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Sample records for atlas trigger design

  1. The ATLAS Data Acquisition and Trigger concept, design and status

    CERN Document Server

    Kordas, K; Alexandrov, I; Amorim, A; Aracena, I; Armstrong, S; Badescu, E; Baines, J T M; Barros, N; Beck, H P; Bee, C; Bellomo, M; Biglietti, M; Blair, R; Bogaerts, J A C; Bold, T; Bosman, M; Burckhart-Chromek, D; Caprini, M; Caramarcu, C; Carlino, G; Caron, B; Casado, M P; Cataldi, G; Ciobotaru, M; Comune, G; Conde-Muíño, P; Conventi, F; Corso-Radu, A; Cranfield, R; Cranmer, K; Crone, G; Damazio, D; Dawson, J; De Santo, A; Del Prete, T; Della Pietra, M; Di Mattia, A; Diaz-Gomaz, M; Dobinson, Robert W; Dobson, M; Dos Anjos, A; Dotti, A; Drake, G; Ellis, Nick; Emeliyanov, D; Ermoline, Y; Ertorer, E; Falciano, S; Ferrari, R; Ferrer, M L; Francis, D; Gadomski, S; Gameiro, S; Garitaonandia, H; Gaudio, G; Gaumer, O; George, S; Gesualdi-Mello, A; Goncalo, R; Gorini, B; Gorini, E; Green, B; Haas, S; Haberichter, W N; Hadavand, H; Haeberli, C; Haller, J; Hansen, J; Hauser, R; Hillier, S J; Höcker, A; Hughes-Jones, R E; Joos, M; Kabana, S; Kazarov, A; Khomich, A; Kieft, G; Kilvington, G; Kirk, J; Klous, S; Kohno, T; Kolos, S; Konstantinidis, N P; Kootz, A; Korcyl, K; Kotov, V; Kugel, A; Landon, M; Lankford, A; Leahu, L; Leahu, M; Lehmann-Miotto, G; Le Vine, M J; Liu, W; Lowe, A; Luminari, L; Maeno, T; Männer, R; Mapelli, L; Martin, B; Marzano, F; Masik, J; McLaren, R; McMahon, T; Meessen, C; Meirosu, C; Mineev, M; Misiejuk, A; Moore, R; Morettini, P; Mornacchi, G; Müller, M; Murillo-García, R; Nagasaka, Y; Negri, A; Nisati, A; Osuna, C; Padilla, C; Panikashvili, N; Parodi, F; Pasqualucci, E; Pauly, T; Perera, V; Pérez-Réale, V; Petersen, J; Pinfold, J L; Pope, B; Portes de Albuquerqu, M; Potter, C; Pretzl, K; Prigent, D; Primavera, M; Rheaum, P; Robertson, S; Roda, C; Ryabov, Yu; Salvatore, D; Santamarina-Rios, C; Scannicchio, D A; Schiavi, C; Schlereth, J L; Scholtes, I; Seixas, M; Sidoti, A; Sivoklokov, S Yu; Sloper, J; Sole-Segura, E; Soloviev, I; Soluk, R A; Spagnolo, S; Spiwoks, R; Stamen, R; Stancu, S; Stefanidis, E; Strong, J; Sushkov, S; Sutton, M; Szymocha, T; Tapprogge, S; Tarem, S; Tarem, Z; Teixeira-Dias, P; Thomas, E; Torres, R; Touchard, F; Tremblet, L; Unel, N G; Usai, G; Vachon, B; Van Wasen, J; Vandelli, W; Vaz-Gil-Lopes, L; Ventura, A; Vercesi, V; Vermeulen, J; von der Schmitt, H; Warburton, A; Watson, A; Wengler, T; Werner, P; Wheeler, S; Wickens, F; Wiedenmann, W; Wielers, M; Wiesmann, M; Woerling, E E; Wu, X; Yasu, Y; Yu, M; Zema, F; Zobernig, H; 10th Topical Seminar on Innovative Particle and Radiation Detectors

    2007-01-01

    This article presents the base-line design and implementation of the ATLAS Trigger and Data Acquisition system, in particular the Data Flow and High Level Trigger components. The status of the installation and commissioning of the system is also presented.

  2. The Run-2 ATLAS Trigger System: Design, Performance and Plan

    CERN Document Server

    zur Nedden, Martin; The ATLAS collaboration

    2016-01-01

    In high-energy physics experiments, online selection is crucial to select interesting collisions from the large data volume. The ATLAS experiment at the Large Hadron Collider (LHC) utilizes the trigger system that consists of a hardware Level-1 (L1) and a software based high-level trigger (HLT), reducing the event rate from the design bunch-crossing rate of 40 MHz to an average recording rate of about 1000 Hz. The ATLAS trigger has been successfully collecting collision data during the first run of the LHC (Run-1) between 2009-2013 at a centre-of-mass energy between 900 GeV and 8 TeV. In the second run of LHC (Run-2) starting from 2015, the LHC operates at centre-of-mass energy of 13 TeV and provides a higher luminosity of collisions. Also, the number of collisions occurring in a same bunch crossing increases. The ATLAS trigger system has to cope with these challenges, while maintaining or even improving the efficiency to select relevant physics processes. In this talk, first we will review the ATLAS trigger ...

  3. Designing the ATLAS trigger menu for high luminosities

    Science.gov (United States)

    Nakahama, Yu

    2012-12-01

    The LHC has a bunch-crossing rate of 20 MHz whereas the ATLAS detector has an average recording rate of about 400 Hz. To reduce the rate of events but still maintain a high efficiency for selecting interesting events needed by ATLAS physics analyses, a three-level trigger system is used in ATLAS. Events are selected based on the Trigger Menu, the definitions of the physics signatures the experiment triggers on. In the 2012 data taking since April, approximately 700 chains are used online. The menu must reflect not only the physics goals of the collaboration but also take into consideration the LHC luminosity and the strict DAQ limitations. An overview of the design, the validation and the performance of the trigger menu for the 2011 data-taking is given. During 2011, the menu had to evolve as the luminosity increase from below 2×1033 cm-2s-1 to almost 5×1033 cm-2s-1. Re-designing the menu for the up-coming high luminosity of around 1034 cm-2s-1 and large number of collision events that take place per each bunch crossing (pile-up) of around 35 interactions per bunch crossing at √s = 8 TeV is described. Initial performance in the 2012 data-taking is also reported.

  4. Design and Prototyping of the ATLAS High Level Trigger

    Institute of Scientific and Technical Information of China (English)

    J.A.C.Bogaerts

    2001-01-01

    This paper outlines the desgn and prototyping of the ATLAS High Level Trigger(HLT)wihch is a combined effort of the Data Collection HLT and PESA(Physics and Event Selection Architecture)subgroups within the ATLAS TDAQ collaboration.Two important issues,alresdy outlined in the ATLAS HLT,DAQ and DCS Technical Proposal [1] will be highlighted:the treatment of the LVL2 Trigger and Event Filter as aspects of a general HLT with a view to easier migration of algorthms between the two levels;unification of the selective data collection for LVL2 and Event Building.

  5. The design and performance of the ATLAS Inner Detector trigger for Run 2

    CERN Document Server

    Penc, Ondrej; The ATLAS collaboration

    2016-01-01

    The design and performance of the ATLAS Inner Detector (ID) trigger algorithms running online on the high level trigger (HLT) processor farm with the early LHC Run 2 data are discussed. The redesign of the ID trigger, which took place during the 2013-15 long shutdown, in order to satisfy the demands of the higher energy LHC Run 2 operation is described. The ID trigger HLT algorithms are essential for nearly all trigger signatures within the ATLAS trigger. The detailed performance of the tracking algorithms with the early Run 2 data for the different trigger signatures is presented, including the detailed timing performance for the algorithms running on the redesigned single stage ATLAS HLT Farm. Comparison with the Run 1 strategy are made and demonstrate the superior performance of the strategy adopted for Run 2.

  6. The design and performance of the ATLAS Inner Detector trigger for Run 2

    CERN Document Server

    Penc, Ondrej; The ATLAS collaboration

    2015-01-01

    The design and performance of the ATLAS Inner Detector (ID) trigger algorithms running online on the high level trigger (HLT) processor farm with the early LHC Run 2 data are discussed. The redesign of the ID trigger, which took place during the 2013-15 long shutdown, in order to satisfy the demands of the higher energy LHC Run 2 operation is described. The ID trigger HLT algorithms are essential for nearly all trigger signatures within the ATLAS trigger. The detailed performance of the tracking algorithms with the early Run 2 data for the different trigger signatures is presented, including the detailed timing performance for the algorithms running on the redesigned single stage ATLAS HLT Farm. Comparison with the Run 1 strategy are made and demonstrate the superior performance of the strategy adopted for Run 2.

  7. Design and performance of the ATLAS jet trigger system

    CERN Document Server

    Tavares Delgado, Ademar; The ATLAS collaboration

    2015-01-01

    The CERN Large Hadron Collider is the biggest and most powerful particle collider made by man. It produces up to 40 million proton-proton collisions per second at unprecedented energies to explore the fundamental laws and properties of Nature. The ATLAS experiment is one of the detectors that analyse and record these collisions. It generates a huge data volume that has to be reduced before it can be permanently stored. The event selection is made by the ATLAS trigger system, which reduces the data volume by a factor of 10^{5}. The trigger system has to be highly configurable in order to adapt to changing running conditions and maximize the physics output whilst keeping the output rate under control. A particularly interesting pattern generated during collisions consists of a collimated spray of particles, known as a hadronic jet. To retain the interesting jets and efficiently reject the overwhelming background, optimal jet energy resolution is needed. Therefore the Jet trigger software requires CPU-intensive ...

  8. The ATLAS Run-2 Trigger: Design, Menu, Performance and Operational Aspects

    CERN Document Server

    Martin, Tim; The ATLAS collaboration

    2016-01-01

    The LHC, at design capacity, has a bunch-crossing rate of 40 MHz whereas the ATLAS experiment at the LHC has an average recording rate of about 1000 Hz. To reduce the rate of events but still maintain a high efficiency of selecting rare events such as physics signals beyond the Standard Model, a two-level trigger system is used in ATLAS. Events are selected based on physics signatures such as presence of energetic leptons, photons, jets or large missing energy. Despite the limited time available for processing collision events, the trigger system is able to exploit topological information, as well as using multi-variate methods. In total, the ATLAS trigger system consists of thousands of different individual triggers. The ATLAS trigger menu specifies which triggers are used during data taking and how much rate a given trigger is allocated. This menu reflects not only the physics goals of the collaboration but also takes the instantaneous luminosity of the LHC, the design limits of the ATLAS detector and the o...

  9. The ATLAS Run-2 Trigger: Design, Menu, Performance and Operational Aspects

    CERN Document Server

    Machado Miguens, Joana; The ATLAS collaboration

    2016-01-01

    The LHC, at design capacity, has a bunch-crossing rate of 40 MHz whereas the ATLAS experiment has an average recording rate of about 1000 Hz. To reduce the rate of events but still maintain high efficiency of selecting rare events such as physics signals beyond the Standard Model, a two-level trigger system is used in ATLAS. Events are selected based on physics signatures such as presence of energetic leptons, photons, jets or large missing energy. Despite the limited time available for processing collision events, the trigger system is able to exploit topological informations, as well as using multi-variate methods. In total, the ATLAS trigger systems consists of thousands of different individual triggers. The ATLAS trigger menu specifies which triggers are used during data taking and how much rate a given trigger is allocated. This menu reflects not only the physics goals of the collaboration but also takes into consideration the instantaneous luminosity of the LHC and the design limits of the ATLAS detecto...

  10. The design of a fast Level 1 track trigger for the ATLAS High Luminosity Upgrade

    CERN Document Server

    Allbrooke, Benedict; The ATLAS collaboration

    2016-01-01

    The design of a fast Level 1 track trigger for the ATLAS High Luminosity Upgrade The ATLAS experiment at the high-luminosity LHC will face a five-fold increase in the number of interactions per collision relative to the ongoing Run 2. This will require a proportional improvement in rejection power at the earliest levels of the detector trigger system, while preserving good signal efficiency. One critical aspect of this improvement will be the implementation of precise track reconstruction, through which sharper turn-on curves, b-tagging and tau-tagging techniques can in principle be implemented. The challenge of such a project comes in the development of a fast, precise custom electronic device integrated in the hardware-based first trigger level of the experiment, with repercussions propagating as far as the detector read-out philosophy. This talk will discuss the projected performance of the system in terms of tracking, timing and physics.

  11. Design of a Hardware Track Finder (Fast Tracker) for the ATLAS Trigger

    CERN Document Server

    Volpi, G; The ATLAS collaboration

    2013-01-01

    The ATLAS Fast TracKer is a custom electronics system that will operate at the full Level-1 accept rate, 100 kHz, to provide high quality tracks as input to the Level-2 trigger. The event reconstruction is performed in hardware, thanks to the massive parallelism of associative memories (AM) and FPGAs. We present the advantages for the physics goals of the ATLAS experiment and the recent results on the design, technological advancements and testing of some of the core components used in the processor.

  12. ATLAS high-level trigger, data-acquisition and controls Technical Design Report

    CERN Document Server

    CERN. Geneva. LHC Experiments Committee; Nessi, Marzio; Nordberg, Markus; Smith, Kenway

    2003-01-01

    This Technical Design Report (TDR) for the High-Level-Trigger (HLT), Data Acquisition (DAQ) and Controls of the ATLAS experiment builds on earlier documents published on these systems: Trigger Performance Status Report [1-1], DAQ, EF, LVL2 and DCS Technical Progress Report [1-2], and HLT/DAQ/DCS Technical Proposal [1-3]. Much background and preparatory work relevant to this TDR is referenced in the above documents. In addition, a large amount of detailed technical documentation has been produced in support of this TDR.

  13. The design and performance of the ATLAS Inner Detector trigger for Run 2

    Science.gov (United States)

    Qin, Yang

    2016-09-01

    The design and performance of the ATLAS Inner Detector (ID) trigger algorithms running online on the High Level Trigger (HLT) computing cluster with the early LHC Run 2 data are discussed. During the LHC shutdown from 2013 to 2015, the HLT farm was redesigned to run in a single HLT stage, rather than in two stages (Level 2 and Event Filter) as was used in Run 1. This allowed for a redesign of the HLT ID tracking algorithm, which aims to satisfy the challenging demands of the higher collision energy of the LHC in Run 2 and is essential for tracking of different charged particles in the ATLAS detector. The detailed performance of the tracking algorithms with the initial Run 2 data is discussed for electrons, muons and other charged particles. Comparison with the Run 1 strategy is made and demonstrates the superior performance of the strategy adopted for Run 2.

  14. The design and performance of the ATLAS Inner Detector trigger for Run-II

    CERN Document Server

    Qin, Yang; The ATLAS collaboration

    2015-01-01

    The design and performance of the ATLAS Inner Detector (ID) trigger algorithms running online on the high level trigger (HLT) processor farm with the early LHC Run 2 data are discussed. During the 2013-15 LHC shutdown, the HLT farm was redesigned to run in a single HLT stage, rather than the two-stage (Level 2 and Event Filter) used in Run 1. This allowed a redesign of the HLT ID tracking algorithms, essential for nearly all physics signatures in ATLAS. The redesign of the ID trigger, required in order to satisfy the challenging demands of the higher energy LHC Run 2 operation, is described. The detailed performance of the tracking algorithms with the initial Run 2 data is discussed, for the different physics signatures. This includes both the physics object reconstruction and timing performance for the algorithms running on the redesigned single stage ATLAS HLT Farm. Comparison with the Run 1 strategy are made and demonstrate the superior performance of the strategy adopted for Run 2.

  15. The design and performance of the ATLAS Inner Detector trigger for Run 2

    CERN Document Server

    Qin, Yang; The ATLAS collaboration

    2015-01-01

    The design and performance of the ATLAS Inner Detector (ID) trigger algorithms running online on the High Level Trigger (HLT) processor farm with the early LHC Run 2 data are discussed. During the 2013-15 LHC shutdown, the HLT farm was redesigned to run in a single HLT stage, rather than the two-stage (Level 2 and Event Filter) used in Run 1. This allowed a redesign of the HLT ID tracking algorithms, essential for nearly all physics signatures in ATLAS. The redesign of the ID trigger, required in order to satisfy the challenging demands of the higher energy LHC Run 2 operation, is described. The detailed performance of the tracking algorithms with the initial Run 2 data is discussed, for the different physics signatures. This includes both the physics object reconstruction and timing performance for the algorithms running on the redesigned single stage ATLAS HLT Farm. Comparison with the Run 1 strategy is made and demonstrates the superior performance of the strategy adopted for Run 2.

  16. The design of a fast Level-1 track trigger for the high luminosity upgrade of ATLAS.

    CERN Document Server

    Gradin, Per Olov Joakim; The ATLAS collaboration

    2016-01-01

    The high/luminosity upgrade of the LHC will increase the rate of the proton-proton collisions by approximately a factor of 5 with respect to the initial LHC-design. The ATLAS experiment will upgrade consequently, increasing its robustness and selectivity in the expected high radiation environment. In particular, the earliest, hardware based, ATLAS trigger stage ("Level 1") will require higher rejection power, still maintaining efficient selection on many various physics signatures. The key ingredient is the possibility of extracting tracking information from the brand new full-silicon detector and use it for the process. While fascinating, this solution poses a big challenge in the choice of the architecture, due to the reduced latency available at this trigger level (few tens of micro-seconds) and the high expected working rates (order of MHz). In this paper, we review the design possibilities of such a system in a potential new trigger and readout architecture, and present the performance resulting from a d...

  17. The ATLAS Data Acquisition and High-Level Trigger Concept, Design and Status

    CERN Document Server

    Gorini, B; Alexandrov, I; Amorim, A; Aracena, I; Armstrong, S; Badescu, E; Baines, J T M; Barros, N; Beck, H P; Bee, C; Bellomo, M; Biglietti, M; Blair, R; Bogaerts, J A C; Bold, T; Bosman, M; Burckhart-Chromek, D; Caprini, M; Caramarcu, C; Carlino, G; Caron, B; Casado, M P; Cataldi, G; Ciobotaru, M; Comune, G; Conde-Muíño, P; Conventi, F; Corso-Radu, A; Cranfield, R; Cranmer, K; Crone, G; Damazio, D; Dawson, J; De Santo, A; Del Prete, T; Della Pietra, M; Di Mattia, A; Diaz-Gomaz, M; Dobinson, Robert W; Dobson, M; Dos Anjos, A; Dotti, A; Drake, G; Ellis, Nick; Emeliyanov, D; Ermoline, Y; Ertorer, E; Falciano, S; Ferrari, R; Ferrer, M L; Francis, D; Gadomski, S; Gameiro, S; Garitaonandia, H; Gaudio, G; Gaumer, O; George, S; Gesualdi-Mello, A; Goncalo, R; Gorini, E; Green, B; Haas, S; Haberichter, W N; Hadavand, H; Haeberli, C; Haller, J; Hansen, J; Hauser, R; Hillier, S J; Höcker, A; Hughes-Jones, R E; Joos, M; Kabana, S; Kazarov, A; Khomich, A; Kieft, G; Kilvington, G; Kirk, J; Klous, S; Kohno, T; Kolos, S; Konstantinidis, N P; Kootz, A; Korcyl, K; Kordas, K; Kotov, V; Kugel, A; Landon, M; Lankford, A; Leahu, L; Leahu, M; Lehmann-Miotto, G; Le Vine, M J; Liu, W; Lowe, A; Luminari, L; Maeno, T; Männer, R; Mapelli, L; Martin, B; Marzano, F; Masik, J; McLaren, R; McMahon, T; Meessen, C; Meirosu, C; Mineev, M; Misiejuk, A; Moore, R; Morettini, P; Mornacchi, G; Müller, M; Murillo-García, R; Nagasaka, Y; Negri, A; Nisati, A; Osuna, C; Padilla, C; Panikashvili, N; Parodi, F; Pasqualucci, E; Pauly, T; Perera, V; Pérez-Réale, V; Petersen, J; Pinfold, J L; Pope, B; Portes de Albuquerqu, M; Potter, C; Pretzl, K; Prigent, D; Primavera, M; Rheaum, P; Robertson, S; Roda, C; Ryabov, Yu; Salvatore, D; Santamarina-Rios, C; Scannicchio, D A; Schiavi, C; Schlereth, J L; Scholtes, I; Seixas, M; Sidoti, A; Sivoklokov, S Yu; Sloper, J; Sole-Segura, E; Soloviev, I; Soluk, R A; Spagnolo, S; Spiwoks, R; Stamen, R; Stancu, S; Stefanidis, E; Strong, J; Sushkov, S; Sutton, M; Szymocha, T; Tapprogge, S; Tarem, S; Tarem, Z; Teixeira-Dias, P; Thomas, E; Torres, R; Touchard, F; Tremblet, L; Unel, N G; Usai, G; Vachon, B; Van Wasen, J; Vandelli, W; Vaz-Gil-Lopes, L; Ventura, A; Vercesi, V; Vermeulen, J; von der Schmitt, H; Warburton, A; Watson, A; Wengler, T; Werner, P; Wheeler, S; Wickens, F; Wiedenmann, W; Wielers, M; Wiesmann, M; Woerling, E E; Wu, X; Yasu, Y; Yu, M; Zema, F; Zobernig, H

    2006-01-01

    The Trigger and Data Acquisition system (TDAQ) of the ATLAS experiment at the CERN Large Hadron Collider is based on a multi-level selection process and a hierarchical acquisition tree. The system, consisting of a combination of custom electronics and commercial products from the computing and telecommunication industry, is required to provide an online selection power of 105 and a total throughput in the range of Terabit/sec. This paper introduces the basic system requirements and concepts, describes the architecture of the system, discusses the basic measurements supporting the validity of the design and reports on the actual status of construction and installation.

  18. The final design of the ATLAS Trigger/DAQ Readout-Buffer Input (ROBIN) Device

    CERN Document Server

    Kugel, A; Müller, M; Yu, M; Krause, E; Gorini, B; Joos, M; Petersen, J; Stancu, S; Green, B; Misiejuk, A; Kieft, G; Van Wasen, J; 10th Workshop on Electronics for LHC and Future Experiments

    2004-01-01

    The ATLAS readout subsystem (ROS) is the main interface between 1600 detector front-end readout links (ROL) and the high level (HLT) trigger farms. Its core device, the readout-buffer input (ROBIN), accepts event data on 3 readout links (ROLs) with a maximum rate of 100 kHz and a bandwidth of up to 160\\,MB/s per link. Incoming event data is temporarily buffered and delivered via PCI or Gigabit Ethernet on request. Two devices, a XILINX XC2V2000 FPGA and an IBM PowerPC 440, are present, implementing the ROBIN's functionality. Furthermore one 64 MB SDRAM event data buffer is available per ROL. The device supports the ATLAS baseline implementation, which foresees the PCI bus as the main communication path inside the ROS, as well as an optional data path using Gigabit Ethernet to increase scalability when needed. The paper presents the final design of the ATLAS ROBIN. Measurement results, obtained with a prototype device in PCI bus and Gigabit Ethernet setups, show the usability and approve the design choices.

  19. ATLAS Muon Trigger

    CERN Document Server

    Woudstra, MJ; The ATLAS collaboration

    2013-01-01

    CERN’s Large Hadron Collider (LHC) is the highest energy proton-proton collider, providing also the highest instantaneous luminosity as a hadron collider. Bunch crossings occurred every 50 ns in 2012 runs. Amongst of which the online event selection system should reduce the event recording rate down to a few 100 Hz, while events are in a harsh condition with many overlapping proton-proton collisions occurring in a same bunch crossing. Muons often provide an important and clear signature of physics processes that are searched for, for instance as in the discovery of Higgs particle in year 2012. The ATLAS experiment deploys a three-levels processing scheme at online. The level-1 muon trigger system gets its input from fast muon trigger detectors. Fast sector logic boards select muon candidates, which are passed via an interface board to the central trigger processor and then to the High Level Trigger (HLT). The muon HLT is purely software based and encompasses a level-2 (L2) trigger followed by an event filte...

  20. ATLAS FTK: Fast Track Trigger

    CERN Document Server

    Volpi, Guido; The ATLAS collaboration

    2015-01-01

    An overview of the ATLAS Fast Tracker processor is presented, reporting the design of the system, its expected performance, and the integration status. The next LHC runs, with a significant increase in instantaneous luminosity, will provide a big challenge to the trigger and data acquisition systems of all the experiments. An intensive use of the tracking information at the trigger level will be important to keep high efficiency in interesting events, despite the increase in multiple p-p collisions per bunch crossing (pile-up). In order to increase the use of tracks within the High Level Trigger (HLT), the ATLAS experiment planned the installation of an hardware processor dedicated to tracking: the Fast TracKer (FTK) processor. The FTK is designed to perform full scan track reconstruction at every Level-1 accept. To achieve this goal, the FTK uses a fully parallel architecture, with algorithms designed to exploit the computing power of custom VLSI chips, the Associative Memory, as well as modern FPGAs. The FT...

  1. The ATLAS Trigger Muon "Vertical Slice"

    CERN Document Server

    Sidoti, A; Biglietti, M; Carlino, G; Cataldi, G; Conventi, F; Del Prete, T; Di Mattia, A; Falciano, S; Gorini, S; Kanaya, N; Kohno, T; Krasznahorkay, A; Lagouri, T; Luci, C; Luminari, L; Marzano, F; Nagano, K; Nisati, A; Panikashvili, N; Pasqualucci, E; Primavera, M; Scannicchio, D A; Spagnolo, S; Tarem, S; Tarem, Z; Tokushuku, K; Usai, G; Ventura, A; Vercesi, V; Yamazaki, Y; 10th Pisa Meeting on Advanced Detectors : Frontier Detectors For Frontier Physics

    2007-01-01

    The muon trigger system is a fundamental component of the ATLAS detector at the LHC collider. In this paper we describe the ATLAS multi-level trigger selecting events with muons: the Muon Trigger Slice.

  2. The Design and Performance of the ATLAS Inner Detector Trigger for Run 2 LHC Collisions at 13 TeV

    CERN Document Server

    Kilby, Callum; The ATLAS collaboration

    2016-01-01

    The design and performance of the ATLAS Inner Detector (ID) trigger algorithms running online on the high level trigger (HLT) processor farm with the LHC Run 2 data with collisions at both 50 ns and 25 ns are discussed. The HLT ID tracking algorithms are essential for the identification of nearly all physics signatures in the ATLAS trigger. In order to deal with the expected higher rates for LHC Run 2, the ID trigger was redesigned during the 2013-15 long shutdown to satisfy the demands of the higher energy LHC operation. The detailed performance of the tracking algorithms with the Run 2 data taken so far for the different trigger signatures in terms of both efficiency, and resolution is presented. The online processing times for running trigger tracking for the different trigger signatures are discussed in detail. Where appropriate, comparison of the new strategy for Run 2, with that adopted in Run 1 are made to demonstrate successful application and superior performance of the strategy adopted for Run 2.

  3. Design of a Hardware Track Finder (Fast Tracker) for the ATLAS Trigger

    CERN Document Server

    Cavaliere, Viviana; The ATLAS collaboration

    2015-01-01

    The use of tracking information at the trigger level in the LHC Run II period is crucial for the trigger an data acquisition (TDAQ) system and will be even more so as contemporary collisions that occur at every bunch crossing will increase in Run III. The Fast TracKer (FTK) is part of the ATLAS trigger upgrade project; it is a hardware processor that will provide every Level-1 accepted event (100 kHz) and within 100$\\mu$s, full tracking information for tracks with momentum as low as 1 GeV. Providing fast, extensive access to tracking information, with resolution comparable to the offline reconstruction, FTK will help in precise detection of the primary and secondary vertices to ensure robust selections and improve the trigger performance.

  4. The ATLAS Hadronic Tau Trigger

    CERN Document Server

    Brost, E; The ATLAS collaboration

    2014-01-01

    As proton-proton collisions at the LHC reach luminosities close to 10$^{\\mathrm{34}}$ cm$^{\\mathrm{-2}}$ s $^{\\mathrm{-1}}$, the strategies for triggering have become more important than ever for physics analyses. Simplistic single tau lepton triggers suffer from severe rate limitation, despite the sophisticated algorithms used in the tau identification. The development of further fast algorithms and the design of topological selections are the main challenges to allow a large program of physics analysis. The tau triggers provide many opportunities to study new physics beyond the Standard Model, and to get precise measurements of the properties of the Higgs boson decaying to tau-leptons. We present the performance of the hadronic tau trigger taken in Run 1 data with the ATLAS detector at $\\sqrt{s}$ = 8 TeV pp collision. One of the major challenges is to sustain high efficiencies in events with multiple interactions. To do this we introduced faster tracking methods, multivariate selection techniques, and new t...

  5. The ATLAS Hadronic Tau Trigger

    CERN Document Server

    Mahlstedt, J; The ATLAS collaboration

    2014-01-01

    During the 2012 run the Large Hadron Collider (LHC) reached instantaneous luminosities of nearly $10^{34}\\,cm^{-2}s^{-1}$, with bunch crossings occuring every 50 ns. In this difficult environment of several overlapping interactions per bunch crossing (pile-up) the trigger system of the ATLAS detector has the task of reducing the event rate from 40 MHz to a few hundred Hz while keeping the most interesting physics events. Being the heaviest of all leptons, the tau lepton plays an important role in many physics processes. The ability to trigger on events containing hadronically decaying taus is therefore of special interest. This paper summarizes the concept of the ATLAS tau trigger and the improvements made in 2012. Furthermore the performance of the triggers including efficiency and rate measurements are presented and an outlook towards future developments of the tau trigger algorithms is given.

  6. ATLAS trigger for first physics and beyond

    CERN Document Server

    Fonseca-Martin, T

    2009-01-01

    ATLAS is a multi-purpose spectrometer built to perform precision measurements of Standard Model parameters and is aiming at discovery of Higgs particle, Super Symmetry and possible other physics channels beyond Standard Model. Operating at 14 TeV center of mass energy ATLAS will see 40 million events per second at nominal luminosity with about 25 overlapping interactions. Most of the events are inelastic proton-proton interactions with only few W, Z bosons or ttbar pairs produced each second, and expectations for Higgs or SUSY production cross-section are much smaller than that. ATLAS trigger has a difficult task to select one out of $10^5$ events online and to ensure that most physics channels of interests are preserved for analysis. In this talk we will review the design of ATLAS trigger system, the trigger menu prepared for initial LHC run as well as for high luminosity run. The expected trigger performance of the base-line ATLAS physics programs will be reviewed and first results from the commissioning pe...

  7. The baseline dataflow system of the ATLAS trigger and DAQ

    CERN Document Server

    Vermeulen, J C; Dos Anjos, A; Barisonzi, M; Beck, H P; Beretta, M; Blair, R; Bogaerts, J A C; Boterenbrood, H; Botterill, David R; Ciobotaru, M; Palencia-Cortezon, E; Cranfield, R; Crone, G J; Dawson, J; Di Girolamo, B; Dobinson, Robert W; Ermoline, Y; Ferrer, M L; Francis, D; Gadomski, S; Gameiro, S; Golonka, P; Gorini, B; Green, B; Gruwé, M; Haas, S; Haeberli, C; Hasegawa, Y; Hauser, R; Hinkelbein, C; Hughes-Jones, R E; Jansweijer, P; Joos, M; Kaczmarska, A; Knezo, E; Kieft, G; Korcyl, K; Kugel, A; Lankford, A; Lehmann, G; Le Vine, M J; Liu, W; Maeno, T; Losada-Maia, L; Mapelli, L; Martin, B; McLaren, R; Meirosu, C; Misiejuk, A; Mommsen, R K; Mornacchi, Giuseppe; Müller, M; Nagasaka, Y; Nakayoshi, K; Papadopoulos, I M; Petersen, J; De Matos-Lopes-Pinto, P; Prigent, D; Pérez-Réale, V; Schlereth, J L; Shimojima, M; Spiwoks, R; Stancu, S; Strong, J; Tremblet, L; Werner, P; Wickens, F J; Yasu, Y; Yu, M; Zobernig, H; Zurek, M

    2003-01-01

    In this paper the baseline design of the ATLAS High Level Trigger and Data Acquisition system with respect to the DataFlow aspects, as presented in the recently submitted ATLAS Trigger/DAQ/Controls Technical Design Report [1], is reviewed and recent results of testbed measurements and from modelling are discussed. [1] ATLAS-TDR-016; CERN-LHCC-2003-022, http://cdsweb.cern.ch/search.py?recid=616089

  8. The design of a fast Level-1 track trigger for the High Luminosity Upgrade of ATLAS

    CERN Document Server

    Gradin, Per Olov Joakim; The ATLAS collaboration

    2016-01-01

    To increase the number of proton-proton collisions the Large Hadron Collider at CERN aims to increase its instantaneuos luminosity to around five times the nominal value for run four, set to begin in 2026. This will force the experiments, including ATLAS, to adapt to the increased event rate which will require substantial hardware upgrades. The current trigger system will not be able to cope with these rates without raised thresholds wich would mean loosing many of the events. To increase the rejection rate without loosing signal efficiency tracking information could be utilized in the first level hardware trigger. This document presents results from simulating a track trigger seeded by regions of interest. It is shown that with this approach we can reach a five times rejection of background events while keeping the single lepton efficiency above 95%. To reduce the amount of track fits needed per event the L1Track trigger is not only seeded by regions of interest corresponding to 10% of the tracking volume, b...

  9. Minimum Bias Trigger in ATLAS

    International Nuclear Information System (INIS)

    Since the restart of the LHC in November 2009, ATLAS has collected inelastic pp collisions to perform first measurements on charged particle densities. These measurements will help to constrain various models describing phenomenologically soft parton interactions. Understanding the trigger efficiencies for different event types are therefore crucial to minimize any possible bias in the event selection. ATLAS uses two main minimum bias triggers, featuring complementary detector components and trigger levels. While a hardware based first trigger level situated in the forward regions with 2.2 < |η| < 3.8 has been proven to select pp-collisions very efficiently, the Inner Detector based minimum bias trigger uses a random seed on filled bunches and central tracking detectors for the event selection. Both triggers were essential for the analysis of kinematic spectra of charged particles. Their performance and trigger efficiency measurements as well as studies on possible bias sources will be presented. We also highlight the advantage of these triggers for particle correlation analyses. (author)

  10. The first-level trigger of ATLAS

    CERN Document Server

    Haller, J; Aielli, G; Aloisio, A; Alviggi, M G; Aprodu, V; Ask, S; Barnett, B M; Bartos, D; Bauss, B; Belkin, A; Benhammou, Ya; Bocci, V; Booth, J R A; Brambilla, Elena; Brawn, I P; Bressler, S; Buda, S; Bohm, C; Canale, V; Caracinha, D; Cardarelli, R; Carlino, G; Cataldi, G; Charlton, D G; Chiodi, G; Ciapetti, G; Constantin, S; Conventi, F; Davis, A O; De Asmundis, R; De Pedis, D; De Seixas, J M; Della Pietra, M; Della Volpe, D; Di Ciaccio, A; Di Girolamo, A; Di Mattia, A; Di Simone, A; Distante, L; Dogaru, M; Edwards, J; Eisenhandler, E F; Ellis, Nick; Etzion, E; Farthouat, P; Fukunaga, C; Föhlisch, F; Gee, C N P; Gennari, E; Geweniger, C; Gillman, A R; Gorini, E; Grancagnolo, F; Gällnö, P; Haas, S; Hanke, P; Harel, A; Hasegawa, Y; Hellman, S; Hidvegi, A; Hillier, S J; Ichimiya, R; Iengo, P; Ikeno, M; Ishino, M; Iwasaki, H; Izzo, V; Kagawa, S; Kanaya, N; Kawagoe, K; Kawamoto, T; Kiyamura, H; Kluge, E -E; Kobayashi, T; Krasznahorkay, A; Kurashige, H; Kuwabara, T; Landon, M; Lellouch, D; Levinson, L; Lifshitz, R; Luci, C; Lupu, N; Magureanu, C; Mahboubi, K; Mahout, G; Meier, K; Migliaccio, A; Mikenberg, G; Mirea, A; Moye, T H; Nagano, K; Nisati, A; Nomachi, M; Nomoto, H; Nozaki, M; Ochi, A; Ogata, T; Omachi, C; Oshita, H; Pasqualucci, E; Pastore, F; Patricelli, S; Pauly, T; Pectu, M; Perantoni, M; Perera, V J O; Perrino, R; Pessoa-Lima, H; Petrolo, E; Primavera, M; Prodan, L; Qian, W; Rieke, S; Rusu, A; Rühr, F; Sakamoto, H; Salamon, A; Sankey, D P C; Santonico, R; Sasaki, O; Schmitt, K; Schuler, G; Schultz-Coulon, H C; Schäfer, U; Sekhniaidze, G; Silverstein, S; Spagnolo, S; Spila, F; Spiwoks, R; Staley, R J; Sugaya, Y; Sugimoto, T; Takeda, H; Takeshita, T; Tanaka, S; Tapprogge, S; Tarem, S; Thomas, J P; Trefzger, T; Typaldos, D; Uroseviteanu, C; Vari, R; Veneziano, Stefano; Watkins, P M; Watson, A; Weber, G A; Weber, P; Wengler, T; Woerling, E E; Yamaguchi, Y; Yasu, Y; Zanello, L

    2006-01-01

    Due to the huge interaction rates and the tough experimental environment of pp collisions at a centre-of-mass energy sqrt(s)=14 TeV and luminosities of up to 10^34cm^-2s^-1, one of the experimental challenges at the LHC is the triggering of interesting events. In the ATLAS experiment a three-level trigger system is foreseen for this purpose. The first-level trigger is implemented in custom hardware and has been designed to reduce the data rate from the initial bunch-crossing rate of 40MHz to around 75 kHz. Its event selection is based on information from the calorimeters and dedicated muon detectors. This article gives an overview over the full first-level trigger system including the Calorimeter Trigger, the Muon Trigger and the Central Trigger Processor. In addition, recent results are reported that have been obtained from test-beam studies performed at CERN where the full first-level trigger chain was established successfully for the first time and used to trigger the read-out of up to nine ATLAS sub-detec...

  11. The Run-2 ATLAS Trigger System

    CERN Document Server

    Ruiz-Martinez, Aranzazu; The ATLAS collaboration

    2016-01-01

    The ATLAS trigger has been successfully collecting collision data during the first run of the LHC between 2009-2013 at a centre-of-mass energy between 900 GeV and 8 TeV. The trigger system consists of a hardware Level-1 (L1) and a software based high-level trigger (HLT) that reduces the event rate from the design bunch-crossing rate of 40 MHz to an average recording rate of a few hundred Hz. In Run-2, the LHC will operate at centre-of-mass energies of 13 and 14 TeV resulting in roughly five times higher trigger rates. We will briefly review the ATLAS trigger system upgrades that were implemented during the shutdown, allowing us to cope with the increased trigger rates while maintaining or even improving our efficiency to select relevant physics processes. This includes changes to the L1 calorimeter and muon trigger systems, the introduction of a new L1 topological trigger module and the merging of the previously two-level HLT system into a single event filter farm. At hand of a few examples, we will show the ...

  12. The Run-2 ATLAS Trigger System

    CERN Document Server

    Ruiz-Martinez, Aranzazu; The ATLAS collaboration

    2016-01-01

    The ATLAS trigger successfully collected collision data during the first run of the LHC between 2009-2013 at different centre-of-mass energies between 900 GeV and 8 TeV. The trigger system consists of a hardware Level-1 and a software-based high level trigger (HLT) that reduces the event rate from the design bunch-crossing rate of 40 MHz to an average recording rate of a few hundred Hz. In Run-2, the LHC will operate at centre-of-mass energies of 13 and 14 TeV and higher luminosity, resulting in roughly five times higher trigger rates. A brief review of the ATLAS trigger system upgrades that were implemented between Run-1 and Run-2, allowing to cope with the increased trigger rates while maintaining or even improving the efficiency to select physics processes of interest, will be given. This includes changes to the Level-1 calorimeter and muon trigger systems, the introduction of a new Level-1 topological trigger module and the merging of the previously two-level HLT system into a single event filter farm. A ...

