain analysis for embedded real-time applications
A method for gamma/neutron event classification based on frequency-domain analysis for mixed radiation environments is proposed. In contrast to the traditional charge comparison method for pulse-shape discrimination, which requires baseline removal and pulse alignment, our method does not need any preprocessing of the digitized data, apart from removing saturated traces in sporadic pile-up scenarios. It also features the identification of neutron events in the detector’s full energy range with a single device, from thermal neutrons to fast neutrons, including low-energy pulses, and still provides a superior figure-of-merit for classification.
The proposed frequency-domain analysis consists of computing the fast Fourier transform of a triggered trace and integrating it through a simplified version of the transform magnitude components that distinguish the neutron features from those of the gamma photons. Owing to this simplification, the proposed method may be easily ported to a real-time embedded deployment based on Field-Programmable Gate Arrays or Digital Signal Processors. We target an off-the-shelf detector based on a small CLYC (Cs2LiYCl6:Ce) crystal coupled to a silicon photomultiplier with an integrated bias and preamplifier, aiming at lightweight embedded mixed radiation monitors and dosimeter applications
Study of MicroPattern Gaseous detectors with novel nanodiamond based photocathodes for single photon detection in EIC RICH
Identification of high momentum hadrons at the future EIC is crucial, gaseous
RICH detectors are therefore viable option. Compact collider setups impose to
construct RICHes with small radiator length, hence significantly limiting the
number of detected photons. More photons can be detected in the far UV region,
using a windowless RICH approach. QE of CsI degrades under strong irradiation
and air contamination. Nanodiamond based photocathodes (PCs) are being
developed as an alternative to CsI. Recent development of layers of
hydrogenated nanodiamond powders as an alternative photosensitive material and
their performance, when coupled to the THick Gaseous Electron Multipliers
(THGEM)-based detectors, are the objects of an ongoing R\&D. We report about
the initial phase of our studies.Comment: 3 pages, 5 figures, RICH2018 conference proceedin
Development and tests of a new prototype detector for the XAFS beamline at Elettra Synchrotron in Trieste
The XAFS beamline at Elettra Synchrotron in Trieste combines X-ray absorption
spectroscopy and X-ray diffraction to provide chemically specific structural
information of materials. It operates in the energy range 2.4-27 keV by using a
silicon double reflection Bragg monochromator. The fluorescence measurement is
performed in place of the absorption spectroscopy when the sample transparency
is too low for transmission measurements or the element to study is too diluted
in the sample. We report on the development and on the preliminary tests of a
new prototype detector based on Silicon Drift Detectors technology and the
SIRIO ultra low noise front-end ASIC. The new system will be able to reduce
drastically the time needed to perform fluorescence measurements, while keeping
a short dead time and maintaining an adequate energy resolution to perform
spectroscopy. The custom-made silicon sensor and the electronics are designed
specifically for the beamline requirements.Comment: Proceeding of the 6YRM 12th-14th Oct 2015 - L'Aquila (Italy).
