3,896 research outputs found
The Magnetic Distortion Calibration System of the LHCb RICH1 Detector
The LHCb RICH1 detector uses hybrid photon detectors (HPDs) as its optical
sensors. A calibration system has been constructed to provide corrections for
distortions that are primarily due to external magnetic fields. We describe
here the system design, construction, operation and performance.Comment: 9 pages, 14 figure
The Level 0 Pixel Trigger System for the ALICE experiment
The ALICE Silicon Pixel Detector contains 1200 readout chips. Fast-OR signals indicate the presence of at least one hit in the 8192 pixel matrix of each chip. The 1200 bits are transmitted every 100 ns on 120 data readout optical links using the G-Link protocol. The Pixel Trigger System extracts and processes them to deliver an input signal to the Level 0 trigger processor targeting a latency of 800 ns. The system is modular and based on FPGA devices. The architecture allows the user to define and implement various trigger algorithms. The system uses advanced 12-channel parallel optical fiber modules operating at 1310 nm as optical receivers. Multi-channel G-Link receivers were realized in programmable hardware and tested. The design of the system and the progress of the ALICE Pixel Trigger project are described in this paper
The pixel Fast-OR signal for the ALICE trigger in p-p collisions
The silicon pixel detector of the ALICE experiment at LHC comprises the two innermost layers of the inner tracking system of the apparatus. It contains 1200 readout chips, each of them corresponding to a 8192 pixel matrix. The single chip outputs a digital Fast-OR signal which is active whenever at least one of the pixels in the matrix records a hit. The 1200 Fast-OR output signals can be used to implement a unique triggering capability: few details on the pixel trigger system and some of the possible applications for p-p collisions are presented
Multiparametric advanced research tool for meteo satellites data interfacing with space observation of ultra high energy cosmic rays
To approach the study of the cosmic rays in the energy range
E > 1020 eV, the upper end of the spectrum observed to date, with a large statistical significance (103 events/year), and hence address the solution of several
astrophysical and cosmological problems related to their existence and behaviour, a new generation of experiments will probably have to be conceived and realised. They will be based on the observation and measurements of cosmic rays from space. The extremely low rate of these events (⌠1 event/(century Ă km2 Ă sr)) imposes a very large effective area to be monitored, of the order of 105 km2, as an observational requirement to meet the target statistics. The Extreme Universe Space Observatory (EUSO)mission has been proposed as the precursor of this new generation of experiments. Its approach consists in fact in looking downwards to the Earth atmosphere by means of a large
field-of-view telescope accommodated aboard an orbiting satellite. The fluorescence strike produced by a cosmic ray through the atmosphere will be recorded by the detector, which will reconstruct the kinematical and dynamical features of the primary cosmic ray. The atmosphere acts therefore as an active target for the detectable event. A strategic tool for the success of EUSO as well as for all the experiments of its category will be a correct and detailed atmospheric sounding system, in order to monitor the atmospheric parameters within the field-of-view of the telescope. Beside an on-board measurement by means of dedicated devices such an infrared camera (IR)and possibly a LIDAR (LIght Detection And Ranging)coupled to the main instrument, the Atmosphere Sounding will take advantage from the continuous observation of the atmospheric parameters given by the orbiting meteorological satellites. Their databases have thus to be interfaced to the experimental data and used picking-up the relevant data according to the space and time coordinates corresponding
to each triggered event. The present work outlines a software module (MARVIN-Multiparametric Advanced Research tool for Visualisation In the Network) able to build-up such an interface, and shows a preliminary implementation
of it, using a sample of existing satellites and ISCCP meteorological data collection. It has been developed during the phase A study of the EUSO mission but is general
enough to be adapted to different missions observing the Earth atmosphere from space
LA COMUNICAZIONE: MEDIA, PROCESSI PRODUTTIVI E NARRAZIONI Atti del workshop 2020 (Lecce, 15 â 16 ottobre)
Il volume, composto da 10 saggi che costituiscono solo una parte dei contributi discussi
nel Workshop âLa comunicazione: media, processi produttivi e narrazioniâ del Dottorato in Human
and Social Sciences dellâUniversitĂ del Salento (Lecce, 15-16 ottobre 2020), attesta la vivacitĂ delle
riflessioni sul tema presenti nelle discipline storiche, geografiche, giuridiche, sociologiche,
pedagogiche e psicologiche e tramite lâopen access consente di rendere disponibili tali prodotti
della ricerca alla comunitĂ globale, scientifica e non, per divulgare le prospettive di sviluppo delle
proposte di cui il Dottorato si Ăš fatto incubator
The ALICE Level 0 Pixel Trigger Driver Layer
The ALICE Silicon Pixel Detector (SPD) comprises the two innermost layers of the ALICE inner tracker system. The SPD contains 120 detector modules each including 10 readout chips. Each of these pixel chips generates a digital Fast-OR output signal indicating the presence of at least one pixel hit in its pixel
matrix.
The Pixel Trigger (PIT) System has been implemented to process the 1200 Fast-Or signals from the SPD and provides an input signal to the ALICE Central Trigger Processor (CTP) for the fastest (Level 0) trigger decision within a latency of 800 ns.
The PIT processor interfaces with several ALICE systems: it receives input data from the SPD, it accepts configuration commands from the CTP and sends status information to the Alice Experimental Control System (ECS). The PIT control system required an accurate design of hardware and software solutions to implement coordinated operation of the PIT and the ALICE systems to which it interfaces to.
We present here the design, the implementation and the first operational experience of the PIT Control and Calibration system. The hardware configuration and control are implemented via the ALICE Detector Data Link, on top of which a custom control system has been implemented.
A driver layer has been realized under stringent requirements of robustness and reusability. It qualifies as a general purpose hardware driver for electronic systems equipped with the ALICE DDL front end board (SIU).
Various testing and calibration procedures need to be performed on the SPD and the PIT systems in order to provide an optimized trigger signal to the CTP.
These include methods to compensate all signals propagation delays and automatic SPD DAC scans to tune the detector response. The PIT control system has been tailored to implement automatically most of the former procedures, requiring coordinated and extensive information exchange between the interfacing systems.CER
Suppression of high transverse momentum D mesons in central Pb-Pb collisions at âsNN= 2.76 TeV
The production of the prompt charm mesons D0, D+, Dâ+, and their antiparticles,
was measured with the ALICE detector in Pb-Pb collisions at the LHC, at a
centre-of-mass energy âsNN = 2.76 TeV per nucleon-nucleon collision. The pt-differential
production yields in the range 2 < pt < 16 GeV/c at central rapidity, |y| < 0.5, were used
to calculate the nuclear modification factor RAA with respect to a proton-proton reference
obtained from the cross section measured at âs = 7 TeV and scaled to âs = 2.76 TeV. For
the three meson species, RAA shows a suppression by a factor 3â4, for transverse momenta
larger than 5 GeV/c in the 20% most central collisions. The suppression is reduced for
peripheral collisions
The Diagnosis and Management of Nonalcoholic Fatty Liver Disease: Practice Guidance from the American Association for the Study of Liver Diseases
This guidance provides a data-supported approach to the diagnostic, therapeutic, and preventive aspects of NAFLD care. A âGuidanceâ document is different from a âGuideline.â Guidelines are developed by a multidisciplinary panel of experts and rate the quality (level) of the evidence and the strength of each recommendation using the Grading of Recommendations, Assessment Development, and Evaluation (GRADE) system. A guidance document is developed by a panel of experts in the topic, and guidance statements, not recommendations, are put forward to help clinicians understand and implement the most recent evidence
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