  13. The ATLAS Trigger Commissioning with cosmic rays

    CERN Document Server

    Abolins, M; Adragna, P; Aielli, G; Aleksandrov, E; Aleksandrov, I; Aloisio, A; Alviggi, M G; Amorim, A; Anderson, K; Andrei, V; Anduaga, X; Antonelli, S; Aracena, I; Ask, S; Asquith, L; Avolio, G; Backlund, S; Badescu, E; Bahat Treidel, O; Baines, J; Barnett, B M; Barria, P; Bartoldus, R; Batreanu, S; Bauss, B; Beck, H P; Bee, C; Bell, P; Bell, W H; Bellagamba, L; Bellomo, M; Ben Ami, S; Bendel, M; Benhammou, Ya; Benslama, K; Berge, D; Berger, N; Berry, T; Bianco, M; Biglietti, M; Blair, R R; Bogaerts, A; Bohm, C; Bold, T; Booth, J R A; Boscherini, D; Bosman, M; Boyd, J; Brawn, I P; Brelier, B; Bressler, S; Bruni, A; Bruni, G; Buda, S; Burckhart-Chromek, D; Buttar, C; Camarri, P; Campanelli, M; Canale, V; Caprini, M; Caracinha, D; Cardarelli, R; Carlino, G; Casadei, D; Casado, M P; Cataldi, G; Cerri, A; Charlton, D G; Chiodini, G; Ciapetti, G; Cimino, D; Ciobotaru, M; Clements, D; Coccaro, A; Coluccia, M R; Conde-Muíño, P; Constantin, S; Conventi, F; Corso-Radu, A; Costa, M J; Coura Torres, R; Cranfield, R; Cranmer, K; Crone, G; Curtis, C J; Dam, M; Damazio, D; Davis, A O; Dawson, I; Dawson, J; De Almeida Simoes, J; De Cecco, S; De Pedis, D; De Santo, A; DeAsmundis, R; DellaPietra, M; DellaVolpe, D; Delsart, P A; Demers, S; Demirkoz, B; Di Mattia, A; Di Ciaccio, A; Di Girolamo, A; Dionisi, C; Djilkibaev, R; Dobinson, Robert W; Dobson, M; Dogaru, M; Dotti, A; Dova, M; Drake, G; Dufour, M -A; Eckweiler, S; Ehrenfeld, W; Eifert, T; Eisenhandler, E F; Ellis, Nick; Emeliyanov, D; Enoque Ferreira de Lima, D; Ermoline, Y; Eschrich, I; Etzion, E; Facius, K; Falciano, S; Farthouat, P; Faulkner, P J W F; Feng, E; Ferland, J; Ferrari, R; Ferrer, M L; Fischer, G; Fonseca-Martin, T; Francis, D; Fukunaga, C; Föhlisch, F; Gadomski, S; Garitaonandia Elejabarrieta, H; Gaudio, G; Gaumer, O; Gee, C N P; George, S; Geweniger, C; Giagu, S; Gillman, A R; Giusti, P; Goncalo, R; Gorini, B; Gorini, E; Gowdy, S; Grabowska-Bold, I; Grancagnolo, F; Grancagnolo, S; Green, B; Galllno, P; Haas, S; Haberichter, W; Hadavand, H; Haeberli, C; Haller, J; Hamilton, A; Hanke, P; Hansen, J R; Hasegawa, Y; Hauschild, M; Hauser, R; Head, S; Hellman, S; Hidvegi, A; Hillier, S J; Höcker, A; Hrynóva, T; Hughes-Jones, R; Huston, J; Iacobucci, G; Idarraga, J; Iengo, P; Igonkina, O; Ikeno, M; Inada, M; Ishino, M; Iwasaki, H; Izzo, V; Jain, V; Johansen, M; Johns, K; Joos, M; Kadosaka, T; Kajomovitz, E; Kama, S; Kanaya, N; Kawagoe, K; Kawamoto, T; Kazarov, A; Kehoe, R; Khoriauli, G; Kieft, G; Kilvington, G; Kirk, J; Kiyamura, H; Klofver, P; Klous, S; Kluge, E E; Kobayashi, T; Kolos, S; Kono, T; Konstantinidis, N; Korcyl, K; Kordas, K; Kotov, V; Krasznahorkay, A; Kubota, T; Kugel, A; Kuhn, D; Kurashige, H; Kurasige, H; Kuwabara, T; Kwee, R; Landon, M; Lankford, A; LeCompte, T; Leahu, L; Leahu, M; Ledroit, F; Lehmann-Miotto, G; Lei, X; Lellouch, D; Lendermann, V; Levinson, L; Leyton, M; Li, S; Liberti, B; Lifshitz, R; Lim, H; Lohse, T; Losada, M; Luci, C; Luminari, L; Lupu, N; Mahboubi, K; Mahout, G; Mapelli, L; Marchese, F; Martin, B; Martin, B T; Martínez, A; Marzano, F; Masik, J; McMahon, T; McPherson, R; Medinnis, M; Meessen, C; Meier, K; Meirosu, C; Messina, A; Migliaccio, A; Mikenberg, G; Mincer, A; Mineev, M; Misiejuk, A; Mönig, K; Monticelli, F; Moraes, A; Moreno, D; Morettini, P; Murillo Garcia, R; Nagano, K; Nagasaka, Y; Negri, A; Némethy, P; Neusiedl, A; Nisati, A; Niwa, T; Nomachi, M; Nomoto, H; Nozaki, M; Nozicka, M; Ochi, A; Ohm, C; Okumura, Y; Omachi, C; Osculati, B; Oshita, H; Osuna, C; Padilla, C; Panikashvili, N; Parodi, F; Pasqualucci, E; Pastore, F; Patricelli, S; Pauly, T; Pectu, M; Perantoni, M; Perera, V; Perera, V J O; Pérez, E; Pérez-Réale, V; Perrino, R; Pessoa Lima Junior, H; Petersen, J; Petrolo, E; Piegaia, R; Pilcher, J E; Pinto, F; Pinzon, G; Polini, A; Pope, B; Potter, C; Prieur, D P F; Primavera, M; Qian, W; Radescu, V; Rajagopalan, S; Renkel, P; Rescigno, M; Rieke, S; Risler, C; Riu, I; Robertson, S; Roda, C; Rodríguez, D; Rogriquez, Y; Roich, A; Romeo, G; Rosati, S; Ryabov, Yu; Ryan, P; Rühr, F; Sakamoto, H; Salamon, A; Salvatore, D; Sankey, D P C; Santamarina, C; Santamarina-Rios, C; Santonico, R; Sasaki, O; Scannicchio, D; Scannicchio, D A; Schiavi, C; Schlereth, J L; Schmitt, K; Scholtes, I; Schooltz, D; Schuler, G; Schultz-Coulon, H -C; Schäfer, U; Scott, W; Segura, E; Sekhniaidze, G; Shimbo, N; Sidoti, A; Silva, L; Silverstein, S; Siragusa, G; Sivoklokov, S; Sloper, J E; Smizanska, M; Solfaroli, E; Soloviev, I; Soluk, R; Spagnolo, S; Spila, F; Spiwoks, R; Staley, R J; Stamen, R; Stancu, S; Steinberg, P; Stelzer, J; Stradling, A; Strom, D; Strong, J; Su, D; Sugaya, Y; Sugimoto, T; Sushkov, S; Sutton, M; Szymocha, T; Takahashi, Y; Takeda, H; Takeshita, T; Tanaka, S; Tapprogge, S; Tarem, S; Tarem, Z; Teixeira-Dias, P; Thomas, J P; Tokoshuku, K; Tomoto, M; Torrence, E; Touchard, F; Trefzger, T; Tremblet, L; Tripiana, M; Usai, G; Vachon, B; Vandelli, W; Vari, R; Veneziano, S; Ventura, A; Vercesi, V; Vermeulen, J; Von Der Schmitt, J; Wang, M; Watkins, P M; Watson, A; Weber, P; Wengler, T; Werner, P; Wheeler-Ellis, S; Wickens, F; Wiedenmann, W; Wielers, M; Wilkens, H; Winklmeier, F; Woerling, E E; Wu, S -L; Wu, X; Xella, S; Yamaguchi, Y; Yamazaki, Y; Yasu, Y; Yu, M; Zanello, L; Zema, F; Zhang, J; Zhao, L; Zobernig, H; De Seixas, J M; Dos Anjos, A; Zur Nedden, M; Ozcan, E; Ünel, G; International Conference on Computing in High Energy and Nuclear Physics

    2008-01-01

    The ATLAS detector at CERN's LHC will be exposed to proton-proton collisions from beams crossing at 40 MHz. At the design luminosity there are roughly 23 collisions per bunch crossing. ATLAS has designed a three-level trigger system to select potentially interesting events. The first-level trigger, implemented in custom-built electronics, reduces the incoming rate to less than 100 kHz with a total latency of less than 2.5$\\mu$s. The next two trigger levels run in software on commercial PC farms. They reduce the output rate to 100-200 Hz. In preparation for collision data-taking which is scheduled to commence in May 2008, several cosmic-ray commissioning runs have been performed. Among the first sub-detectors available for commissioning runs are parts of the barrel muon detector including the RPC detectors that are used in the first-level trigger. Data have been taken with a full slice of the muon trigger and readout chain, from the detectors in one sector of the RPC system, to the second-level trigger algorit...

  14. The design and performance of the ATLAS Inner Detector Trigger for Run 2 LHC collisions at 13 TeV

    CERN Document Server

    Miano, Fabrizio; The ATLAS collaboration

    2016-01-01

    LHC Run 2 presents challenging high rate conditions for data analysis and processing within the ATLAS trigger systems. The ATLAS Inner Detector (ID) trigger implements the algorithms used for identification of tracks in nearly all physics signatures within the ATLAS trigger. The ID trigger was updated and redesigned during the 2013-2015 long shutdown to meet the challenging conditions of Run 2. As well, for Run 2 a new pixel detector layer was added in very close proximity to the beam pipe, which enhances the ID Trigger performance. The redesigned ID trigger algorithms for Run 2 are described, illustrating the significant improvements gained by the new tracking strategies adopted to deal with the increased rate. Performance of the ID trigger in Run 2 is shown in terms of algorithm timing, efficiency and resolution, using data collected by ATLAS in Run 2. The ID trigger continues to show excellent performance, with efficiencies greater than 99%, and track reconstruction times well within the required latency b...

  15. The ATLAS Hadronic Tau Trigger

    CERN Document Server

    Mahlstedt, J; The ATLAS collaboration

    2013-01-01

    During the 2012 run the Large Hadron Collider (LHC) reached instantaneous luminosities of nearly $10^{34} cm^{-2} s^{-1}$, with bunch crossings occurring every 50 ns. In this difficult environment of several overlapping interactions per bunch crossing (pile-up) the trigger system of the ATLAS detector has the task of reducing the event rate from 40 MHz to a few hundred Hz while keeping the most interesting physics events. Being the heaviest of all leptons, the tau lepton plays an important role in many physics processes. The ability to trigger on events containing hadronically decaying taus is therefore of special interest. In this poster the hadronic tau trigger is described and its performance during 2012 is shown.

  16. Event reconstruction algorithms for the ATLAS trigger

    CERN Document Server

    Fonseca-Martin, T; Adragna, P; Aleksandrov, E; Aleksandrov, I; Amorim, A; Anderson, K; Anduaga, X; Aracena, I; Asquith, L; Avolio, G; Backlund, S; Badescu, E; Baines, J; Barria, P; Bartoldus, R; Batreanu, S; Beck, H P; Bee, C; Bell, P; Bell, W H; Bellomo, M; Benslama, K; Berge, D; Berger, N; Berry, T; Biglietti, M; Blair, R R; Bogaerts, A; Bold, T; Bosman, M; Boyd, J; Brelier, B; Burckhart-Chromek, D; Buttar, C; Campanelli, M; Caprini, M; Carlino, G; Casadei, D; Casado, M P; Cataldi, G; Cimino, D; Ciobotaru, M; Clements, D; Coccaro, A; Conde-Muíño, P; Conventi, F; Corso-Radu, A; Costa, M J; Coura Torres, R; Cranfeld, R; Cranmer, K; Crone, G; Dam, M; Damazio, D; Dawson, I; Dawson, J; De Almeida Simoes, J; De Cecco, S; De Santo, A; DellaPietra, M; Delsart, P A; Demers, S; Demirkoz, B; Di Mattia, A; Dionisi, C; Djilkibaev, R; Dobinson, R; Dobson, M; Dotti, A; Dova, M; Drake, G; Dufour, M A; Eckweiler, S; Ehrenfeld, W; Eifert, T; Ellis, Nick; Emeliyanov, D; Enoque Ferreira de Lima, D; Ermoline, Y; Eschrich, I; Facius, K; Falciano, S; Farthouat, P; Feng, E; Ferland, J; Ferrari, R; Ferrer, M L; Fischer, G; Francis, D; Gadomski, S; Garitaonandia Elejabarrieta, H; Gaudio, G; Gaumer, O; George, S; Giagu, S; Goncalo, R; Gorini, B; Gorini, E; Gowdy, S; Grabowska-Bold, I; Grancagnolo, S; Green, B; Haas, S; Haberichter, W; Hadavand, H; Haeberli, C; Haller, J; Hamilton, A; Hansen, J R; Hauschild, M; Hauser, R; Head, S; Hillier, S J; Höcker, A; Hrynóva, T; Hughes-Jones, R; Huston, J; Idarraga, J; Igonkina, O; Inada, M; Jain, V; Johns, K; Joos, M; Kama, S; Kanaya, N; Kazarov, A; Kehoe, R; Khoriauli, G; Kieft, G; Kilvington, G; Kirk, J; Kiyamura, H; Kolos, S; Kono, T; Konstantinidis, N; Korcyl, K; Kordas, K; Kotov, V; Krasznahorkay, A; Kubota, T; Kugel, A; Kuhn, D; Kurasige, H; Kuwabara, T; Kwee, R; Lankford, A; LeCompte, T; Leahu, L; Leahu, M; Ledroit, F; Lehmann-Miotto, G; Lei, X; Lellouch, D; Leyton, M; Li, S; Lim, H; Lohse, T; Losada, M; Luci, C; Luminari, L; Mapelli, L; Martin, B; Martin, B T; Marzano, F; Masik, J; McMahon, T; McPherson, R; Medinnis, M; Meessen, C; Meirosu, C; Messina, A; Mincer, A; Mineev, M; Misiejuk, A; Mönig, K; Monticelli, F; Moraes, A; Moreno, D; Morettini, P; Murillo Garcia, R; Nagano, K; Nagasaka, Y; Negri, A; Némethy, P; Neusiedl, A; Nisati, A; Nozicka, M; Omachi, C; Osculati, B; Osuna, C; Padilla, C; Panikashvili, N; Parodi, F; Pasqualucci, E; Pauly, T; Perera, V; Pérez, E; Pérez-Réale, V; Petersen, J; Piegaia, R; Pilcher, J E; Pinzon, G; Pope, B; Potter, C; Primavera, M; Radescu, V; Rajagopalan, S; Renkel, P; Rescigno, M; Rieke, S; Risler, C; Riu, I; Robertson, S; Roda, C; Rodríguez, D; Rogriquez, Y; Ryabov, Yu; Ryan, P; Salvatore, D; Santamarina, C; Santamarina-Rios, C; Scannicchio, D; Scannicchio, D A; Schiavi, C; Schlereth, J L; Scholtes, I; Schooltz, D; Scott, W; Segura, E; Shimbo, N; Sidoti, A; Siragusa, G; Sivoklokov, S; Sloper, J E; Smizanska, M; Soloviev, I; Soluk, R; Spagnolo, S; Spiwoks, R; Stancu, S; Steinberg, P; Stelzer, J; Stradling, A; Strom, David M; Strong, J; Su, D; Sushkov, S; Sutton, M; Szymocha, T; Tapprogge, S; Tarem, S; Tarem, Z; Teixeira-Dias, P; Tokoshuku, K; Torrence, E; Touchard, F; Tremblet, L; Tripiana, M; Usai, G; Vachon, B; Vandelli, W; Ventura, A; Vercesi, V; Vermeulen, J; Von Der Schmitt, J; Wang, M; Watson, A; Wengler, T; Werner, P; Wheeler-Ellis, S; Wickens, F; Wiedenmann, W; Wielers, M; Wilkens, H; Winklmeier, F; Woerling, E E; Wu, S L; Wu, X; Xella, S; Yamazaki, Y; Yu, M; Zema, F; Zhang, J; Zhao, L; Zobernig, H; Dos Anjos, A; Zur Nedden, M; Ozcan, E; Ünel, G

    2008-01-01

    The ATLAS experiment under construction at CERN is due to begin operation at the end of 2007. The detector will record the results of proton-proton collisions at a center-of-mass energy of 14 TeV. The trigger is a three-tier system designed to identify in real-time potentially interesting events that are then saved for detailed offline analysis. The trigger system will select approximately 200 Hz of potentially interesting events out of the 40 MHz bunch-crossing rate (with 109 interactions per second at the nominal luminosity).