Accepted for publication on Journal of Physics: Conference Serie
Remote Laboratory for E-Learning of Systems on Chip and Their Applications to Nuclear and Scientific Instrumentation
Configuring and setting up a remote access laboratory for an advanced online school on fully programmable System-on-Chip (SoC) proved to be an outstanding challenge. The school, jointly organized by the International Centre for Theoretical Physics (ICTP) and the International Atomic Energy Agency (IAEA), focused on SoC and its applications to nuclear and scientific instrumentation and was mainly addressed to physicists, computer scientists and engineers from developing countries. The use of e-learning tools, which some of them adopted and others developed, allowed the school participants to directly access both integrated development environment software and programmable SoC platforms. This facilitated the follow-up of all proposed exercises and the final project. During the four weeks of the training activity, we faced and overcame different technology and communication challenges, whose solutions we describe in detail together with dedicated tools and design methodology. We finally present a summary of the gained experience and an assessment of the results we achieved, addressed to those who foresee to organize similar initiatives using e-learning for advanced training with remote access to SoC platforms
Exotic tick Amblyomma varanense (Acari: Ixodidae) in imported specimens from Varanus salvator (Squamata: Varanidae) in Argentina
La importación de animales vivos, especialmente reptiles, ha contribuido al transporte e introducción de garrapatas exóticas en muchas regiones del mundo. Se describe el hallazgo de 11 especímenes (un macho, dos hembras y ocho ninfas) de Amblyomma varanense colectados de dos varanos acuáticos (Varanus salvator) importados legalmente desde Jakarta, Indonesia. Amblyomma varanense es una garrapata distribuida en las regiones zoogeográficas Oriental y de Australasia, y V. salvator se encuentra entre los principales hospedadores. Es necesario prevenir la introducción de garrapatas exóticas y microrganismos asociados, poniéndose en evidencia el riesgo que conlleva la importación de vertebrados exóticos.The importation of live animals, especially reptiles, has contributed to the transport and introduction of exotic ticks in many regions of the world. We describe the finding of 11 specimens (one male, two females and eight nymphs) of Amblyomma varanense collected from two common water monitors (Varanus salvator) legally imported from Jakarta, Indonesia. Amblyomma varanense is a tick distributed in the Eastern and Australasian zoogeographic regions, and V. salvator is among the main hosts. It is necessary to prevent the introduction of exotic ticks and associated microorganisms, highlighting the risk involved in the importation of exotic vertebrates.Fil: Cicuttin, Gabriel Leonardo. Gobierno de la Ciudad Autónoma de Buenos Aires. Ministerio de Salud. Instituto de Zoonosis Luis Pasteur; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Wiemeyer, Guillermo. No especifíca;Fil: Pérez, M. A.. No especifíca;Fil: Guglielmone, Alberto Alejandro. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria Rafaela; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: Nava, Santiago. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria Rafaela; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentin
Nanodiamond photocathodes for MPGD-based single photon detectors at future EIC
The design of a Ring Imaging CHerenkov (RICH) detector for the identification
of high momentum particles at the future Electron Ion Collider (EIC) is
extremely challenging by using current technology. Compact collider setups
impose to construct RICH with short radiator length, hence limiting the number
of generated photons. The number of detected photons can be increased by
selecting the far UV region. As standard fused-silica windows is opaque below
165 nm, a windowless RICH can be a possible approach. CsI is widely used
photocathode (PC) for photon detection in the far UV range. Due to its
hygroscopic nature it is very delicate to handle. In addition, its Quantum
Efficiency (QE) degrades in high intensity ion fluxes. These are the key
reasons to quest for novel PC with sensitivity in the far UV region. Recent
development of layers of hydrogenated nanodiamond powders as an alternative PC
material and their performance, when coupled to the THick Gaseous Electron
Multipliers (THGEM)-based detectors, are the objects of an ongoing R\&D. We
report here some preliminary results on the initial phase of these studies.Comment: 6 pages, 5 figures, MPGD-2019 La Rochelle, Proceedin
Long term experience with perfluorobutane in COMPASS RICH
COMPASS RICH-1 has used high-purity perfluorobutane as radiator gas since
2001. The operation and control of the radiator gas has evolved over years with
continuous improvements. We report on the experience gained in the 20 year-long
operation of perfluorobutane as COMPASS RICH radiator. Very accurate values for
the radiator gas refractive index are needed for high-performance particle
identification. The procedure has evolved over years and the one presently in
use, which provides refractive index estimate at the 1 ppm level, is discussed.
Perfluorobutane procurement is becoming challenging, and the minimization of
material waste is now a priority for the protection of the environment.
Commercially available perfluorobutane needs dedicated filtering before usage
and typical material losses in the filtering procedure were around 30%. Recent
efforts allowed us to reduce them to about 5%. A potential alternative to
fluorocarbon radiators in gaseous RICHes is also presented.Comment: 4 pages, 3 figures 2 table
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