  17. Performance of the ATLAS Trigger System in 2010

    CERN Document Server

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Duxfield, Robert; Dwuznik, Michal; Dydak, Friedrich; Dzahini, Daniel; Düren, Michael; Ebenstein, William; Ebke, Johannes; Eckert, Simon; Eckweiler, Sebastian; Edmonds, Keith; Edwards, Clive; Edwards, Nicholas Charles; Ehrenfeld, Wolfgang; Ehrich, Thies; Eifert, Till; Eigen, Gerald; Einsweiler, Kevin; Eisenhandler, Eric; Ekelof, Tord; El Kacimi, Mohamed; Ellert, Mattias; Elles, Sabine; Ellinghaus, Frank; Ellis, Katherine; Ellis, Nicolas; Elmsheuser, Johannes; Elsing, Markus; Ely, Robert; Emeliyanov, Dmitry; Engelmann, Roderich; Engl, Albert; Epp, Brigitte; Eppig, Andrew; Erdmann, Johannes; Ereditato, Antonio; Eriksson, Daniel; Ernst, Jesse; Ernst, Michael; Ernwein, Jean; Errede, Deborah; Errede, Steven; Ertel, Eugen; Escalier, Marc; Escobar, Carlos; Espinal Curull, Xavier; Esposito, Bellisario; Etienne, Francois; Etienvre, Anne-Isabelle; Etzion, Erez; Evangelakou, Despoina; Evans, Hal; Fabbri, Laura; Fabre, Caroline; Fakhrutdinov, Rinat; Falciano, Speranza; Falou, Alain; Fang, Yaquan; Fanti, Marcello; Farbin, Amir; Farilla, Addolorata; Farley, Jason; Farooque, Trisha; Farrington, Sinead; Farthouat, Philippe; Fassnacht, Patrick; Fassouliotis, Dimitrios; Fatholahzadeh, Baharak; Favareto, Andrea; Fayard, Louis; Fazio, Salvatore; Febbraro, Renato; Federic, Pavol; Fedin, Oleg; Fedorko, Ivan; Fedorko, Woiciech; Fehling-Kaschek, Mirjam; Feligioni, Lorenzo; Fellmann, Denis; Felzmann, Ulrich; Feng, Cunfeng; Feng, Eric; Fenyuk, Alexander; Ferencei, Jozef; Ferland, Jonathan; Fernando, Waruna; Ferrag, Samir; Ferrando, James; Ferrara, Valentina; Ferrari, Arnaud; Ferrari, Pamela; Ferrari, Roberto; Ferrer, Antonio; Ferrer, Maria Lorenza; Ferrere, Didier; Ferretti, Claudio; Ferretto Parodi, Andrea; Fiascaris, Maria; Fiedler, Frank; Filipčič, Andrej; Filippas, Anastasios; Filthaut, Frank; Fincke-Keeler, Margret; Fiolhais, Miguel; Fiorini, Luca; Firan, Ana; Fischer, Gordon; Fischer, Peter; Fisher, Matthew; Fisher, Steve; Flechl, Martin; Fleck, Ivor; Fleckner, Johanna; Fleischmann, Philipp; Fleischmann, Sebastian; Flick, Tobias; Flores Castillo, Luis; Flowerdew, Michael; Föhlisch, Florian; Fokitis, Manolis; Fonseca Martin, Teresa; Forbush, David Alan; Formica, Andrea; Forti, Alessandra; Fortin, Dominique; Foster, Joe; Fournier, Daniel; Foussat, Arnaud; Fowler, Andrew; Fowler, Ken; Fox, Harald; Francavilla, Paolo; Franchino, Silvia; Francis, David; Frank, Tal; Franklin, Melissa; Franz, Sebastien; Fraternali, Marco; Fratina, Sasa; French, Sky; Froeschl, Robert; Froidevaux, Daniel; Frost, James; Fukunaga, Chikara; Fullana Torregrosa, Esteban; Fuster, Juan; Gabaldon, Carolina; Gabizon, Ofir; Gadfort, Thomas; Gadomski, Szymon; Gagliardi, Guido; Gagnon, Pauline; Galea, Cristina; Gallas, Elizabeth; Gallas, Manuel; Gallo, Valentina Santina; Gallop, Bruce; Gallus, Petr; Galyaev, Eugene; Gan, KK; Gao, Yongsheng; Gapienko, Vladimir; Gaponenko, Andrei; Garberson, Ford; Garcia-Sciveres, Maurice; García, Carmen; García Navarro, José Enrique; Gardner, Robert; Garelli, Nicoletta; Garitaonandia, Hegoi; Garonne, Vincent; Garvey, John; Gatti, Claudio; Gaudio, Gabriella; Gaumer, Olivier; Gaur, Bakul; Gauthier, Lea; Gavrilenko, Igor; Gay, Colin; Gaycken, Goetz; Gayde, Jean-Christophe; Gazis, Evangelos; Ge, Peng; Gee, Norman; Geerts, Daniël Alphonsus Adrianus; Geich-Gimbel, Christoph; Gellerstedt, Karl; Gemme, Claudia; Gemmell, Alistair; Genest, Marie-Hélène; Gentile, Simonetta; George, Matthias; George, Simon; Gerlach, Peter; Gershon, Avi; Geweniger, Christoph; Ghazlane, Hamid; Ghez, Philippe; Ghodbane, Nabil; Giacobbe, Benedetto; Giagu, Stefano; Giakoumopoulou, Victoria; Giangiobbe, Vincent; Gianotti, Fabiola; Gibbard, Bruce; Gibson, Adam; Gibson, Stephen; Gilbert, Laura; Gilchriese, Murdock; Gilewsky, Valentin; Gillberg, Dag; Gillman, Tony; Gingrich, Douglas; Ginzburg, Jonatan; Giokaris, Nikos; Giordano, Raffaele; Giorgi, Francesco Michelangelo; Giovannini, Paola; Giraud, Pierre-Francois; Giugni, Danilo; Giunta, Michele; Giusti, Paolo; Gjelsten, Børge Kile; Gladilin, Leonid; Glasman, Claudia; Glatzer, Julian; Glazov, Alexandre; Glitza, Karl-Walter; Glonti, George; Godfrey, Jennifer; Godlewski, Jan; Goebel, Martin; Göpfert, Thomas; Goeringer, Christian; Gössling, Claus; Göttfert, Tobias; Goldfarb, Steven; Goldin, Daniel; Golling, Tobias; Golovnia, Serguei; Gomes, Agostinho; Gomez Fajardo, Luz Stella; Gonçalo, Ricardo; Goncalves Pinto Firmino Da Costa, Joao; Gonella, Laura; Gonidec, Allain; Gonzalez, Saul; González de la Hoz, Santiago; Gonzalez Silva, Laura; Gonzalez-Sevilla, Sergio; Goodson, Jeremiah Jet; Goossens, Luc; Gorbounov, Petr Andreevich; Gordon, Howard; Gorelov, Igor; Gorfine, Grant; Gorini, Benedetto; Gorini, Edoardo; Gorišek, Andrej; Gornicki, Edward; Gorokhov, Serguei; Goryachev, Vladimir; Gosdzik, Bjoern; Gosselink, Martijn; Gostkin, Mikhail Ivanovitch; Gouanère, Michel; Gough Eschrich, Ivo; Gouighri, Mohamed; Goujdami, Driss; Goulette, Marc Phillippe; Goussiou, Anna; Goy, Corinne; Grabowska-Bold, Iwona; Grabski, Varlen; Grafström, Per; Grah, Christian; Grahn, Karl-Johan; Grancagnolo, Francesco; Grancagnolo, Sergio; Grassi, Valerio; Gratchev, Vadim; Grau, Nathan; Gray, Heather; Gray, Julia Ann; Graziani, Enrico; Grebenyuk, Oleg; Greenfield, Debbie; Greenshaw, Timothy; Greenwood, Zeno Dixon; Gregor, Ingrid-Maria; Grenier, Philippe; Griesmayer, Erich; Griffiths, Justin; Grigalashvili, Nugzar; Grillo, Alexander; Grinstein, Sebastian; Grishkevich, Yaroslav; Grivaz, Jean-Francois; Grognuz, Joel; Groh, Manfred; Gross, Eilam; Grosse-Knetter, Joern; Groth-Jensen, Jacob; Grybel, Kai; Guarino, Victor; Guest, Daniel; Guicheney, Christophe; Guida, Angelo; Guillemin, Thibault; Guindon, Stefan; Guler, Hulya; Gunther, Jaroslav; Guo, Bin; Guo, Jun; Gupta, Ambreesh; Gusakov, Yury; Gushchin, Vladimir; Gutierrez, Andrea; Gutierrez, Phillip; Guttman, Nir; Gutzwiller, Olivier; Guyot, Claude; Gwenlan, Claire; Gwilliam, Carl; Haas, Andy; Haas, Stefan; Haber, Carl; Hackenburg, Robert; Hadavand, Haleh Khani; Hadley, David; Haefner, Petra; Hahn, Ferdinand; Haider, Stefan; Hajduk, Zbigniew; Hakobyan, Hrachya; Haller, Johannes; Hamacher, Klaus; Hamal, Petr; Hamilton, Andrew; Hamilton, Samuel; Han, Hongguang; Han, Liang; Hanagaki, Kazunori; Hance, Michael; Handel, Carsten; Hanke, Paul; Hansen, John Renner; Hansen, Jørgen Beck; Hansen, Jorn Dines; Hansen, Peter Henrik; Hansson, Per; Hara, Kazuhiko; Hare, Gabriel; Harenberg, Torsten; Harkusha, Siarhei; Harper, Devin; Harrington, Robert; Harris, Orin; Harrison, Karl; Hartert, Jochen; Hartjes, Fred; Haruyama, Tomiyoshi; Harvey, Alex; Hasegawa, Satoshi; Hasegawa, Yoji; Hassani, Samira; Hatch, Mark; Hauff, Dieter; Haug, Sigve; Hauschild, Michael; Hauser, Reiner; Havranek, Miroslav; Hawes, Brian; Hawkes, Christopher; Hawkings, Richard John; Hawkins, Donovan; Hayakawa, Takashi; Hayden, Daniel; Hayward, Helen; Haywood, Stephen; Hazen, Eric; He, Mao; Head, Simon; Hedberg, Vincent; Heelan, Louise; Heim, Sarah; Heine, Kristin; Heinemann, Beate; Heisterkamp, Simon; Helary, Louis; Heldmann, Michael; Heller, Mathieu; Hellman, Sten; Helsens, Clement; Henderson, Robert; Henke, Michael; Henrichs, Anna; Henriques Correia, Ana Maria; Henrot-Versille, Sophie; Henry-Couannier, Frédéric; Hensel, Carsten; Henß, Tobias; Hernandez, Carlos Medina; Hernández Jiménez, Yesenia; Herrberg, Ruth; Hershenhorn, Alon David; Herten, Gregor; Hertenberger, Ralf; Hervas, Luis; Hessey, Nigel; Hidvegi, Attila; Higón-Rodriguez, Emilio; Hill, Daniel; Hill, John; Hill, Norman; Hiller, Karl Heinz; Hillert, Sonja; Hillier, Stephen; Hinchliffe, Ian; Hines, Elizabeth; Hirose, Minoru; Hirsch, Florian; Hirschbuehl, Dominic; Hobbs, John; Hod, Noam; Hodgkinson, Mark; Hodgson, Paul; Hoecker, Andreas; Hoeferkamp, Martin; Hoffman, Julia; Hoffmann, Dirk; Hohlfeld, Marc; Holder, Martin; Holmes, Alan; Holmgren, Sven-Olof; Holy, Tomas; Holzbauer, Jenny; Homma, Yasuhiro; Hong, Tae Min; Hooft van Huysduynen, Loek; Horazdovsky, Tomas; Horn, Claus; Horner, Stephan; Horton, Katherine; Hostachy, Jean-Yves; Hou, Suen; Houlden, Michael; Hoummada, Abdeslam; Howarth, James; Howell, David; Hristova, Ivana; Hrivnac, Julius; Hruska, Ivan; Hryn'ova, Tetiana; Hsu, Pai-hsien Jennifer; Hsu, Shih-Chieh; Huang, Guang Shun; Hubacek, Zdenek; Hubaut, Fabrice; Huegging, Fabian; Huffman, Todd Brian; Hughes, Emlyn; Hughes, Gareth; Hughes-Jones, Richard; Huhtinen, Mika; Hurst, Peter; Hurwitz, Martina; Husemann, Ulrich; Huseynov, Nazim; Huston, Joey; Huth, John; Iacobucci, Giuseppe; Iakovidis, Georgios; Ibbotson, Michael; Ibragimov, Iskander; Ichimiya, Ryo; Iconomidou-Fayard, Lydia; Idarraga, John; Idzik, Marek; Iengo, Paolo; Igonkina, Olga; Ikegami, Yoichi; Ikeno, Masahiro; Ilchenko, Yuri; Iliadis, Dimitrios; Imbault, Didier; Imhaeuser, Martin; Imori, Masatoshi; Ince, Tayfun; Inigo-Golfin, Joaquin; Ioannou, Pavlos; Iodice, Mauro; Ionescu, Gelu; Irles Quiles, Adrian; Ishii, Koji; Ishikawa, Akimasa; Ishino, Masaya; Ishmukhametov, Renat; Issever, Cigdem; Istin, Serhat; Itoh, Yuki; Ivashin, Anton; Iwanski, Wieslaw; Iwasaki, Hiroyuki; Izen, Joseph; Izzo, Vincenzo; Jackson, Brett; Jackson, John; Jackson, Paul; Jaekel, Martin; Jain, Vivek; Jakobs, Karl; Jakobsen, Sune; Jakubek, Jan; Jana, Dilip; Jankowski, Ernest; Jansen, Eric; Jantsch, Andreas; Janus, Michel; Jarlskog, Göran; Jeanty, Laura; Jelen, Kazimierz; Jen-La Plante, Imai; Jenni, Peter; Jeremie, Andrea; Jež, Pavel; Jézéquel, Stéphane; Jha, Manoj Kumar; Ji, Haoshuang; Ji, Weina; Jia, Jiangyong; Jiang, Yi; Jimenez Belenguer, Marcos; Jin, Ge; Jin, Shan; Jinnouchi, Osamu; Joergensen, Morten Dam; Joffe, David; Johansen, Lars; Johansen, Marianne; Johansson, Erik; Johansson, Per; Johnert, Sebastian; Johns, Kenneth; Jon-And, Kerstin; Jones, Graham; Jones, Roger; Jones, Tegid; Jones, Tim; Jonsson, Ove; Joram, Christian; Jorge, Pedro; Joseph, John; Ju, Xiangyang; Juranek, Vojtech; Jussel, Patrick; Kabachenko, Vasily; Kabana, Sonja; Kaci, Mohammed; Kaczmarska, Anna; Kadlecik, Peter; Kado, Marumi; Kagan, Harris; Kagan, Michael; Kaiser, Steffen; Kajomovitz, Enrique; Kalinin, Sergey; Kalinovskaya, Lidia; Kama, Sami; Kanaya, Naoko; Kaneda, Michiru; Kanno, Takayuki; Kantserov, Vadim; Kanzaki, Junichi; Kaplan, Benjamin; Kapliy, Anton; Kaplon, Jan; Kar, Deepak; Karagoz, Muge; Karnevskiy, Mikhail; Karr, Kristo; Kartvelishvili, Vakhtang; Karyukhin, Andrey; Kashif, Lashkar; Kasmi, Azzedine; Kass, Richard; Kastanas, Alex; Kataoka, Mayuko; Kataoka, Yousuke; Katsoufis, Elias; Katzy, Judith; Kaushik, Venkatesh; Kawagoe, Kiyotomo; Kawamoto, Tatsuo; Kawamura, Gen; Kayl, Manuel; Kazanin, Vassili; Kazarinov, Makhail; Keates, James Robert; Keeler, Richard; Kehoe, Robert; Keil, Markus; Kekelidze, George; Kelly, Marc; Kennedy, John; Kenney, Christopher John; Kenyon, Mike; Kepka, Oldrich; Kerschen, Nicolas; Kerševan, Borut Paul; Kersten, Susanne; Kessoku, Kohei; Ketterer, Christian; Keung, Justin; Khakzad, Mohsen; Khalil-zada, Farkhad; Khandanyan, Hovhannes; Khanov, Alexander; Kharchenko, Dmitri; Khodinov, Alexander; Kholodenko, Anatoli; Khomich, Andrei; Khoo, Teng Jian; Khoriauli, Gia; Khoroshilov, Andrey; Khovanskiy, Nikolai; Khovanskiy, Valery; Khramov, Evgeniy; Khubua, Jemal; Kim, Hyeon Jin; Kim, Min Suk; Kim, Peter; Kim, Shinhong; Kimura, Naoki; Kind, Oliver; King, Barry; King, Matthew; King, Robert Steven Beaufoy; Kirk, Julie; Kirsch, Guillaume; Kirsch, Lawrence; Kiryunin, Andrey; Kisielewska, Danuta; Kittelmann, Thomas; Kiver, Andrey; Kiyamura, Hironori; Kladiva, Eduard; Klaiber-Lodewigs, Jonas; Klein, Max; Klein, Uta; Kleinknecht, Konrad; Klemetti, Miika; Klier, Amit; Klimentov, Alexei; Klingenberg, Reiner; Klinkby, Esben; Klioutchnikova, Tatiana; Klok, Peter; Klous, Sander; Kluge, Eike-Erik; Kluge, Thomas; Kluit, Peter; Kluth, Stefan; Kneringer, Emmerich; Knobloch, Juergen; Knoops, Edith; Knue, Andrea; Ko, Byeong Rok; Kobayashi, Tomio; Kobel, Michael; Kocian, Martin; Kocnar, Antonin; Kodys, Peter; Köneke, Karsten; König, Adriaan; Koenig, Sebastian; Köpke, Lutz; Koetsveld, Folkert; Koevesarki, Peter; Koffas, Thomas; Koffeman, Els; Kohn, Fabian; Kohout, Zdenek; Kohriki, Takashi; Koi, Tatsumi; Kokott, Thomas; Kolachev, Guennady; Kolanoski, Hermann; Kolesnikov, Vladimir; Koletsou, Iro; Koll, James; Kollar, Daniel; Kollefrath, Michael; Kolya, Scott; Komar, Aston; Komaragiri, Jyothsna Rani; Komori, Yuto; Kondo, Takahiko; Kono, Takanori; Kononov, Anatoly; Konoplich, Rostislav; Konstantinidis, Nikolaos; Kootz, Andreas; Koperny, Stefan; Kopikov, Sergey; Korcyl, Krzysztof; Kordas, Kostantinos; Koreshev, Victor; Korn, Andreas; Korol, Aleksandr; Korolkov, Ilya; Korolkova, Elena; Korotkov, Vladislav; Kortner, Oliver; Kortner, Sandra; Kostyukhin, Vadim; Kotamäki, Miikka Juhani; Kotov, Sergey; Kotov, Vladislav; Kotwal, Ashutosh; Kourkoumelis, Christine; Kouskoura, Vasiliki; Koutsman, Alex; Kowalewski, Robert Victor; Kowalski, Tadeusz; Kozanecki, Witold; Kozhin, Anatoly; Kral, Vlastimil; Kramarenko, Viktor; Kramberger, Gregor; Krasel, Olaf; Krasny, Mieczyslaw Witold; Krasznahorkay, Attila; Kraus, James; Kreisel, Arik; Krejci, Frantisek; Kretzschmar, Jan; Krieger, Nina; Krieger, Peter; Kroeninger, Kevin; Kroha, Hubert; Kroll, Joe; Kroseberg, Juergen; Krstic, Jelena; Kruchonak, Uladzimir; Krüger, Hans; Kruker, Tobias; Krumshteyn, Zinovii; Kruth, Andre; Kubota, Takashi; Kuehn, Susanne; Kugel, Andreas; Kuhl, Thorsten; Kuhn, Dietmar; Kukhtin, Victor; Kulchitsky, Yuri; Kuleshov, Sergey; Kummer, Christian; Kuna, Marine; Kundu, Nikhil; Kunkle, Joshua; Kupco, Alexander; Kurashige, Hisaya; Kurata, Masakazu; Kurochkin, Yurii; Kus, Vlastimil; Kuykendall, William; Kuze, Masahiro; Kuzhir, Polina; Kvasnicka, Ondrej; Kvita, Jiri; Kwee, Regina; La Rosa, Alessandro; La Rotonda, Laura; Labarga, Luis; Labbe, Julien; Lablak, Said; Lacasta, Carlos; Lacava, Francesco; Lacker, Heiko; Lacour, Didier; Lacuesta, Vicente Ramón; Ladygin, Evgueni; Lafaye, Rémi; Laforge, Bertrand; Lagouri, Theodota; Lai, Stanley; Laisne, Emmanuel; Lamanna, Massimo; Lampen, Caleb; Lampl, Walter; Lancon, Eric; Landgraf, Ulrich; Landon, Murrough; Landsman, Hagar; Lane, Jenna; Lange, Clemens; Lankford, Andrew; Lanni, Francesco; Lantzsch, Kerstin; Lapin, Vladimir; Laplace, Sandrine; Lapoire, Cecile; Laporte, Jean-Francois; Lari, Tommaso; Larionov, Anatoly; Larner, Aimee; Lasseur, Christian; Lassnig, Mario; Lau, Wing; Laurelli, Paolo; Lavorato, Antonia; Lavrijsen, Wim; Laycock, Paul; Lazarev, Alexandre; Lazzaro, Alfio; Le Dortz, Olivier; Le Guirriec, Emmanuel; Le Maner, Christophe; Le Menedeu, Eve; Lebedev, Alexander; Lebel, Céline; LeCompte, Thomas; Ledroit-Guillon, Fabienne Agnes Marie; Lee, Hurng-Chun; Lee, Jason; Lee, Shih-Chang; Lee, Lawrence; Lefebvre, Michel; Legendre, Marie; Leger, Annie; LeGeyt, Benjamin; Legger, Federica; Leggett, Charles; Lehmacher, Marc; Lehmann Miotto, Giovanna; Lei, Xiaowen; Leite, Marco Aurelio Lisboa; Leitner, Rupert; Lellouch, Daniel; Leltchouk, Mikhail; Lendermann, Victor; Leney, Katharine; Lenz, Tatiana; Lenzen, Georg; Lenzi, Bruno; Leonhardt, Kathrin; Leontsinis, Stefanos; Leroy, Claude; Lessard, Jean-Raphael; Lesser, Jonas; Lester, Christopher; Leung Fook Cheong, Annabelle; Levêque, Jessica; Levin, Daniel; Levinson, Lorne; Levitski, Mikhail; Lewandowska, Marta; Lewis, Adrian; Lewis, George; Leyko, Agnieszka; Leyton, Michael; Li, Bo; Li, Haifeng; Li, Shu; Li, Xuefei; Liang, Zhihua; Liang, Zhijun; Liberti, Barbara; Lichard, Peter; Lichtnecker, Markus; Lie, Ki; Liebig, Wolfgang; Lifshitz, Ronen; Lilley, Joseph; Limbach, Christian; Limosani, Antonio; Limper, Maaike; Lin, Simon; Linde, Frank; Linnemann, James; Lipeles, Elliot; Lipinsky, Lukas; Lipniacka, Anna; Liss, Tony; Lissauer, David; Lister, Alison; Litke, Alan; Liu, Chuanlei; Liu, Dong; Liu, Hao; Liu, Jianbei; Liu, Minghui; Liu, Shengli; Liu, Yanwen; Livan, Michele; Livermore, Sarah; Lleres, Annick; Llorente Merino, Javier; Lloyd, Stephen; Lobodzinska, Ewelina; Loch, Peter; Lockman, William; Lockwitz, Sarah; Loddenkoetter, Thomas; Loebinger, Fred; Loginov, Andrey; Loh, Chang Wei; Lohse, Thomas; Lohwasser, Kristin; Lokajicek, Milos; Loken, James; Lombardo, Vincenzo Paolo; Long, Robin Eamonn; Lopes, Lourenco; Lopez Mateos, David; Losada, Marta; Loscutoff, Peter; Lo Sterzo, Francesco; Losty, Michael; Lou, Xinchou; Lounis, Abdenour; Loureiro, Karina; Love, Jeremy; Love, Peter; Lowe, Andrew; Lu, Feng; Lu, Liang; Lubatti, Henry; Luci, Claudio; Lucotte, Arnaud; Ludwig, Andreas; Ludwig, Dörthe; Ludwig, Inga; Ludwig, Jens; Luehring, Frederick; Luijckx, Guy; Lumb, Debra; Luminari, Lamberto; Lund, Esben; Lund-Jensen, Bengt; Lundberg, Björn; Lundberg, Johan; Lundquist, Johan; Lungwitz, Matthias; Lupi, Anna; Lutz, Gerhard; Lynn, David; Lys, Jeremy; Lytken, Else; Ma, Hong; Ma, Lian Liang; Macana Goia, Jorge Andres; Maccarrone, Giovanni; Macchiolo, Anna; Maček, Boštjan; Machado Miguens, Joana; Mackeprang, Rasmus; Madaras, Ronald; Mader, Wolfgang; Maenner, Reinhard; Maeno, Tadashi; Mättig, Peter; Mättig, Stefan; Magalhaes Martins, Paulo Jorge; Magnoni, Luca; Magradze, Erekle; Mahalalel, Yair; Mahboubi, Kambiz; Mahout, Gilles; Maiani, Camilla; Maidantchik, Carmen; Maio, Amélia; Majewski, Stephanie; Makida, Yasuhiro; Makovec, Nikola; Mal, Prolay; Malecki, Pawel; Malecki, Piotr; Maleev, Victor; Malek, Fairouz; Mallik, Usha; Malon, David; Maltezos, Stavros; Malyshev, Vladimir; Malyukov, Sergei; Mameghani, Raphael; Mamuzic, Judita; Manabe, Atsushi; Mandelli, Luciano; Mandić, Igor; Mandrysch, Rocco; Maneira, José; Mangeard, Pierre-Simon; Manjavidze, Ioseb; Mann, Alexander; Manning, Peter; Manousakis-Katsikakis, Arkadios; Mansoulie, Bruno; Manz, Andreas; Mapelli, Alessandro; Mapelli, Livio; March, Luis; Marchand, Jean-Francois; Marchese, Fabrizio; Marchiori, Giovanni; Marcisovsky, Michal; Marin, Alexandru; Marino, Christopher; Marroquim, Fernando; Marshall, Robin; Marshall, Zach; Martens, Kalen; Marti-Garcia, Salvador; Martin, Andrew; Martin, Brian; Martin, Brian; Martin, Franck Francois; Martin, Jean-Pierre; Martin, Philippe; Martin, Tim; Martin dit Latour, Bertrand; Martinez, Mario; Martinez Outschoorn, Verena; Martyniuk, Alex; Marx, Marilyn; Marzano, Francesco; Marzin, Antoine; Masetti, Lucia; Mashimo, Tetsuro; Mashinistov, Ruslan; Masik, Jiri; Maslennikov, Alexey; Maß, Martin; Massa, Ignazio; Massaro, Graziano; Massol, Nicolas; Mastrandrea, Paolo; Mastroberardino, Anna; Masubuchi, Tatsuya; Mathes, Markus; Matricon, Pierre; Matsumoto, Hiroshi; Matsunaga, Hiroyuki; Matsushita, Takashi; Mattravers, Carly; Maugain, Jean-Marie; Maxfield, Stephen; Maximov, Dmitriy; May, Edward; Mayne, Anna; Mazini, Rachid; Mazur, Michael; Mazzanti, Marcello; Mazzoni, Enrico; Mc Kee, Shawn Patrick; McCarn, Allison; McCarthy, Robert; McCarthy, Tom; McCubbin, Norman; McFarlane, Kenneth; Mcfayden, Josh; McGlone, Helen; Mchedlidze, Gvantsa; McLaren, Robert Andrew; Mclaughlan, Tom; McMahon, Steve; McPherson, Robert; Meade, Andrew; Mechnich, Joerg; Mechtel, Markus; Medinnis, Mike; Meera-Lebbai, Razzak; Meguro, Tatsuma; Mehdiyev, Rashid; Mehlhase, Sascha; Mehta, Andrew; Meier, Karlheinz; Meinhardt, Jens; Meirose, Bernhard; Melachrinos, Constantinos; Mellado Garcia, Bruce Rafael; Mendoza Navas, Luis; Meng, Zhaoxia; Mengarelli, Alberto; Menke, Sven; Menot, Claude; Meoni, Evelin; Mercurio, Kevin Michael; Mermod, Philippe; Merola, Leonardo; Meroni, Chiara; Merritt, Frank; Messina, Andrea; Metcalfe, Jessica; Mete, Alaettin Serhan; Meuser, Stefan; Meyer, Carsten; Meyer, Jean-Pierre; Meyer, Jochen; Meyer, Joerg; Meyer, Thomas Christian; Meyer, W Thomas; Miao, Jiayuan; Michal, Sebastien; Micu, Liliana; Middleton, Robin; Miele, Paola; Migas, Sylwia; Mijović, Liza; Mikenberg, Giora; Mikestikova, Marcela; Mikuž, Marko; Miller, David; Miller, Robert; Mills, Bill; Mills, Corrinne; Milov, Alexander; Milstead, David; Milstein, Dmitry; Minaenko, Andrey; Miñano, Mercedes; Minashvili, Irakli; Mincer, Allen; Mindur, Bartosz; Mineev, Mikhail; Ming, Yao; Mir, Lluisa-Maria; Mirabelli, Giovanni; Miralles Verge, Lluis; Misiejuk, Andrzej; Mitrevski, Jovan; Mitrofanov, Gennady; Mitsou, Vasiliki A; Mitsui, Shingo; Miyagawa, Paul; Miyazaki, Kazuki; Mjörnmark, Jan-Ulf; Moa, Torbjoern; Mockett, Paul; Moed, Shulamit; Moeller, Victoria; Mönig, Klaus; Möser, Nicolas; Mohapatra, Soumya; Mohn, Bjarte; Mohr, Wolfgang; Mohrdieck-Möck, Susanne; Moisseev, Artemy; Moles-Valls, Regina; Molina-Perez, Jorge; Monk, James; Monnier, Emmanuel; Montesano, Simone; Monticelli, Fernando; Monzani, Simone; Moore, Roger; Moorhead, Gareth; Mora Herrera, Clemencia; Moraes, Arthur; Morais, Antonio; Morange, Nicolas; Morel, Julien; Morello, Gianfranco; Moreno, Deywis; Moreno Llácer, María; Morettini, Paolo; Morii, Masahiro; Morin, Jerome; Morita, Youhei; Morley, Anthony Keith; Mornacchi, Giuseppe; Morone, Maria-Christina; Morozov, Sergey; Morris, John; Morvaj, Ljiljana; Moser, Hans-Guenther; Mosidze, Maia; Moss, Josh; Mount, Richard; Mountricha, Eleni; Mouraviev, Sergei; Moyse, Edward; Mudrinic, Mihajlo; Mueller, Felix; Mueller, James; Mueller, Klemens; Müller, Thomas; Muenstermann, Daniel; Muijs, Sandra; Muir, Alex; Munwes, Yonathan; Murakami, Koichi; Murray, Bill; Mussche, Ido; Musto, Elisa; Myagkov, Alexey; Myska, Miroslav; Nadal, Jordi; Nagai, Koichi; Nagano, Kunihiro; Nagasaka, Yasushi; Nairz, Armin Michael; Nakahama, Yu; Nakamura, Koji; Nakano, Itsuo; Nanava, Gizo; Napier, Austin; Nash, Michael; Nation, Nigel; Nattermann, Till; Naumann, Thomas; Navarro, Gabriela; Neal, Homer; Nebot, Eduardo; Nechaeva, Polina; Negri, Andrea; Negri, Guido; Nektarijevic, Snezana; Nelson, Andrew; Nelson, Silke; Nelson, Timothy Knight; Nemecek, Stanislav; Nemethy, Peter; Nepomuceno, Andre Asevedo; Nessi, Marzio; Nesterov, Stanislav; Neubauer, Mark; Neusiedl, Andrea; Neves, Ricardo; Nevski, Pavel; Newman, Paul; Nguyen Thi Hong, Van; Nickerson, Richard; Nicolaidou, Rosy; Nicolas, Ludovic; Nicquevert, Bertrand; Niedercorn, Francois; Nielsen, Jason; Niinikoski, Tapio; Nikiforov, Andriy; Nikolaenko, Vladimir; Nikolaev, Kirill; Nikolic-Audit, Irena; Nikolopoulos, Konstantinos; Nilsen, Henrik; Nilsson, Paul; Ninomiya, Yoichi; Nisati, Aleandro; Nishiyama, Tomonori; Nisius, Richard; Nodulman, Lawrence; Nomachi, Masaharu; Nomidis, Ioannis; Nomoto, Hiroshi; Nordberg, Markus; Nordkvist, Bjoern; Norton, Peter; Novakova, Jana; Nozaki, Mitsuaki; Nožička, Miroslav; Nozka, Libor; Nugent, Ian Michael; Nuncio-Quiroz, Adriana-Elizabeth; Nunes Hanninger, Guilherme; Nunnemann, Thomas; Nurse, Emily; Nyman, Tommi; O'Brien, Brendan Joseph; O'Neale, Steve; O'Neil, Dugan; O'Shea, Val; Oakham, Gerald; Oberlack, Horst; Ocariz, Jose; Ochi, Atsuhiko; Oda, Susumu; Odaka, Shigeru; Odier, Jerome; Ogren, Harold; Oh, Alexander; Oh, Seog; Ohm, Christian; Ohshima, Takayoshi; Ohshita, Hidetoshi; Ohska, Tokio Kenneth; Ohsugi, Takashi; Okada, Shogo; Okawa, Hideki; Okumura, Yasuyuki; Okuyama, Toyonobu; Olcese, Marco; Olchevski, Alexander; Oliveira, Miguel Alfonso; Oliveira Damazio, Denis; Oliver Garcia, Elena; Olivito, Dominick; Olszewski, Andrzej; Olszowska, Jolanta; Omachi, Chihiro; Onofre, António; Onyisi, Peter; Oram, Christopher; Oreglia, Mark; Oren, Yona; Orestano, Domizia; Orlov, Iliya; Oropeza Barrera, Cristina; Orr, Robert; Ortega, Eduardo; Osculati, Bianca; Ospanov, Rustem; Osuna, Carlos; Otero y Garzon, Gustavo; Ottersbach, John; Ouchrif, Mohamed; Ould-Saada, Farid; Ouraou, Ahmimed; Ouyang, Qun; Owen, Mark; Owen, Simon; Øye, Ola; Ozcan, Veysi Erkcan; Ozturk, Nurcan; Pacheco Pages, Andres; Padilla Aranda, Cristobal; Paganis, Efstathios; Paige, Frank; Pajchel, Katarina; Palestini, Sandro; Pallin, Dominique; Palma, Alberto; Palmer, Jody; Pan, Yibin; Panagiotopoulou, Evgenia; Panes, Boris; Panikashvili, Natalia; Panitkin, Sergey; Pantea, Dan; Panuskova, Monika; Paolone, Vittorio; Papadelis, Aras; Papadopoulou, Theodora; Paramonov, Alexander; Park, Woochun; Parker, Andy; Parodi, Fabrizio; Parsons, John; Parzefall, Ulrich; Pasqualucci, Enrico; Passeri, Antonio; Pastore, Fernanda; Pastore, Francesca; Pásztor, Gabriella; Pataraia, Sophio; Patel, Nikhul; Pater, Joleen; Patricelli, Sergio; Pauly, Thilo; Pecsy, Martin; Pedraza Morales, Maria Isabel; Peleganchuk, Sergey; Peng, Haiping; Pengo, Ruggero; Penson, Alexander; Penwell, John; Perantoni, Marcelo; Perez, Kerstin; Perez Cavalcanti, Tiago; Perez Codina, Estel; Pérez García-Estañ, María Teresa; Perez Reale, Valeria; Peric, Ivan; Perini, Laura; Pernegger, Heinz; Perrino, Roberto; Perrodo, Pascal; Persembe, Seda; Peshekhonov, Vladimir; Peters, Onne; Petersen, Brian; Petersen, Jorgen; Petersen, Troels; Petit, Elisabeth; Petridis, Andreas; Petridou, Chariclia; Petrolo, Emilio; Petrucci, Fabrizio; Petschull, Dennis; Petteni, Michele; Pezoa, Raquel; Phan, Anna; Phillips, Alan; Phillips, Peter William; Piacquadio, Giacinto; Piccaro, Elisa; Piccinini, Maurizio; Pickford, Andrew; Piec, Sebastian Marcin; Piegaia, Ricardo; Pilcher, James; Pilkington, Andrew; Pina, João Antonio; Pinamonti, Michele; Pinder, Alex; Pinfold, James; Ping, Jialun; Pinto, Belmiro; Pirotte, Olivier; Pizio, Caterina; Placakyte, Ringaile; Plamondon, Mathieu; Plano, Will; Pleier, Marc-Andre; Pleskach, Anatoly; Poblaguev, Andrei; Poddar, Sahill; Podlyski, Fabrice; Poggioli, Luc; Poghosyan, Tatevik; Pohl, Martin; Polci, Francesco; Polesello, Giacomo; Policicchio, Antonio; Polini, Alessandro; Poll, James; Polychronakos, Venetios; Pomarede, Daniel Marc; Pomeroy, Daniel; Pommès, Kathy; Pontecorvo, Ludovico; Pope, Bernard; Popeneciu, Gabriel Alexandru; Popovic, Dragan; Poppleton, Alan; Portell Bueso, Xavier; Porter, Robert; Posch, Christoph; Pospelov, Guennady; Pospisil, Stanislav; Potrap, Igor; Potter, Christina; Potter, Christopher; Poulard, Gilbert; Poveda, Joaquin; Prabhu, Robindra; Pralavorio, Pascal; Prasad, Srivas; Pravahan, Rishiraj; Prell, Soeren; Pretzl, Klaus Peter; Pribyl, Lukas; Price, Darren; Price, Lawrence; Price, Michael John; Prichard, Paul; Prieur, Damien; Primavera, Margherita; Prokofiev, Kirill; Prokoshin, Fedor; Protopopescu, Serban; Proudfoot, James; Prudent, Xavier; Przysiezniak, Helenka; Psoroulas, Serena; Ptacek, Elizabeth; Purdham, John; Purohit, Milind; Puzo, Patrick; Pylypchenko, Yuriy; Qian, Jianming; Qian, Zuxuan; Qin, Zhonghua; Quadt, Arnulf; Quarrie, David; Quayle, William; Quinonez, Fernando; Raas, Marcel; Radescu, Voica; Radics, Balint; Rador, Tonguc; Ragusa, Francesco; Rahal, Ghita; Rahimi, Amir; Rahm, David; Rajagopalan, Srinivasan; Rammensee, Michael; Rammes, Marcus; Ramstedt, Magnus; Randrianarivony, Koloina; Ratoff, Peter; Rauscher, Felix; Rauter, Emanuel; Raymond, Michel; Read, Alexander Lincoln; Rebuzzi, Daniela; Redelbach, Andreas; Redlinger, George; Reece, Ryan; Reeves, Kendall; Reichold, Armin; Reinherz-Aronis, Erez; Reinsch, Andreas; Reisinger, Ingo; Reljic, Dusan; Rembser, Christoph; Ren, Zhongliang; Renaud, Adrien; Renkel, Peter; Rensch, Bertram; Rescigno, Marco; Resconi, Silvia; Resende, Bernardo; Reznicek, Pavel; Rezvani, Reyhaneh; Richards, Alexander; Richter, Robert; Richter-Was, Elzbieta; Ridel, Melissa; Rieke, Stefan; Rijpstra, Manouk; Rijssenbeek, Michael; Rimoldi, Adele; Rinaldi, Lorenzo; Rios, Ryan Randy; Riu, Imma; Rivoltella, Giancesare; Rizatdinova, Flera; Rizvi, Eram; Robertson, Steven; Robichaud-Veronneau, Andree; Robinson, Dave; Robinson, James; Robinson, Mary; Robson, Aidan; Rocha de Lima, Jose Guilherme; Roda, Chiara; Roda Dos Santos, Denis; 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Ryder, Nick; Rzaeva, Sevda; Saavedra, Aldo; Sadeh, Iftach; Sadrozinski, Hartmut; Sadykov, Renat; Safai Tehrani, Francesco; Sakamoto, Hiroshi; Salamanna, Giuseppe; Salamon, Andrea; Saleem, Muhammad; Salihagic, Denis; Salnikov, Andrei; Salt, José; Salvachua Ferrando, Belén; Salvatore, Daniela; Salvatore, Pasquale Fabrizio; Salvucci, Antonio; Salzburger, Andreas; Sampsonidis, Dimitrios; Samset, Björn Hallvard; Sandaker, Heidi; Sander, Heinz Georg; Sanders, Michiel; Sandhoff, Marisa; Sandoval, Tanya; Sandstroem, Rikard; Sandvoss, Stephan; Sankey, Dave; Sansoni, Andrea; Santamarina Rios, Cibran; Santoni, Claudio; Santonico, Rinaldo; Santos, Helena; Saraiva, João; Sarangi, Tapas; Sarkisyan-Grinbaum, Edward; Sarri, Francesca; Sartisohn, Georg; Sasaki, Osamu; Sasaki, Takashi; Sasao, Noboru; Satsounkevitch, Igor; Sauvage, Gilles; Sauvan, Jean-Baptiste; Savard, Pierre; Savinov, Vladimir; Savu, Dan Octavian; Savva, Panagiota; Sawyer, Lee; Saxon, David; Says, Louis-Pierre; Sbarra, Carla; Sbrizzi, Antonio; Scallon, Olivia; Scannicchio, Diana; Scarcella, Mark; Schaarschmidt, Jana; Schacht, Peter; Schäfer, Uli; Schaepe, Steffen; Schaetzel, Sebastian; Schaffer, Arthur; Schaile, Dorothee; Schamberger, R~Dean; Schamov, Andrey; Scharf, Veit; Schegelsky, Valery; Scheirich, Daniel; Schernau, Michael; Scherzer, Max; Schiavi, Carlo; Schieck, Jochen; Schioppa, Marco; Schlenker, Stefan; Schlereth, James; Schmidt, Evelyn; Schmidt, Michael; Schmieden, Kristof; Schmitt, Christian; Schmitt, Sebastian; Schmitz, Martin; Schöning, André; Schott, Matthias; Schouten, Doug; Schovancova, Jaroslava; Schram, Malachi; Schroeder, Christian; Schroer, Nicolai; Schuh, Silvia; Schuler, Georges; Schultes, Joachim; Schultz-Coulon, Hans-Christian; Schulz, Holger; Schumacher, Jan; Schumacher, Markus; Schumm, Bruce; Schune, Philippe; Schwanenberger, Christian; Schwartzman, Ariel; Schwemling, Philippe; Schwienhorst, Reinhard; Schwierz, Rainer; Schwindling, Jerome; Scott, Bill; Searcy, Jacob; Sedykh, Evgeny; Segura, Ester; Seidel, Sally; Seiden, Abraham; Seifert, Frank; Seixas, José; Sekhniaidze, Givi; Seliverstov, Dmitry; Sellden, Bjoern; Sellers, Graham; Seman, Michal; Semprini-Cesari, Nicola; Serfon, Cedric; Serin, Laurent; Seuster, Rolf; Severini, Horst; Sevior, Martin; Sfyrla, Anna; Shabalina, Elizaveta; Shamim, Mansoora; Shan, Lianyou; Shank, James; Shao, Qi Tao; Shapiro, Marjorie; Shatalov, Pavel; Shaver, Leif; Shaw, Christian; Shaw, Kate; Sherman, Daniel; Sherwood, Peter; Shibata, Akira; Shichi, Hideharu; Shimizu, Shima; Shimojima, Makoto; Shin, Taeksu; Shmeleva, Alevtina; Shochet, Mel; Short, Daniel; Shupe, Michael; Sicho, Petr; Sidoti, Antonio; Siebel, Anca-Mirela; Siegert, Frank; Siegrist, James; Sijacki, Djordje; Silbert, Ohad; Silva, José; Silver, Yiftah; Silverstein, Daniel; Silverstein, Samuel; Simak, Vladislav; Simard, Olivier; Simic, Ljiljana; Simion, Stefan; Simmons, Brinick; Simonyan, Margar; Sinervo, Pekka; Sinev, Nikolai; Sipica, Valentin; Siragusa, Giovanni; Sisakyan, Alexei; Sivoklokov, Serguei; Sjölin, Jörgen; Sjursen, Therese; Skinnari, Louise Anastasia; Skovpen, Kirill; Skubic, Patrick; Skvorodnev, Nikolai; Slater, Mark; Slavicek, Tomas; Sliwa, Krzysztof; Sloan, Terrence; Sloper, John erik; Smakhtin, Vladimir; Smirnov, Sergei; Smirnova, Lidia; Smirnova, Oxana; Smith, Ben Campbell; Smith, Douglas; Smith, Kenway; Smizanska, Maria; Smolek, Karel; Snesarev, Andrei; Snow, Steve; Snow, Joel; Snuverink, Jochem; Snyder, Scott; Soares, Mara; Sobie, Randall; Sodomka, Jaromir; Soffer, Abner; Solans, Carlos; Solar, Michael; Solc, Jaroslav; Soldatov, Evgeny; Soldevila, Urmila; Solfaroli Camillocci, Elena; Solodkov, Alexander; Solovyanov, Oleg; Sondericker, John; Soni, Nitesh; Sopko, Vit; Sopko, Bruno; Sorbi, Massimo; Sosebee, Mark; Soukharev, Andrey; Spagnolo, Stefania; Spanò, Francesco; Spighi, Roberto; Spigo, Giancarlo; Spila, Federico; Spiriti, Eleuterio; Spiwoks, Ralf; Spousta, Martin; Spreitzer, Teresa; Spurlock, Barry; St Denis, Richard Dante; Stahl, Thorsten; Stahlman, Jonathan; Stamen, Rainer; Stanecka, Ewa; Stanek, Robert; Stanescu, Cristian; Stapnes, Steinar; Starchenko, Evgeny; Stark, Jan; Staroba, Pavel; Starovoitov, Pavel; Staude, Arnold; Stavina, Pavel; Stavropoulos, Georgios; Steele, Genevieve; Steinbach, Peter; Steinberg, Peter; Stekl, Ivan; Stelzer, Bernd; Stelzer, Harald Joerg; Stelzer-Chilton, Oliver; Stenzel, Hasko; Stevenson, Kyle; Stewart, Graeme; Stillings, Jan Andre; Stockmanns, Tobias; Stockton, Mark; Stoerig, Kathrin; Stoicea, Gabriel; Stonjek, Stefan; Strachota, Pavel; Stradling, Alden; Straessner, Arno; Strandberg, Jonas; Strandberg, Sara; Strandlie, Are; Strang, Michael; Strauss, Emanuel; Strauss, Michael; Strizenec, Pavol; Ströhmer, Raimund; Strom, David; Strong, John; Stroynowski, Ryszard; Strube, Jan; Stugu, Bjarne; Stumer, Iuliu; Stupak, John; Sturm, Philipp; Soh, Dart-yin; Su, Dong; Subramania, Halasya Siva; Succurro, Antonella; Sugaya, Yorihito; Sugimoto, Takuya; Suhr, Chad; Suita, Koichi; Suk, Michal; Sulin, Vladimir; Sultansoy, Saleh; Sumida, Toshi; Sun, Xiaohu; Sundermann, Jan Erik; Suruliz, Kerim; Sushkov, Serge; Susinno, Giancarlo; Sutton, Mark; Suzuki, Yu; Svatos, Michal; Sviridov, Yuri; Swedish, Stephen; Sykora, Ivan; Sykora, Tomas; Szeless, Balazs; Sánchez, Javier; Ta, Duc; Tackmann, Kerstin; Taffard, Anyes; Tafirout, Reda; Taga, Adrian; Taiblum, Nimrod; Takahashi, Yuta; Takai, Helio; Takashima, Ryuichi; Takeda, Hiroshi; Takeshita, Tohru; Talby, Mossadek; Talyshev, Alexey; Tamsett, Matthew; Tanaka, Junichi; Tanaka, Reisaburo; Tanaka, Satoshi; Tanaka, Shuji; Tanaka, Yoshito; Tani, Kazutoshi; Tannoury, Nancy; Tappern, Geoffrey; Tapprogge, Stefan; Tardif, Dominique; Tarem, Shlomit; Tarrade, Fabien; Tartarelli, Giuseppe Francesco; Tas, Petr; Tasevsky, Marek; Tassi, Enrico; Tatarkhanov, Mous; Tayalati, Yahya; Taylor, Christopher; Taylor, Frank; Taylor, Geoffrey; Taylor, Wendy; Teixeira Dias Castanheira, Matilde; Teixeira-Dias, Pedro; Temming, Kim Katrin; Ten Kate, Herman; Teng, Ping-Kun; Terada, Susumu; Terashi, Koji; Terron, Juan; Terwort, Mark; Testa, Marianna; Teuscher, Richard; Thadome, Jocelyn; Therhaag, Jan; Theveneaux-Pelzer, Timothée; Thioye, Moustapha; Thoma, Sascha; Thomas, Juergen; Thompson, Emily; Thompson, Paul; Thompson, Peter; Thompson, Stan; Thomson, Evelyn; Thomson, Mark; Thun, Rudolf; Tic, Tomáš; Tikhomirov, Vladimir; Tikhonov, Yury; Timmermans, Charles; Tipton, Paul; Tique Aires Viegas, Florbela De Jes; Tisserant, Sylvain; Tobias, Jürgen; Toczek, Barbara; Todorov, Theodore; Todorova-Nova, Sharka; Toggerson, Brokk; Tojo, Junji; Tokár, Stanislav; Tokunaga, Kaoru; Tokushuku, Katsuo; Tollefson, Kirsten; Tomoto, Makoto; Tompkins, Lauren; Toms, Konstantin; Tong, Guoliang; Tonoyan, Arshak; Topfel, Cyril; Topilin, Nikolai; Torchiani, Ingo; Torrence, Eric; Torró Pastor, Emma; Toth, Jozsef; Touchard, Francois; Tovey, Daniel; Traynor, Daniel; Trefzger, Thomas; Treis, Johannes; Tremblet, Louis; Tricoli, Alesandro; Trigger, Isabel Marian; Trincaz-Duvoid, Sophie; Trinh, Thi Nguyet; Tripiana, Martin; Trischuk, William; Trivedi, Arjun; Trocmé, Benjamin; Troncon, Clara; Trottier-McDonald, Michel; Trzupek, Adam; Tsarouchas, Charilaos; Tseng, Jeffrey; Tsiakiris, Menelaos; Tsiareshka, Pavel; Tsionou, Dimitra; Tsipolitis, Georgios; Tsiskaridze, Vakhtang; Tskhadadze, Edisher; Tsukerman, Ilya; Tsulaia, Vakhtang; Tsung, Jieh-Wen; Tsuno, Soshi; Tsybychev, Dmitri; Tua, Alan; Tuggle, Joseph; Turala, Michal; Turecek, Daniel; Turk Cakir, Ilkay; Turlay, Emmanuel; Turra, Ruggero; Tuts, Michael; Tykhonov, Andrii; Tylmad, Maja; Tyndel, Mike; Tyrvainen, Harri; Tzanakos, George; Uchida, Kirika; Ueda, Ikuo; Ueno, Ryuichi; Ugland, Maren; Uhlenbrock, Mathias; Uhrmacher, Michael; Ukegawa, Fumihiko; Unal, Guillaume; Underwood, David; Undrus, Alexander; Unel, Gokhan; Unno, Yoshinobu; Urbaniec, Dustin; Urkovsky, Evgeny; Urrejola, Pedro; Usai, Giulio; Uslenghi, Massimiliano; Vacavant, Laurent; Vacek, Vaclav; Vachon, Brigitte; Vahsen, Sven; Valenta, Jan; Valente, Paolo; Valentinetti, Sara; Valkar, Stefan; Valladolid Gallego, Eva; Vallecorsa, Sofia; Valls Ferrer, Juan Antonio; van der Graaf, Harry; van der Kraaij, Erik; Van Der Leeuw, Robin; van der Poel, Egge; van der Ster, Daniel; Van Eijk, Bob; van Eldik, Niels; van Gemmeren, Peter; van Kesteren, Zdenko; van Vulpen, Ivo; Vandelli, Wainer; Vandoni, Giovanna; Vaniachine, Alexandre; Vankov, Peter; Vannucci, Francois; Varela Rodriguez, Fernando; Vari, Riccardo; Varnes, Erich; Varouchas, Dimitris; Vartapetian, Armen; Varvell, Kevin; Vassilakopoulos, Vassilios; Vazeille, Francois; Vegni, Guido; Veillet, Jean-Jacques; Vellidis, Constantine; Veloso, Filipe; Veness, Raymond; Veneziano, Stefano; Ventura, Andrea; Ventura, Daniel; Venturi, Manuela; Venturi, Nicola; Vercesi, Valerio; Verducci, Monica; Verkerke, Wouter; Vermeulen, Jos; Vest, Anja; Vetterli, Michel; Vichou, Irene; Vickey, Trevor; Viehhauser, Georg; Viel, Simon; Villa, Mauro; Villaplana Perez, Miguel; Vilucchi, Elisabetta; Vincter, Manuella; Vinek, Elisabeth; Vinogradov, Vladimir; Virchaux, Marc; Viret, Sébastien; Virzi, Joseph; Vitale, Antonio; Vitells, Ofer; Viti, Michele; Vivarelli, Iacopo; Vives Vaque, Francesc; Vlachos, Sotirios; Vlasak, Michal; Vlasov, Nikolai; Vogel, Adrian; Vokac, Petr; Volpi, Guido; Volpi, Matteo; Volpini, Giovanni; von der Schmitt, Hans; von Loeben, Joerg; von Radziewski, Holger; von Toerne, Eckhard; Vorobel, Vit; Vorobiev, Alexander; Vorwerk, Volker; Vos, Marcel; Voss, Rudiger; Voss, Thorsten Tobias; Vossebeld, Joost; Vranjes, Nenad; Vranjes Milosavljevic, Marija; Vrba, Vaclav; Vreeswijk, Marcel; Vu Anh, Tuan; Vuillermet, Raphael; Vukotic, Ilija; Wagner, Wolfgang; Wagner, Peter; Wahlen, Helmut; Wakabayashi, Jun; Walbersloh, Jorg; Walch, Shannon; Walder, James; Walker, Rodney; Walkowiak, Wolfgang; Wall, Richard; Waller, Peter; Wang, Chiho; Wang, Haichen; Wang, Hulin; Wang, Jike; Wang, Jin; Wang, Joshua C; Wang, Rui; Wang, Song-Ming; Warburton, Andreas; Ward, Patricia; Warsinsky, Markus; Watkins, Peter; Watson, Alan; Watson, Miriam; Watts, Gordon; Watts, Stephen; Waugh, Anthony; Waugh, Ben; Weber, Jens; Weber, Marc; Weber, Michele; Weber, Pavel; Weidberg, Anthony; Weigell, Philipp; Weingarten, Jens; Weiser, Christian; Wellenstein, Hermann; Wells, Phillippa; Wen, Mei; Wenaus, Torre; Wendler, Shanti; Weng, Zhili; Wengler, Thorsten; Wenig, Siegfried; Wermes, Norbert; Werner, Matthias; Werner, Per; Werth, Michael; Wessels, Martin; Weydert, Carole; Whalen, Kathleen; Wheeler-Ellis, Sarah Jane; Whitaker, Scott; White, Andrew; White, Martin; White, Sebastian; Whitehead, Samuel Robert; Whiteson, Daniel; Whittington, Denver; Wicek, Francois; Wicke, Daniel; Wickens, Fred; Wiedenmann, Werner; Wielers, Monika; Wienemann, Peter; Wiglesworth, Craig; Wiik, Liv Antje Mari; Wijeratne, Peter Alexander; Wildauer, Andreas; Wildt, Martin Andre; Wilhelm, Ivan; Wilkens, Henric George; Will, Jonas Zacharias; Williams, Eric; Williams, Hugh; Willis, William; Willocq, Stephane; Wilson, John; Wilson, Michael Galante; Wilson, Alan; Wingerter-Seez, Isabelle; Winkelmann, Stefan; Winklmeier, Frank; 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Zeller, Michael; Zemla, Andrzej; Zendler, Carolin; Zenin, Anton; Zenin, Oleg; Ženiš, Tibor; Zenonos, Zenonas; Zenz, Seth; Zerwas, Dirk; Zevi della Porta, Giovanni; Zhan, Zhichao; Zhang, Dongliang; Zhang, Huaqiao; Zhang, Jinlong; Zhang, Xueyao; Zhang, Zhiqing; Zhao, Long; Zhao, Tianchi; Zhao, Zhengguo; Zhemchugov, Alexey; Zheng, Shuchen; Zhong, Jiahang; Zhou, Bing; Zhou, Ning; Zhou, Yue; Zhu, Cheng Guang; Zhu, Hongbo; Zhu, Yingchun; Zhuang, Xuai; Zhuravlov, Vadym; Zieminska, Daria; Zimmermann, Robert; Zimmermann, Simone; Zimmermann, Stephanie; Ziolkowski, Michael; Zitoun, Robert; Živković, Lidija; Zmouchko, Viatcheslav; Zobernig, Georg; Zoccoli, Antonio; Zolnierowski, Yves; Zsenei, Andras; zur Nedden, Martin; Zutshi, Vishnu; Zwalinski, Lukasz

    2012-01-01

    Proton-proton collisions at $\\sqrt{s}=7$ TeV and heavy ion collisions at $\\sqrt{s_{NN}}$=2.76 TeV were produced by the LHC and recorded using the ATLAS experiment's trigger system in 2010. The LHC is designed with a maximum bunch crossing rate of 40 MHz and the ATLAS trigger system is designed to record approximately 200 of these per second. The trigger system selects events by rapidly identifying signatures of muon, electron, photon, tau lepton, jet, and B meson candidates, as well as using global event signatures, such as missing transverse energy. An overview of the ATLAS trigger system, the evolution of the system during 2010 and the performance of the trigger system components and selections based on the 2010 collision data are shown. A brief outline of plans for the trigger system in 2011 is presented

  18. Performance of the ATLAS trigger system

    Science.gov (United States)

    Casadei, Diego

    2012-12-01

    The ATLAS trigger has been used very successfully to collect collision data during 2009-2011 LHC running at centre of mass energies between 900 GeV and 7 TeV. The three-level trigger system reduces the event rate from the design bunch-crossing rate of 40 MHz to an average recording rate of about 300 Hz. The first level uses custom electronics to reject most background events, in less than 2.5 μs, using information from the calorimeter and muon detectors. The upper two trigger levels are software-based triggers. The trigger system selects events by identifying signatures of muon, electron, photon, tau lepton, jet, and B meson candidates, as well as using global event signatures, such as missing transverse energy. We give an overview of the performance of these trigger selections based on extensive online running during the 2011 LHC run and discuss issues encountered during 2011 operations. We describe how the trigger has evolved with increasing LHC luminosity coping with pile-up conditions close to LHC design luminosity.

  19. The ATLAS trigger - commissioning with cosmic rays

    Science.gov (United States)

    Boyd, J.

    2008-07-01

    The ATLAS detector at CERN's LHC will be exposed to proton-proton collisions from beams crossing at 40 MHz. At the design luminosity there are roughly 23 collisions per bunch crossing. ATLAS has designed a three-level trigger system to select potentially interesting events. The first-level trigger, implemented in custom-built electronics, reduces the incoming rate to less than 100 kHz with a total latency of less than 2.5μs. The next two trigger levels run in software on commercial PC farms. They reduce the output rate to 100-200 Hz. In preparation for collision data-taking which is scheduled to commence in May 2008, several cosmic-ray commissioning runs have been performed. Among the first sub-detectors available for commissioning runs are parts of the barrel muon detector including the RPC detectors that are used in the first-level trigger. Data have been taken with a full slice of the muon trigger and readout chain, from the detectors in one sector of the RPC system, to the second-level trigger algorithms and the data-acquisition system. The system is being prepared to include the inner-tracking detector in the readout and second-level trigger. We will present the status and results of these cosmic-ray based commissioning activities. This work will prove to be invaluable not only during the commissioning phase but also for cosmic-ray data-taking during the normal running for detector performance studies.

  20. The ATLAS trigger - high-level trigger commissioning and operation during early data taking

    CERN Document Server

    Goncalo, R; Achenbach, R; Adragna, P; Aielli, G; Aleksandrov, E; Aleksandrov, I; Aloisio, A; Alviggi, M G; Amorim, A; Anderson, K; Andrei, V; Anduaga, X; Antonelli, S; Aracena, I; Ask, S; Asquith, L; Avolio, G; Backlund, S; Badescu, E; Bahat Treidel, O; Baines, J; Barnett, B M; Barria, P; Bartoldus, R; Batreanu, S; Bauss, B; Beck, H P; Bee, C; Bell, P; Bell, W H; Bellagamba, L; Bellomo, M; Ben Ami, S; Bendel, M; Benhammou, Ya; Benslama, K; Berge, D; Berger, N; Berry, T; Bianco, M; Biglietti, M; Blair, R R; Bogaerts, A; Bohm, C; Bold, T; Booth, J R A; Boscherini, D; Bosman, M; Boyd, J; Brawn, I P; Brelier, B; Bressler, S; Bruni, A; Bruni, G; Buda, S; Burckhart-Chromek, D; Buttar, C; Camarri, P; Campanelli, M; Canale, V; Caprini, M; Caracinha, D; Cardarelli, R; Carlino, G; Casadei, D; Casado, M P; Cataldi, G; Cerri, A; Charlton, D G; Chiodini, G; Ciapetti, G; Cimino, D; Ciobotaru, M; Clements, D; Coccaro, A; Coluccia, M R; Conde-Muíño, P; Constantin, S; Conventi, F; Corso-Radu, A; Costa, M J; Coura Torres, R; Cranfield, R; Cranmer, K; Crone, G; Curtis, C J; Dam, M; Damazio, D; Davis, A O; Dawson, I; Dawson, J; De Almeida Simoes, J; De Cecco, S; De Pedis, D; De Santo, A; DeAsmundis, R; DellaPietra, M; DellaVolpe, D; Delsart, P -A; Demers, S; Di Mattia, A; Di Ciaccio, A; Di Girolamo, A; Dionisi, C; Djilkibaev, R; Dobinson, Robert W; Dobson, M; Dogaru, M; Dotti, A; Dova, M; Drake, G; Dufour, M -A; Eckweiler, S; Ehrenfeld, W; Eifert, T; Eisenhandler, E F; Ellis, Nick; Emeliyanov, D; Enoque Ferreira de Lima, D; Ermoline, Y; Eschrich, I; Etzion, E; Facius, K; Falciano, S; Farthouat, P; Faulkner, P J W F; Feng, E; Ferland, J; Ferrari, R; Ferrer, M L; Fischer, G; Fonseca-Martin, T; Francis, D; Fukunaga, C; Föhlisch, F; Gadomski, S; Garitaonandia Elejabarrieta, H; Gaudio, G; Gaumer, O; Gee, C N P; George, S; Geweniger, C; Giagu, S; Gillman, A R; Giusti, P; Gorini, B; Gorini, E; Gowdy, S; Grabowska-Bold, I; Grancagnolo, F; Grancagnolo, S; Green, B; Galllno, P; Haas, S; Haberichter, W; Hadavand, H; Haeberli, C; Haller, J; Hamilton, A; Hanke, P; Hansen, J R; Hasegawa, Y; Hauschild, M; Hauser, R; Head, S; Hellman, S; Hidvegi, A; Hillier, S J; Höcker, A; Hrynóva, T; Hughes-Jones, R; Huston, J; Iacobucci, G; Idarraga, J; Iengo, P; Igonkina, O; Ikeno, M; Inada, M; Ishino, M; Iwasaki, H; Izzo, V; Jain, V; Johansen, M; Johns, K; Joos, M; Kadosaka, T; Kajomovitz, E; Kama, S; Kanaya, N; Kawagoe, K; Kawamoto, T; Kazarov, A; Kehoe, R; Khoriauli, G; Kieft, G; Kilvington, G; Kirk, J; Kiyamura, H; Klofver, P; Klous, S; Kluge, E -E; Kobayashi, T; Kolos, S; Kono, T; Konstantinidis, N; Korcyl, K; Kordas, K; Kotov, V; Krasznahorkay, A; Kubota, T; Kugel, A; Kuhn, D; Kurashige, H; Kurasige, H; Kuwabara, T; Kwee, R; Landon, M; Lankford, A; LeCompte, T; Leahu, L; Leahu, M; Ledroit, F; Lehmann-Miotto, G; Lei, X; Lellouch, D; Lendermann, V; Levinson, L; Leyton, M; Li, S; Liberti, B; Lifshitz, R; Lim, H; Lohse, T; Losada, M; Luci, C; Luminari, L; Lupu, N; Mahboubi, K; Mahout, G; Mapelli, L; Marchese, F; Martin, B; Martin, B T; Martínez, A; Marzano, F; Masik, J; McMahon, T; McPherson, R; Medinnis, M; Meessen, C; Meier, K; Meirosu, C; Messina, A; Migliaccio, A; Mikenberg, G; Mincer, A; Mineev, M; Misiejuk, A; Mönig, K; Monticelli, F; Moraes, A; Moreno, D; Morettini, P; Murillo Garcia, R; Nagano, K; Nagasaka, Y; Negri, A; Némethy, P; Neusiedl, A; Nisati, A; Niwa, T; Nomachi, M; Nomoto, H; Nozaki, M; Nozicka, M; Ochi, A; Ohm, C; Okumura, Y; Omachi, C; Osculati, B; Oshita, H; Osuna, C; Padilla, C; Panikashvili, N; Parodi, F; Pasqualucci, E; Pastore, F; Patricelli, S; Pauly, T; Pectu, M; Perantoni, M; Perera, V; Perera, V J O; Pérez, E; Pérez-Réale, V; Perrino, R; Pessoa Lima Junior, H; Petersen, J; Petrolo, E; Piegaia, R; Pilcher, J E; Pinto, F; Pinzon, G; Polini, A; Pope, B; Potter, C; Prieur, D P F; Primavera, M; Qian, W; Radescu, V; Rajagopalan, S; Renkel, P; Rescigno, M; Rieke, S; Risler, C; Riu, I; Robertson, S; Roda, C; Rodríguez, D; Rogriquez, Y; Roich, A; Romeo, G; Rosati, S; Ryabov, Yu; Ryan, P; Rühr, F; Sakamoto, H; Salamon, A; Salvatore, D; Sankey, D P C; Santamarina, C; Santamarina-Rios, C; Santonico, R; Sasaki, O; Scannicchio, D; Scannicchio, D A; Schiavi, C; Schlereth, J L; Schmitt, K; Scholtes, I; Schooltz, D; Schuler, G; Schultz-Coulon, H -C; Schäfer, U; Scott, W; Segura, E; Sekhniaidze, G; Shimbo, N; Sidoti, A; Silva, L; Silverstein, S; Siragusa, G; Sivoklokov, S; Sloper, J E; Smizanska, M; Solfaroli, E; Soloviev, I; Soluk, R; Spagnolo, S; Spila, F; Spiwoks, R; Staley, R J; Stamen, R; Stancu, S; Steinberg, P; Stelzer, J; Stradling, A; Strom, D; Strong, J; Su, D; Sugaya, Y; Sugimoto, T; Sushkov, S; Sutton, M; Szymocha, T; Takahashi, Y; Takeda, H; Takeshita, T; Tanaka, S; Tapprogge, S; Tarem, S; Tarem, Z; Teixeira-Dias, P; Thomas, J P; Tokoshuku, K; Tomoto, M; Torrence, E; Touchard, F; Trefzger, T; Tremblet, L; Tripiana, M; Usai, G; Vachon, B; Vandelli, W; Vari, R; Veneziano, S; Ventura, A; Vercesi, V; Vermeulen, J; Von Der Schmitt, J; Wang, M; Watkins, P M; Watson, A; Weber, P; Wengler, T; Werner, P; Wheeler-Ellis, S; Wickens, F; Wiedenmann, W; Wielers, M; Wilkens, H; Winklmeier, F; Woehrling, E -E; Wu, S -L; Wu, X; Xella, S; Yamaguchi, Y; Yamazaki, Y; Yasu, Y; Yu, M; Zanello, L; Zema, F; Zhang, J; Zhao, L; Zobernig, H; De Seixas, J M; Dos Anjos, A; Zur Nedden, M; Ozcan, E; Ünel, G; International Europhysics Conference on High Energy Physics

    2008-01-01

    The ATLAS experiment is one of the two general-purpose experiments due to start operation soon at the Large Hadron Collider (LHC). The LHC will collide protons at a centre of mass energy of 14~TeV, with a bunch-crossing rate of 40~MHz. The ATLAS three-level trigger will reduce this input rate to match the foreseen offline storage capability of 100-200~Hz. This paper gives an overview of the ATLAS High Level Trigger focusing on the system design and its innovative features. We then present the ATLAS trigger strategy for the initial phase of LHC exploitation. Finally, we report on the valuable experience acquired through in-situ commissioning of the system where simulated events were used to exercise the trigger chain. In particular we show critical quantities such as event processing times, measured in a large-scale HLT farm using a complex trigger menu.

  1. Event Reconstruction Algorithms for the ATLAS Trigger

    Energy Technology Data Exchange (ETDEWEB)

    Fonseca-Martin, T.; /CERN; Abolins, M.; /Michigan State U.; Adragna, P.; /Queen Mary, U. of London; Aleksandrov, E.; /Dubna, JINR; Aleksandrov, I.; /Dubna, JINR; Amorim, A.; /Lisbon, LIFEP; Anderson, K.; /Chicago U., EFI; Anduaga, X.; /La Plata U.; Aracena, I.; /SLAC; Asquith, L.; /University Coll. London; Avolio, G.; /CERN; Backlund, S.; /CERN; Badescu, E.; /Bucharest, IFIN-HH; Baines, J.; /Rutherford; Barria, P.; /Rome U. /INFN, Rome; Bartoldus, R.; /SLAC; Batreanu, S.; /Bucharest, IFIN-HH /CERN; Beck, H.P.; /Bern U.; Bee, C.; /Marseille, CPPM; Bell, P.; /Manchester U.; Bell, W.H.; /Glasgow U. /Pavia U. /INFN, Pavia /Regina U. /CERN /Annecy, LAPP /Paris, IN2P3 /Royal Holloway, U. of London /Napoli Seconda U. /INFN, Naples /Argonne /CERN /UC, Irvine /Barcelona, IFAE /Barcelona, Autonoma U. /CERN /Montreal U. /CERN /Glasgow U. /Michigan State U. /Bucharest, IFIN-HH /Napoli Seconda U. /INFN, Naples /New York U. /Barcelona, IFAE /Barcelona, Autonoma U. /Salento U. /INFN, Lecce /Pisa U. /INFN, Pisa /Bucharest, IFIN-HH /UC, Irvine /CERN /Glasgow U. /INFN, Genoa /Genoa U. /Lisbon, LIFEP /Napoli Seconda U. /INFN, Naples /UC, Irvine /Valencia U. /Rio de Janeiro Federal U. /University Coll. London /New York U.; /more authors..

    2011-11-09

    The ATLAS experiment under construction at CERN is due to begin operation at the end of 2007. The detector will record the results of proton-proton collisions at a center-of-mass energy of 14 TeV. The trigger is a three-tier system designed to identify in real-time potentially interesting events that are then saved for detailed offline analysis. The trigger system will select approximately 200 Hz of potentially interesting events out of the 40 MHz bunch-crossing rate (with 10{sup 9} interactions per second at the nominal luminosity). Algorithms used in the trigger system to identify different event features of interest will be described, as well as their expected performance in terms of selection efficiency, background rejection and computation time per event. The talk will concentrate on recent improvements and on performance studies, using a very detailed simulation of the ATLAS detector and electronics chain that emulates the raw data as it will appear at the input to the trigger system.

  2. A Hardware Track Trigger (FTK) for the ATLAS Trigger

    CERN Document Server

    Zhang, J; The ATLAS collaboration

    2014-01-01

    The design and studies of the performance for the ATLAS hardware Fast TracKer (FTK) are presented. The existing trigger system of the ATLAS experiment is deployed to reduce the event rate from the bunch crossing rate of 40 MHz to < 1 KHz for permanent storage at the LHC design luminosity of 10^34 cm^-2 s^-1. The LHC has performed exceptionally well and routinely exceeds the design luminosity and from 2015 is due to operate with higher still luminosities. This will place a significant load on the High Level trigger (HLT) system, both due to the need for more sophisticated algorithms to reject background, and from the larger data volumes that will need to be processed. The Fast TracKer is a custom electronics system that will operate at the full Level-1 accepted rate of 100 KHz and provide high quality tracks at the beginning of processing in the HLT. This will be performing by track reconstruction using hardware with massive parallelism using associative memories (AM) and FPGAs. The availability of the full...

  3. The Design and Performance of the ATLAS Inner Detector Trigger for Run 2 LHC Collisions at $\\sqrt{s} = 13$ TeV

    CERN Document Server

    Kilby, Callum; The ATLAS collaboration

    2016-01-01

    The design and performance of the ATLAS Inner Detector (ID) trigger algorithms running online on the high level trigger (HLT) processor farm with the LHC Run 2 data with collisions at both 50 ns and 25 ns are discussed. The HLT ID tracking algorithms are essential for the identification of nearly all physics signatures in the ATLAS trigger. In order to deal with the expected higher rates for LHC Run 2, the ID trigger was redesigned during the 2013-15 long shutdown to satisfy the demands of the higher energy LHC operation. The detailed performance of the tracking algorithms with the Run 2 data taken so far for the different trigger signatures in terms of both efficiency, and resolution is presented. The online processing times for running trigger tracking for the different trigger signatures are discussed in detail. Where appropriate, comparison of the new strategy for Run 2, with that adopted in Run 1 are made to demonstrate successful application and superior performance of the strategy adopted for Run 2.

  4. ATLAS High Level Trigger Infrastructure, ROI Collection and Event Building

    CERN Document Server

    Kordas, K; Baines, J T M; Beck, H P; Bee, C; Bogaerts, A; Bold, T; Bosman, M; Comune, G; Cranfield, R; Crone, G; Di Mattia, A; Dos Anjos, A; Ellis, Nick; Ertorer, E; Falciano, S; Ferrari, R; Ferrer, M L; Gadomski, S; Gameiro, S; Garitaonandia, H; George, S; Gesualdi-Mello, A; Gorini, B; Green, B; Haeberli, C; Haller, J; Hauser, R; Joos, M; Kieft, G; Klous, S; Kugel, A; Lankford, A; Liu, W; Maeno, T; Masik, J; Meessen, C; Misiejuk, A; Morettini, P; Müller, M; Nagasaka, Y; Negri, A; Padilla, C; Pasqualucci, E; Pauly, T; Perera, V J O; Petersen, J; Portes de Albuquerque, M; Schiavi, C; Schlereth, J L; Segura, E; Seixas, M; Spiwoks, R; Stamen, R; Strong, J; Sushkov, S; Tapprogge, S; Teixeira-Dias, P; Torres, R; Touchard, F; Tremblet, L; Ünel, G; Vandelli, W; Van Wasen, J; Vermeulen, J; Werner, P; Wheeler, S; Wickens, F; Wiedenmann, W; Wu, X; Yasu, Y; Yu, M; Zobernig, H

    2006-01-01

    We describe the base-line design and implementation of the Data Flow and High Level Trigger (HLT) part of the ATLAS Trigger and Data Acquisition (TDAQ) system. We then discuss improvements and generalization of the system design to allow the handling of events in parallel data streams and we present the possibility for event duplication, partial Event Building and data stripping. We then present tests on the deployment and integration of the TDAQ infrastructure and algorithms at the TDAQ â€?pre-series” cluster (~10% of full ATLAS TDAQ). Finally, we tackle two HLT performance issues.

  5. The ATLAS b-jet Trigger

    CERN Document Server

    Ferreira de Lima, D E; The ATLAS collaboration

    2011-01-01

    The ATLAS b-jet Trigger The online event selection is crucial to reject most of the events containing uninteresting background collisions while preserving as much as possible the interesting physical signals. The b-jet selection is part of the trigger strategy of the ATLAS experiment and a set of dedicated triggers is presently contributing to the event selection for the 2011 running. The b-jets acceptance is increased and the background reduced by lowering jet transverse energy thresholds at the first trigger level and applying b-tagging techniques at the subsequent levels. Different physics channels, especially topologies containing more than one b-jet where higher rejection factors are achieved, benefit from requesting this trigger to be fired. An overview of the status-of-art of the b-jet trigger menu and performance on real data is presented in this poster.

  6. The ATLAS High Level Trigger Steering Framework and the Trigger 
Configuration System.

    CERN Document Server

    Pérez Cavalcanti, Tiago; The ATLAS collaboration

    2011-01-01

    The ATLAS High Level Trigger Steering Framework and the Trigger 
Configuration System.
 
The ATLAS detector system installed in the Large Hadron Collider (LHC) 
at CERN is designed to study proton-proton and nucleus-nucleus 
collisions with a maximum center of mass energy of 14 TeV at a bunch 
collision rate of 40MHz.  In March 2010 the four LHC experiments saw 
the first proton-proton collisions at 7 TeV. Still within the year a 
collision rate of nearly 10 MHz is expected. At ATLAS, events of 
potential interest for ATLAS physics are selected by a three-level 
trigger system, with a final recording rate of about 200 Hz. The first 
level (L1) is implemented in custom hardware; the two levels of 
the high level trigger (HLT) are software triggers, running on large 
farms of standard computers and network devices. 

Within the ATLAS physics program more than 500 trigger signatures are 
defined. The HLT tests each signature on each L1-accepted event; the 
test outcome is recor...

  7. The ATLAS Level-1 Topological Trigger Performance

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00371751; The ATLAS collaboration

    2016-01-01

    The LHC will collide protons in the ATLAS detector with increasing luminosity through 2016, placing stringent operational and physical requirements to the ATLAS trigger system in order to reduce the 40 MHz collision rate to a manageable event storage rate of 1 kHz, while not rejecting interesting physics events. The Level-1 trigger is the first rate-reducing step in the ATLAS trigger system with an output rate of 100 kHz and decision latency smaller than 2.5 μs. It consists of a calorimeter trigger, muon trigger and a central trigger processor. During the LHC shutdown after the Run 1 finished in 2013, the Level-1 trigger system was upgraded including hardware, firmware and software updates. In particular, new electronics modules were introduced in the real-time data processing path: the Topological Processor System (L1Topo). It consists of a single AdvancedCTA shelf equipped with two Level-1 topological processor blades. They receive real-time information from the Level-1 calorimeter and muon triggers, which...

  8. The Database Driven ATLAS Trigger Configuration System

    CERN Document Server

    Martyniuk, Alex; The ATLAS collaboration

    2015-01-01

    This contribution describes the trigger selection configuration system of the ATLAS low- and high-level trigger (HLT) and the upgrades it received in preparation for LHC Run 2. The ATLAS trigger configuration system is responsible for applying the physics selection parameters for the online data taking at both trigger levels and the proper connection of the trigger lines across those levels. Here the low-level trigger consists of the already existing central trigger (CT) and the new Level-1 Topological trigger (L1Topo), which has been added for Run 2. In detail the tasks of the configuration system during the online data taking are Application of the selection criteria, e.g. energy cuts, minimum multiplicities, trigger object correlation, at the three trigger components L1Topo, CT, and HLT On-the-fly, e.g. rate-dependent, generation and application of prescale factors to the CT and HLT to adjust the trigger rates to the data taking conditions, such as falling luminosity or rate spikes in the detector readout ...

  9. The design and performance of the ATLAS inner detector trigger for Run-2 LHC collisions at $\\sqrt{s} = 13$ TeV

    CERN Document Server

    Miano, Fabrizio; The ATLAS collaboration

    2016-01-01

    The Run-2 of the Large Hadron Collider presents challenging high rate conditions for data analysis and processing within the ATLAS trigger system. The ATLAS Inner Detector (ID) trigger implements the algorithms used for identification of tracks for all physics signatures within the ATLAS trigger. The ID trigger was updated and redesigned during the 2013-2015 long shutdown to meet the challenging conditions of Run-2. As well, for Run-2 a new pixel detector layer was added in very close proximity to the beam pipe, to enhance the ID Trigger performance. The redesigned ID trigger algorithms for Run-2 are described, illustrating the significant improvements gained by the new tracking strategies adopted to deal with the increased rate. The performance of the ID trigger in Run-2 is shown in terms of efficiency and resolution, using data collected from the 25 ns bunch spacing data collected in 2015. The ID trigger continues to show excellent performance, with efficiencies greater than 99%.

  10. The TriggerTool Graphical User Interface to the ATLAS Trigger Configuration Database

    CERN Document Server

    Bell, P; Brunet, S; Fischer, G; Goebel, M; Haller, J; Head, S; Höcker, A; Kohno, T; Martyniuk, A; Nozicka, M; Owen, M; Spiwoks, R; Stelzer, J; Wengler, T; Wiedenmann, W

    2009-01-01

    A system has been designed and implemented to configure all three levels of the ATLAS trigger system from a centrally provided relational database, in which an archive of all trigger configurations used in data taking is also maintained. The user interaction with this database is via a Java-based graphical user interface known as the TriggerTool. We describe here how the TriggerTool has been designed to fulfill several different roles for users of varying expertise, from being a browser of the database to a tool for creating and modifying configurations

  11. Resource Utilization by the ATLAS High Level Trigger during 2010 and 2011 LHC running

    CERN Document Server

    Schaefer, D; The ATLAS collaboration; Ospanov, R

    2012-01-01

    Since starting in 2010, the Large Hadron Collider (LHC) has produced collisions at an ever increasing rate. The ATLAS experiment successfully records the collision data with high efficiency and excellent data quality. Events are selected using a three-level trigger system, where each level makes a more re ned selection. The level-1 trigger (L1) consists of a custom-designed hardware trigger which seeds two higher software based trigger levels. Over 300 triggers compose a trigger menu which selects physics signatures such as electrons, muons, particle jets, etc. Each trigger consumes computing resources of the ATLAS trigger system and online storage. The LHC instantaneous luminosity conditions, desired physics goals of the collaboration, and the limits of the trigger infrastructure determine the composition of the ATLAS trigger menu. We describe a trigger monitoring framework for computing the costs of individual trigger algorithms such as data request rates and CPU consumption. This framework has been used to...

  12. Commissioning of the ATLAS Muon Trigger Selection

    CERN Document Server

    Musto, Elisa

    2010-01-01

    The performance of the three-level ATLAS muon trigger as evaluated by using LHC data is presented. Events have been selected by using only the hardware-based Level-1 trigger in order to commission and to subsequently enable the (software-based) selections of the High Level Trigger. Studies aiming at selecting prompt muons from J/{\\psi} and at reducing non prompt muon contamination have been performed. A brief overview on how the muon triggers evolve with increasing luminosity is given.

  13. The ATLAS Data Acquisition and High Level Trigger system

    Science.gov (United States)

    The ATLAS TDAQ Collaboration

    2016-06-01

    This paper describes the data acquisition and high level trigger system of the ATLAS experiment at the Large Hadron Collider at CERN, as deployed during Run 1. Data flow as well as control, configuration and monitoring aspects are addressed. An overview of the functionality of the system and of its performance is presented and design choices are discussed.

  14. Operation of the Upgraded ATLAS Level-1 Central Trigger System

    Science.gov (United States)

    Glatzer, Julian

    2015-12-01

    The ATLAS Level-1 Central Trigger (L1CT) system is a central part of ATLAS data-taking and has undergone a major upgrade for Run 2 of the LHC, in order to cope with the expected increase of instantaneous luminosity of a factor of two with respect to Run 1. The upgraded hardware offers more flexibility in the trigger decisions due to the factor of two increase in the number of trigger inputs and usable trigger channels. It also provides an interface to the new topological trigger system. Operationally - particularly useful for commissioning, calibration and test runs - it allows concurrent running of up to three different subdetector combinations. An overview of the operational software framework of the L1CT system with particular emphasis on the configuration, controls and monitoring aspects is given. The software framework allows a consistent configuration with respect to the ATLAS experiment and the LHC machine, upstream and downstream trigger processors, and the data acquisition system. Trigger and dead-time rates are monitored coherently at all stages of processing and are logged by the online computing system for physics analysis, data quality assurance and operational debugging. In addition, the synchronisation of trigger inputs is watched based on bunch-by-bunch trigger information. Several software tools allow for efficient display of the relevant information in the control room in a way useful for shifters and experts. The design of the framework aims at reliability, flexibility, and robustness of the system and takes into account the operational experience gained during Run 1. The Level-1 Central Trigger was successfully operated with high efficiency during the cosmic-ray, beam-splash and first Run 2 data taking with the full ATLAS detector.

  15. Towards a Level-1 Tracking Trigger for the ATLAS Experiment

    CERN Document Server

    De Santo, A; The ATLAS collaboration

    2014-01-01

    Plans for a physics-driven upgrade of the LHC foresee staged increases of the accelerator's average instantaneous luminosity, of up to a factor of five compared to the original design. In order to cope with the sustained luminosity increase, and the resulting higher detector occupancy and particle interaction rates, the ATLAS experiment is planning phased upgrades of the trigger system and of the DAQ infrastructure. In the new conditions, maintaining an adequate signal acceptance for electro-weak processes will pose unprecedented challenges, as the default solution to cope with the higher rates would be to increase thresholds on the transverse momenta of physics objects (leptons, jets, etc). Therefore the possibility to apply fast processing at the first trigger level in order to use tracking information as early as possible in the trigger selection represents a most appealing opportunity, which can preserve the ATLAS trigger's selectivity without reducing its flexibility. Studies to explore the feasibility o...

  16. ATLAS Phase-II trigger upgrade

    CERN Document Server

    Sankey, Dave; The ATLAS collaboration

    2016-01-01

    This talk for ACES summarises the current status of the ATLAS Phase-II trigger upgrade, describing and comparing the two architectures under consideration, namely the two hardware level system described in the Phase-II Upgrade Scoping Document and the more recent single hardware level system.

  17. Tools for Trigger Aware Analyses in ATLAS

    CERN Document Server

    Krasznahorkay, A; The ATLAS collaboration; Stelzer, J

    2010-01-01

    In order to search for rare processes, all four LHC experiments have to use advanced triggering methods for selecting and recording the events of interest. At the expected nominal LHC operating conditions only about 0.0005% of the collision events can be kept for physics analysis in ATLAS. Therefore the understanding and evaluation of the trigger performance is one of the most crucial parts of any physics analysis. ATLAS’s first level trigger is composed of custom-built hardware, while the second and third levels are implemented using regular PCs running reconstruction and selection algorithms. Because of this split, accessing the results of the trigger execution for the two stages is different. The complexity of the software trigger presents further difficulties in accessing the trigger data. To make the job of the physicists easier when evaluating the trigger performance, multiple general-use tools are provided by the ATLAS Trigger Analysis Tools group. The TrigDecisionTool, a general tool, is provided to...

  18. The ATLAS level-1 Central Trigger

    CERN Document Server

    Spiwoks, R; Berge, D; Caracinha, D; Ellis, Nick; Farthouat, P; Gällnö, P; Haas, S; Klofver, P; Krasznahorkay, A; Messina, A; Ohm, C; Pauly, T; Perantoni, M; Pessoa Lima Junior, H; Schuler, G; De Seixas, J M; Wengler, T; PH-EP

    2007-01-01

    The ATLAS Level-1 Central Trigger consists of the Muon-to-Central-Trigger-Processor Interface (MUCTPI), the Central Trigger Processor (CTP), and the Timing, Trigger and Control (TTC) partitions of the sub-detectors. The MUCTPI connects the output of the muon trigger system to the CTP. At every bunch crossing it receives information on muon candidates from each of the 208 muon trigger sectors and calculates the total multiplicity for each of six pT thresholds. The CTP combines information from the calorimeter trigger and the MUCTPI and makes the final Level-1 Accept (L1A) decision on the basis of lists of selection criteria (trigger menus). The MUCTPI and the CTP provide trigger summary information to the Level-2 trigger and to the data acquisition (DAQ) for every event selected at the Level-1. They further provide accumulated and, for the CTP, bunch-by-bunch counter data for monitoring of the trigger, detector and beam conditions. The TTC partitions send timing, trigger and control signals from the CTP to the...

  19. ATLAS Jet Trigger Efficiency in 2015 Data

    CERN Document Server

    Christodoulou, Valentinos; The ATLAS collaboration

    2016-01-01

    The ATLAS experiment at the LHC uses a two-level trigger system to preferentially select events with a predefined topology of interest for future analysis. In this poster, the hadronic jet trigger efficiency for proton-proton collision data at a centre-of-mass energy of 13TeV is presented. The single-jet and multi-jet efficiency is presented as a function of the jet transverse momentum. In addition, the efficiency of specialist triggers that use large radius jets and scalar-summed jet transverse momenta are also presented.

  20. The ATLAS Level-1 Central Trigger System 012

    CERN Document Server

    Borrego-Amaral, P; Farthouat, Philippe; Gällnö, P; Haller, J; Maeno, T; Pauly, T; Schuler, G; Spiwoks, R; Torga-Teixeira, R; Wengler, T; Pessoa-Lima, H; De Seixas, J M

    2004-01-01

    The central part of the ATLAS Level-1 trigger system consists of the Central Trigger Processor (CTP), the Local Trigger Processors (LTPs), the Timing, Trigger and Control (TTC) system, and the Read-out Driver Busy (ROD_BUSY) modules. The CTP combines information from calorimeter and muon trigger processors, as well as from other sources and makes the final Level-1 Accept decision (L1A) on the basis of lists of selection criteria, implemented as a trigger menu. Timing and trigger signals are fanned out to about 40 LTPs which inject them into the sub-detector TTC partitions. The LTPs also support stand-alone running and can generate all necessary signals from memory. The TTC partitions fan out the timing and trigger signals to the sub-detector front-end electronics. The ROD_BUSY modules receive busy signals from the front-end electronics and send them to the CTP (via an LTP) to throttle the generation of L1As. An overview of the ATLAS Level-1 Central trigger system will be presented, with emphasis on the design...

  1. The ATLAS Trigger System: Ready for Run-2

    CERN Document Server

    Maeda, Junpei; The ATLAS collaboration

    2015-01-01

    The ATLAS trigger has been successfully collecting collision data during the first run of the LHC between 2009-2013 at a centre-of-mass energy between 900 GeV and 8 TeV. The trigger system consists of a hardware Level-1 and a software based high-level trigger that reduces the event rate from the design bunch-crossing rate of 40 MHz to an average recording rate of a few hundred Hz. During the data-taking period of Run-2 the LHC will operate at a centre-of-mass energy of about 13 TeV resulting in roughly five times higher trigger rates. In these proceedings, we briefly review the ATLAS trigger system upgrades that were implemented during the shutdown, allowing us to cope with the increased trigger rates while maintaining or even improving our efficiency to select relevant physics processes. This includes changes to the Level-1 calorimeter and muon trigger system, the introduction of a new Level-1 topological trigger module and themerging of the previously two-level higher-level trigger system into a single even...

  2. Triggering events with GPUs at ATLAS

    Science.gov (United States)

    Kama, S.; Soares, J. Augusto; Baines, J.; Bauce, M.; Bold, T.; Conde Muino, P.; Emeliyanov, D.; Goncalo, R.; Messina, A.; Negrini, M.; Rinaldi, L.; Sidoti, A.; Tavares Delgado, A.; Tupputi, S.; Vaz Gil Lopes, L.

    2015-12-01

    The growing complexity of events produced in LHC collisions demands increasing computing power both for the online selection and for the offline reconstruction of events. In recent years there have been significant advances in the performance of Graphics Processing Units (GPUs) both in terms of increased compute power and reduced power consumption that make GPUs extremely attractive for use in a complex particle physics experiments such as ATLAS. A small scale prototype of the full ATLAS High Level Trigger has been implemented that exploits reconstruction algorithms optimized for this new massively parallel paradigm. We discuss the integration procedure followed for this prototype and present the performance achieved and the prospects for the future.

  3. Performance and Improvements of the ATLAS Jet Trigger System

    CERN Document Server

    Conde Muino, P; The ATLAS collaboration

    2012-01-01

    At the harsh conditions of the LHC, with proton bunches colliding every 50 ns and up to 40 pp interactions per bunch crossing, the ATLAS trigger system has to be flexible to maintaining an unbiased efficiency for a wide variety of physics studies while providing a fast rejection of non-interesting events. Jets are the most commonly produced objects at the LHC, essential for many physics measurements that range from precise QCD studies to searches for New Physics beyond the Standard Model, or even unexpected physics signals. The ATLAS jet trigger is the primary mean for selecting events with high pT jets and its good performance is fundamental to achieve the physics goals of ATLAS. The ATLAS trigger system is divided in three levels, the first one (L1) being hardware based, with a 2 μs latency, and the two following ones (called collectively High Level Triggers or HLT) being softwared based with larger processing times. It was designed to work in a Region of Interest (RoI) based approach, where the second lev...

  4. Performance and Improvements of the ATLAS Jet Trigger System

    CERN Document Server

    Lang, V; The ATLAS collaboration

    2012-01-01

    At the harsh conditions of the LHC, with proton bunches colliding every 50ns and up to 40 pp interactions per bunch crossing, the ATLAS trigger system has to be flexible to maintaining an unbiased efficiency for a wide variety of physics studies while providing a fast rejection of non-interesting events. Jets are the most commonly produced objects at the LHC, essential for many physics measurements that range from precise QCD studies to searches for New Physics beyond the Standard Model, or even unexpected physics signals. The ATLAS jet trigger is the primary means of selecting events with high p_T jets and its good performance is fundamental to achieve the physics goals of ATLAS. The ATLAS trigger system is divided in three levels, the first one (L1) being hardware based, with a 2mu s latency, and the two following ones (called collectively High Level Triggers or HLT) being software based with larger processing times. It was designed to work in a Region of Interest (RoI) based approach, where the second leve...

  5. Performance and Improvements of the ATLAS Jet Trigger System

    CERN Document Server

    Lang, V; The ATLAS collaboration

    2012-01-01

    At the harsh conditions of the LHC, with proton bunches colliding every 50ns and up to 40 pp interactions per bunch crossing, the ATLAS trigger system has to be flexible to maintaining an unbiased efficiency for a wide variety of physics studies while providing a fast rejection of non-interesting events. Jets are the most commonly produced objects at the LHC, essential for many physics measurements that range from precise QCD studies to searches for New Physics beyond the Standard Model, or even unexpected physics signals. The ATLAS jet trigger is the primary means of selecting events with high p_T jets and its good performance is fundamental to achieve the physics goals of ATLAS. The ATLAS trigger system is divided in three levels, the first one (L1) being hardware based, with a 2$mu s$ latency, and the two following ones (called collectively High Level Triggers or HLT) being software based with larger processing times. It was designed to work in a Region of Interest (RoI) based approach, where the second le...

  6. ATLAS jet trigger performance in 2015 data

    CERN Document Server

    Herwig, Theodor Christian; The ATLAS collaboration

    2016-01-01

    The ATLAS experiment at the LHC uses a two-level trigger system to preferentially select events with a predefined topology of interest for future analysis. The hadronic jet trigger is used to select several different topologies containing different types and multiplicities of hadronic jets, thus supporting many different physics searches and measurements. The hadronic jet trigger efficiency for proton-proton collision data at a centre-of-mass energy of 13 TeV is presented. The efficient selection of events containing hadronic jets requires the characteristics of trigger-level jets and offline jets to be very similar. A comparison of relevant characteristics demonstrates that trigger-level jets and offline jets are in excellent agreement.

  7. ATLAS jet trigger performance in 2016 data

    CERN Document Server

    Herwig, Theodor Christian; The ATLAS collaboration

    2016-01-01

    The ATLAS experiment at the LHC uses a two-level trigger system to preferentially select events with a predefined topology of interest for future analysis. The hadronic jet trigger is used to select several different topologies containing different types and multiplicities of hadronic jets, thus supporting many different physics searches and measurements. The hadronic jet trigger efficiency for proton-proton collision data at a centre-of-mass energy of 13 TeV is presented. The efficient selection of events containing hadronic jets requires the characteristics of trigger-level jets and offline jets to be very similar. A comparison of relevant characteristics demonstrates that trigger-level jets and offline jets are in excellent agreement.

  8. The ATLAS b-jet Trigger

    CERN Document Server

    Hansson Adrian, P; The ATLAS collaboration

    2011-01-01

    The online event selection is crucial to reject most of the events containing uninteresting background collisions while preserving as much as possible the interesting physical signals. The b-jet selection is part of the trigger strategy of the ATLAS experiment and a set of dedicated triggers is presently contributing to the event selection for the 2011 running. The b-jets acceptance is increased and the background reduced by lowering jet transverse energy thresholds at the first trigger level and applying b-tagging techniques at the subsequent levels. Different physics channels, especially topologies containing more than one b-jet where higher rejection factors are achieved, benefit from requesting this trigger to be fired. An overview of the status-of-art of the b-jet trigger menu and performance on real data is presented in this contribution.

  9. The ATLAS Trigger System: Ready for Run II

    CERN Document Server

    Czodrowski, Patrick; The ATLAS collaboration

    2015-01-01

    The ATLAS trigger system has been used successfully for data collection in the 2009-2013 Run 1 operation cycle of the CERN Large Hadron Collider (LHC) at center-of-mass energies of up to 8 TeV. With the restart of the LHC for the new Run 2 data-taking period at 13 TeV, the trigger rates are expected to rise by approximately a factor of 5. The trigger system consists of a hardware-based first level (L1) and a software-based high-level trigger (HLT) that reduces the event rate from the design bunch-crossing rate of 40 MHz to an average recording rate of ~ 1kHz. This presentation will give an overview of the upgrades to the ATLAS trigger system that have been implemented during the LHC shutdown period in order to deal with the increased trigger rates while efficiently selecting the physics processes of interest. These upgrades include changes to the L1 calorimeter trigger, the introduction of a new L1 topological trigger module, improvements in the L1 muon system, and the merging of the previously two-level HLT ...

  10. The ATLAS Trigger System - Ready for Run-2

    CERN Document Server

    Backes, Moritz; The ATLAS collaboration

    2015-01-01

    The ATLAS trigger has been successfully collecting collision data during the first run of the LHC between 2009-2013 at a centre-of-mass energy between 900 GeV and 8 TeV. The trigger system consists of a hardware based Level-1 (L1) and a software based high-level trigger (HLT) that reduces the event rate from the design bunch-crossing rate of 40 MHz to an average recording rate of a few hundred Hz. During the course of the ongoing Run-2 data-taking campaign at 13 TeV centre-of-mass energy the trigger rates will be approximately 5 times higher compared to Run-1. In these proceedings we briefly review the ATLAS trigger system upgrades that were implemented during the shutdown, allowing us to cope with the increased trigger rates while maintaining or even improving our efficiency to select relevant physics processes. This includes changes to the L1 calorimeter and muon trigger system, the introduction of a new L1 topological trigger subsystem and the merging of the previously two-level HLT system into a single ev...

  11. The ATLAS Trigger System: Ready for Run-2

    CERN Document Server

    Backes, Moritz; The ATLAS collaboration

    2015-01-01

    The ATLAS trigger has been successfully collecting collision data during the first run of the LHC between 2009-2013 at a centre-of-mass energy between 900 GeV and 8 TeV. The trigger system consists of a hardware Level-1 (L1) and a software based high-level trigger (HLT) that reduces the event rate from the design bunch-crossing rate of 40 MHz to an average recording rate of a few hundred Hz. During the next data-taking period starting in 2015 (Run-2) the LHC will operate at a centre-of-mass energy of about 13 TeV resulting in roughly five times higher trigger rates. We will briefly review the ATLAS trigger system upgrades that were implemented during the shutdown, allowing us to cope with the increased trigger rates while maintaining or even improving our efficiency to select relevant physics processes. This includes changes to the L1 calorimeter and muon trigger system, the introduction of a new L1 topological trigger module and the merging of the previously two-level HLT system into a single event filter fa...

  12. The ATLAS Trigger System: Ready for Run-2

    CERN Document Server

    Nakahama, Yu; The ATLAS collaboration

    2015-01-01

    The ATLAS trigger has been used very successfully for the online event selection during the first run of the LHC between 2009-2013 at a centre-of-mass energy between 900 GeV and 8 TeV. The trigger system consists of a hardware Level-1 (L1) and a software based high-level trigger (HLT) that reduces the event rate from the design bunch-crossing rate of 40 MHz to an average recording rate of a few hundred Hz. During the next data-taking period starting in early 2015 (Run-2) the LHC will operate at a centre-of-mass energy of about 13 TeV resulting in roughly five times higher trigger rates. We will review the upgrades to the ATLAS Trigger system that have been implemented during the shutdown and that will allow us to cope with these increased trigger rates while maintaining or even improving our efficiency to select relevant physics processes. This includes changes to the L1 calorimeter trigger, the introduction of a new L1 topological trigger module, improvements in the L1 muon system and the merging of the prev...

  13. ATLAS triggers for B-physics

    CERN Document Server

    George, S

    2000-01-01

    The LHC will produce bb events at an unprecedented rate. The number of events recorded by ATLAS will be limited by the rate at which they can be stored offline and subsequently analysed. Despite the huge number of events, the small branching ratios mean that analysis of many of the most interesting channels for CP violation and other measurements will be limited by statistics. The challenge for the Trigger and Data Acquisition (DAQ) system is therefore to maximise the fraction of interesting B decays in the B-physics data stream. The ATLAS Trigger/DAQ system is split into three levels. The initial B-physics selection is made in the first-level trigger by an inclusive low-p/sub t/ muon trigger (~6 GeV). The second-level trigger strategy is based on identifying classes of final states by their partial reconstruction. The muon trigger is confirmed before proceeding to a track search. Electron/hadron separation is given by the transition radiation tracking detector and the electromagnetic calorimeter. Muon identi...

  14. Performance of ATLAS L1 Calorimeter Trigger with data

    CERN Document Server

    Bracinik, J; The ATLAS collaboration

    2010-01-01

    The ATLAS first-level calorimeter trigger is a hardware-based system designed to identify high-pT jets, electron/photon and tau candidates and to measure total and missing ET in the ATLAS calorimeters. After more than two years of commissioning in situ with calibration data and cosmic rays, the system has now been extensively used to select the most interesting proton-proton collision events. Final tuning of timing and energy calibration has been carried out in 2010 to improve the trigger response to physics objects. An analysis of the performance of the level-1 calorimeter trigger will be presented, along with the techniques used to achieve these results.

  15. ATLAS Trigger/DAQ RobIn Prototype

    CERN Document Server

    Green, B; Kugel, A; Müller, M; Yu, M; RT 2003 13th IEEE-NPSS Real Time Conference

    2004-01-01

    The ATLAS Trigger/DAQ (TDAQ) system connects via 1600 Read-Out-Links (ROL) to the ATLAS sub-detectors. Each Read-Out-Buffer (RobIn) prototype attaches to 2 ROLs, buffers the incoming event data stream of 160MB/s each and provides samples upon request to the TDAQ system. We present the design of the PCI-based RobIn module, which is built around a XILINX XV2V1500 Field-Programmable-Gate-Array (FPGA), together with initial results from rapid prototyping studies.

  16. The ATLAS Muon and Tau Trigger

    CERN Document Server

    Dell'Asta, L; The ATLAS collaboration

    2013-01-01

    [Muon] The ATLAS experiment at CERN's Large Hadron Collider (LHC) deploys a three-levels processing scheme for the trigger system. The level-1 muon trigger system gets its input from fast muon trigger detectors. Fast sector logic boards select muon candidates, which are passed via an interface board to the central trigger processor and then to the High Level Trigger (HLT). The muon HLT is purely software based and encompasses a level-2 (L2) trigger followed by an event filter (EF) for a staged trigger approach. It has access to the data of the precision muon detectors and other detector elements to refine the muon hypothesis. Trigger-specific algorithms were developed and are used for the L2 to increase processing speed for instance by making use of look-up tables and simpler algorithms, while the EF muon triggers mostly benefit from offline reconstruction software to obtain most precise determination of the track parameters. There are two algorithms with different approaches, namely inside-out and outside-in...

  17. Resource Utilization by the ATLAS High Level Trigger during 2010 and 2011 LHC running

    Science.gov (United States)

    Lipeles, Elliot; Ospanov, Rustem; Schaefer, Doug

    2012-12-01

    Since starting in 2010, the Large Hadron Collider (LHC) has produced collisions at an ever increasing rate. The ATLAS experiment successfully recorded the collision data with high efficiency and excellent data quality. Events were selected using a three-level trigger system, where each level made a more refined selection. The Level 1 (L1) trigger consisted of a custom-designed hardware trigger which seeded two higher software based trigger levels. Over 300 triggers composed a trigger menu which selected physics signatures such as electrons, muons, particle jets, etc. Each trigger consumed computing resources of the ATLAS Trigger system and offline storage. The LHC instantaneous luminosity conditions, desired physics goals of the collaboration, and the limits of the trigger infrastructure determined the composition of the ATLAS Trigger menu. We describe a trigger monitoring framework called the Cost Monitoring Framework for computing the costs of individual trigger algorithms such as data request rates and CPU consumption. This framework was used to prepare the ATLAS Trigger for data taking during increases of more than six orders of magnitude in the LHC luminosity and has been influential in guiding ATLAS Trigger computing upgrades.

  18. The ATLAS High Level Trigger Steering Framework and the Trigger Configuration System.

    CERN Document Server

    Perez Cavalcanti, Tiago; The ATLAS collaboration

    2011-01-01

    The ATLAS detector system installed in the Large Hadron Collider (LHC) at CERN is designed to study proton-proton and nucleus-nucleus collisions with a maximum centre of mass energy of 14 TeV at a bunch collision rate of 40MHz. In March 2010 the four LHC experiments saw the first proton-proton collisions at 7 TeV. Still within the year a collision rate of nearly 10 MHz is expected. At ATLAS, events of potential interest for ATLAS physics are selected by a three-level trigger system, with a final recording rate of about 200 Hz. The first level (L1) is implemented in custom hardware; the two levels of the high level trigger (HLT) are software triggers, running on large farms of standard computers and network devices. Within the ATLAS physics program more than 500 trigger signatures are defined. The HLT tests each signature on each L1-accepted event; the test outcome is recorded for later analysis. The HLT-Steering is responsible for this. It foremost ensures the independent test of each signature, guarantying u...

  19. Software Validation Infrastructure for the ATLAS Trigger

    CERN Document Server

    Adorisio, C; Beauchemin, P; Bell, P; Biglietti, M; Coccaro, A; Damazio, D; Ehrenfeld, W; Faulkner, P; George, S; Giagu, S; Goncalo, R; Hamilton, A; Jones, G; Kirk, J; Kwee, R; Lane, J; Enoque Ferreira de Lima, D; Masik, J; Mincer, A; Monticelli, F; Omachi, C; Oyarzun, A; Panikashvili, N; Potter, C; Quinonez, F; Reinsch, A; Robinson, M; Rodríguez, D; Sarkisyan-Grinbaum, E; Sidoti, A; Sinev, N; Strom, D; Sutton, M; Ventura, A; Winklmeier, F; Zhao, L

    2009-01-01

    The ATLAS trigger system is responsible for selecting the interesting collision events delivered by the Large Hadron Collider (LHC). The ATLAS trigger will need to achieve a ~10^-7 rejection factor against random proton-proton collisions, and still be able to efficiently select interesting events. After a first processing level based on hardware, the final event selection is based on custom software running on two CPU farms, containing around two thousand multi-core machines. This is known as the high-level trigger. Running the trigger online during long periods demands very high quality software. It must be fast, performant, and essentially bug-free. With more than 100 contributors and around 250 different packages, a thorough validation of the HLT software is essential. This relies on a variety of unit and integration tests as well as on software metrics, and uses both in-house and open source software. This presentation presents the existing infrastructure used for validating the high-level trigger softwar...

  20. Run-2 ATLAS Trigger and Detector Performance

    CERN Document Server

    Winklmeier, Frank; The ATLAS collaboration

    2016-01-01

    The 2nd LHC run has started in June 2015 with a pp centre-of-mass collision energy of 13 TeV, and ATLAS has taken first data at this new energy. In this talk the improvements made to the ATLAS experiment during the 2-year shutdown 2013/2014 will be discussed, and first detector and trigger performance results from the Run-2 will be shown. In general, reconstruction algorithms of tracks, e/gamma, muons, taus, jets and flavour tag- ging have been improved for Run-2. The new reconstruction algorithms and their performance measured using the data taken in 2015 at sqrt(s)=13 TeV will be discussed. Reconstruction efficiency, isolation performance, transverse momentum resolution and momentum scales are measured in various regions of the detector and in momentum intervals enlarged with respect to those measured in the Run-1. This presentation will also give an overview of the upgrades to the ATLAS trigger system that have been implemented during the LHC shutdown in order to deal with the increased trigger rates (fact...

  1. Architecture of the ATLAS High Level Trigger Event Selection Software

    CERN Document Server

    Grothe, M; Baines, J T M; Bee, C P; Biglietti, M; Bogaerts, A; Boisvert, V; Bosman, M; Brandt, S; Caron, B; Casado, M P; Cataldi, G; Cavalli, D; Cervetto, M; Comune, G; Corso-Radu, A; Di Mattia, A; Díaz-Gómez, M; Dos Anjos, A; Drohan, J; Ellis, Nick; Elsing, M; Epp, B; Etienne, F; Falciano, S; Farilla, A; George, S; Ghete, V M; González, S; Kaczmarska, A; Karr, K M; Khomich, A; Konstantinidis, N P; Krasny, W; Li, W; Lowe, A; Luminari, L; Ma, H; Meessen, C; Mello, A G; Merino, G; Morettini, P; Moyse, E; Nairz, A; Negri, A; Nikitin, N V; Nisati, A; Padilla, C; Parodi, F; Pérez-Réale, V; Pinfold, J L; Pinto, P; Polesello, G; Qian, Z; Rajagopalan, S; Resconi, S; Rosati, S; Scannicchio, D A; Schiavi, C; Schörner-Sadenius, T; Segura, E; De Seixas, J M; Shears, T G; Sivoklokov, S Yu; Smizanska, M; Soluk, R A; Stanescu, C; Tapprogge, Stefan; Touchard, F; Vercesi, V; Watson, A; Wengler, T; Werner, P; Wheeler, S; Wickens, F J; Wiedenmann, W; Wielers, M; Zobernig, G; CHEP 2003 Computing in High Energy Physics; Grothe, Monika

    2004-01-01

    The ATLAS High Level Trigger (HLT) consists of two selection steps: the second level trigger and the event filter. Both will be implemented in software, running on mostly commodity hardware. Both levels have a coherent approach to event selection, so a common core software framework has been designed to maximize this coherency, while allowing sufficient flexibility to meet the different interfaces and requirements of the two different levels. The approach is extended further to allow the software to run in an off-line simulation and reconstruction environment for the purposes of development. This paper describes the architecture and high level design of the software.

  2. The ATLAS Level-1 Central Trigger Processor

    CERN Document Server

    Pauly, T; Ellis, Nick; Farthouat, P; Gällnö, P; Haller, J; Krasznahorkay, A; Maeno, T; Pessoa-Lima, H; Resurreccion-Arcas, I; Schuler, G; De Seixas, J M; Spiwoks, R; Torga-Teixeira, R; Wengler, T; 14th IEEE-NPSS Real Time Conference 2005

    2005-01-01

    ATLAS is a multi-purpose particle physics detector at CERN’s Large Hadron Collider where two pulsed beams of protons are brought to collision at very high energy. There are collisions every 25 ns, corresponding to a rate of 40 MHz. A three-level trigger system reduces this rate to about 200 Hz while keeping bunch crossings which potentially contain interesting processes. The Level-1 trigger, implemented in electronics and firmware, makes an initial selection in under 2.5 us with an output rate of less than 100 kHz. A key element of this is the Central Trigger Processor (CTP) which combines trigger information from the calorimeter and muon trigger processors to make the final Level-1 accept decision in under 100 ns on the basis of lists of selection criteria, implemented as a trigger menu. Timing and trigger signals are fanned out to all sub-detectors, while busy signals from all sub-detector read-out systems are collected and fed into the CTP in order to throttle the generation of Level-1 triggers.

  3. Triggering on hadronic tau decays: ATLAS meets the challenge

    Indian Academy of Sciences (India)

    Mark Scarcella; on behalf of the ATLAS Collaboration

    2012-11-01

    Hadronic tau decays play a crucial role in taking Standard Model (SM) measurements as well as in the search for physics beyond the SM. However, hadronic tau decays are difficult to identify and trigger on due to their resemblance to QCD jets. Given the large production crosssection of QCD processes, designing and operating a trigger system to efficiently select hadronic tau decays, while maintaining the rate within the bandwidth limits, is a difficult challenge. This contribution will summarize the status and performance of the ATLAS tau trigger system during the 2010–2011 data taking period. Different methods that have been explored to obtain the trigger efficiency curves from data will be shown. Finally, the status of the measurements, which include hadronic tau decays in the final state, will be summarized. In light of the vast statistics collected in 2011, future prospects for triggering on hadronic tau decays in this exciting new period of increased instantaneous luminosity will be presented.

  4. The ATLAS Level-1 Central Trigger

    CERN Document Server

    Stockton, M; The ATLAS collaboration

    2011-01-01

    The ATLAS Level-1 trigger system is responsible for reducing the anticipated LHC collision rate from 40 MHz to less than 100 kHz. This Level-1 selection identifies, jet, tau/hadron, electron/photon and muon candidates, with additional triggers for missing and total energy. These inputs are used by the Level-1 Central Trigger to form a Level-1 Accept decision. This decision, along with summary information, is then passed into the higher levels of the trigger system and sub-detectors, which also receive the clock from the Level-1 Central trigger. The performance of the Central Trigger during the first collisions will be shown. This includes details of how the trigger information, along with dead-time rates, are monitored and logged by the online system for physics analysis, data quality assurance and operational debugging. Also presented are the software tools used to efficiently display the relevant information in the control room in a way useful for shifters and experts.

  5. Digital Filter Performance for the ATLAS Level-1 Calorimeter Trigger

    CERN Document Server

    Hadley, D R; The ATLAS collaboration

    2010-01-01

    The ATLAS Level-1 Calorimeter Trigger is a hardware-based system designed to identify high-pT jets, electron/photon and tau candidates, and to measure total and missing ET in the ATLAS Liquid Argon and Tile calorimeters. It is a pipelined processor system, with a new set of inputs being evaluated every 25ns. The overall trigger decision has a latency budget of 2µs, including all transmission delays. The calorimeter trigger uses about 7200 reduced granularity analogue signals, which are first digitized at the 40 MHz LHC bunch-crossing frequency, before being passed to a digital Finite Impulse Response (FIR) filter. Due to latency and chip real-estate constraints, only a simple 5-element filter with limited precision can be used. Nevertheless this filter achieves a significant reduction in noise, along with improving the bunch-crossing assignment and energy resolution for small signals. The context in which digital filters are used for the ATLAS Level-1 Calorimeter Trigger will be presented, before describing ...

  6. Digital Filtering Performance in the ATLAS Level-1 Calorimeter Trigger

    CERN Document Server

    Hadley, D R; The ATLAS collaboration

    2010-01-01

    The ATLAS Level-1 Calorimeter Trigger is a hardware-based system designed to identify high-pT jets, elec- tron/photon and tau candidates, and to measure total and missing ET in the ATLAS Liquid Argon and Tile calorimeters. It is a pipelined processor system, with a new set of inputs being evaluated every 25ns. The overall trigger decision has a latency budget of 2µs, including all transmission delays. The calorimeter trigger uses about 7200 reduced granularity analogue signals, which are first digitized at the 40 MHz LHC bunch-crossing frequency, before being passed to a digital Finite Impulse Re- sponse (FIR) filter. Due to latency and chip real-estate constraints, only a simple 5-element filter with limited precision can be used. Nevertheless, this filter achieves a significant reduction in noise, along with improving the bunch-crossing assignment and energy resolution for small signals. The context in which digital filters are used for the ATLAS Level-1 Calorimeter Trigger is presented, before descr...

  7. Trigger Menu-aware Monitoring for the ATLAS experiment

    CERN Document Server

    Hoad, Xanthe; The ATLAS collaboration

    2016-01-01

    Changes in the trigger menu, the online algorithmic event-selection of the ATLAS experiment at the LHC in response to luminosity and detector changes are followed by adjustments in their monitoring system. This is done to ensure that the collected data is useful, and can be properly reconstructed at Tier-0, the first level of the computing grid. During Run 1, ATLAS deployed monitoring updates with the installation of new software releases at Tier-0. This created unnecessary overhead for developers and operators, and unavoidably led to different releases for the data-taking and the monitoring setup. We present a "trigger menu-aware" monitoring system designed for the ATLAS Run 2 data-taking. The new monitoring system aims to simplify the ATLAS operational workflows, and allows for easy and flexible monitoring configuration changes at the Tier-0 site via an Oracle DB interface. We present the design and the implementation of the menu-aware monitoring, along with lessons from the operational experience of the ne...

  8. Steering the ATLAS High Level Trigger

    CERN Document Server

    Comune, G; Morettini, P; Stamen, R; Tapprogge, S; George, S; Schiavi, C; Computing In High Energy and Nuclear Physics

    2006-01-01

    This paper describes the Steering mechanism of the ATLAS High Level Trigger (HLT). The Steering software is responsible for the implementation of the seeded and stepwise execution of algorithms in a portion of the full event called Region of Interest (RoI). The Steering is responsible for the global event accept/reject decision based on a static configuration matched against the dynamic event outcome in terms of Trigger Conditions validated by the Trigger algorithms. In the case of an event being accepted the Steering is in charge of the creation of the Detailed Event Result and in order to enable this it provides tools for reconstructed objects serialization and a fast data navigation mechanism that allows to organize the objects in memory with logical relations and all objects in an RoI back to the initial RoI seed.

  9. Implementation of the ATLAS trigger within the ATLAS Multi­Threaded Software Framework AthenaMT

    CERN Document Server

    Wynne, Benjamin; The ATLAS collaboration

    2016-01-01

    We present an implementation of the ATLAS High Level Trigger that provides parallel execution of trigger algorithms within the ATLAS multi­threaded software framework, AthenaMT. This development will enable the ATLAS High Level Trigger to meet future challenges due to the evolution of computing hardware and upgrades of the Large Hadron Collider, LHC, and ATLAS Detector. During the LHC data­taking period starting in 2021, luminosity will reach up to three times the original design value. Luminosity will increase further, to up to 7.5 times the design value, in 2026 following LHC and ATLAS upgrades. This includes an upgrade of the ATLAS trigger architecture that will result in an increase in the High Level Trigger input rate by a factor of 4 to 10 compared to the current maximum rate of 100 kHz. The current ATLAS multiprocess framework, AthenaMP, manages a number of processes that process events independently, executing algorithms sequentially in each process. AthenaMT will provide a fully multi­threaded env...

  10. The ATLAS Level-2 Trigger Pilot Project

    CERN Document Server

    Blair, R; Haberichter, W N; Schlereth, J L; Bock, R; Bogaerts, A; Boosten, M; Dobinson, Robert W; Dobson, M; Ellis, Nick; Elsing, M; Giacomini, F; Knezo, E; Martin, B; Shears, T G; Tapprogge, Stefan; Werner, P; Hansen, J R; Wäänänen, A; Korcyl, K; Lokier, J; George, S; Green, B; Strong, J; Clarke, P; Cranfield, R; Crone, G J; Sherwood, P; Wheeler, S; Hughes-Jones, R E; Kolya, S; Mercer, D; Hinkelbein, C; Kornmesser, K; Kugel, A; Männer, R; Müller, M; Sessler, M; Simmler, H; Singpiel, H; Abolins, M; Ermoline, Y; González-Pineiro, B; Hauser, R; Pope, B; Sivoklokov, S Yu; Boterenbrood, H; Jansweijer, P; Kieft, G; Scholte, R; Slopsema, R; Vermeulen, J C; Baines, J T M; Belias, A; Botterill, David R; Middleton, R; Wickens, F J; Falciano, S; Bystrický, J; Calvet, D; Gachelin, O; Huet, M; Le Dû, P; Mandjavidze, I D; Levinson, L; González, S; Wiedenmann, W; Zobernig, H

    2002-01-01

    The Level-2 Trigger Pilot Project of ATLAS, one of the two general purpose LHC experiments, is part of the on-going program to develop the ATLAS high-level triggers (HLT). The Level-2 Trigger will receive events at up to 100 kHz, which has to be reduced to a rate suitable for full event-building of the order of 1 kHz. To reduce the data collection bandwidth and processing power required for the challenging Level-2 task it is planned to use Region of Interest guidance (from Level-1) and sequential processing. The Pilot Project included the construction and use of testbeds of up to 48 processing nodes, development of optimized components and computer simulations of a full system. It has shown how the required performance can be achieved, using largely commodity components and operating systems, and validated an architecture for the Level-2 system. This paper describes the principal achievements and conclusions of this project. (28 refs).

  11. The ATLAS Transverse Momentum Trigger at the LHC

    CERN Document Server

    Mincer, Allen; The ATLAS collaboration; Struebig, Antonia; Schouwenberg, Jeroen; Beacham, James Baker

    2015-01-01

    The transverse momentum triggers of the ATLAS experiment at the CERN Large Hadron Collider (LHC) are designed to select collision events with non-interacting particles passing through the detector. Such events provide an interesting probe for new-physics interactions beyond the Standard Model, and also provide the basis for precise measurements of Standard Model parameters such as Higgs couplings. The transverse momentum used in the trigger system is calculated from calorimeter- based global energy sums and supplemented with information from the muon detection system. The trigger successfully operated during the first running period of the LHC. Starting in 2015 the LHC will produce collisions at higher energy and increased luminosity; improving on the trigger performance from the previous run period will be challenging.

  12. A Fast hardware tracker for the ATLAS Trigger

    CERN Document Server

    Pandini, Carlo Enrico; The ATLAS collaboration

    2015-01-01

    The trigger system at the ATLAS experiment is designed to lower the event rate occurring from the nominal bunch crossing at 40 MHz to about 1 kHz for a designed LHC luminosity of 10$^{34}$ cm$^{-2}$ s$^{-1}$. To achieve high background rejection while maintaining good efficiency for interesting physics signals, sophisticated algorithms are needed which require extensive use of tracking information. The Fast TracKer (FTK) trigger system, part of the ATLAS trigger upgrade program, is a highly parallel hardware device designed to perform track-finding at 100 kHz and based on a mixture of advanced technologies. Modern, powerful Field Programmable Gate Arrays (FPGA) form an important part of the system architecture, and the combinatorial problem of pattern recognition is solved by ~8000 standard-cell ASICs named Associative Memories. The availability of the tracking and subsequent vertex information within a short latency ensures robust selections and allows improved trigger performance for the most difficult sign...

  13. A Fast hardware Tracker for the ATLAS Trigger system

    CERN Document Server

    Pandini, Carlo Enrico; The ATLAS collaboration

    2015-01-01

    The trigger system at the ATLAS experiment is designed to lower the event rate occurring from the nominal bunch crossing at 40 MHz to about 1 kHz for a designed LHC luminosity of 10$^{34}$ cm$^{-2}$ s$^{-1}$. After a very successful data taking run the LHC is expected to run starting in 2015 with much higher instantaneous luminosities and this will increase the load on the High Level Trigger system. More sophisticated algorithms will be needed to achieve higher background rejection while maintaining good efficiency for interesting physics signals, which requires a more extensive use of tracking information. The Fast Tracker (FTK) trigger system, part of the ATLAS trigger upgrade program, is a highly parallel hardware device designed to perform full-scan track-finding at the event rate of 100 kHz. FTK is a dedicated processor based on a mixture of advanced technologies. Modern, powerful, Field Programmable Gate Arrays form an important part of the system architecture, and the combinatorial problem of pattern r...

  14. The ATLAS High Level Trigger Steering

    CERN Document Server

    Berger, N; Eifert, T; Fischer, G; George, S; Haller, J; Höcker, A; Masik, J; Zur Nedden, M; Pérez-Réale, V; Risler, C; Schiavi, C; Stelzer, J; Wu, X; International Conference on Computing in High Energy and Nuclear Physics

    2008-01-01

    The High Level Trigger (HLT) of the ATLAS experiment at the Large Hadron Collider receives events which pass the LVL1 trigger at ~75 kHz and has to reduce the rate to ~200 Hz while retaining the most interesting physics. It is a software trigger and performs the reduction in two stages: the LVL2 trigger and the Event Filter (EF). At the heart of the HLT is the Steering software. To minimise processing time and data transfers it implements the novel event selection strategies of seeded, step-wise reconstruction and early rejection. The HLT is seeded by regions of interest identified at LVL1. These and the static configuration determine which algorithms are run to reconstruct event data and test the validity of trigger signatures. The decision to reject the event or continue is based on the valid signatures, taking into account pre-scale and pass-through. After the EF, event classification tags are assigned for streaming purposes. Several powerful new features for commissioning and operation have been added: co...

  15. b-jet triggering in ATLAS

    CERN Document Server

    Cavaliere, V; The ATLAS collaboration

    2012-01-01

    The online event selection is crucial to reject most of the events containing uninteresting background collisions while preserving as much as possible the interesting physical signals. The b-jet selection is part of the trigger strategy of the ATLAS experiment and a set of dedicated triggers is in place from the beginning of the 2011 data-taking period and is contributing to keep the total bandwidth to an affordable rate. The b-jets acceptance is increased and the background reduced by lowering jet transverse energy thresholds at the first trigger level and applying b-tagging techniques at the subsequent levels. Different physics channels, especially topologies containing more than one b-jet where higher rejection factors are achieved, benefit from requesting this trigger to be fired. An overview of the status-of-art of the b-jet trigger menu and the performance on real data is presented in this contribution. Data-driven techniques to extract the online b-tagging efficiency and mis-tag rate, key ingredients f...

  16. Performance of the ATLAS Tau Trigger in Run 2

    CERN Document Server

    Besjes, Geert-Jan; The ATLAS collaboration

    2016-01-01

    Tau leptons are used in a range of important ATLAS physics analyses, including the measurement of the SM Higgs boson coupling to fermions and searches for Higgs boson partners or heavy resonances decaying into pairs of tau leptons. Events for analyses are provided by a number of single and di-tau triggers, as well as triggers requiring tau lepton in combination with other objects. As the luminosity of proton-proton collisions at the LHC is going to exceed the design of $10^{34}$ cm$^{-2}$s$^{-1}$ in Run 2, the tau trigger strategies have to become more sophisticated than in Run 1. Topological selections at the first trigger level, fast tracking algorithms and improved identification requirements are the main developments to allow a large program of physics analyses with tau leptons. The performance of the ATLAS tau trigger during the 2015 and early 2016 data taking will be presented, together with the plans for further developments envisaged during the Run 2.

  17. ATLAS Level-1 Calorimeter Trigger: Status and Development

    CERN Document Server

    Bracinik, J; The ATLAS collaboration

    2013-01-01

    The ATLAS Level-1 Calorimeter Trigger seeds all the calorimeter-based triggers in the ATLAS experiment at LHC. The inputs to the system are analogue signals of reduced granularity, formed by summing cells from both the ATLAS Liquid Argon and Tile calorimeters. Several stages of analogue then digital processing, largely performed in FPGAs, refine these signals via configurable and flexible algorithms into identified physics objects, for example electron, tau or jet candidates. The complete processing chain is performed in a pipelined system at the LHC bunch-crossing frequency, and with a fixed latency of about 1us. The first LHC run from 2009-2013 provided a varied and challenging environment for first level triggers. While the energy and luminosity were below the LHC design, the pile-up conditions were similar to the nominal conditions. The physics ambitions of the experiment also tested the performance of the Level-1 system while keeping within the rate limits set by detector readout. This presentation will ...

  18. Expected Performance of the ATLAS Experiment - Detector, Trigger and Physics

    Energy Technology Data Exchange (ETDEWEB)

    Aad, G.; Abat, E.; Abbott, B.; Abdallah, J.; Abdelalim, A.A.; Abdesselam, A.; Abdinov, O.; Abi, B.; Abolins, M.; Abramowicz, H.; Acharya, Bobby Samir; Adams, D.L.; Addy, T.N.; Adorisio, C.; Adragna, P.; Adye, T.; Aguilar-Saavedra, J.A.; Aharrouche, M.; Ahlen, S.P.; Ahles, F.; Ahmad, A.; /SUNY, Albany /Alberta U. /Ankara U. /Annecy, LAPP /Argonne /Arizona U. /Texas U., Arlington /Athens U. /Natl. Tech. U., Athens /Baku, Inst. Phys. /Barcelona, IFAE /Belgrade U. /VINCA Inst. Nucl. Sci., Belgrade /Bergen U. /LBL, Berkeley /Humboldt U., Berlin /Bern U., LHEP /Birmingham U. /Bogazici U. /INFN, Bologna /Bologna U.

    2011-11-28

    The Large Hadron Collider (LHC) at CERN promises a major step forward in the understanding of the fundamental nature of matter. The ATLAS experiment is a general-purpose detector for the LHC, whose design was guided by the need to accommodate the wide spectrum of possible physics signatures. The major remit of the ATLAS experiment is the exploration of the TeV mass scale where groundbreaking discoveries are expected. In the focus are the investigation of the electroweak symmetry breaking and linked to this the search for the Higgs boson as well as the search for Physics beyond the Standard Model. In this report a detailed examination of the expected performance of the ATLAS detector is provided, with a major aim being to investigate the experimental sensitivity to a wide range of measurements and potential observations of new physical processes. An earlier summary of the expected capabilities of ATLAS was compiled in 1999 [1]. A survey of physics capabilities of the CMS detector was published in [2]. The design of the ATLAS detector has now been finalised, and its construction and installation have been completed [3]. An extensive test-beam programme was undertaken. Furthermore, the simulation and reconstruction software code and frameworks have been completely rewritten. Revisions incorporated reflect improved detector modelling as well as major technical changes to the software technology. Greatly improved understanding of calibration and alignment techniques, and their practical impact on performance, is now in place. The studies reported here are based on full simulations of the ATLAS detector response. A variety of event generators were employed. The simulation and reconstruction of these large event samples thus provided an important operational test of the new ATLAS software system. In addition, the processing was distributed world-wide over the ATLAS Grid facilities and hence provided an important test of the ATLAS computing system - this is the origin of

  19. A hardware fast tracker for the ATLAS trigger

    Science.gov (United States)

    Asbah, Nedaa

    2016-09-01

    The trigger system of the ATLAS experiment is designed to reduce the event rate from the LHC nominal bunch crossing at 40 MHz to about 1 kHz, at the design luminosity of 1034 cm-2 s-1. After a successful period of data taking from 2010 to early 2013, the LHC already started with much higher instantaneous luminosity. This will increase the load on High Level Trigger system, the second stage of the selection based on software algorithms. More sophisticated algorithms will be needed to achieve higher background rejection while maintaining good efficiency for interesting physics signals. The Fast TracKer (FTK) is part of the ATLAS trigger upgrade project. It is a hardware processor that will provide, at every Level-1 accepted event (100 kHz) and within 100 microseconds, full tracking information for tracks with momentum as low as 1 GeV. Providing fast, extensive access to tracking information, with resolution comparable to the offline reconstruction, FTK will help in precise detection of the primary and secondary vertices to ensure robust selections and improve the trigger performance. FTK exploits hardware technologies with massive parallelism, combining Associative Memory ASICs, FPGAs and high-speed communication links.

  20. The ATLAS Level-1 Muon to Central Trigger Processor Interface

    CERN Document Server

    Berge, D; Farthouat, P; Haas, S; Klofver, P; Krasznahorkay, A; Messina, A; Pauly, T; Schuler, G; Spiwoks, R; Wengler, T; PH-EP

    2007-01-01

    The Muon to Central Trigger Processor Interface (MUCTPI) is part of the ATLAS Level-1 trigger system and connects the output of muon trigger system to the Central Trigger Processor (CTP). At every bunch crossing (BC), the MUCTPI receives information on muon candidates from each of the 208 muon trigger sectors and calculates the total multiplicity for each of six transverse momentum (pT) thresholds. This multiplicity value is then sent to the CTP, where it is used together with the input from the Calorimeter trigger to make the final Level-1 Accept (L1A) decision. In addition the MUCTPI provides summary information to the Level-2 trigger and to the data acquisition (DAQ) system for events selected at Level-1. This information is used to define the regions of interest (RoIs) that drive the Level-2 muontrigger processing. The MUCTPI system consists of a 9U VME chassis with a dedicated active backplane and 18 custom designed modules. The design of the modules is based on state-of-the-art FPGA devices and special ...

  1. ATLAS calorimetry. Trigger, simulation and jet calibration

    International Nuclear Information System (INIS)

    The Pre-Processor system of the ATLAS Level-1 Calorimeter Trigger performs complex processing of analog trigger tower signals from electromagnetic and hadronic calorimeters. The main processing block of the Pre-Processor System is the Multi-Chip Module (MCM). The first part of this thesis describes MCM quality assurance tests that have been developed, their use in the MCM large scale production and the results that have been obtained. In the second part of the thesis a validation of a shower parametrisation model for the ATLAS fast simulation package ATLFAST based on QCD dijet events is performed. A detailed comparison of jet response and jet energy resolution between the fast and the full simulation is presented. The uniformity of the calorimeter response has a significant impact on the accuracy of the jet energy measurement. A study of the calorimeter intercalibration using QCD dijet events is presented in the last part of the thesis. The intercalibration study is performed in azimuth angle φ and in pseudorapidity η. The performance of the calibration methods including possible systematic and statistical effects is described. (orig.)

  2. ATLAS calorimetry. Trigger, simulation and jet calibration

    Energy Technology Data Exchange (ETDEWEB)

    Weber, P.

    2007-02-06

    The Pre-Processor system of the ATLAS Level-1 Calorimeter Trigger performs complex processing of analog trigger tower signals from electromagnetic and hadronic calorimeters. The main processing block of the Pre-Processor System is the Multi-Chip Module (MCM). The first part of this thesis describes MCM quality assurance tests that have been developed, their use in the MCM large scale production and the results that have been obtained. In the second part of the thesis a validation of a shower parametrisation model for the ATLAS fast simulation package ATLFAST based on QCD dijet events is performed. A detailed comparison of jet response and jet energy resolution between the fast and the full simulation is presented. The uniformity of the calorimeter response has a significant impact on the accuracy of the jet energy measurement. A study of the calorimeter intercalibration using QCD dijet events is presented in the last part of the thesis. The intercalibration study is performed in azimuth angle {phi} and in pseudorapidity {eta}. The performance of the calibration methods including possible systematic and statistical effects is described. (orig.)

  3. Power distribution for the ATLAS LAr Trigger Digitizer Board

    International Nuclear Information System (INIS)

    The R and D activity for the design of the power distribution section of the ATLAS Liquid Argon (LAr) Calorimeter Trigger Digitizer Board board (LTDB) is presented. Many aspects concerning the radiation hardness and the ability to operate Point-of-load converters also in presence of high magnetic fields are covered. Devices designed by CERN for experiments at LHC have been used and their capability for implementation in the LTDB has been exploited with the aim to have a power distribution section with the required performances

  4. Triggers for displaced decays of long-lived neutral particles in the ATLAS detector

    CERN Document Server

    Aad, Georges; Abbott, Brad; Abdallah, Jalal; Abdel Khalek, Samah; Abdelalim, Ahmed Ali; Abdinov, Ovsat; Aben, Rosemarie; Abi, Babak; Abolins, Maris; AbouZeid, Ossama; Abramowicz, Halina; Abreu, Henso; Abulaiti, Yiming; Acharya, Bobby Samir; Adamczyk, Leszek; Adams, David; Addy, Tetteh; Adelman, Jahred; Adomeit, Stefanie; Adye, Tim; Aefsky, Scott; Aguilar-Saavedra, Juan Antonio; Agustoni, Marco; Ahlen, Steven; Ahles, Florian; Ahmad, Ashfaq; Ahsan, Mahsana; Aielli, Giulio; Åkesson, Torsten Paul Ake; Akimoto, Ginga; Akimov, Andrei; Alam, Muhammad Aftab; Albert, Justin; Albrand, Solveig; Alconada Verzini, Maria Josefina; Aleksa, Martin; Aleksandrov, Igor; Alessandria, Franco; Alexa, Calin; Alexander, Gideon; Alexandre, Gauthier; Alexopoulos, Theodoros; Alhroob, Muhammad; Aliev, Malik; Alimonti, Gianluca; Alison, John; Allbrooke, Benedict; Allison, Lee John; Allport, Phillip; Allwood-Spiers, Sarah; Almond, John; Aloisio, Alberto; Alon, Raz; Alonso, Alejandro; Alonso, Francisco; Altheimer, Andrew David; Alvarez Gonzalez, Barbara; Alviggi, Mariagrazia; Amako, Katsuya; Amaral Coutinho, Yara; Amelung, Christoph; Ammosov, Vladimir; Amor Dos Santos, Susana Patricia; Amorim, Antonio; Amoroso, Simone; Amram, Nir; Anastopoulos, Christos; Ancu, Lucian Stefan; Andari, Nansi; Andeen, Timothy; Anders, Christoph Falk; Anders, Gabriel; Anderson, Kelby; Andreazza, Attilio; Andrei, George Victor; Anduaga, Xabier; Angelidakis, Stylianos; Anger, Philipp; Angerami, Aaron; Anghinolfi, Francis; Anisenkov, Alexey; Anjos, Nuno; Annovi, Alberto; Antonaki, Ariadni; Antonelli, Mario; Antonov, Alexey; Antos, Jaroslav; Anulli, Fabio; Aoki, Masato; Aperio Bella, Ludovica; Apolle, Rudi; Arabidze, Giorgi; Aracena, Ignacio; Arai, Yasuo; Arce, Ayana; Arfaoui, Samir; Arguin, Jean-Francois; Argyropoulos, Spyridon; Arik, Engin; Arik, Metin; Armbruster, Aaron James; Arnaez, Olivier; Arnal, Vanessa; Artamonov, Andrei; Artoni, Giacomo; Arutinov, David; Asai, Shoji; Asbah, Nedaa; Ask, Stefan; Åsman, Barbro; Asquith, Lily; Assamagan, Ketevi; Astalos, Robert; Astbury, Alan; Atkinson, Markus; Auerbach, Benjamin; Auge, Etienne; Augsten, Kamil; Aurousseau, Mathieu; Avolio, Giuseppe; Axen, David; Azuelos, Georges; Azuma, Yuya; Baak, Max; Baccaglioni, Giuseppe; Bacci, Cesare; Bach, Andre; Bachacou, Henri; Bachas, Konstantinos; Backes, Moritz; Backhaus, Malte; Backus Mayes, John; Badescu, Elisabeta; Bagiacchi, Paolo; Bagnaia, Paolo; Bai, Yu; Bailey, David; Bain, Travis; Baines, John; Baker, Oliver Keith; Baker, Sarah; Balek, Petr; Balli, Fabrice; Banas, Elzbieta; Banerjee, Piyali; Banerjee, Swagato; Banfi, Danilo; Bangert, Andrea Michelle; Bansal, Vikas; Bansil, Hardeep Singh; Barak, Liron; Baranov, Sergei; Barber, Tom; Barberio, Elisabetta Luigia; Barberis, Dario; Barbero, Marlon; Bardin, Dmitri; Barillari, Teresa; Barisonzi, Marcello; Barklow, Timothy; Barlow, Nick; Barnett, Bruce; Barnett, Michael; Baroncelli, Antonio; Barone, Gaetano; Barr, Alan; Barreiro, Fernando; Barreiro Guimarães da Costa, João; Bartoldus, Rainer; Barton, Adam Edward; Bartsch, Valeria; Basye, Austin; Bates, Richard; Batkova, Lucia; Batley, Richard; Battaglia, Andreas; Battistin, Michele; Bauer, Florian; Bawa, Harinder Singh; Beale, Steven; Beau, Tristan; Beauchemin, Pierre-Hugues; Beccherle, Roberto; Bechtle, Philip; Beck, Hans Peter; Becker, Anne Kathrin; Becker, Sebastian; Beckingham, Matthew; Becks, Karl-Heinz; Beddall, Andrew; Beddall, Ayda; Bedikian, Sourpouhi; Bednyakov, Vadim; Bee, Christopher; Beemster, Lars; Beermann, Thomas; Begel, Michael; Belanger-Champagne, Camille; Bell, Paul; Bell, William; Bella, Gideon; Bellagamba, Lorenzo; Bellerive, Alain; Bellomo, Massimiliano; Belloni, Alberto; Beloborodova, Olga; Belotskiy, Konstantin; Beltramello, Olga; Benary, Odette; Benchekroun, Driss; Bendtz, Katarina; Benekos, Nektarios; Benhammou, Yan; Benhar Noccioli, Eleonora; Benitez Garcia, Jorge-Armando; Benjamin, Douglas; Bensinger, James; Benslama, Kamal; Bentvelsen, Stan; Berge, David; Bergeaas Kuutmann, Elin; Berger, Nicolas; Berghaus, Frank; Berglund, Elina; Beringer, Jürg; Bernat, Pauline; Bernhard, Ralf; Bernius, Catrin; Bernlochner, Florian Urs; Berry, Tracey; Bertella, Claudia; Bertolucci, Federico; Besana, Maria Ilaria; Besjes, Geert-Jan; Besson, Nathalie; Bethke, Siegfried; Bhimji, Wahid; Bianchi, Riccardo-Maria; Bianchini, Louis; Bianco, Michele; Biebel, Otmar; Bieniek, Stephen Paul; Bierwagen, Katharina; Biesiada, Jed; Biglietti, Michela; Bilokon, Halina; Bindi, Marcello; Binet, Sebastien; Bingul, Ahmet; Bini, Cesare; Bittner, Bernhard; Black, Curtis; Black, James

    2013-01-01

    A set of three dedicated triggers designed to detect long-lived neutral particles decaying throughout the ATLAS detector to a pair of hadronic jets is described. The efficiencies of the triggers for selecting displaced decays as a function of the decay position are presented for simulated events. The effect of pile-up interactions on the trigger efficiencies and the dependence of the trigger rate on instantaneous luminosity during the 2012 data-taking period at the LHC are discussed.

  5. Dedicated Trigger for Highly Ionising Particles at ATLAS

    CERN Document Server

    Katre, Akshay; The ATLAS collaboration

    2015-01-01

    In 2012, a novel strategy was designed to detect signatures of Highly Ionising Particles (HIPs) such as magnetic monopoles, dyons or Qballs with the ATLAS trigger system. With proton-proton collisions at a centre of mass enegy of 8 TeV, the trigger was designed to have unique properties as a tracker for HIPs. It uses only the Transition Radiation Tracker (TRT) system, applying an algorithm distinct from standard tracking ones. The unique high threshold readout capability of the TRT is used at the location where HIPs in the detector are looked for. In particular the number and the fraction of TRT high threshold hits is used to distinguish HIPs from background processes. The trigger requires significantly lower energy depositions in the electro-magnetic calorimeters as a seed unlike previously used trigger algorithms for such searches. Thus the new trigger is capable of probing a large range of HIP masses and charges. We will give a description of the algorithms for this newly developed trigger for HIP searches...

  6. A Hardware Fast Tracker for the ATLAS trigger

    CERN Document Server

    Asbah, Nedaa; The ATLAS collaboration

    2015-01-01

    The trigger system of the ATLAS experiment is designed to reduce the event rate from the LHC nominal bunch crossing at 40 MHz to about 1 kHz, at the design luminosity of 10^{34} cm^{-2}s^{-1}. After a successful period of data taking from 2010 to early 2013, the LHC restarted with much higher instantaneous luminosity. This will increase the load on High Level Trigger system, the second stage of the selection based on software algorithms. More sophisticated algorithms will be needed to achieve higher background rejection while maintaining good efficiency for interesting physics signals. The Fast TracKer (FTK) is part of the ATLAS trigger upgrade project; it is a hardware processor that will provide, at every level-1 accepted event (100 kHz) and within 100 microseconds, full tracking information for tracks with momentum as low as 1 GeV. Providing fast extensive access to tracking information, with resolution comparable to the offline reconstruction, FTK will help in precise detection of the primary and secondar...

  7. A study of a second level track trigger for ATLAS

    Energy Technology Data Exchange (ETDEWEB)

    Borer, K.; Bates, S.; Munday, D.J.; Parker, M.A.; Poppleton, A.; Goessling, C.; Lisowski, B.; Reichold, A.; Spiwoks, R.; Tsesmelis, E.; Clark, A.G.; Bonino, R.; Wu, X.; Moorhead, G.F.; Taylor, G.N.; Tovey, S.N.; Stapnes, S.; Hawkings, R.J.; Weidberg, A.R.; Lubrano, P.; Scampoli, P.; Teiger, J.; Gheorghe, A.; Bock, R.; Krischer, W. (Lab. fuer Hochenergiephysik, Univ. Bern (Switzerland) Cavendish Lab., Univ. of Cambridge (United Kingdom) CERN, Geneva (Switzerland) Inst. fuer Physik, Univ. Dortmund (Germany) DPNC, Univ. de Geneve (Switzerland) School of Physics, Univ. of Melbourne (Australia) Univ. of Oslo (Norway) Dept. of Nuclear Physics, Oxford Univ. (United Kingdom) Dipt. di Fisica dell' Univ. di Perugia (Italy) INFN Sezione di Perugia (Italy) Centre d' Etudes Nucleaires de Saclay, Gif-sur-Yvette (France) Inst. of Atomic Physics and Polytecnic Inst., Bucharest (Romania) CERN, Geneva (Switzerland)); RD2 Collaboration; RD11 Collaboration

    1993-11-15

    This paper discusses some of the problems of triggering at a high energy, high luminosity pp collider. A suggested second level track trigger for the ATLAS detector is described, based on hit information from a silicon tracker. Detailed Monte Carlo simulations have been performed to assess the performance of the trigger in accepting electrons and in rejecting the QCD jets that would fake electrons in the first level calorimeter trigger. Studies of the feasibility of implementing such a trigger are also presented. (orig.)

  8. The ATLAS Level-1 Calorimeter Trigger Architecture

    CERN Document Server

    Garvey, J; Mahout, G; Moye, T H; Staley, R J; Watkins, P M; Watson, A T; Achenbach, R; Hanke, P; Kluge, E E; Meier, K; Meshkov, P; Nix, O; Penno, K; Schmitt, K; Ay, Cc; Bauss, B; Dahlhoff, A; Jakobs, K; Mahboubi, K; Schäfer, U; Trefzger, T M; Eisenhandler, E F; Landon, M; Moyse, E; Thomas, J; Apostoglou, P; Barnett, B M; Brawn, I P; Davis, A O; Edwards, J; Gee, C N P; Gillman, A R; Perera, V J O; Qian, W; Bohm, C; Hellman, S; Hidvégi, A; Silverstein, S; RT 2003 13th IEEE-NPSS Real Time Conference

    2004-01-01

    The architecture of the ATLAS Level-1 Calorimeter Trigger system (L1Calo) is presented. Common approaches have been adopted for data distribution, result merging, readout, and slow control across the three different subsystems. A significant amount of common hardware is utilized, yielding substantial savings in cost, spares, and development effort. A custom, high-density backplane has been developed with data paths suitable for both the em/tt cluster processor (CP) and jet/energy-summation processor (JEP) subsystems. Common modules also provide interfaces to VME, CANbus and the LHC Timing, Trigger and Control system (TTC). A common data merger module (CMM) uses FPGAs with multiple configurations for summing electron/photon and tau/hadron cluster multiplicities, jet multiplicities, or total and missing transverse energy. The CMM performs both crate- and system-level merging. A common, FPGA-based readout driver (ROD) is used by all of the subsystems to send input, intermediate and output data to the data acquis...

  9. Operational Experience of the ATLAS High Level Trigger with Single-Beam and Cosmic Rays

    CERN Document Server

    Aracena, I; The ATLAS collaboration

    2009-01-01

    After giving an overview of the ATLAS trigger design and its innovative features, this paper focuses on the operational experience gained in running the trigger in the fast-changing environment of the detector commissioning. It will emphasize the commissioning of the High Level Trigger (HLT) system, including its monitoring and configuration. Preliminary results from initial LHC running in 2009 will be included if available. ATLAS is one of two general-purpose detectors at the LHC. Using fast reconstruction algorithms, the trigger system needs to efficiently reject a large rate of background events while keeping potentially interesting ones with high efficiency. After a first level trigger implemented in custom electronics, the trigger selection is made by software running on two processor farms (the High Level Trigger system), containing a total of around two thousand multi-core machines. To reduce the network data traffic and the processing time to manageable levels, the HLT uses seeded, step-wise event rec...

  10. The upgrade of the ATLAS first-level calorimeter trigger

    Science.gov (United States)

    Yamamoto, Shimpei

    2016-07-01

    The first-level calorimeter trigger (L1Calo) had operated successfully through the first data taking phase of the ATLAS experiment at the CERN Large Hadron Collider. Towards forthcoming LHC runs, a series of upgrades is planned for L1Calo to face new challenges posed by the upcoming increases of the beam energy and the luminosity. This paper reviews the ATLAS L1Calo trigger upgrade project that introduces new architectures for the liquid-argon calorimeter trigger readout and the L1Calo trigger processing system.

  11. Diagnostic Systems and Resources utilization of the ATLAS High Level Trigger

    CERN Document Server

    Sidoti, A; The ATLAS collaboration; Ospanov, R

    2010-01-01

    Since the LHC started colliding protons in December 2009, the ATLAS trigger has operated very successfully with a collision rate which has increased by several orders of magnitude. The trigger monitoring and data quality infrastructure was essential to this success. We describe the software tools used to monitor the trigger system performance and assess the overall quality of the trigger selection during collisions running. ATLAS has broad physics goals which require a large number of different active triggers due to complex event topology, requiring quite sophisticated software structures and concepts. The trigger of the ATLAS experiment is built as a three level system. The first level is realized in hardware while the high level triggers (HLT) are software based and run on large PC farms. The trigger reduces the bunch crossing rate of 40 MHz, at design, to an average event rate of about 200 Hz for storage. Since the ATLAS detector is a general purpose detector, the trigger must be sensitive to a large numb...

  12. A Fast Hardware Tracker for the ATLAS Trigger System

    CERN Document Server

    Kimura, N; The ATLAS collaboration

    2012-01-01

    Selecting interesting events with triggering is very challenging at the LHC due to the busy hadronic environment. Starting in 2014 the LHC will run with an energy of 14TeV and instantaneous luminosities which could exceed 10^34 interactions per cm^2 and per second. The triggering in the ATLAS detector is realized using a three level trigger approach, in which the first level (L1) is hardware based and the second (L2) and third (EF) stag are realized using large computing farms. It is a crucial and non-trivial task for triggering to maintain a high efficiency for events of interest while suppressing effectively the very high rates of inclusive QCD process, which constitute mainly background. At the same time the trigger system has to be robust and provide sufficient operational margins to adapt to changes in the running environment. In the current design track reconstruction can be performed only in limited regions of interest at L2 and the CPU requirements may limit this even further at the highest instantane...

  13. A Fast Hardware Tracker for the ATLAS Trigger System

    CERN Document Server

    Kimura, N; The ATLAS collaboration

    2012-01-01

    Selecting interesting events with triggering is very challenging at the LHC due to the busy hadronic environment. Starting in 2014 the LHC will run with an energy of 13 or 14 TeV and instantaneous luminosities which could exceed 1034 interactions per cm2 and per second. The triggering in the ATLAS detector is realized using a three level trigger approach, in which the first level (Level-1) is hardware based and the second (Level-2) and third (EF) stag are realized using large computing farms. It is a crucial and non-trivial task for triggering to maintain a high efficiency for events of interest while suppressing effectively the very high rates of inclusive QCD process, which constitute mainly background. At the same time the trigger system has to be robust and provide sufficient operational margins to adapt to changes in the running environment. In the current design track reconstruction can be performed only in limited regions of interest at L2 and the CPU requirements may limit this even further at the hig...

  14. The ATLAS High Level Trigger Infrastructure, Performance and Future Developments

    CERN Document Server

    Winklmeier, F; The ATLAS collaboration

    2009-01-01

    The ATLAS High Level Trigger (HLT) is a distributed real-time software system that performs the final online selection of events produced during proton-proton collisions at the Large Hadron Collider (LHC). It is designed as a two-stage event filter running on a farm of commodity PC hardware. Currently the system consists of about 850 multi-core processing nodes that will be extended incrementally following the increasing luminosity of the LHC to about 2000 nodes depending on the evolution of the processor technology. Due to the complexity and similarity of the algorithms a large fraction of the software is shared between the online and offline event reconstruction. The HLT Infrastructure serves as the interface between the two domains and provides common services for the trigger algorithms. The consequences of this design choice will be discussed and experiences from the operation of the ATLAS HLT during cosmic ray data taking and first beam in 2008 will be presented. Since the event processing time at the HL...

  15. B-physics trigger for the ATLAS detector at LHC: recent developments

    International Nuclear Information System (INIS)

    Full text: A re-assessment of the B-physics trigger strategy was done for the ATLAS high level trigger, data acquisition and controls technical design report. It takes into account the effects of the increase of the LHC luminosity target, the possibility to have a reduced detector at the start of running, as well as various trigger deferral scenarios due to financial constraints and uncertainties. (author)

  16. ATLAS Trigger and Data Acquisition Upgrades for High Luminosity LHC

    CERN Document Server

    George, Simon; The ATLAS collaboration

    2016-01-01

    The ATLAS experiment at CERN is planning a second phase of upgrades to prepare for the "High Luminosity LHC", a 4th major run due to start in 2026. In order to deliver an order of magnitude more data than previous runs, 14 TeV protons will collide with an instantaneous luminosity of 7.5 × 10^{34} cm^{−2}s^{−1}, resulting in much higher pileup and data rates than the current experiment was designed to handle. While this extreme scenario is essential to realise the physics programme, it is a huge challenge for the detector, trigger, data acquisition and computing. The detector upgrades themselves also present new requirements and opportunities for the trigger and data acquisition system. Initial upgrade designs for the trigger and data acquisition system are shown, including the real time low latency hardware trigger, hardware-based tracking, the high throughput data acquisition system and the commodity hardware and software-based data handling and event filtering. The motivation, overall architecture and ...

  17. ATLAS Trigger and Data Acquisition Upgrades for High Luminosity LHC

    CERN Document Server

    Balunas, William Keaton; The ATLAS collaboration

    2016-01-01

    The ATLAS experiment at CERN is planning a second phase of upgrades to prepare for the "High Luminosity LHC", a 4th major run due to start in 2026. In order to deliver an order of magnitude more data than previous runs, 14 TeV protons will collide with an instantaneous luminosity of $7.5 × 10^{34}$ cm$^{−2}$s$^{−1}$, resulting in much higher pileup and data rates than the current experiment was designed to handle. While this extreme scenario is essential to realise the physics programme, it is a huge challenge for the detector, trigger, data acquisition and computing. The detector upgrades themselves also present new requirements and opportunities for the trigger and data acquisition system. Initial upgrade designs for the trigger and data acquisition system are shown, including the real time low latency hardware trigger, hardware-based tracking, the high throughput data acquisition system and the commodity hardware and software-based data handling and event filtering. The motivation, overall architectur...

  18. ATLAS Trigger and Data Acquisition Upgrades for High Luminosity LHC

    CERN Document Server

    Allen, Benjamin William; The ATLAS collaboration

    2016-01-01

    The ATLAS experiment at CERN is planning a second phase of upgrades to prepare for the "High Luminosity LHC", a 4th major run due to start in 2026. In order to deliver an order of magnitude more data than previous runs, 14 TeV protons will collide with an instantaneous luminosity of 7.5 × 1034 cm−2s−1, resulting in much higher pileup and data rates than the current experiment was designed to handle. While this extreme scenario is essential to realise the physics programme, it is a huge challenge for the detector, trigger, data acquisition and computing. The detector upgrades themselves also present new requirements and opportunities for the trigger and data acquisition system. Initial upgrade designs for the trigger and data acquisition system are shown, including the real time low latency hardware trigger, hardware-based tracking, the high throughput data acquisition system and the commodity hardware and software-based data handling and event filtering. The motivation, overall architecture and expected ...

  19. ATLAS Trigger and Data Acquisition Upgrades for High Luminosity LHC

    CERN Document Server

    Balunas, William Keaton; The ATLAS collaboration

    2016-01-01

    The ATLAS experiment at CERN is planning a second phase of upgrades to prepare for the "High Luminosity LHC", a 4th major run due to start in 2026. In order to deliver an order of magnitude more data than previous runs, 14 TeV protons will collide with an instantaneous luminosity of $7.5 \\times 10^{34} cm^{-2}s^{-1}$, resulting in much higher pileup and data rates than the current experiment was designed to handle. While this extreme scenario is essential to realise the physics programme, it is a huge challenge for the detector, trigger, data acquisition and computing. The detector upgrades themselves also present new requirements and opportunities for the trigger and data acquisition system. Initial upgrade designs for the trigger and data acquisition system are shown, including the real time low latency hardware trigger, hardware-based tracking, the high throughput data acquisition system and the commodity hardware and software-based data handling and event filtering. The motivation, overall architecture an...

  20. Hardware and firmware developments for the upgrade of the ATLAS Level-1 Central Trigger Processor

    CERN Document Server

    Anders, G; Boisen, A; Childers, T; Dam, M; Ellis, N; Farthouat, P; Gabaldon Ruiz, C; Ghibaudi, M; Gorini, B; Haas, S; Kaneda, M; Ohm, C; Silva Oliveira, M; Pauly, T; Pottgen, R; Schmieden, K; Spiwoks, R; Xella, S

    2014-01-01

    The Central Trigger Processor (CTP) is the final stage of the ATLAS first level trigger system which reduces the collision rate of 40 MHz to a Level-1 event rate of 100 kHz. An upgrade of the CTP is currently underway to significantly increase the number of trigger inputs and trigger combinations, allowing additional flexibility for the trigger menu. We present the hardware and FPGA firmware of the newly designed core module (CTPCORE+) module of the CTP, as well as results from a system used for early firmware and software prototyping based on commercial FPGA evaluation boards. First test result from the CTPCORE+ module will also be shown.

  1. The FTK: A Hardware Track Finder for the ATLAS Trigger

    CERN Document Server

    Alison, J; Anderson, J; Andreani, A; Andreazza, A; Annovi, A; Antonelli, M; Atkinson, M; Auerbach, B; Baines, J; Barberio, E; Beccherle, R; Beretta, M; Biesuz, N V; Blair, R; Blazey, G; Bogdan, M; Boveia, A; Britzger, D; Bryant, P; Burghgrave, B; Calderini, G; Cavaliere, V; Cavasinni, V; Chakraborty, D; Chang, P; Cheng, Y; Cipriani, R; Citraro, S; Citterio, M; Crescioli, F; Dell'Orso, M; Donati, S; Dondero, P; Drake, G; Gadomski, S; Gatta, M; Gentsos, C; Giannetti, P; Giulini, M; Gkaitatzis, S; Howarth, J W; Iizawa, T; Kapliy, A; Kasten, M; Kim, Y K; Kimura, N; Klimkovich, T; Kordas, K; Korikawa, T; Krizka, K; Kubota, T; Lanza, A; Lasagni, F; Liberali, V; Li, H L; Love, J; Luciano, P; Luongo, C; Magalotti, D; Melachrinos, C; Meroni, C; Mitani, T; Negri, A; Neroutsos, P; Neubauer, M; Nikolaidis, S; Okumura, Y; Pandini, C; Penning, B; Petridou, C; Piendibene, M; Proudfoot, J; Rados, P; Roda, C; Rossi, E; Sakurai, Y; Sampsonidis, D; Sampsonidou, D; Schmitt, S; Schoening, A; Shochet, M; Shojaii, S; Soltveit, H; Sotiropoulou, C L; Stabile, A; Tang, F; Testa, M; Tompkins, L; Vercesi, V; Villa, M; Volpi, G; Webster, J; Wu, X; Yorita, K; Yurkewicz, A; Zeng, J C; Zhang, J

    2014-01-01

    The ATLAS experiment trigger system is designed to reduce the event rate, at the LHC design luminosity of 1034 cm-2 s-1, from the nominal bunch crossing rate of 40 MHz to less than 1 kHz for permanent storage. During Run 1, the LHC has performed exceptionally well, routinely exceeding the design luminosity. From 2015 the LHC is due to operate with higher still luminosities. This will place a significant load on the High Level Trigger system, both due to the need for more sophisticated algorithms to reject background, and from the larger data volumes that will need to be processed. The Fast TracKer is a hardware upgrade for Run 2, consisting of a custom electronics system that will operate at the full rate for Level-1 accepted events of 100 kHz and provide high quality tracks at the beginning of processing in the High Level Trigger. This will perform track reconstruction using hardware with massive parallelism using associative memories and FPGAs. The availability of the full tracking information will enable r...

  2. The First Result of Global Commissioning of the ATLAS Endcap Muon Trigger System in ATLAS Cavern

    CERN Document Server

    Sugimoto, T; Takahashi, Y; Tomoto, M; Fukunaga, C; Ikeno, M; Iwasaki, H; Nagano, K; Nozaki, M; Sasaki, O; Tanaka, S; Yasu, Y; Hasegawa, Y; Oshita, H; Takeshita, T; Nomachi, M; Sugaya, Y; Kubota, T; Ishino, M; Kanaya, N; Kawamoto, T; Kobayashi, T; Kuwabara, T; Nomoto, H; Sakamoto, H; Yamaguchi, T; Kadosaka, T; Kawagoe, K; Kiyamura, H; Kurashige, H; Niwa, T; Ochi, A; Omachi, C; Takeda, H; Lifshitz, R; Lupu, N; Bressler, S; Tarem, S; Kajomovitz, E; Ben Ami, S; Bahat Treidel, O; Benhammou, Ya; Etzion, E; Lellouch, D; Levinson, L; Mikenberg, G; Roich, A

    2007-01-01

    We report on the ATLAS commissioning run from the view point of the Thin Gap Chamber (TGC), which is the ATLAS end cap muon trigger detector. All the TGC sectors with on-detector electronics are going to be installed to the ATLAS cavern by the end of September 2007. To integrate all sub-detectors before the physics run starting from early 2008, the global commissioning run together with other sub-detectors has been performed from June 2007. We have evaluated the performance of the complete trigger chain of the TGC electronics and provide the trigger signal using cosmic-ray to the sub-systems in the global run environment.

  3. Trigger selection software for beauty physics in ATLAS

    Energy Technology Data Exchange (ETDEWEB)

    Emeliyanov, D; Baines, J; Kirk, J [Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot (United Kingdom); Panikashvili, N; Tarem, S [Department of Physics, Technion, Haifa (Israel); Parodi, F; Schiavi, C [Dipartimento di Fisica dell' Universita di Genova e I.N.F.N., Genova (Italy); Sivoklokov, S [Moscow State University, Moscow (Russian Federation); Watson, A [School of Physics and Astronomy, University of Birmingham, Birmingham (United Kingdom)], E-mail: Dmitry.Emeliyanov@cern.ch

    2008-07-01

    The unprecedented rate of beauty production at the LHC will yield high statistics for measurements such as CP violation and B{sub a} oscillations and will provide the opportunity to search for and study very rare decays, such as B {yields} {mu}{mu}. The trigger is a vital component for this work and must select events containing the channels of interest from a huge background in order to reduce the 40 MHz bunch crossing rate down to 100-200 Hz for recording, of which only a part will be assigned to B-physics. Requiring a single or di-muon trigger provides the first stage of the B-trigger selection. Track reconstruction is then performed in the Inner Detector, either using the full detector, at initial luminosity, or within Regions of Interest identified by the first level trigger at higher luminosities. Based on invariant mass, combinations of tracks are selected as likely decay products of the channel of interest and secondary vertex fits are performed. Events are selected based on properties such as fit quality and invariant mass. We present fast vertex reconstruction algorithms suitable for use in the second level trigger and event filter (level three). We discuss the selection software and the flexible trigger strategies that will enable ATLAS to pursue a B-physics programme from the first running at a luminosity of about 10{sup 31}cm{sup -2}s-{sup 1} through to the design luminosity running at 10{sup 34}cm{sup -2}s-{sup 1}.

  4. An Upgraded ATLAS Central Trigger for 2014 LHC Luminosities

    CERN Document Server

    Kaneda, M; The ATLAS collaboration

    2012-01-01

    During 2011, the LHC reached instantaneous luminosities of 4*10^33 cm-2*s-1 and produced events with up to 24 interactions per colliding proton bunch. Thisplaces stringent operational and physical requirements on the ATLAS Trigger in order to reduce the 40MHz collision rate to a manageable event storage rate of ~400Hz and, atthe same time, selecting those events considered interesting. The Level-1 Trigger is the first rate-reducing step in the ATLAS Trigger, with an output rate of 75kHz and adecision latency of less than 2.5us. It is primarily composed of the Calorimeter Trigger, Muon Trigger, and the Central Trigger Processor which are implemented in custom builtVME electronics. The Central Trigger Processor collects trigger information from all Level-1 systems and produces a Level-1 trigger decision that initiates the readout of all ATLAS subdetectors. In 2014, the LHC will run at a center of mass energy of 14 TeV, compared to the current 8 TeV, and the luminosity will exceed 10^34 cm^-2*s^-1. With higher l...

  5. An Upgraded ATLAS Central Trigger for 2014 Luminosities

    CERN Document Server

    Anders, G; The ATLAS collaboration; Bertelsen, H; Childers, T; Dam, M; Dobson, E; Ellis, N; Farthouat, P; Gabaldon, C; Gorini, B; Haas, S; Kaneda, M; Maettig, S; Messina, A; Pauly, T; Pöttgen, R; Spiwoks, R; Wengler, T; Xella, S

    2012-01-01

    During 2011, the LHC reached instantaneous luminosities of 4*10^33 cm-2*s-1 and produced events with up to 24 interactions per colliding proton bunch. This places stringent operational and physical requirements on the ATLAS Trigger in order to reduce the 40MHz collision rate to a manageable event storage rate of ~400Hz and, at the same time, selecting those events considered interesting. The Level-1 Trigger is the first rate-reducing step in the ATLAS Trigger, with an output rate of 75kHz and a decision latency of less than 2.5us. It is primarily composed of the Calorimeter Trigger, Muon Trigger, and the Central Trigger Processor which are implemented in custom built VME electronics. The Central Trigger Processor collects trigger information from all Level-1 systems and produces a Level-1 trigger decision that initiates the readout of all ATLAS detectors. In 2014, the LHC will run at a center of mass energy of 14 TeV, compared to the current 8 TeV, and the luminosity will exceed 10^34 cm^-2*s^-1. With higher ...

  6. An Upgraded ATLAS Central Trigger for 2014 LHC Luminosities

    CERN Document Server

    Kaneda, M; The ATLAS collaboration

    2012-01-01

    During 2011, the LHC reached instantaneous luminosities of 4*10^33 cm^-1*s^-1 and produced events with up to 24 interactions per colliding proton bunch. This places stringent operational and physical requirements on the ATLAS Trigger in order to reduce the 40MHz collision rate to a manageable event storage rate of ~400Hz and, at the same time, selecting those events considered interesting. The Level-1 Trigger is the first rate-reducing step in the ATLAS Trigger, with an output rate of 75kHz and a decision latency of less than 2.5us. It is primarily composed of the Calorimeter Trigger, Muon Trigger, and the Central Trigger Processor which are implemented in custom built VME electronics. The Central Trigger Processor collects trigger information from all Level-1 systems and produces a Level-1 trigger decision that initiates the readout of all ATLAS sub-detectors. In 2014, the LHC will run at a center of mass energy of 14 TeV, compared to the current 8 TeV, and the luminosity will exceed 10^34 cm^-1*s^-1. With h...

  7. An upgraded ATLAS Central Trigger for post-2014 LHC luminosities

    CERN Document Server

    Anders, G; The ATLAS collaboration; Bertelsen, H; Childers, T; Dam, M; Dobson, E; Ellis, N; Farthouat, P; Gabaldon, C; Gorini, B; Haas, S; Kaneda, M; Maettig, S; Messina, A; Ohm, C; Pauly, T; Poettgen, R; Spiwoks, R; Wengler, T; Xella, S

    2012-01-01

    During 2011, the LHC reached instantaneous luminosities of 6.7 · 10^33 cm−2s−1 and produced events with up to 40 interactions per colliding proton bunch. This places stringent operational and physical requirements on the ATLAS trigger in order to reduce the 40 MHz collision rate to a manageable event storage rate of 400 Hz without discarding those events considered interesting. The Level-1 trigger is the first rate-reducing step in the ATLAS trigger, with an output rate of 75 kHz and a decision latency of less than 2.5 μ s. It is primarily composed of the Calorimeter Trigger, Muon Trigger, and the Central Trigger Processor which are implemented in custom built VME electronics. The Central Trigger Processor collects trigger information from all Level-1 systems and produces a Level-1 trigger decision that initiates the readout of all ATLAS detectors. After 2014, the LHC will run at a center of mass energy of up to 14 TeV, compared to the current 8 TeV, and the luminosity will exceed 10^34 cm−2s−1. Wit...

  8. The performance of the jet trigger for the ATLAS detector during 2011 data taking

    Science.gov (United States)

    Aad, G.; Abbott, B.; Abdallah, J.; Abdinov, O.; Abeloos, B.; Aben, R.; Abolins, M.; AbouZeid, O. S.; Abraham, N. L.; Abramowicz, H.; Abreu, H.; Abreu, R.; Abulaiti, Y.; Acharya, B. S.; Adamczyk, L.; Adams, D. L.; Adelman, J.; Adomeit, S.; Adye, T.; Affolder, A. A.; Agatonovic-Jovin, T.; Agricola, J.; Aguilar-Saavedra, J. A.; Ahlen, S. P.; Ahmadov, F.; Aielli, G.; Akerstedt, H.; Åkesson, T. P. A.; Akimov, A. V.; Alberghi, G. L.; Albert, J.; Albrand, S.; Verzini, M. J. Alconada; Aleksa, M.; Aleksandrov, I. N.; Alexa, C.; Alexander, G.; Alexopoulos, T.; Alhroob, M.; Aliev, M.; Alimonti, G.; Alison, J.; Alkire, S. P.; Allbrooke, B. M. M.; Allen, B. W.; Allport, P. P.; Aloisio, A.; Alonso, A.; Alonso, F.; Alpigiani, C.; Gonzalez, B. Alvarez; Piqueras, D. Álvarez; Alviggi, M. G.; Amadio, B. T.; Amako, K.; Coutinho, Y. Amaral; Amelung, C.; Amidei, D.; Santos, S. P. Amor Dos; Amorim, A.; Amoroso, S.; Amram, N.; Amundsen, G.; Anastopoulos, C.; Ancu, L. S.; Andari, N.; Andeen, T.; Anders, C. F.; Anders, G.; Anders, J. K.; Anderson, K. J.; Andreazza, A.; Andrei, V.; Angelidakis, S.; Angelozzi, I.; Anger, P.; Angerami, A.; Anghinolfi, F.; Anisenkov, A. V.; Anjos, N.; Annovi, A.; Antonelli, M.; Antonov, A.; Antos, J.; Anulli, F.; Aoki, M.; Bella, L. Aperio; Arabidze, G.; Arai, Y.; Araque, J. P.; Arce, A. T. H.; Arduh, F. A.; Arguin, J.-F.; Argyropoulos, S.; Arik, M.; Armbruster, A. J.; Armitage, L. J.; Arnaez, O.; Arnold, H.; Arratia, M.; Arslan, O.; Artamonov, A.; Artoni, G.; Artz, S.; Asai, S.; Asbah, N.; Ashkenazi, A.; Åsman, B.; Asquith, L.; Assamagan, K.; Astalos, R.; Atkinson, M.; Atlay, N. B.; Augsten, K.; Avolio, G.; Axen, B.; Ayoub, M. K.; Azuelos, G.; Baak, M. A.; Baas, A. E.; Baca, M. J.; Bachacou, H.; Bachas, K.; Backes, M.; Backhaus, M.; Bagiacchi, P.; Bagnaia, P.; Bai, Y.; Baines, J. T.; Baker, O. K.; Baldin, E. M.; Balek, P.; Balestri, T.; Balli, F.; Balunas, W. K.; Banas, E.; Banerjee, Sw.; Bannoura, A. A. E.; Barak, L.; Barberio, E. L.; Barberis, D.; Barbero, M.; Barillari, T.; Barklow, T.; Barlow, N.; Barnes, S. L.; Barnett, B. M.; Barnett, R. M.; Barnovska, Z.; Baroncelli, A.; Barone, G.; Barr, A. J.; Navarro, L. Barranco; Barreiro, F.; da Costa, J. Barreiro Guimarães; Bartoldus, R.; Barton, A. E.; Bartos, P.; Basalaev, A.; Bassalat, A.; Basye, A.; Bates, R. L.; Batista, S. J.; Batley, J. R.; Battaglia, M.; Bauce, M.; Bauer, F.; Bawa, H. S.; Beacham, J. B.; Beattie, M. D.; Beau, T.; Beauchemin, P. H.; Bechtle, P.; Beck, H. P.; Becker, K.; Becker, M.; Beckingham, M.; Becot, C.; Beddall, A. J.; Beddall, A.; Bednyakov, V. A.; Bedognetti, M.; Bee, C. P.; Beemster, L. J.; Beermann, T. A.; Begel, M.; Behr, J. K.; Belanger-Champagne, C.; Bell, A. S.; Bella, G.; Bellagamba, L.; Bellerive, A.; Bellomo, M.; Belotskiy, K.; Beltramello, O.; Belyaev, N. L.; Benary, O.; Benchekroun, D.; Bender, M.; Bendtz, K.; Benekos, N.; Benhammou, Y.; Noccioli, E. Benhar; Benitez, J.; Garcia, J. A. Benitez; Benjamin, D. P.; Bensinger, J. R.; Bentvelsen, S.; Beresford, L.; Beretta, M.; Berge, D.; Kuutmann, E. Bergeaas; Berger, N.; Berghaus, F.; Beringer, J.; Berlendis, S.; Bernard, N. R.; Bernius, C.; Bernlochner, F. U.; Berry, T.; Berta, P.; Bertella, C.; Bertoli, G.; Bertolucci, F.; Bertram, I. A.; Bertsche, C.; Bertsche, D.; Besjes, G. J.; Bylund, O. Bessidskaia; Bessner, M.; Besson, N.; Betancourt, C.; Bethke, S.; Bevan, A. J.; Bhimji, W.; Bianchi, R. M.; Bianchini, L.; Bianco, M.; Biebel, O.; Biedermann, D.; Bielski, R.; Biesuz, N. V.; Biglietti, M.; De Mendizabal, J. Bilbao; Bilokon, H.; Bindi, M.; Binet, S.; Bingul, A.; Bini, C.; Biondi, S.; Bjergaard, D. M.; Black, C. W.; Black, J. E.; Black, K. M.; Blackburn, D.; Blair, R. E.; Blanchard, J.-B.; Blanco, J. E.; Blazek, T.; Bloch, I.; Blocker, C.; Blum, W.; Blumenschein, U.; Blunier, S.; Bobbink, G. J.; Bobrovnikov, V. S.; Bocchetta, S. S.; Bocci, A.; Bock, C.; Boehler, M.; Boerner, D.; Bogaerts, J. A.; Bogavac, D.; Bogdanchikov, A. G.; Bohm, C.; Boisvert, V.; Bold, T.; Boldea, V.; Boldyrev, A. S.; Bomben, M.; Bona, M.; Boonekamp, M.; Borisov, A.; Borissov, G.; Bortfeldt, J.; Bortoletto, D.; Bortolotto, V.; Bos, K.; Boscherini, D.; Bosman, M.; Sola, J. D. Bossio; Boudreau, J.; Bouffard, J.; Bouhova-Thacker, E. V.; Boumediene, D.; Bourdarios, C.; Boutle, S. K.; Boveia, A.; Boyd, J.; Boyko, I. R.; Bracinik, J.; Brandt, A.; Brandt, G.; Brandt, O.; Bratzler, U.; Brau, B.; Brau, J. E.; Braun, H. M.; Madden, W. D. Breaden; Brendlinger, K.; Brennan, A. J.; Brenner, L.; Brenner, R.; Bressler, S.; Bristow, T. M.; Britton, D.; Britzger, D.; Brochu, F. M.; Brock, I.; Brock, R.; Brooijmans, G.; Brooks, T.; Brooks, W. K.; Brosamer, J.; Brost, E.; Broughton, J. H.; de Renstrom, P. A. Bruckman; Bruncko, D.; Bruneliere, R.; Bruni, A.; Bruni, G.

    2016-10-01

    The performance of the jet trigger for the ATLAS detector at the LHC during the 2011 data taking period is described. During 2011 the LHC provided proton-proton collisions with a centre-of-mass energy of 7 TeV and heavy ion collisions with a 2.76 TeV per nucleon-nucleon collision energy. The ATLAS trigger is a three level system designed to reduce the rate of events from the 40 MHz nominal maximum bunch crossing rate to the approximate 400 Hz which can be written to offline storage. The ATLAS jet trigger is the primary means for the online selection of events containing jets. Events are accepted by the trigger if they contain one or more jets above some transverse energy threshold. During 2011 data taking the jet trigger was fully efficient for jets with transverse energy above 25 GeV for triggers seeded randomly at Level 1. For triggers which require a jet to be identified at each of the three trigger levels, full efficiency is reached for offline jets with transverse energy above 60 GeV. Jets reconstructed in the final trigger level and corresponding to offline jets with transverse energy greater than 60 GeV, are reconstructed with a resolution in transverse energy with respect to offline jets, of better than 4 % in the central region and better than 2.5 % in the forward direction.

  9. Studies for a common selection software environment in ATLAS from the Level-2 Trigger to the offline reconstruction

    CERN Document Server

    Wiedenmann, W; Baines, J T M; Bee, C P; Biglietti, M; Bogaerts, A; Boisvert, V; Bosman, M; Brandt, S; Caron, B; Casado, M P; Cataldi, G; Cavalli, D; Cervetto, M; Comune, G; Corso-Radu, A; Di Mattia, A; Díaz-Gómez, M; Dos Anjos, A; Drohan, J; Ellis, Nick; Elsing, M; Epp, B; Etienne, F; Falciano, S; Farilla, A; George, S; Ghete, V M; González, S; Grothe, M; Kaczmarska, A; Karr, K M; Khomich, A; Konstantinidis, N P; Krasny, W; Li, W; Lowe, A; Luminari, L; Meessen, C; Mello, A G; Merino, G; Morettini, P; Moyse, E; Nairz, A; Negri, A; Nikitin, N V; Nisati, A; Padilla, C; Parodi, F; Pérez-Réale, V; Pinfold, J L; Pinto, P; Polesello, G; Qian, Z; Resconi, S; Rosati, S; Scannicchio, D A; Schiavi, C; Schörner-Sadenius, T; Segura, E; De Seixas, J M; Shears, T G; Sivoklokov, S Yu; Smizanska, M; Soluk, R A; Stanescu, C; Tapprogge, Stefan; Touchard, F; Vercesi, V; Watson, A T; Wengler, T; Werner, P; Wheeler, S; Wickens, F J; Wielers, M; Zobernig, G; NSS-MIC 2003 - IEEE Nuclear Science Symposium and Medical Imaging Conference, Part 1

    2004-01-01

    The Atlas High Level Trigger's primary function of event selection will be accomplished with a Level-2 trigger farm and an Event Filter farm, both running software components developed in the Atlas offline reconstruction framework. While this approach provides a unified software framework for event selection, it poses strict requirements on offline components critical for the Level-2 trigger. A Level-2 decision in Atlas must typically be accomplished within 10 ms and with multiple event processing in concurrent threads. In order to address these constraints, prototypes have been developed that incorporate elements of the Atlas Data Flow -, High Level Trigger -, and offline framework software. To realize a homogeneous software environment for offline components in the High Level Trigger, the Level-2 Steering Controller was developed. With electron/gamma- and muon-selection slices it has been shown that the required performance can be reached, if the offline components used are carefully designed and optimized ...

  10. Measurement of the inclusive pp→Z/γ*→e+e- cross section at √(s)=7 TeV with the ATLAS experiment and design studies for a first level track trigger for the ATLAS trigger upgrade at the future high luminosity LHC

    International Nuclear Information System (INIS)

    This dissertation presents in the first part a measurement of the inclusive pp→ Z/gamma*→e+e- production cross section with the ATLAS experiment at the Large Hadron Collider (LHC). For this, proton-proton collisions at a center-of-mass energy of √(s)=7 TeV collected in 2011 corresponding to an integrated luminosity of 4.6 fb-1 are analyzed. The cross section is determined in three regions of Z/γ* mass, 46-66 GeV, 66-116 GeV and 116-150 GeV; and in addition differentially in Z/γ* rapidity. The mass determines the scale of the interaction, whereas the rapidity gives information about the momentum fractions of the initial protons the interacting partons carry. This makes the measurement valuable for the study of the proton structure, i.e. as input to fits of parton density functions (PDF). Backgrounds are taken from simulation with the exception of the multi-jet background which is estimated using a data-driven technique. The resulting cross sections are compared to predictions of next-to next-to-leading order QCD calculations using different PDFs. Differences are observed and only some PDFs show good agreement with the data. The presented measurement can thus be used in future PDF fits to better constrain the quark and gluon densities in the proton. The second part studies a possible design for adding track information to the first level trigger of the ATLAS detector in the scope of the proposed upgrade of the LHC, the High Luminosity LHC (HL-LHC). The planned increase in luminosity by a factor 5-10 w.r.t. the nominal LHC conditions puts strong demands on the rejection capability of the trigger. Using track information in conjunction with information from the calorimeter and muon system helps to maintain pT thresholds at the electroweak scale. A fast decision within the trigger latency can be achieved exploiting hardware based pattern matching using Content-Addressable-Memories. The number of necessary patterns and the expected number of fake tracks per event

  11. The Performance and Development of the ATLAS Inner Detector Trigger

    CERN Document Server

    Washbrook, A; The ATLAS collaboration

    2014-01-01

    A description of the ATLAS Inner Detector (ID) software trigger algorithms and the performance of the ID trigger for LHC Run 1 are presented, as well as prospects for a redesign of the tracking algorithms in Run 2. The ID trigger HLT algorithms are essential for a large number of signatures within the ATLAS trigger. During the shutdown, modifications are being made to the LHC machine, to increase both the beam energy and luminosity. This in turn poses significant challenges for the trigger algorithms both in terms of execution time and physics performance. To meet these challenges the ATLAS HLT software is being restructured to run as a single stage rather than in the two distinct levels present during the Run 1 operation. This is allowing the tracking algorithms to be redesigned to make more optimal use of the CPU resources available and integrate new detector systems being added to ATLAS for post-shutdown running. Expected future improvements in the timing and efficiencies of the Inner Detector triggers wit...

  12. Commissioning of the ATLAS Level-1 Central Trigger

    CERN Document Server

    Berge, D; Ellis, N; Farthouat, P; Fischer, G; Haas, S; Haller, J; Maettig, S; Messina, A; Pauly, T; Sherman, D; Spiwoks, R

    2010-01-01

    The ATLAS Level-1 Central Trigger (L1CT) consists of the Central Trigger Processor (CTP) and the Muon to Central Trigger Processor Interface (MUCTPI). The CTP forms the final Level-1 Accept (L1A) decision based on the information received from the Level-1 Calorimeter Trigger system and from the muon trigger system through the MUCTPI. Additional inputs are provided for the forward detectors, the filled-bunch trigger, and the minimum-bias trigger scintillators. The CTP also receives timing signals from the Large Hadron Collider (LHC) machine. It fans out the L1A together with timing and control signals to the Local Trigger Processor (LTP) of the subdetectors. Via the same connections it receives the Busy signal to throttle the Level-1 generation. Upon generation of L1A the L1CT sends trigger summary information to the DAQ and Region-of-Interest to the Level-2 Trigger system. In this contribution we present an overview of the final L1CT trigger system as it is now installed in the ATLAS experiment and we describ...

  13. The performance of the jet trigger for the ATLAS detector during 2011 data taking

    CERN Document Server

    Aad, Georges; Abdallah, Jalal; Abdinov, Ovsat; Abeloos, Baptiste; Aben, Rosemarie; Abolins, Maris; AbouZeid, Ossama; Abraham, Nicola; Abramowicz, Halina; Abreu, Henso; Abreu, Ricardo; Abulaiti, Yiming; Acharya, Bobby Samir; Adamczyk, Leszek; Adams, David; Adelman, Jahred; Adomeit, Stefanie; Adye, Tim; Affolder, Tony; Agatonovic-Jovin, Tatjana; Agricola, Johannes; Aguilar-Saavedra, Juan Antonio; Ahlen, Steven; Ahmadov, Faig; Aielli, Giulio; Akerstedt, Henrik; Åkesson, Torsten Paul Ake; Akimov, Andrei; Alberghi, Gian Luigi; Albert, Justin; Albrand, Solveig; Alconada Verzini, Maria Josefina; Aleksa, Martin; Aleksandrov, Igor; Alexa, Calin; Alexander, Gideon; Alexopoulos, Theodoros; Alhroob, Muhammad; Aliev, Malik; Alimonti, Gianluca; Alison, John; Alkire, Steven Patrick; Allbrooke, Benedict; Allen, Benjamin William; Allport, Phillip; Aloisio, Alberto; Alonso, Alejandro; Alonso, Francisco; Alpigiani, Cristiano; Alvarez Gonzalez, Barbara; Άlvarez Piqueras, Damián; Alviggi, Mariagrazia; Amadio, Brian Thomas; Amako, Katsuya; Amaral Coutinho, Yara; Amelung, Christoph; Amidei, Dante; Amor Dos Santos, Susana Patricia; Amorim, Antonio; Amoroso, Simone; Amram, Nir; Amundsen, Glenn; Anastopoulos, Christos; Ancu, Lucian Stefan; Andari, Nansi; Andeen, Timothy; Anders, Christoph Falk; Anders, Gabriel; Anders, John Kenneth; Anderson, Kelby; Andreazza, Attilio; Andrei, George Victor; Angelidakis, Stylianos; Angelozzi, Ivan; Anger, Philipp; Angerami, Aaron; Anghinolfi, Francis; Anisenkov, Alexey; Anjos, Nuno; Annovi, Alberto; Antonelli, Mario; Antonov, Alexey; Antos, Jaroslav; Anulli, Fabio; Aoki, Masato; Aperio Bella, Ludovica; Arabidze, Giorgi; Arai, Yasuo; Araque, Juan Pedro; Arce, Ayana; Arduh, Francisco Anuar; Arguin, Jean-Francois; Argyropoulos, Spyridon; Arik, Metin; Armbruster, Aaron James; Armitage, Lewis James; Arnaez, Olivier; Arnold, Hannah; Arratia, Miguel; Arslan, Ozan; Artamonov, Andrei; Artoni, Giacomo; Artz, Sebastian; Asai, Shoji; Asbah, Nedaa; Ashkenazi, Adi; Åsman, Barbro; Asquith, Lily; Assamagan, Ketevi; Astalos, Robert; Atkinson, Markus; Atlay, Naim Bora; Augsten, Kamil; Avolio, Giuseppe; Axen, Bradley; Ayoub, Mohamad Kassem; Azuelos, Georges; Baak, Max; Baas, Alessandra; Baca, Matthew John; Bachacou, Henri; Bachas, Konstantinos; Backes, Moritz; Backhaus, Malte; Bagiacchi, Paolo; Bagnaia, Paolo; Bai, Yu; Baines, John; Baker, Oliver Keith; Baldin, Evgenii; Balek, Petr; Balestri, Thomas; Balli, Fabrice; Balunas, William Keaton; Banas, Elzbieta; Banerjee, Swagato; Bannoura, Arwa A E; Barak, Liron; Barberio, Elisabetta Luigia; Barberis, Dario; Barbero, Marlon; Barillari, Teresa; Barklow, Timothy; Barlow, Nick; Barnes, Sarah Louise; Barnett, Bruce; Barnett, Michael; Barnovska, Zuzana; Baroncelli, Antonio; Barone, Gaetano; Barr, Alan; Barranco Navarro, Laura; Barreiro, Fernando; Barreiro Guimarães da Costa, João; Bartoldus, Rainer; Barton, Adam Edward; Bartos, Pavol; Basalaev, Artem; Bassalat, Ahmed; Basye, Austin; Bates, Richard; Batista, Santiago Juan; Batley, Richard; Battaglia, Marco; Bauce, Matteo; Bauer, Florian; Bawa, Harinder Singh; Beacham, James; Beattie, Michael David; Beau, Tristan; Beauchemin, Pierre-Hugues; Bechtle, Philip; Beck, Hans~Peter; Becker, Kathrin; Becker, Maurice; Beckingham, Matthew; Becot, Cyril; Beddall, Andrew; Beddall, Ayda; Bednyakov, Vadim; Bedognetti, Matteo; Bee, Christopher; Beemster, Lars; Beermann, Thomas; Begel, Michael; Behr, Janna Katharina; Belanger-Champagne, Camille; Bell, Andrew Stuart; Bella, Gideon; Bellagamba, Lorenzo; Bellerive, Alain; Bellomo, Massimiliano; Belotskiy, Konstantin; Beltramello, Olga; Belyaev, Nikita; Benary, Odette; Benchekroun, Driss; Bender, Michael; Bendtz, Katarina; Benekos, Nektarios; Benhammou, Yan; Benhar Noccioli, Eleonora; Benitez, Jose; Benitez Garcia, Jorge-Armando; Benjamin, Douglas; Bensinger, James; Bentvelsen, Stan; Beresford, Lydia; Beretta, Matteo; Berge, David; Bergeaas Kuutmann, Elin; Berger, Nicolas; Berghaus, Frank; Beringer, Jürg; Berlendis, Simon; Bernard, Nathan Rogers; Bernius, Catrin; Bernlochner, Florian Urs; Berry, Tracey; Berta, Peter; Bertella, Claudia; Bertoli, Gabriele; Bertolucci, Federico; Bertram, Iain Alexander; Bertsche, Carolyn; Bertsche, David; Besjes, Geert-Jan; Bessidskaia Bylund, Olga; Bessner, Martin Florian; Besson, Nathalie; Betancourt, Christopher; Bethke, Siegfried; Bevan, Adrian John; Bhimji, Wahid; Bianchi, Riccardo-Maria; Bianchini, Louis; Bianco, Michele; Biebel, Otmar; Biedermann, Dustin; Bielski, Rafal; Biesuz, Nicolo Vladi; Biglietti, Michela; Bilbao De Mendizabal, Javier; Bilokon, Halina; Bindi, Marcello; Binet, Sebastien; Bingul, Ahmet; Bini, Cesare; Biondi, Silvia; Bjergaard, David Martin; Black, Curtis; Black, James; Black, Kevin; Blackburn, Daniel; Blair, Robert; Blanchard, Jean-Baptiste; Blanco, Jacobo Ezequiel; Blazek, Tomas; Bloch, Ingo; Blocker, Craig; Blum, Walter; Blumenschein, Ulrike; Blunier, Sylvain; Bobbink, Gerjan; Bobrovnikov, Victor; Bocchetta, Simona Serena; Bocci, Andrea; Bock, Christopher; Boehler, Michael; Boerner, Daniela; Bogaerts, Joannes Andreas; Bogavac, Danijela; Bogdanchikov, Alexander; Bohm, Christian; Boisvert, Veronique; Bold, Tomasz; Boldea, Venera; Boldyrev, Alexey; Bomben, Marco; Bona, Marcella; Boonekamp, Maarten; Borisov, Anatoly; Borissov, Guennadi; Bortfeldt, Jonathan; Bortoletto, Daniela; Bortolotto, Valerio; Bos, Kors; Boscherini, Davide; Bosman, Martine; Bossio Sola, Jonathan David; Boudreau, Joseph; Bouffard, Julian; Bouhova-Thacker, Evelina Vassileva; Boumediene, Djamel Eddine; Bourdarios, Claire; Boutle, Sarah Kate; Boveia, Antonio; Boyd, James; Boyko, Igor; Bracinik, Juraj; Brandt, Andrew; Brandt, Gerhard; Brandt, Oleg; Bratzler, Uwe; Brau, Benjamin; Brau, James; Braun, Helmut; Breaden Madden, William Dmitri; Brendlinger, Kurt; Brennan, Amelia Jean; Brenner, Lydia; Brenner, Richard; Bressler, Shikma; Bristow, Timothy Michael; Britton, Dave; Britzger, Daniel; Brochu, Frederic; Brock, Ian; Brock, Raymond; Brooijmans, Gustaaf; Brooks, Timothy; Brooks, William; Brosamer, Jacquelyn; Brost, Elizabeth; Broughton, James; Bruckman de Renstrom, Pawel; Bruncko, Dusan; Bruneliere, Renaud; Bruni, Alessia; Bruni, Graziano; Brunt, Benjamin; Bruschi, Marco; Bruscino, Nello; Bryant, Patrick; Bryngemark, Lene; Buanes, Trygve; Buat, Quentin; Buchholz, Peter; Buckley, Andrew; Budagov, Ioulian; Buehrer, Felix; Bugge, Magnar Kopangen; Bulekov, Oleg; Bullock, Daniel; Burckhart, Helfried; Burdin, Sergey; Burgard, Carsten Daniel; Burghgrave, Blake; Burka, Klaudia; Burke, Stephen; Burmeister, Ingo; Busato, Emmanuel; Büscher, Daniel; Büscher, Volker; Bussey, Peter; Butler, John; Butt, Aatif Imtiaz; Buttar, Craig; Butterworth, Jonathan; Butti, Pierfrancesco; Buttinger, William; Buzatu, Adrian; Buzykaev, Aleksey; Cabrera Urbán, Susana; Caforio, Davide; Cairo, Valentina; Cakir, Orhan; Calace, Noemi; Calafiura, Paolo; Calandri, Alessandro; Calderini, Giovanni; Calfayan, Philippe; Caloba, Luiz; Calvet, David; Calvet, Samuel; Calvet, Thomas Philippe; Camacho Toro, Reina; Camarda, Stefano; Camarri, Paolo; Cameron, David; Caminal Armadans, Roger; Camincher, Clement; Campana, Simone; Campanelli, Mario; Campoverde, Angel; Canale, Vincenzo; Canepa, Anadi; Cano Bret, Marc; Cantero, Josu; Cantrill, Robert; Cao, Tingting; Capeans Garrido, Maria Del Mar; Caprini, Irinel; Caprini, Mihai; Capua, Marcella; Caputo, Regina; Carbone, Ryne Michael; Cardarelli, Roberto; Cardillo, Fabio; Carli, Ina; Carli, Tancredi; Carlino, Gianpaolo; Carminati, Leonardo; Caron, Sascha; Carquin, Edson; Carrillo-Montoya, German D; Carter, Janet; Carvalho, João; Casadei, Diego; Casado, Maria Pilar; Casolino, Mirkoantonio; Casper, David William; Castaneda-Miranda, Elizabeth; Castelli, Angelantonio; Castillo Gimenez, Victoria; Castro, Nuno Filipe; Catinaccio, Andrea; Catmore, James; Cattai, Ariella; Caudron, Julien; Cavaliere, Viviana; Cavallaro, Emanuele; Cavalli, Donatella; Cavalli-Sforza, Matteo; Cavasinni, Vincenzo; Ceradini, Filippo; Cerda Alberich, Leonor; Cerio, Benjamin; Cerqueira, Augusto Santiago; Cerri, Alessandro; Cerrito, Lucio; Cerutti, Fabio; Cerv, Matevz; Cervelli, Alberto; Cetin, Serkant Ali; Chafaq, Aziz; Chakraborty, Dhiman; Chan, Stephen Kam-wah; Chan, Yat Long; Chang, Philip; Chapman, John Derek; Charlton, Dave; Chatterjee, Avishek; Chau, Chav Chhiv; Chavez Barajas, Carlos Alberto; Che, Siinn; Cheatham, Susan; Chegwidden, Andrew; Chekanov, Sergei; Chekulaev, Sergey; Chelkov, Gueorgui; Chelstowska, Magda Anna; Chen, Chunhui; Chen, Hucheng; Chen, Karen; Chen, Shenjian; Chen, Shion; Chen, Xin; Chen, Ye; Cheng, Hok Chuen; Cheng, Huajie; Cheng, Yangyang; Cheplakov, Alexander; Cheremushkina, Evgenia; Cherkaoui El Moursli, Rajaa; Chernyatin, Valeriy; Cheu, Elliott; Chevalier, Laurent; Chiarella, Vitaliano; Chiarelli, Giorgio; Chiodini, Gabriele; Chisholm, Andrew; Chitan, Adrian; Chizhov, Mihail; Choi, Kyungeon; Chomont, Arthur Rene; Chouridou, Sofia; Chow, Bonnie Kar Bo; Christodoulou, Valentinos; Chromek-Burckhart, Doris; Chudoba, Jiri; Chuinard, Annabelle Julia; Chwastowski, Janusz; Chytka, Ladislav; Ciapetti, Guido; Ciftci, Abbas Kenan; Cinca, Diane; Cindro, Vladimir; Cioara, Irina Antonela; Ciocio, Alessandra; Cirotto, Francesco; Citron, Zvi Hirsh; Ciubancan, Mihai; Clark, Allan G; Clark, Brian Lee; Clark, Michael; Clark, Philip James; Clarke, Robert; Clement, Christophe; Coadou, Yann; Cobal, Marina; Coccaro, Andrea; Cochran, James H; Coffey, Laurel; Colasurdo, Luca; Cole, Brian; Cole, Stephen; Colijn, Auke-Pieter; Collot, Johann; Colombo, Tommaso; Compostella, Gabriele; Conde Muiño, Patricia; Coniavitis, Elias; Connell, Simon Henry; Connelly, Ian; Consorti, Valerio; Constantinescu, Serban; Conta, Claudio; Conti, Geraldine; Conventi, Francesco; Cooke, Mark; Cooper, Ben; Cooper-Sarkar, Amanda; Cornelissen, Thijs; Corradi, Massimo; Corriveau, Francois; Corso-Radu, Alina; Cortes-Gonzalez, Arely; Cortiana, Giorgio; Costa, Giuseppe; Costa, María José; Costanzo, Davide; Cottin, Giovanna; Cowan, Glen; Cox, Brian; Cranmer, Kyle; Crawley, Samuel Joseph; Cree, Graham; Crépé-Renaudin, Sabine; Crescioli, Francesco; Cribbs, Wayne Allen; Crispin Ortuzar, Mireia; Cristinziani, Markus; Croft, Vince; Crosetti, Giovanni; Cuhadar Donszelmann, Tulay; Cummings, Jane; Curatolo, Maria; Cúth, Jakub; Cuthbert, Cameron; Czirr, Hendrik; Czodrowski, Patrick; D'Auria, Saverio; D'Onofrio, Monica; Da Cunha Sargedas De Sousa, Mario Jose; Da Via, Cinzia; Dabrowski, Wladyslaw; Dai, Tiesheng; Dale, Orjan; Dallaire, Frederick; Dallapiccola, Carlo; Dam, Mogens; Dandoy, Jeffrey Rogers; Dang, Nguyen Phuong; Daniells, Andrew Christopher; Dann, Nicholas Stuart; Danninger, Matthias; Dano Hoffmann, Maria; Dao, Valerio; Darbo, Giovanni; Darmora, Smita; Dassoulas, James; Dattagupta, Aparajita; Davey, Will; David, Claire; Davidek, Tomas; Davies, Merlin; Davison, Peter; Davygora, Yuriy; Dawe, Edmund; Dawson, Ian; Daya-Ishmukhametova, Rozmin; De, Kaushik; de Asmundis, Riccardo; De Benedetti, Abraham; De Castro, Stefano; De Cecco, Sandro; De Groot, Nicolo; de Jong, Paul; De la Torre, Hector; De Lorenzi, Francesco; De Pedis, Daniele; De Salvo, Alessandro; De Sanctis, Umberto; De Santo, Antonella; De Vivie De Regie, Jean-Baptiste; Dearnaley, William James; Debbe, Ramiro; Debenedetti, Chiara; Dedovich, Dmitri; Deigaard, Ingrid; Del Peso, Jose; Del Prete, Tarcisio; Delgove, David; Deliot, Frederic; Delitzsch, Chris Malena; Deliyergiyev, Maksym; Dell'Acqua, Andrea; Dell'Asta, Lidia; Dell'Orso, Mauro; Della Pietra, Massimo; della Volpe, Domenico; Delmastro, Marco; Delsart, Pierre-Antoine; Deluca, Carolina; DeMarco, David; Demers, Sarah; Demichev, Mikhail; Demilly, Aurelien; Denisov, Sergey; Denysiuk, Denys; Derendarz, Dominik; Derkaoui, Jamal Eddine; Derue, Frederic; Dervan, Paul; Desch, Klaus Kurt; Deterre, Cecile; Dette, Karola; Deviveiros, Pier-Olivier; Dewhurst, Alastair; Dhaliwal, Saminder; Di Ciaccio, Anna; Di Ciaccio, Lucia; Di Clemente, William Kennedy; Di Donato, Camilla; Di Girolamo, Alessandro; Di Girolamo, Beniamino; Di Micco, Biagio; Di Nardo, Roberto; Di Simone, Andrea; Di Sipio, Riccardo; Di Valentino, David; Diaconu, Cristinel; Diamond, Miriam; Dias, Flavia; Diaz, Marco Aurelio; Diehl, Edward; Dietrich, Janet; Diglio, Sara; Dimitrievska, Aleksandra; Dingfelder, Jochen; Dita, Petre; Dita, Sanda; Dittus, Fridolin; Djama, Fares; Djobava, Tamar; Djuvsland, Julia Isabell; do Vale, Maria Aline Barros; Dobos, Daniel; Dobre, Monica; Doglioni, Caterina; Dohmae, Takeshi; Dolejsi, Jiri; Dolezal, Zdenek; Dolgoshein, Boris; Donadelli, Marisilvia; Donati, Simone; Dondero, Paolo; Donini, Julien; Dopke, Jens; Doria, Alessandra; Dova, Maria-Teresa; Doyle, Tony; Drechsler, Eric; Dris, Manolis; Du, Yanyan; Duarte-Campderros, Jorge; Duchovni, Ehud; Duckeck, Guenter; Ducu, Otilia Anamaria; Duda, Dominik; Dudarev, Alexey; Duflot, Laurent; Duguid, Liam; Dührssen, Michael; Dunford, Monica; Duran Yildiz, Hatice; Düren, Michael; Durglishvili, Archil; Duschinger, Dirk; Dutta, Baishali; Dyndal, Mateusz; Eckardt, Christoph; Ecker, Katharina Maria; Edgar, Ryan Christopher; Edson, William; Edwards, Nicholas Charles; Eifert, Till; Eigen, Gerald; Einsweiler, Kevin; Ekelof, Tord; El Kacimi, Mohamed; Ellajosyula, Venugopal; Ellert, Mattias; Elles, Sabine; Ellinghaus, Frank; Elliot, Alison; Ellis, Nicolas; Elmsheuser, Johannes; Elsing, Markus; Emeliyanov, Dmitry; Enari, Yuji; Endner, Oliver Chris; Endo, Masaki; Ennis, Joseph Stanford; Erdmann, Johannes; Ereditato, Antonio; Ernis, Gunar; Ernst, Jesse; Ernst, Michael; Errede, Steven; Ertel, Eugen; Escalier, Marc; Esch, Hendrik; Escobar, Carlos; Esposito, Bellisario; Etienvre, Anne-Isabelle; Etzion, Erez; Evans, Hal; Ezhilov, Alexey; Fabbri, Federica; Fabbri, Laura; Facini, Gabriel; Fakhrutdinov, Rinat; Falciano, Speranza; Falla, Rebecca Jane; Faltova, Jana; Fang, Yaquan; Fanti, Marcello; Farbin, Amir; Farilla, Addolorata; Farina, Christian; Farooque, Trisha; Farrell, Steven; Farrington, Sinead; Farthouat, Philippe; Fassi, Farida; Fassnacht, Patrick; Fassouliotis, Dimitrios; Faucci Giannelli, Michele; Favareto, Andrea; Fawcett, William James; Fayard, Louis; Fedin, Oleg; Fedorko, Wojciech; Feigl, Simon; Feligioni, Lorenzo; Feng, Cunfeng; Feng, Eric; Feng, Haolu; Fenyuk, Alexander; Feremenga, Last; Fernandez Martinez, Patricia; Fernandez Perez, Sonia; Ferrando, James; Ferrari, Arnaud; Ferrari, Pamela; Ferrari, Roberto; Ferreira de Lima, Danilo Enoque; Ferrer, Antonio; Ferrere, Didier; Ferretti, Claudio; Ferretto Parodi, Andrea; Fiedler, Frank; Filipčič, Andrej; Filipuzzi, Marco; Filthaut, Frank; Fincke-Keeler, Margret; Finelli, Kevin Daniel; Fiolhais, Miguel; Fiorini, Luca; Firan, Ana; Fischer, Adam; Fischer, Cora; Fischer, Julia; Fisher, Wade Cameron; Flaschel, Nils; Fleck, Ivor; Fleischmann, Philipp; Fletcher, Gareth Thomas; Fletcher, Gregory; Fletcher, Rob Roy MacGregor; Flick, Tobias; Floderus, Anders; Flores Castillo, Luis; Flowerdew, Michael; Forcolin, Giulio Tiziano; Formica, Andrea; Forti, Alessandra; Foster, Andrew Geoffrey; Fournier, Daniel; Fox, Harald; Fracchia, Silvia; Francavilla, Paolo; Franchini, Matteo; Francis, David; Franconi, Laura; Franklin, Melissa; Frate, Meghan; Fraternali, Marco; Freeborn, David; Fressard-Batraneanu, Silvia; Friedrich, Felix; Froidevaux, Daniel; Frost, James; Fukunaga, Chikara; Fullana Torregrosa, Esteban; Fusayasu, Takahiro; Fuster, Juan; Gabaldon, Carolina; Gabizon, Ofir; Gabrielli, Alessandro; Gabrielli, Andrea; Gach, Grzegorz; Gadatsch, Stefan; Gadomski, Szymon; Gagliardi, Guido; Gagnon, Louis Guillaume; Gagnon, Pauline; Galea, Cristina; Galhardo, Bruno; Gallas, Elizabeth; Gallop, Bruce; Gallus, Petr; Galster, Gorm Aske Gram Krohn; Gan, KK; Gao, Jun; Gao, Yanyan; Gao, Yongsheng; Garay Walls, Francisca; García, Carmen; García Navarro, José Enrique; Garcia-Sciveres, Maurice; Gardner, Robert; Garelli, Nicoletta; Garonne, Vincent; Gascon Bravo, Alberto; Gatti, Claudio; Gaudiello, Andrea; Gaudio, Gabriella; Gaur, Bakul; Gauthier, Lea; Gavrilenko, Igor; Gay, Colin; Gaycken, Goetz; Gazis, Evangelos; Gecse, Zoltan; Gee, Norman; Geich-Gimbel, Christoph; Geisler, Manuel Patrice; Gemme, Claudia; Genest, Marie-Hélène; Geng, Cong; Gentile, Simonetta; George, Simon; Gerbaudo, Davide; Gershon, Avi; Ghasemi, Sara; Ghazlane, Hamid; Ghneimat, Mazuza; Giacobbe, Benedetto; Giagu, Stefano; Giannetti, Paola; Gibbard, Bruce; Gibson, Stephen; Gignac, Matthew; Gilchriese, Murdock; Gillam, Thomas; Gillberg, Dag; Gilles, Geoffrey; Gingrich, Douglas; Giokaris, Nikos; Giordani, MarioPaolo; Giorgi, Filippo Maria; Giorgi, Francesco Michelangelo; Giraud, Pierre-Francois; Giromini, Paolo; Giugni, Danilo; Giuli, Francesco; Giuliani, Claudia; Giulini, Maddalena; Gjelsten, Børge Kile; Gkaitatzis, Stamatios; Gkialas, Ioannis; Gkougkousis, Evangelos Leonidas; Gladilin, Leonid; Glasman, Claudia; Glatzer, Julian; Glaysher, Paul; Glazov, Alexandre; Goblirsch-Kolb, Maximilian; Godlewski, Jan; Goldfarb, Steven; Golling, Tobias; Golubkov, Dmitry; Gomes, Agostinho; Gonçalo, Ricardo; Goncalves Pinto Firmino Da Costa, Joao; Gonella, Laura; Gongadze, Alexi; González de la Hoz, Santiago; Gonzalez Parra, Garoe; Gonzalez-Sevilla, Sergio; Goossens, Luc; Gorbounov, Petr Andreevich; Gordon, Howard; Gorelov, Igor; Gorini, Benedetto; Gorini, Edoardo; Gorišek, Andrej; Gornicki, Edward; Goshaw, Alfred; Gössling, Claus; Gostkin, Mikhail Ivanovitch; Goudet, Christophe Raymond; Goujdami, Driss; Goussiou, Anna; Govender, Nicolin; Gozani, Eitan; Graber, Lars; Grabowska-Bold, Iwona; Gradin, Per Olov Joakim; Grafström, Per; Gramling, Johanna; Gramstad, Eirik; Grancagnolo, Sergio; Gratchev, Vadim; Gray, Heather; Graziani, Enrico; Greenwood, Zeno Dixon; Grefe, Christian; Gregersen, Kristian; Gregor, Ingrid-Maria; Grenier, Philippe; Grevtsov, Kirill; Griffiths, Justin; Grillo, Alexander; Grimm, Kathryn; Grinstein, Sebastian; Gris, Philippe Luc Yves; Grivaz, Jean-Francois; Groh, Sabrina; Grohs, Johannes Philipp; Gross, Eilam; Grosse-Knetter, Joern; Grossi, Giulio Cornelio; Grout, Zara Jane; Guan, Liang; Guan, Wen; Guenther, Jaroslav; Guescini, Francesco; Guest, Daniel; Gueta, Orel; Guido, Elisa; Guillemin, Thibault; Guindon, Stefan; Gul, Umar; Gumpert, Christian; Guo, Jun; Guo, Yicheng; Gupta, Shaun; Gustavino, Giuliano; Gutierrez, Phillip; Gutierrez Ortiz, Nicolas Gilberto; Gutschow, Christian; Guyot, Claude; Gwenlan, Claire; Gwilliam, Carl; Haas, Andy; Haber, Carl; Hadavand, Haleh Khani; Haddad, Nacim; Hadef, Asma; Haefner, Petra; Hageböck, Stephan; Hajduk, Zbigniew; Hakobyan, Hrachya; Haleem, Mahsana; Haley, Joseph; Hall, David; Halladjian, Garabed; Hallewell, Gregory David; Hamacher, Klaus; Hamal, Petr; Hamano, Kenji; Hamilton, Andrew; Hamity, Guillermo Nicolas; Hamnett, Phillip George; Han, Liang; Hanagaki, Kazunori; Hanawa, Keita; Hance, Michael; Haney, Bijan; Hanke, Paul; Hanna, Remie; Hansen, Jørgen Beck; Hansen, Jorn Dines; Hansen, Maike Christina; Hansen, Peter Henrik; Hara, Kazuhiko; Hard, Andrew; Harenberg, Torsten; Hariri, Faten; Harkusha, Siarhei; Harrington, Robert; Harrison, Paul Fraser; Hartjes, Fred; Hasegawa, Makoto; Hasegawa, Yoji; Hasib, A; Hassani, Samira; Haug, Sigve; Hauser, Reiner; Hauswald, Lorenz; Havranek, Miroslav; Hawkes, Christopher; Hawkings, Richard John; Hawkins, Anthony David; Hayden, Daniel; Hays, Chris; Hays, Jonathan Michael; Hayward, Helen; Haywood, Stephen; Head, Simon; Heck, Tobias; Hedberg, Vincent; Heelan, Louise; Heim, Sarah; Heim, Timon; Heinemann, Beate; Heinrich, Jochen Jens; Heinrich, Lukas; Heinz, Christian; Hejbal, Jiri; Helary, Louis; Hellman, Sten; Helsens, Clement; Henderson, James; Henderson, Robert; Heng, Yang; Henkelmann, Steffen; Henriques Correia, Ana Maria; Henrot-Versille, Sophie; Herbert, Geoffrey Henry; Hernández Jiménez, Yesenia; Herten, Gregor; Hertenberger, Ralf; Hervas, Luis; Hesketh, Gavin Grant; Hessey, Nigel; Hetherly, Jeffrey Wayne; Hickling, Robert; Higón-Rodriguez, Emilio; Hill, Ewan; Hill, John; Hiller, Karl Heinz; Hillier, Stephen; Hinchliffe, Ian; Hines, Elizabeth; Hinman, Rachel Reisner; Hirose, Minoru; Hirschbuehl, Dominic; Hobbs, John; Hod, Noam; Hodgkinson, Mark; Hodgson, Paul; Hoecker, Andreas; Hoeferkamp, Martin; Hoenig, Friedrich; Hohlfeld, Marc; Hohn, David; Holmes, Tova Ray; Homann, Michael; Hong, Tae Min; Hooberman, Benjamin Henry; Hopkins, Walter; Horii, Yasuyuki; Horton, Arthur James; Hostachy, Jean-Yves; Hou, Suen; Hoummada, Abdeslam; Howard, Jacob; Howarth, James; Hrabovsky, Miroslav; Hristova, Ivana; Hrivnac, Julius; Hryn'ova, Tetiana; Hrynevich, Aliaksei; Hsu, Catherine; Hsu, Pai-hsien Jennifer; Hsu, Shih-Chieh; Hu, Diedi; Hu, Qipeng; Huang, Yanping; Hubacek, Zdenek; Hubaut, Fabrice; Huegging, Fabian; Huffman, Todd Brian; Hughes, Emlyn; Hughes, Gareth; Huhtinen, Mika; Hülsing, Tobias Alexander; Huseynov, Nazim; Huston, Joey; Huth, John; Iacobucci, Giuseppe; Iakovidis, Georgios; Ibragimov, Iskander; Iconomidou-Fayard, Lydia; Ideal, Emma; Idrissi, Zineb; Iengo, Paolo; Igonkina, Olga; Iizawa, Tomoya; Ikegami, Yoichi; Ikeno, Masahiro; Ilchenko, Iurii; Iliadis, Dimitrios; Ilic, Nikolina; Ince, Tayfun; Introzzi, Gianluca; Ioannou, Pavlos; Iodice, Mauro; Iordanidou, Kalliopi; Ippolito, Valerio; Irles Quiles, Adrian; Isaksson, Charlie; Ishino, Masaya; Ishitsuka, Masaki; Ishmukhametov, Renat; Issever, Cigdem; Istin, Serhat; Ito, Fumiaki; Iturbe Ponce, Julia Mariana; Iuppa, Roberto; Ivarsson, Jenny; Iwanski, Wieslaw; Iwasaki, Hiroyuki; Izen, Joseph; Izzo, Vincenzo; Jabbar, Samina; Jackson, Brett; Jackson, Matthew; Jackson, Paul; Jain, Vivek; Jakobi, Katharina Bianca; Jakobs, Karl; Jakobsen, Sune; Jakoubek, Tomas; Jamin, David Olivier; Jana, Dilip; Jansen, Eric; Jansky, Roland; Janssen, Jens; Janus, Michel; Jarlskog, Göran; Javadov, Namig; Javůrek, Tomáš; Jeanneau, Fabien; Jeanty, Laura; Jejelava, Juansher; Jeng, Geng-yuan; Jennens, David; Jenni, Peter; Jentzsch, Jennifer; Jeske, Carl; Jézéquel, Stéphane; Ji, Haoshuang; Jia, Jiangyong; Jiang, Hai; Jiang, Yi; Jiggins, Stephen; Jimenez Pena, Javier; Jin, Shan; Jinaru, Adam; Jinnouchi, Osamu; Johansson, Per; Johns, Kenneth; Johnson, William Joseph; Jon-And, Kerstin; Jones, Graham; Jones, Roger; Jones, Sarah; Jones, Tim; Jongmanns, Jan; Jorge, Pedro; Jovicevic, Jelena; Ju, Xiangyang; Juste Rozas, Aurelio; Köhler, Markus Konrad; Kaczmarska, Anna; Kado, Marumi; Kagan, Harris; Kagan, Michael; Kahn, Sebastien Jonathan; Kajomovitz, Enrique; Kalderon, Charles William; Kaluza, Adam; Kama, Sami; Kamenshchikov, Andrey; Kanaya, Naoko; Kaneti, Steven; Kantserov, Vadim; Kanzaki, Junichi; Kaplan, Benjamin; Kaplan, Laser Seymour; Kapliy, Anton; Kar, Deepak; Karakostas, Konstantinos; Karamaoun, Andrew; Karastathis, Nikolaos; Kareem, Mohammad Jawad; Karentzos, Efstathios; Karnevskiy, Mikhail; Karpov, Sergey; Karpova, Zoya; Karthik, Krishnaiyengar; Kartvelishvili, Vakhtang; Karyukhin, Andrey; Kasahara, Kota; Kashif, Lashkar; Kass, Richard; Kastanas, Alex; Kataoka, Yousuke; Kato, Chikuma; Katre, Akshay; Katzy, Judith; Kawagoe, Kiyotomo; Kawamoto, Tatsuo; Kawamura, Gen; Kazama, Shingo; Kazanin, Vassili; Keeler, Richard; Kehoe, Robert; Keller, John; Kempster, Jacob Julian; Kentaro, Kawade; Keoshkerian, Houry; Kepka, Oldrich; Kerševan, Borut Paul; Kersten, Susanne; Keyes, Robert; Khalil-zada, Farkhad; Khandanyan, Hovhannes; Khanov, Alexander; Kharlamov, Alexey; Khoo, Teng Jian; Khovanskiy, Valery; Khramov, Evgeniy; Khubua, Jemal; Kido, Shogo; Kim, Hee Yeun; Kim, Shinhong; Kim, Young-Kee; Kimura, Naoki; Kind, Oliver Maria; King, Barry; King, Matthew; King, Samuel Burton; Kirk, Julie; Kiryunin, Andrey; Kishimoto, Tomoe; Kisielewska, Danuta; Kiss, Florian; Kiuchi, Kenji; Kivernyk, Oleh; Kladiva, Eduard; Klein, Matthew Henry; Klein, Max; Klein, Uta; Kleinknecht, Konrad; Klimek, Pawel; Klimentov, Alexei; Klingenberg, Reiner; Klinger, Joel Alexander; Klioutchnikova, Tatiana; Kluge, Eike-Erik; Kluit, Peter; Kluth, Stefan; Knapik, Joanna; Kneringer, Emmerich; Knoops, Edith; Knue, Andrea; Kobayashi, Aine; Kobayashi, Dai; Kobayashi, Tomio; Kobel, Michael; Kocian, Martin; Kodys, Peter; Koffas, Thomas; Koffeman, Els; Kogan, Lucy Anne; Koi, Tatsumi; Kolanoski, Hermann; Kolb, Mathis; Koletsou, Iro; Komar, Aston; Komori, Yuto; Kondo, Takahiko; Kondrashova, Nataliia; Köneke, Karsten; König, Adriaan; Kono, Takanori; Konoplich, Rostislav; Konstantinidis, Nikolaos; Kopeliansky, Revital; Koperny, Stefan; Köpke, Lutz; Kopp, Anna Katharina; Korcyl, Krzysztof; Kordas, Kostantinos; Korn, Andreas; Korol, Aleksandr; Korolkov, Ilya; Korolkova, Elena; Kortner, Oliver; Kortner, Sandra; Kosek, Tomas; Kostyukhin, Vadim; Kotwal, Ashutosh; Kourkoumeli-Charalampidi, Athina; Kourkoumelis, Christine; Kouskoura, Vasiliki; Koutsman, Alex; Kowalewska, Anna Bozena; Kowalewski, Robert Victor; Kowalski, Tadeusz; Kozanecki, Witold; Kozhin, Anatoly; Kramarenko, Viktor; Kramberger, Gregor; Krasnopevtsev, Dimitriy; Krasny, Mieczyslaw Witold; Krasznahorkay, Attila; Kraus, Jana; Kravchenko, Anton; Kretz, Moritz; Kretzschmar, Jan; Kreutzfeldt, Kristof; Krieger, Peter; Krizka, Karol; Kroeninger, Kevin; Kroha, Hubert; Kroll, Joe; Kroseberg, Juergen; Krstic, Jelena; Kruchonak, Uladzimir; Krüger, Hans; Krumnack, Nils; Kruse, Amanda; Kruse, Mark; Kruskal, Michael; Kubota, Takashi; Kucuk, Hilal; Kuday, Sinan; Kuechler, Jan Thomas; Kuehn, Susanne; Kugel, Andreas; Kuger, Fabian; Kuhl, Andrew; Kuhl, Thorsten; Kukhtin, Victor; Kukla, Romain; Kulchitsky, Yuri; Kuleshov, Sergey; Kuna, Marine; Kunigo, Takuto; Kupco, Alexander; Kurashige, Hisaya; Kurochkin, Yurii; Kus, Vlastimil; Kuwertz, Emma Sian; Kuze, Masahiro; Kvita, Jiri; Kwan, Tony; Kyriazopoulos, Dimitrios; La Rosa, Alessandro; La Rosa Navarro, Jose Luis; La Rotonda, Laura; Lacasta, Carlos; Lacava, Francesco; Lacey, James; Lacker, Heiko; Lacour, Didier; Lacuesta, Vicente Ramón; Ladygin, Evgueni; Lafaye, Remi; Laforge, Bertrand; Lagouri, Theodota; Lai, Stanley; Lammers, Sabine; Lampl, Walter; Lançon, Eric; Landgraf, Ulrich; Landon, Murrough; Lang, Valerie Susanne; Lange, J örn Christian; Lankford, Andrew; Lanni, Francesco; Lantzsch, Kerstin; Lanza, Agostino; Laplace, Sandrine; Lapoire, Cecile; Laporte, Jean-Francois; Lari, Tommaso; Lasagni Manghi, Federico; Lassnig, Mario; Laurelli, Paolo; Lavrijsen, Wim; Law, Alexander; Laycock, Paul; Lazovich, Tomo; Lazzaroni, Massimo; Le Dortz, Olivier; Le Guirriec, Emmanuel; Le Menedeu, Eve; Le Quilleuc, Eloi; LeBlanc, Matthew Edgar; LeCompte, Thomas; Ledroit-Guillon, Fabienne Agnes Marie; Lee, Claire Alexandra; Lee, Shih-Chang; Lee, Lawrence; Lefebvre, Guillaume; Lefebvre, Michel; Legger, Federica; Leggett, Charles; Lehan, Allan; Lehmann Miotto, Giovanna; Lei, Xiaowen; Leight, William Axel; Leisos, Antonios; Leister, Andrew Gerard; Leite, Marco Aurelio Lisboa; Leitner, Rupert; Lellouch, Daniel; Lemmer, Boris; Leney, Katharine; Lenz, Tatjana; Lenzi, Bruno; Leone, Robert; Leone, Sandra; Leonidopoulos, Christos; Leontsinis, Stefanos; Lerner, Giuseppe; Leroy, Claude; Lesage, Arthur; Lester, Christopher; Levchenko, Mikhail; Levêque, Jessica; Levin, Daniel; Levinson, Lorne; Levy, Mark; Leyko, Agnieszka; Leyton, Michael; Li, Bing; Li, Haifeng; Li, Ho Ling; Li, Lei; Li, Liang; Li, Qi; Li, Shu; Li, Xingguo; Li, Yichen; Liang, Zhijun; Liao, Hongbo; Liberti, Barbara; Liblong, Aaron; Lichard, Peter; Lie, Ki; Liebal, Jessica; Liebig, Wolfgang; Limbach, Christian; Limosani, Antonio; Lin, Simon; Lin, Tai-Hua; Lindquist, Brian Edward; Lipeles, Elliot; Lipniacka, Anna; Lisovyi, Mykhailo; Liss, Tony; Lissauer, David; Lister, Alison; Litke, Alan; Liu, Bo; Liu, Dong; Liu, Hao; Liu, Hongbin; Liu, Jian; Liu, Jianbei; Liu, Kun; Liu, Lulu; Liu, Miaoyuan; Liu, Minghui; Liu, Yanlin; Liu, Yanwen; Livan, Michele; Lleres, Annick; Llorente Merino, Javier; Lloyd, Stephen; Lo Sterzo, Francesco; Lobodzinska, Ewelina; Loch, Peter; Lockman, William; Loebinger, Fred; Loevschall-Jensen, Ask Emil; Loew, Kevin Michael; Loginov, Andrey; Lohse, Thomas; Lohwasser, Kristin; Lokajicek, Milos; Long, Brian Alexander; Long, Jonathan David; Long, Robin Eamonn; Longo, Luigi; Looper, Kristina Anne; Lopes, Lourenco; Lopez Mateos, David; Lopez Paredes, Brais; Lopez Paz, Ivan; Lopez Solis, Alvaro; Lorenz, Jeanette; Lorenzo Martinez, Narei; Losada, Marta; L{ö}sel, Philipp Jonathan; Lou, XinChou; Lounis, Abdenour; Love, Jeremy; Love, Peter; Lu, Haonan; Lu, Nan; Lubatti, Henry; Luci, Claudio; Lucotte, Arnaud; Luedtke, Christian; Luehring, Frederick; Lukas, Wolfgang; Luminari, Lamberto; Lundberg, Olof; Lund-Jensen, Bengt; Lynn, David; Lysak, Roman; Lytken, Else; Lyubushkin, Vladimir; Ma, Hong; Ma, Lian Liang; Ma, Yanhui; Maccarrone, Giovanni; Macchiolo, Anna; Macdonald, Calum Michael; Maček, Boštjan; Machado Miguens, Joana; Madaffari, Daniele; Madar, Romain; Maddocks, Harvey Jonathan; Mader, Wolfgang; Madsen, Alexander; Maeda, Junpei; Maeland, Steffen; Maeno, Tadashi; Maevskiy, Artem; Magradze, Erekle; Mahlstedt, Joern; Maiani, Camilla; Maidantchik, Carmen; Maier, Andreas Alexander; Maier, Thomas; Maio, Amélia; Majewski, Stephanie; Makida, Yasuhiro; Makovec, Nikola; Malaescu, Bogdan; Malecki, Pawel; Maleev, Victor; Malek, Fairouz; Mallik, Usha; Malon, David; Malone, Caitlin; Maltezos, Stavros; Malyukov, Sergei; Mamuzic, Judita; Mancini, Giada; Mandelli, Beatrice; Mandelli, Luciano; Mandić, Igor; Maneira, José; Manhaes de Andrade Filho, Luciano; Manjarres Ramos, Joany; Mann, Alexander; Mansoulie, Bruno; Mantifel, Rodger; Mantoani, Matteo; Manzoni, Stefano; Mapelli, Livio; Marceca, Gino; March, Luis; Marchiori, Giovanni; Marcisovsky, Michal; Marjanovic, Marija; Marley, Daniel; Marroquim, Fernando; Marsden, Stephen Philip; Marshall, Zach; Marti, Lukas Fritz; Marti-Garcia, Salvador; Martin, Brian; Martin, Tim; Martin, Victoria Jane; Martin dit Latour, Bertrand; Martinez, Mario; Martin-Haugh, Stewart; Martoiu, Victor Sorin; Martyniuk, Alex; Marx, Marilyn; Marzano, Francesco; Marzin, Antoine; Masetti, Lucia; Mashimo, Tetsuro; Mashinistov, Ruslan; Masik, Jiri; Maslennikov, Alexey; Massa, Ignazio; Massa, Lorenzo; Mastrandrea, Paolo; Mastroberardino, Anna; Masubuchi, Tatsuya; Mättig, Peter; Mattmann, Johannes; Maurer, Julien; Maxfield, Stephen; Maximov, Dmitriy; Mazini, Rachid; Mazza, Simone Michele; Mc Fadden, Neil Christopher; Mc Goldrick, Garrin; Mc Kee, Shawn Patrick; McCarn, Allison; McCarthy, Robert; McCarthy, Tom; McClymont, Laurie; McFarlane, Kenneth; Mcfayden, Josh; Mchedlidze, Gvantsa; McMahon, Steve; McPherson, Robert; Medinnis, Michael; Meehan, Samuel; Mehlhase, Sascha; Mehta, Andrew; Meier, Karlheinz; Meineck, Christian; Meirose, Bernhard; Mellado Garcia, Bruce Rafael; Meloni, Federico; Mengarelli, Alberto; Menke, Sven; Meoni, Evelin; Mercurio, Kevin Michael; Mergelmeyer, Sebastian; Mermod, Philippe; Merola, Leonardo; Meroni, Chiara; Merritt, Frank; Messina, Andrea; Metcalfe, Jessica; Mete, Alaettin Serhan; Meyer, Carsten; Meyer, Christopher; Meyer, Jean-Pierre; Meyer, Jochen; Meyer Zu Theenhausen, Hanno; Middleton, Robin; Miglioranzi, Silvia; Mijović, Liza; Mikenberg, Giora; Mikestikova, Marcela; Mikuž, Marko; Milesi, Marco; Milic, Adriana; Miller, David; Mills, Corrinne; Milov, Alexander; Milstead, David; Minaenko, Andrey; Minami, Yuto; Minashvili, Irakli; Mincer, Allen; Mindur, Bartosz; Mineev, Mikhail; Ming, Yao; Mir, Lluisa-Maria; Mistry, Khilesh; Mitani, Takashi; Mitrevski, Jovan; Mitsou, Vasiliki A; Miucci, Antonio; Miyagawa, Paul; Mjörnmark, Jan-Ulf; Moa, Torbjoern; Mochizuki, Kazuya; Mohapatra, Soumya; Mohr, Wolfgang; Molander, Simon; Moles-Valls, Regina; Monden, Ryutaro; Mondragon, Matthew Craig; Mönig, Klaus; Monk, James; Monnier, Emmanuel; Montalbano, Alyssa; Montejo Berlingen, Javier; Monticelli, Fernando; Monzani, Simone; Moore, Roger; Morange, Nicolas; Moreno, Deywis; Moreno Llácer, María; Morettini, Paolo; Mori, Daniel; Mori, Tatsuya; Morii, Masahiro; Morinaga, Masahiro; Morisbak, Vanja; Moritz, Sebastian; Morley, Anthony Keith; Mornacchi, Giuseppe; Morris, John; Mortensen, Simon Stark; Morvaj, Ljiljana; Mosidze, Maia; Moss, Josh; Motohashi, Kazuki; Mount, Richard; Mountricha, Eleni; Mouraviev, Sergei; Moyse, Edward; Muanza, Steve; Mudd, Richard; Mueller, Felix; Mueller, James; Mueller, Ralph Soeren Peter; Mueller, Thibaut; Muenstermann, Daniel; Mullen, Paul; Mullier, Geoffrey; Munoz Sanchez, Francisca Javiela; Murillo Quijada, Javier Alberto; Murray, Bill; Musheghyan, Haykuhi; Muškinja, Miha; Myagkov, Alexey; Myska, Miroslav; Nachman, Benjamin Philip; Nackenhorst, Olaf; Nadal, Jordi; Nagai, Koichi; Nagai, Ryo; Nagano, Kunihiro; Nagasaka, Yasushi; Nagata, Kazuki; Nagel, Martin; Nagy, Elemer; Nairz, Armin Michael; Nakahama, Yu; Nakamura, Koji; Nakamura, Tomoaki; Nakano, Itsuo; Namasivayam, Harisankar; Naranjo Garcia, Roger Felipe; Narayan, Rohin; Narrias Villar, Daniel Isaac; Naryshkin, Iouri; Naumann, Thomas; Navarro, Gabriela; Nayyar, Ruchika; Neal, Homer; Nechaeva, Polina; Neep, Thomas James; Nef, Pascal Daniel; Negri, Andrea; Negrini, Matteo; Nektarijevic, Snezana; Nellist, Clara; Nelson, Andrew; Nemecek, Stanislav; Nemethy, Peter; Nepomuceno, Andre Asevedo; Nessi, Marzio; Neubauer, Mark; Neumann, Manuel; Neves, Ricardo; Nevski, Pavel; Newman, Paul; Nguyen, Duong Hai; Nickerson, Richard; Nicolaidou, Rosy; Nicquevert, Bertrand; Nielsen, Jason; Nikiforov, Andriy; Nikolaenko, Vladimir; Nikolic-Audit, Irena; Nikolopoulos, Konstantinos; Nilsen, Jon Kerr; Nilsson, Paul; Ninomiya, Yoichi; Nisati, Aleandro; Nisius, Richard; Nobe, Takuya; Nodulman, Lawrence; Nomachi, Masaharu; Nomidis, Ioannis; Nooney, Tamsin; Norberg, Scarlet; Nordberg, Markus; Norjoharuddeen, Nurfikri; Novgorodova, Olga; Nowak, Sebastian; Nozaki, Mitsuaki; Nozka, Libor; Ntekas, Konstantinos; Nurse, Emily; Nuti, Francesco; O'grady, Fionnbarr; O'Neil, Dugan; O'Rourke, Abigail Alexandra; O'Shea, Val; Oakham, Gerald; Oberlack, Horst; Obermann, Theresa; Ocariz, Jose; Ochi, Atsuhiko; Ochoa, Ines; Ochoa-Ricoux, Juan Pedro; Oda, Susumu; Odaka, Shigeru; Ogren, Harold; Oh, Alexander; Oh, Seog; Ohm, Christian; Ohman, Henrik; Oide, Hideyuki; Okawa, Hideki; Okumura, Yasuyuki; Okuyama, Toyonobu; Olariu, Albert; Oleiro Seabra, Luis Filipe; Olivares Pino, Sebastian Andres; Oliveira Damazio, Denis; Olszewski, Andrzej; Olszowska, Jolanta; Onofre, António; Onogi, Kouta; Onyisi, Peter; Oram, Christopher; Oreglia, Mark; Oren, Yona; Orestano, Domizia; Orlando, Nicola; Orr, Robert; Osculati, Bianca; Ospanov, Rustem; Otero y Garzon, Gustavo; Otono, Hidetoshi; Ouchrif, Mohamed; Ould-Saada, Farid; Ouraou, Ahmimed; Oussoren, Koen Pieter; Ouyang, Qun; Ovcharova, Ana; Owen, Mark; Owen, Rhys Edward; Ozcan, Veysi Erkcan; Ozturk, Nurcan; Pachal, Katherine; Pacheco Pages, Andres; Padilla Aranda, Cristobal; Pagáčová, Martina; Pagan Griso, Simone; Paige, Frank; Pais, Preema; Pajchel, Katarina; Palacino, Gabriel; Palestini, Sandro; Palka, Marek; Pallin, Dominique; Palma, Alberto; Panagiotopoulou, Evgenia; Pandini, Carlo Enrico; Panduro Vazquez, William; Pani, Priscilla; Panitkin, Sergey; Pantea, Dan; Paolozzi, Lorenzo; Papadopoulou, Theodora; Papageorgiou, Konstantinos; Paramonov, Alexander; Paredes Hernandez, Daniela; Parker, Adam Jackson; Parker, Michael Andrew; Parker, Kerry Ann; Parodi, Fabrizio; Parsons, John; Parzefall, Ulrich; Pascuzzi, Vincent; Pasqualucci, Enrico; Passaggio, Stefano; Pastore, Fernanda; Pastore, Francesca; Pásztor, Gabriella; Pataraia, Sophio; Patel, Nikhul; Pater, Joleen; Pauly, Thilo; Pearce, James; Pearson, Benjamin; Pedersen, Lars Egholm; Pedersen, Maiken; Pedraza Lopez, Sebastian; Pedro, Rute; Peleganchuk, Sergey; Pelikan, Daniel; Penc, Ondrej; Peng, Cong; Peng, Haiping; Penwell, John; Peralva, Bernardo; Perego, Marta Maria; Perepelitsa, Dennis; Perez Codina, Estel; Perini, Laura; Pernegger, Heinz; Perrella, Sabrina; Peschke, Richard; Peshekhonov, Vladimir; Peters, Krisztian; Peters, Yvonne; Petersen, Brian; Petersen, Troels; Petit, Elisabeth; Petridis, Andreas; Petridou, Chariclia; Petroff, Pierre; Petrolo, Emilio; Petrov, Mariyan; Petrucci, Fabrizio; Pettersson, Nora Emilia; Peyaud, Alan; Pezoa, Raquel; Phillips, Peter William; Piacquadio, Giacinto; Pianori, Elisabetta; Picazio, Attilio; Piccaro, Elisa; Piccinini, Maurizio; Pickering, Mark Andrew; Piegaia, Ricardo; Pilcher, James; Pilkington, Andrew; Pin, Arnaud Willy J; Pina, João Antonio; Pinamonti, Michele; Pinfold, James; Pingel, Almut; Pires, Sylvestre; Pirumov, Hayk; Pitt, Michael; Plazak, Lukas; Pleier, Marc-Andre; Pleskot, Vojtech; Plotnikova, Elena; 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Radhakrishnan, Sooraj Krishnan; Radloff, Peter; Rados, Pere; Ragusa, Francesco; Rahal, Ghita; Raine, John Andrew; Rajagopalan, Srinivasan; Rammensee, Michael; Rangel-Smith, Camila; Ratti, Maria Giulia; Rauscher, Felix; Rave, Stefan; Ravenscroft, Thomas; Raymond, Michel; Read, Alexander Lincoln; Readioff, Nathan Peter; Rebuzzi, Daniela; Redelbach, Andreas; Redlinger, George; Reece, Ryan; Reeves, Kendall; Rehnisch, Laura; Reichert, Joseph; Reisin, Hernan; Rembser, Christoph; Ren, Huan; Rescigno, Marco; Resconi, Silvia; Rezanova, Olga; Reznicek, Pavel; Rezvani, Reyhaneh; Richter, Robert; Richter, Stefan; Richter-Was, Elzbieta; Ricken, Oliver; Ridel, Melissa; Rieck, Patrick; Riegel, Christian Johann; Rieger, Julia; Rifki, Othmane; Rijssenbeek, Michael; Rimoldi, Adele; Rinaldi, Lorenzo; Ristić, Branislav; Ritsch, Elmar; Riu, Imma; Rizatdinova, Flera; Rizvi, Eram; Rizzi, Chiara; Robertson, Steven; Robichaud-Veronneau, Andree; Robinson, Dave; Robinson, James; Robson, Aidan; Roda, Chiara; Rodina, Yulia; Rodriguez Perez, Andrea; Rodriguez Rodriguez, Daniel; Roe, Shaun; Rogan, Christopher Sean; Røhne, Ole; Romaniouk, Anatoli; Romano, Marino; Romano Saez, Silvestre Marino; Romero Adam, Elena; Rompotis, Nikolaos; Ronzani, Manfredi; Roos, Lydia; Ros, Eduardo; Rosati, Stefano; Rosbach, Kilian; Rose, Peyton; Rosenthal, Oliver; Rossetti, Valerio; Rossi, Elvira; Rossi, Leonardo Paolo; Rosten, Jonatan; Rosten, Rachel; Rotaru, Marina; Roth, Itamar; Rothberg, Joseph; Rousseau, David; Royon, Christophe; Rozanov, Alexandre; Rozen, Yoram; Ruan, Xifeng; Rubbo, Francesco; Rubinskiy, Igor; Rud, Viacheslav; Rudolph, Matthew Scott; Rühr, Frederik; Ruiz-Martinez, Aranzazu; Rurikova, Zuzana; Rusakovich, Nikolai; Ruschke, Alexander; Russell, Heather; Rutherfoord, John; Ruthmann, Nils; Ryabov, Yury; Rybar, Martin; Rybkin, Grigori; Ryu, Soo; Ryzhov, Andrey; Saavedra, Aldo; Sabato, Gabriele; Sacerdoti, Sabrina; Sadrozinski, Hartmut; Sadykov, Renat; Safai Tehrani, Francesco; Saha, Puja; Sahinsoy, Merve; Saimpert, Matthias; Saito, Tomoyuki; Sakamoto, Hiroshi; Sakurai, Yuki; Salamanna, Giuseppe; Salamon, Andrea; Salazar Loyola, Javier Esteban; Salek, David; Sales De Bruin, Pedro Henrique; Salihagic, Denis; Salnikov, Andrei; Salt, José; Salvatore, Daniela; Salvatore, Pasquale Fabrizio; Salvucci, Antonio; Salzburger, Andreas; Sammel, Dirk; Sampsonidis, Dimitrios; Sanchez, Arturo; Sánchez, Javier; Sanchez Martinez, Victoria; Sandaker, Heidi; Sandbach, Ruth Laura; Sander, Heinz Georg; Sanders, Michiel; Sandhoff, Marisa; Sandoval, Carlos; Sandstroem, Rikard; Sankey, Dave; Sannino, Mario; Sansoni, Andrea; Santoni, Claudio; Santonico, Rinaldo; Santos, Helena; Santoyo Castillo, Itzebelt; Sapp, Kevin; Sapronov, Andrey; Saraiva, João; Sarrazin, Bjorn; Sasaki, Osamu; Sasaki, Yuichi; Sato, Koji; Sauvage, Gilles; Sauvan, Emmanuel; Savage, Graham; Savard, Pierre; Sawyer, Craig; Sawyer, Lee; Saxon, James; Sbarra, Carla; Sbrizzi, Antonio; Scanlon, Tim; Scannicchio, Diana; Scarcella, Mark; Scarfone, Valerio; Schaarschmidt, Jana; Schacht, Peter; Schaefer, Douglas; Schaefer, Ralph; Schaeffer, Jan; Schaepe, Steffen; Schaetzel, Sebastian; Schäfer, Uli; Schaffer, Arthur; Schaile, Dorothee; Schamberger, R Dean; Scharf, Veit; Schegelsky, Valery; Scheirich, Daniel; Schernau, Michael; Schiavi, Carlo; Schillo, Christian; Schioppa, Marco; Schlenker, Stefan; Schmieden, Kristof; Schmitt, Christian; Schmitt, Stefan; Schmitz, Simon; Schneider, Basil; Schnellbach, Yan Jie; Schnoor, Ulrike; Schoeffel, Laurent; Schoening, Andre; Schoenrock, Bradley Daniel; Schopf, Elisabeth; Schorlemmer, Andre Lukas; Schott, Matthias; Schovancova, Jaroslava; Schramm, Steven; Schreyer, Manuel; Schuh, Natascha; Schultens, Martin Johannes; Schultz-Coulon, Hans-Christian; Schulz, Holger; Schumacher, Markus; Schumm, Bruce; Schune, Philippe; Schwanenberger, Christian; Schwartzman, Ariel; Schwarz, Thomas Andrew; Schwegler, Philipp; Schweiger, Hansdieter; Schwemling, Philippe; Schwienhorst, Reinhard; Schwindling, Jerome; Schwindt, Thomas; Sciolla, Gabriella; Scuri, Fabrizio; Scutti, Federico; Searcy, Jacob; Seema, Pienpen; Seidel, Sally; Seiden, Abraham; Seifert, Frank; Seixas, José; Sekhniaidze, Givi; Sekhon, Karishma; Sekula, Stephen; Seliverstov, Dmitry; Semprini-Cesari, Nicola; Serfon, Cedric; Serin, Laurent; Serkin, Leonid; Sessa, Marco; Seuster, Rolf; Severini, Horst; Sfiligoj, Tina; Sforza, Federico; Sfyrla, Anna; Shabalina, Elizaveta; Shaikh, Nabila Wahab; Shan, Lianyou; Shang, Ruo-yu; Shank, James; Shapiro, Marjorie; Shatalov, Pavel; Shaw, Kate; Shaw, Savanna Marie; Shcherbakova, Anna; Shehu, Ciwake Yusufu; Sherwood, Peter; Shi, Liaoshan; Shimizu, Shima; Shimmin, Chase Owen; Shimojima, Makoto; Shiyakova, Mariya; Shmeleva, Alevtina; Shoaleh Saadi, Diane; Shochet, Mel; Shojaii, Seyedruhollah; Shrestha, Suyog; Shulga, Evgeny; Shupe, Michael; Sicho, Petr; Sidebo, Per Edvin; Sidiropoulou, Ourania; Sidorov, Dmitri; Sidoti, Antonio; Siegert, Frank; Sijacki, Djordje; Silva, José; Silverstein, Samuel; Simak, Vladislav; Simard, Olivier; Simic, Ljiljana; 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South, David; Sowden, Benjamin; Spagnolo, Stefania; Spalla, Margherita; Spangenberg, Martin; Spanò, Francesco; Sperlich, Dennis; Spettel, Fabian; Spighi, Roberto; Spigo, Giancarlo; Spiller, Laurence Anthony; Spousta, Martin; St Denis, Richard Dante; Stabile, Alberto; Stahlman, Jonathan; Stamen, Rainer; Stamm, Soren; Stanecka, Ewa; Stanek, Robert; Stanescu, Cristian; Stanescu-Bellu, Madalina; Stanitzki, Marcel Michael; Stapnes, Steinar; Starchenko, Evgeny; Stark, Giordon; Stark, Jan; Staroba, Pavel; Starovoitov, Pavel; Stärz, Steffen; Staszewski, Rafal; Steinberg, Peter; Stelzer, Bernd; Stelzer, Harald Joerg; Stelzer-Chilton, Oliver; Stenzel, Hasko; Stewart, Graeme; Stillings, Jan Andre; Stockton, Mark; Stoebe, Michael; Stoicea, Gabriel; Stolte, Philipp; Stonjek, Stefan; Stradling, Alden; Straessner, Arno; Stramaglia, Maria Elena; Strandberg, Jonas; Strandberg, Sara; Strandlie, Are; Strauss, Michael; Strizenec, Pavol; Ströhmer, Raimund; Strom, David; Stroynowski, Ryszard; Strubig, Antonia; Stucci, Stefania Antonia; Stugu, Bjarne; Styles, Nicholas Adam; Su, Dong; Su, Jun; Subramaniam, Rajivalochan; Suchek, Stanislav; Sugaya, Yorihito; Suk, Michal; Sulin, Vladimir; Sultansoy, Saleh; Sumida, Toshi; Sun, Siyuan; Sun, Xiaohu; Sundermann, Jan Erik; Suruliz, Kerim; Susinno, Giancarlo; Sutton, Mark; Suzuki, Shota; Svatos, Michal; Swiatlowski, Maximilian; Sykora, Ivan; Sykora, Tomas; Ta, Duc; Taccini, Cecilia; Tackmann, Kerstin; Taenzer, Joe; Taffard, Anyes; Tafirout, Reda; Taiblum, Nimrod; Takai, Helio; Takashima, Ryuichi; Takeda, Hiroshi; Takeshita, Tohru; Takubo, Yosuke; Talby, Mossadek; Talyshev, Alexey; Tam, Jason; Tan, Kong Guan; Tanaka, Junichi; Tanaka, Reisaburo; Tanaka, Shuji; Tannenwald, Benjamin Bordy; Tapia Araya, Sebastian; Tapprogge, Stefan; Tarem, Shlomit; Tartarelli, Giuseppe Francesco; Tas, Petr; Tasevsky, Marek; Tashiro, Takuya; Tassi, Enrico; Tavares Delgado, Ademar; Tayalati, Yahya; Taylor, Aaron; Taylor, Geoffrey; Taylor, Pierre Thor Elliot; Taylor, Wendy; Teischinger, Florian Alfred; Teixeira-Dias, Pedro; Temming, Kim Katrin; Temple, Darren; Ten Kate, Herman; Teng, Ping-Kun; Teoh, Jia Jian; Tepel, Fabian-Phillipp; Terada, Susumu; Terashi, Koji; Terron, Juan; Terzo, Stefano; Testa, Marianna; Teuscher, Richard; Theveneaux-Pelzer, Timothée; Thomas, Juergen; Thomas-Wilsker, Joshuha; Thompson, Emily; Thompson, Paul; Thompson, Ray; Thompson, Stan; Thomsen, Lotte Ansgaard; Thomson, Evelyn; Thomson, Mark; Tibbetts, Mark James; Ticse Torres, Royer Edson; Tikhomirov, Vladimir; Tikhonov, Yury; Timoshenko, Sergey; Tipton, Paul; Tisserant, Sylvain; Todome, Kazuki; Todorov, Theodore; Todorova-Nova, Sharka; Tojo, Junji; Tokár, Stanislav; Tokushuku, Katsuo; Tolley, Emma; Tomlinson, Lee; Tomoto, Makoto; Tompkins, Lauren; Toms, Konstantin; Tong, Baojia(Tony); Torrence, Eric; Torres, Heberth; Torró Pastor, Emma; Toth, Jozsef; Touchard, Francois; Tovey, Daniel; Trefzger, Thomas; Tricoli, Alessandro; Trigger, Isabel Marian; Trincaz-Duvoid, Sophie; Tripiana, Martin; Trischuk, William; Trocmé, Benjamin; 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Valkar, Stefan; Vallecorsa, Sofia; Valls Ferrer, Juan Antonio; Van Den Wollenberg, Wouter; Van Der Deijl, Pieter; van der Geer, Rogier; van der Graaf, Harry; van Eldik, Niels; van Gemmeren, Peter; Van Nieuwkoop, Jacobus; van Vulpen, Ivo; van Woerden, Marius Cornelis; Vanadia, Marco; Vandelli, Wainer; Vanguri, Rami; Vaniachine, Alexandre; Vankov, Peter; Vardanyan, Gagik; Vari, Riccardo; Varnes, Erich; Varol, Tulin; Varouchas, Dimitris; Vartapetian, Armen; Varvell, Kevin; Vasquez, Jared Gregory; Vazeille, Francois; Vazquez Schroeder, Tamara; Veatch, Jason; Veloce, Laurelle Maria; Veloso, Filipe; Veneziano, Stefano; Ventura, Andrea; Venturi, Manuela; Venturi, Nicola; Venturini, Alessio; Vercesi, Valerio; Verducci, Monica; Verkerke, Wouter; Vermeulen, Jos; Vest, Anja; Vetterli, Michel; Viazlo, Oleksandr; Vichou, Irene; Vickey, Trevor; Vickey Boeriu, Oana Elena; Viehhauser, Georg; Viel, Simon; Vigani, Luigi; Vigne, Ralph; Villa, Mauro; Villaplana Perez, Miguel; Vilucchi, Elisabetta; Vincter, Manuella; Vinogradov, Vladimir; Vittori, Camilla; Vivarelli, Iacopo; Vlachos, Sotirios; Vlasak, Michal; Vogel, Marcelo; Vokac, Petr; Volpi, Guido; Volpi, Matteo; von der Schmitt, Hans; von Toerne, Eckhard; Vorobel, Vit; Vorobev, Konstantin; Vos, Marcel; Voss, Rudiger; Vossebeld, Joost; Vranjes, Nenad; Vranjes Milosavljevic, Marija; Vrba, Vaclav; Vreeswijk, Marcel; Vuillermet, Raphael; Vukotic, Ilija; Vykydal, Zdenek; Wagner, Peter; Wagner, Wolfgang; Wahlberg, Hernan; Wahrmund, Sebastian; Wakabayashi, Jun; Walder, James; Walker, Rodney; Walkowiak, Wolfgang; Wallangen, Veronica; Wang, Chao; Wang, Chao; Wang, Fuquan; Wang, Haichen; Wang, Hulin; Wang, Jike; Wang, Jin; Wang, Kuhan; Wang, Rui; Wang, Song-Ming; Wang, Tan; Wang, Tingting; Wang, Xiaoxiao; Wanotayaroj, Chaowaroj; Warburton, Andreas; Ward, Patricia; Wardrope, David Robert; Washbrook, Andrew; Watkins, Peter; Watson, Alan; Watson, Ian; Watson, Miriam; Watts, Gordon; Watts, Stephen; Waugh, Ben; Webb, Samuel; Weber, Michele; Weber, Stefan Wolf; Webster, Jordan S; Weidberg, Anthony; Weinert, Benjamin; Weingarten, Jens; Weiser, Christian; Weits, Hartger; Wells, Phillippa; Wenaus, Torre; Wengler, Thorsten; Wenig, Siegfried; Wermes, Norbert; Werner, Matthias; Werner, Per; Wessels, Martin; Wetter, Jeffrey; Whalen, Kathleen; Whallon, Nikola Lazar; Wharton, Andrew Mark; White, Andrew; White, Martin; White, Ryan; White, Sebastian; Whiteson, Daniel; Wickens, Fred; Wiedenmann, Werner; Wielers, Monika; Wienemann, Peter; Wiglesworth, Craig; Wiik-Fuchs, Liv Antje Mari; Wildauer, Andreas; Wilk, Fabian; Wilkens, Henric George; Williams, Hugh; Williams, Sarah; Willis, Christopher; Willocq, Stephane; Wilson, John; Wingerter-Seez, Isabelle; Winklmeier, Frank; Winston, Oliver James; Winter, Benedict Tobias; Wittgen, Matthias; Wittkowski, Josephine; Wollstadt, Simon Jakob; Wolter, Marcin Wladyslaw; Wolters, Helmut; Wosiek, Barbara; Wotschack, Jorg; Woudstra, Martin; Wozniak, Krzysztof; Wu, Mengqing; Wu, Miles; Wu, Sau Lan; Wu, Xin; Wu, Yusheng; Wyatt, Terry Richard; Wynne, Benjamin; Xella, Stefania; Xu, Da; Xu, Lailin; Yabsley, Bruce; Yacoob, Sahal; Yakabe, Ryota; Yamaguchi, Daiki; Yamaguchi, Yohei; Yamamoto, Akira; Yamamoto, Shimpei; Yamanaka, Takashi; Yamauchi, Katsuya; Yamazaki, Yuji; Yan, Zhen; Yang, Haijun; Yang, Hongtao; Yang, Yi; Yang, Zongchang; Yao, Weiming; Yap, Yee Chinn; Yasu, Yoshiji; Yatsenko, Elena; Yau Wong, Kaven Henry; Ye, Jingbo; Ye, Shuwei; Yeletskikh, Ivan; Yen, Andy L; Yildirim, Eda; Yorita, Kohei; Yoshida, Rikutaro; Yoshihara, Keisuke; Young, Charles; Young, Christopher John; Youssef, Saul; Yu, David Ren-Hwa; Yu, Jaehoon; Yu, Jiaming; Yu, Jie; Yuan, Li; Yuen, Stephanie P; Yusuff, Imran; Zabinski, Bartlomiej; Zaidan, Remi; Zaitsev, Alexander; Zakharchuk, Nataliia; Zalieckas, Justas; Zaman, Aungshuman; Zambito, Stefano; Zanello, Lucia; Zanzi, Daniele; Zeitnitz, Christian; Zeman, Martin; Zemla, Andrzej; Zeng, Jian Cong; Zeng, Qi; Zengel, Keith; Zenin, Oleg; Ženiš, Tibor; Zerwas, Dirk; Zhang, Dongliang; Zhang, Fangzhou; Zhang, Guangyi; Zhang, Huijun; Zhang, Jinlong; Zhang, Lei; Zhang, Rui; Zhang, Ruiqi; Zhang, Xueyao; Zhang, Zhiqing; Zhao, Xiandong; Zhao, Yongke; Zhao, Zhengguo; Zhemchugov, Alexey; Zhong, Jiahang; Zhou, Bing; Zhou, Chen; Zhou, Lei; Zhou, Li; Zhou, Mingliang; Zhou, Ning; Zhu, Cheng Guang; Zhu, Hongbo; Zhu, Junjie; Zhu, Yingchun; Zhuang, Xuai; Zhukov, Konstantin; Zibell, Andre; Zieminska, Daria; Zimine, Nikolai; Zimmermann, Christoph; Zimmermann, Stephanie; Zinonos, Zinonas; Zinser, Markus; Ziolkowski, Michael; Živković, Lidija; Zobernig, Georg; Zoccoli, Antonio; zur Nedden, Martin; Zurzolo, Giovanni; Zwalinski, Lukasz

    2016-01-01

    The performance of the jet trigger for the ATLAS detector at the LHC during the 2011 data taking period is described. During 2011 the LHC provided proton–proton collisions with a centre-of-mass energy of 7 TeV and heavy ion collisions with a 2.76 TeV per nucleon–nucleon collision energy. The ATLAS trigger is a three level system designed to reduce the rate of events from the 40 MHz nominal maximum bunch crossing rate to the approximate 400 Hz which can be written to offline storage. The ATLAS jet trigger is the primary means for the online selection of events containing jets. Events are accepted by the trigger if they contain one or more jets above some transverse energy threshold. During 2011 data taking the jet trigger was fully efficient for jets with transverse energy above 25 GeV for triggers seeded randomly at Level 1. For triggers which require a jet to be identified at each of the three trigger levels, full efficiency is reached for offline jets with transverse energy above 60 GeV. Jets reconstruc...

  14. Trigger Algorithms and Electronics for the ATLAS Muon New Small Wheel Upgrade

    CERN Document Server

    Guan, Liang; The ATLAS collaboration

    2015-01-01

    The New Small Wheel Upgrade for the ATLAS experiment will replace the innermost station of the Muon Spectrometer in the forward region in order to maintain its current performance during high luminosity data-taking after the LHC Phase-I upgrade. The New Small Wheel, comprising Micromegas and small Thin Gap Chambers, will reduce the rate of fake triggers coming from backgrounds in the forward region and significantly improve the Level-1 muon trigger selectivity by providing precise on-line segment measurements with $\\sim$1 mrad angular resolution. Such demanding precision, together with the short time ($\\sim$ 1 $\\mu$s) to prepare trigger data and perform on-line reconstruction, implies very stringent requirements on the design of trigger system and trigger electronics. This paper presents an overview of the design of the New Small Wheel trigger system, trigger algorithms and processor hardware.

  15. ATLAS Level-1 Muon Barrel Trigger robustness study at X5 test facility

    CERN Document Server

    Di Mattia, A; Nisati, A; Pastore, F C; Vari, R; Veneziano, Stefano; Aielli, G; Camarri, P; Cardarelli, R; Di Ciaccio, A; Di Simone, A; Liberti, B; Santonico, R

    2004-01-01

    The present paper describes the Level-1 Barrel Muon Trigger performance as expected with the current configuration of the RPC detectors, as designed for the Barrel Muon Spectrometer of ATLAS. Results of a beam test performed at the X5-GIF facility at CERN are presented in order to show the trigger efficiency with different conditions of RPC detection efficiency and several background rates. Small RPC chambers with part of the final trigger electronics are used, while the trigger coincidence logic is applied off-line using a detailed simulation model. copy 2003 Published by Esevier B.V. 3 Refs.

  16. Operation of the enhanced ATLAS First Level Calorimeter Trigger at the start of Run-2

    CERN Document Server

    Palka, Marek; The ATLAS collaboration

    2015-01-01

    In 2015 the LHC will operate with a higher center-of-mass energy and proton beams luminosity. To keep a high trigger efficiency against an increased event rate, part of ATLAS Level-1 Calorimeter Trigger electronics have been re-designed or newly introduced (Pre-Processors, Merging Modules and Topological Processors). Additionally, to achieve the best possible resolution for the reconstructed physics objects, complex calibration and monitoring systems are employed. Hit rates and energy spectra down to channel level, based on reconstructed events, are supervised with the calorimeter trigger hardware. The performance of the upgraded Level-1 Calorimeter Trigger at the beginning of LHC Run-2 is illustrated.

  17. The Resource Manager the ATLAS Trigger and Data Acquisition System

    CERN Document Server

    Aleksandrov, Igor; The ATLAS collaboration

    2016-01-01

    The Resource Manager of the ATLAS Trigger and Data Acquisition system The Resource Manager is one of the core components of the Data Acquisition system of the ATLAS experiment at the LHC. The Resource Manager marshals the right for applications to access resources which may exist in multiple but limited copies, in order to avoid conflicts due to program faults or operator errors. The access to resources is managed in a manner similar to what a lock manager would do in other software systems. All the available resources and their association to software processes are described in the Data Acquisition configuration database. The Resource Manager is queried about the availability of resources every time an application needs to be started. The Resource Manager’s design is based on a client-server model, hence it consists of two components: the Resource Manager "server" application and the "client" shared library. The Resource Manager server implements all the needed functionalities, while the Resource Manager c...

  18. Operation of the Upgraded ATLAS Level-1 Central Trigger System

    CERN Document Server

    Glatzer, Julian Maximilian Volker; The ATLAS collaboration

    2015-01-01

    The ATLAS Level-1 Central Trigger (L1CT) system is a central part of ATLAS data-taking and has undergone a major upgrade for Run 2 of the LHC, in order to cope with the expected increase of instantaneous luminosity of a factor of 2 with respect to Run 1. The upgraded hardware offers more flexibility in the trigger decisions due to the double amount of trigger inputs and usable trigger channels. It also provides an interface to the new topological trigger system. Operationally - particularly useful for commissioning, calibration and test runs - it allows concurrent running of up to 3 different subdetector combinations. An overview of the operational software framework of the L1CT system with particular emphasis of the configuration, controls and monitoring aspects is given. The software framework allows a consistent configuration with respect to the ATLAS experiment and the LHC machine, upstream and downstream trigger processors, and the data acquisition. Trigger and dead-time rates are monitored coherently at...

  19. Operation of the Upgraded ATLAS Level-1 Central Trigger System

    CERN Document Server

    Glatzer, Julian Maximilian Volker; The ATLAS collaboration

    2015-01-01

    The ATLAS Level-1 Central Trigger (L1CT) system is a central part of ATLAS data-taking and has undergone a major upgrade for Run 2 of the LHC, in order to cope with the expected increase of instantaneous luminosity of a factor of 2 with respect to Run 1. The upgraded hardware offers more flexibility in the trigger decisions due to the double amount of trigger inputs and usable trigger channels. It also provides an interface to the new topological trigger system. Operationally - particularly useful for commissioning, calibration and test runs - it allows concurrent running of up to 3 different sub-detector combinations. In this contribution, we give an overview of the operational software framework of the L1CT system with particular emphasis of the configuration, controls and monitoring aspects. The software framework allows a consistent configuration with respect to the ATLAS experiment and the LHC machine, upstream and downstream trigger processors, and the data acquisition. Trigger and dead-time rates are m...

  20. Phase-I trigger readout electronics upgrade of the ATLAS liquid-argon calorimeters

    Science.gov (United States)

    Mori, Tatsuya

    2016-09-01

    This article gives an overview of the Phase-I Upgrade of the ATLAS LAr Calorimeter Trigger Readout. The design of custom developed hardware for fast real-time data processing and transfer are presented. Performance results from the prototype boards operated in the demonstrator system, first measurements of noise behavior and responses on the test pulses to the demonstrator system are shown.

  1. The Performance and Development of the Inner Detector Trigger Algorithms at ATLAS for LHC Run 2

    CERN Document Server

    Sowden, Benjamin; The ATLAS collaboration

    2015-01-01

    The upgrade to the ATLAS trigger for LHC Run 2 is presented including a description of the design and performance of the newly reimplemented tracking algorithms. The profiling infrastructure, constructed to provide prompt feedback from the optimisation is described including the methods used to monitor the relative performance improvements as the code evolves. The performance of the trigger on the first data collected as part of the LHC Run 2 are presented.

  2. Technical Design Report for the Phase-I Upgrade of the ATLAS TDAQ System

    CERN Document Server

    Aad, Georges; Abbott, Brad; Abdallah, Jalal; Abdel Khalek, Samah; Abdinov, Ovsat; Aben, Rosemarie; Abi, Babak; AbouZeid, Ossama; Abramowicz, Halina; Abreu, Henso; Abreu, Ricardo; Abulaiti, Yiming; Acharya, Bobby Samir; Achenbach, Ralf; Adamczyk, Leszek; Adams, David; Adelman, Jahred; Adomeit, Stefanie; Adye, Tim; Aefsky, Scott; Agatonovic-Jovin, Tatjana; Aguilar-Saavedra, Juan Antonio; Agustoni, Marco; Ahlen, Steven; Ahmad, Ashfaq; Ahmadov, Faig; Aielli, Giulio; Åkesson, Torsten Paul Ake; Akimoto, Ginga; Akimov, Andrei; Alam, Muhammad Aftab; Albert, Justin; Albrand, Solveig; Alconada Verzini, Maria Josefina; Aleksa, Martin; Aleksandrov, Igor; Alexa, Calin; Alexander, Gideon; Alexandre, Gauthier; Alexandrov, Evgeny; Alexopoulos, Theodoros; Alhroob, Muhammad; Alimonti, Gianluca; Alio, Lion; Alison, John; Allbrooke, Benedict; Allison, Lee John; Allport, Phillip; Allwood-Spiers, Sarah; Almond, John; Aloisio, Alberto; Alon, Raz; Alonso, Alejandro; Alonso, Francisco; Altheimer, Andrew David; Alvarez Gonzalez, Barbara; Alviggi, Mariagrazia; Amaral Coutinho, Yara; Amelung, Christoph; Amor Dos Santos, Susana Patricia; Amoroso, Simone; Amram, Nir; Amundsen, Glenn; Anastopoulos, Christos; Ancu, Lucian Stefan; Andari, Nansi; Andeen, Timothy; Anders, Christoph Falk; Anders, Gabriel; Anderson, John Thomas; Anderson, Kelby; Andreazza, Attilio; Andrei, George Victor; Anduaga, Xabier; Angelidakis, Stylianos; Angelozzi, Ivan; Anger, Philipp; Angerami, Aaron; Anisenkov, Alexey; Anjos, Nuno; Annovi, Alberto; Antonaki, Ariadni; Antonelli, Mario; Antonov, Alexey; Antos, Jaroslav; Anulli, Fabio; Aoki, Masato; Aperio Bella, Ludovica; Apolle, Rudi; Arabidze, Giorgi; Aracena, Ignacio; Arai, Yasuo; Araujo Ferraz, Victor; Arce, Ayana; Arguin, Jean-Francois; Argyropoulos, Spyridon; Arik, Metin; Armbruster, Aaron James; Arnaez, Olivier; Arnal, Vanessa; Arslan, Ozan; Artamonov, Andrei; Artoni, Giacomo; Asai, Shoji; Asbah, Nedaa; Ask, Stefan; Åsman, Barbro; Asquith, Lily; Assamagan, Ketevi; Astalos, Robert; Atkinson, Markus; Atlay, Naim Bora; Auerbach, Benjamin; Augsten, Kamil; Augusto, José; Aurousseau, Mathieu; Avolio, Giuseppe; Azuelos, Georges; Azuma, Yuya; Baak, Max; Baas, Alessandra; Bach, Andre; Bachacou, Henri; Bachas, Konstantinos; Backes, Moritz; Backhaus, Malte; Backus Mayes, John; Badescu, Elisabeta; Bagiacchi, Paolo; Bagnaia, Paolo; Bai, Yu; Bain, Travis; Baines, John; Baker, Oliver Keith; Baker, Sarah; Balek, Petr; Ballestrero, Sergio; Balli, Fabrice; Banas, Elzbieta; Banerjee, Swagato; Bangert, Andrea Michelle; Bansal, Vikas; Bansil, Hardeep Singh; Barak, Liron; Barber, Tom; Barberio, Elisabetta Luigia; Barberis, Dario; Barbero, Marlon; Barillari, Teresa; Barisonzi, Marcello; Barklow, Timothy; Barlow, Nick; Barnett, Bruce; Barnett, Michael; Baroncelli, Antonio; Barone, Gaetano; Barr, Alan; Barreiro, Fernando; Barreiro Guimarães da Costa, João; Bartoldus, Rainer; Barton, Adam Edward; Bartos, Pavol; Bartsch, Valeria; Bassalat, Ahmed; Basye, Austin; Bates, Richard; Batkova, Lucia; Batley, Richard; Batraneanu, Silvia; Battistin, Michele; Bauer, Florian; Bauss, Bruno; Bawa, Harinder Singh; Beacham, James Baker; Beau, Tristan; Beauchemin, Pierre-Hugues; Bechtle, Philip; Beck, Hans Peter; Becker, Anne Kathrin; Becker, Sebastian; Beckingham, Matthew; Beddall, Andrew; Beddall, Ayda; Bedikian, Sourpouhi; Bednyakov, Vadim; Bee, Christopher; Beemster, Lars; Beermann, Thomas; Begel, Michael; Behr, Katharina; Belanger-Champagne, Camille; Bell, Paul; Bell, William; Bella, Gideon; Bellagamba, Lorenzo; Bellerive, Alain; Bellomo, Massimiliano; Belloni, Alberto; Belotskiy, Konstantin; Beltramello, Olga; Benary, Odette; Benchekroun, Driss; Bendtz, Katarina; Benekos, Nektarios; Benhammou, Yan; Benhar Noccioli, Eleonora; Benitez Garcia, Jorge-Armando; Benjamin, Douglas; Bensinger, James; Bentvelsen, Stan; Beretta, Matteo; Berge, David; Bergeaas Kuutmann, Elin; Berger, Nicolas; Berghaus, Frank; Berglund, Elina; Beringer, Jürg; Bernard, Clare; Bernat, Pauline; Bernius, Catrin; Bernlochner, Florian Urs; Berry, Tracey; Berta, Peter; Bertella, Claudia; Bertelsen, Henrik; Bertolucci, Federico; Besana, Maria Ilaria; Besjes, Geert-Jan; Bessidskaia Bylund, Olga; Besson, Nathalie; Betancourt, Christopher; Bethke, Siegfried; Bhimji, Wahid; Bianchi, Riccardo-Maria; Bianchini, Louis; Bianco, Michele; Biebel, Otmar; Bieniek, Stephen Paul; Bierwagen, Katharina; Biesiada, Jed; Biglietti, Michela; Bilbao De Mendizabal, Javier; Bilokon, Halina; Bindi, Marcello; Binet, Sebastien; Bingul, Ahmet; Bini, Cesare; Bittner, Bernhard; Black, Curtis; Black, James

    2013-01-01

    The Phase-I upgrade of the ATLAS Trigger and Data Acquisition (TDAQ) system is to allow the ATLAS experiment to efficiently trigger and record data at instantaneous luminosities that are up to three times that of the original LHC design while maintaining trigger thresholds close to those used in the initial run of the LHC.

  3. ATLAS Jet Trigger Update for the LHC Run II

    CERN Document Server

    Prince, Sebastien; The ATLAS collaboration

    2015-01-01

    After the current shutdown, the LHC is about to resume operation for a new data-taking period, when it will operate with increased luminosity, event rate and centre of mass energy. The new conditions will impose more demanding constraints on the ATLAS online trigger reconstruction and selection system. To cope with such increased constraints, the ATLAS High Level Trigger, placed after a first hardware-based Level-1 trigger, has been redesigned by merging two previously separated software-based processing levels. In the new joint processing level, the algorithms run in the same computing nodes, thus sharing resources, minimizing the data transfer from the detector buffers and increasing the algorithm flexibility. The Jet trigger software selects events containing high transverse momentum hadronic jets. It needs optimal jet energy resolution to help rejecting an overwhelming background while retaining good efficiency for interesting jets. In particular, this requires the CPU-intensive reconstruction of tridimen...

  4. The updated ATLAS Jet Trigger for the LHC Run II

    CERN Document Server

    Prince, Sebastien; The ATLAS collaboration

    2015-01-01

    After the current shutdown, the LHC is about to resume operation for a new data-taking period, when it will operate with increased luminosity, event rate and center of mass energy. The new conditions will impose more demanding constraints on the ATLAS online trigger reconstruction and selection system. To cope with such increased constraints, the ATLAS High Level Trigger, placed after a first hardware-based Level-1 trigger, has been redesigned by merging two previously separated software-based processing levels. In the new joint processing level, the algorithms run in the same computing nodes, thus sharing resources, minimizing the data transfer from the detector buffers and increasing the algorithm flexibility. The jet trigger software selects events containing high transverse momentum hadronic jets. It needs optimal jet energy resolution to help rejecting an overwhelming background while retaining good efficiency for interesting jets. In particular, this requires the CPU-intensive reconstruction of tridimen...

  5. The updated ATLAS Jet Trigger for the LHC Run II

    CERN Document Server

    Prince, Sebastien

    2015-01-01

    After the current shutdown, the LHC is about to resume operation for a new data-taking period, when it will operate with increased luminosity, event rate and center of mass energy. The new conditions will impose more demanding constraints on the ATLAS online trigger reconstruction and selection system. To cope with such increased constraints, the ATLAS High-Level Trigger, placed after a first hardware-based Level~1 trigger, has been redesigned by merging two previously separated software-based processing levels. In the new joint processing level, the algorithms run in the same computing nodes, thus sharing resources, minimizing the data transfer from the detector buffers and increasing the algorithm flexibility. The jet trigger software selects events containing high transverse momentum hadronic jets. It needs optimal jet energy resolution to help rejecting an overwhelming background while retaining good efficiency for interesting jets. In particular, this requires the CPU-intensive reconstruction of tridimen...

  6. The ATLAS Level-1 Central Trigger Processor (CTP)

    CERN Document Server

    Spiwoks, Ralf; Ellis, Nick; Farthouat, P; Gällnö, P; Haller, J; Krasznahorkay, A; Maeno, T; Pauly, T; Pessoa-Lima, H; Resurreccion-Arcas, I; Schuler, G; De Seixas, J M; Torga-Teixeira, R; Wengler, T

    2005-01-01

    The ATLAS Level-1 Central Trigger Processor (CTP) combines information from calorimeter and muon trigger processors and makes the final Level-1 Accept (L1A) decision on the basis of lists of selection criteria (trigger menus). In addition to the event-selection decision, the CTP also provides trigger summary information to the Level-2 trigger and the data acquisition system. It further provides accumulated and bunch-by-bunch scaler data for monitoring of the trigger, detector and beam conditions. The CTP is presented and results are shown from tests with the calorimeter adn muon trigger processors connected to detectors in a particle beam, as well as from stand-alone full-system tests in the laboratory which were used to validate the CTP.

  7. First data with the ATLAS Level-1 Calorimeter Trigger

    CERN Document Server

    Achenbach, R; Aharrouche, M; Andrei, V; Åsman, B; Barnett, BM; Bauss, B; Bendel, M; Bohm, C; Booth, JRA; Bracinik, J; Brawn, IP; Charlton, DG; Childers, JT; Collins, NC; Curtis, CJ; Davis, AO; Eckweiler, S; Eisenhandler, E F; Faulkner, PJW; Fleckner, J; Föhlisch, F; Gee, CNP; Gillman, AR; Goeringer, C; Groll, M; Hadley, DR; Hanke, P; Hellman, S; Hidvegi, A; Hillier, SJ; Johansen, M; Kluge, E-E; Kühl, T; Landon, M; Lendermann, V; Lilley, JN; Mahboubi, K; Mahout, G; Meier, K; Middleton, RP; Moa, T; Morris, JD; Müller, F; Neusiedl, A; Ohm, C; Oltmann, B; Perera, VJO; Prieur, D; Qian, W; Rieke, S; Rühr, F; Sankey, DPC; Schäfer, U; Schmitt, K; Schultz-Coulon, H-C; Seidler, P; Silverstein, S; Sjölin, J; Staley, RJ; Stamen, R; Stockton, MC; Tan, CLA; Tapprogge, S; Thomas, JP; Thompson, PD; Watkins, PM; Watson, A; Weber, P; Wessels, M; Wildt, M

    2008-01-01

    The ATLAS Level-1 Calorimeter Trigger is one of the main elements of the first stage of event selection for the ATLAS experiment at the LHC. The input stage consists of a mixed analogue/digital component taking trigger sums from the ATLAS calorimeters. The trigger logic is performed in a digital, pipelined system with several stages of processing, largely based on FPGAs, which perform programmable algorithms in parallel with a fixed latency to process about 300 Gbyte/s of input data. The real-time output consists of counts of different types of physics objects, and energy sums. The final system consists of over 300 custom-built VME modules, of several different types. The installation at ATLAS of these modules, and the necessary infrastructure, was completed at the end of 2007. The system has since undergone intensive testing, both in standalone mode, and in conjunction with the whole of the ATLAS detector in combined running. The final steps of commissioning, and experience with running the full-scale system...

  8. Calibration for the ATLAS Level-1 Calorimeter-Trigger

    Energy Technology Data Exchange (ETDEWEB)

    Foehlisch, F.

    2007-12-19

    This thesis describes developments and tests that are necessary to operate the Pre-Processor of the ATLAS Level-1 Calorimeter Trigger for data acquisition. The major tasks of Pre-Processor comprise the digitizing, time-alignment and the calibration of signals that come from the ATLAS calorimeter. Dedicated hardware has been developed that must be configured in order to fulfill these tasks. Software has been developed that implements the register-model of the Pre-Processor Modules and allows to set up the Pre-Processor. In order to configure the Pre-Processor in the context of an ATLAS run, user-settings and the results of calibration measurements are used to derive adequate settings for registers of the Pre-Processor. The procedures that allow to perform the required measurements and store the results into a database are demonstrated. Furthermore, tests that go along with the ATLAS installation are presented and results are shown. (orig.)

  9. Calibration for the ATLAS Level-1 Calorimeter-Trigger

    International Nuclear Information System (INIS)

    This thesis describes developments and tests that are necessary to operate the Pre-Processor of the ATLAS Level-1 Calorimeter Trigger for data acquisition. The major tasks of Pre-Processor comprise the digitizing, time-alignment and the calibration of signals that come from the ATLAS calorimeter. Dedicated hardware has been developed that must be configured in order to fulfill these tasks. Software has been developed that implements the register-model of the Pre-Processor Modules and allows to set up the Pre-Processor. In order to configure the Pre-Processor in the context of an ATLAS run, user-settings and the results of calibration measurements are used to derive adequate settings for registers of the Pre-Processor. The procedures that allow to perform the required measurements and store the results into a database are demonstrated. Furthermore, tests that go along with the ATLAS installation are presented and results are shown. (orig.)

  10. The ATLAS High Level Trigger Configuration and Steering

    CERN Document Server

    Stelzer, J; The ATLAS collaboration

    2010-01-01

    In March 2010 the four LHC experiments saw the first proton-proton collisions at 7 TeV. Still within the year a collision rate of nearly 10 MHz is expected. At ATLAS, events of potential interest for ATLAS physics are selected by a three level trigger system, with a final recording rate of about 200 Hz. The first level (L1) is implemented in customized hardware, the two levels of the high level trigger (HLT) are software triggers. Within the ATLAS physics program more than 500 trigger signatures are defined. The HLT tests each signature on each L1-accepted event, the test outcome is recorded for later analysis. The HLT-Steering is responsible for this. It foremost ensures the independent test of each signature, guarantying unbiased trigger decisions. Yet, to minimize data readout and execution time, cached detector data and once-calculated trigger objects are reused to form the decision. Some signature tests are performed only on a scaled-down fraction of candidate events, in order to reduce the output rate a...

  11. The Topological Processor for the future ATLAS Level-1 Trigger

    CERN Document Server

    Kahra, C; The ATLAS collaboration

    2014-01-01

    ATLAS is an experiment on the Large Hadron Collider (LHC), located at the European Organization for Nuclear Research (CERN) in Switzerland. By 2015 the LHC instantaneous luminosity will be increased from $10^{34}$ up to $3\\cdot 10^{34} \\mathrm{cm}^{-2} \\mathrm{s}^{-1}$. This places stringent operational and physical requirements on the ATLAS Trigger in order to reduce the 40MHz collision rate to a manageable event storage rate of 1kHz while at the same time, selecting those events that contain interesting physics events. The Level-1 Trigger is the first rate-reducing step in the ATLAS Trigger, with an output rate of 100kHz and decision latency of less than $2.5 \\mu \\mathrm{s}$. It is composed of the Calorimeter Trigger, the Muon Trigger and the Central Trigger Processor (CTP). In 2014, there will be a new electronics module: the Topological Processor (L1Topo). The L1Topo will make it possible, for the first time, to use detailed information from subdetectors in a single Level-1 module. This allows the determi...

  12. Performance of ATLAS RPC Level-1 muon trigger during the 2015 data taking

    Science.gov (United States)

    Corradi, M.

    2016-09-01

    RPCs are used in the ATLAS experiment at the LHC for the muon trigger system in the barrel region, which corresponds to a pseudorapidity range of |η|ATLAS data taking, showing very good reliability. The RPC detector efficiencies were close to Run 1 and to design values. The trigger efficiency for the high-pT thresholds used in single-muon triggers has been approximately 4% lower than in Run 1, mostly because of chambers disconnected from HV due to gas leaks. Two minor upgrades have been performed in preparation of Run 2 by adding the so-called feet and elevator chambers to increase the system acceptance. The feet chambers have been commissioned during 2015 and are included in the trigger since the last 2015 runs. Part of the elevator chambers are still in a commissioning phase and will probably need a replacement at the end of 2016.

  13. {Performance of the ATLAS Inner Detector Trigger algorithms in pp collisions at 7TeV

    CERN Document Server

    Masik, Jiri; The ATLAS collaboration

    2011-01-01

    The ATLAS trigger performs online event selection in three stages. The Inner Detector information is used in the second (Level 2) and third (Event Filter) stages. Track reconstruction in the silicon detectors and transition radiation tracker contributes significantly to the rejection of uninteresting events while retaining a high signal efficiency. To achieve an overall trigger execution time of 40 ms per event, Level 2 tracking uses fast custom algorithms. The Event Filter tracking uses modified offline algorithms, with an overall execution time of 4s per event. Performance of the trigger tracking algorithms with data collected by ATLAS in 2011 is shown. The high efficiency and track quality of the trigger tracking algorithms for identification of physics signatures is presented. We also discuss the robustness of the reconstruction software with respect to the presence of multiple interactions per bunch crossing, an increasingly important feature for optimal performance moving towards the design luminosities...

  14. Performance of the ATLAS Inner Detector Trigger algorithms in pp collisions at 7TeV

    CERN Document Server

    Masik, Jiri; The ATLAS collaboration

    2011-01-01

    The ATLAS trigger performs online event selection in three stages. The Inner Detector information is used in the second (Level 2) and third (Event Filter) stages. Track reconstruction in the silicon detectors and transition radiation tracker contributes significantly to the rejection of uninteresting events while retaining a high signal efficiency. To achieve an overall trigger execution time of 40 ms per event, Level 2 tracking uses fast custom algorithms. The Event Filter tracking uses modified offline algorithms, with an overall execution time of 4s per event. Performance of the trigger tracking algorithms with data collected by ATLAS in 2011 is shown. The high efficiency and track quality of the trigger tracking algorithms for identification of physics signatures is presented. We also discuss the robustness of the reconstruction software with respect to the presence of multiple interactions per bunch crossing, an increasingly important feature for optimal performance moving towards the design luminosities...

  15. The ATLAS Jet Trigger for LHC Run 2

    CERN Document Server

    Anjos, Nuno; The ATLAS collaboration

    2015-01-01

    The ATLAS Jet Trigger for LHC Run 2 The new centre of mass energy and high luminosity conditions expected for Run 2 at the Large Hadron Collider (LHC) impose more demanding constraints on the ATLAS online trigger than ever before. An immense rate of proton-proton collisions must be reduced from the bunch-crossing rate of 40 MHz to approximately 1 kHz before data can be written on disk for offline analysis. The ATLAS trigger system performs real-time reconstruction and selection of these events in order to achieve this reduction. The selection of events containing jets is uniquely challenging at a hadron collider where nearly every event contains significant hadronic activity. It is, however, of crucial importance to exploit the new data in many physics topics in the new kinematic regime, ranging from early Standard Model measurements to searches for New Physics. Following the very successful first LHC run in 2010/12, the ATLAS trigger was much improved, including a new hardware topological processor and the r...

  16. Monitoring and Tracking the LHC Beam Spot within the ATLAS High Level Trigger

    CERN Document Server

    Winklmeier, F; The ATLAS collaboration

    2012-01-01

    The parameters of the beam spot produced by the LHC in the ATLAS interaction region are computed online using the ATLAS High Level Trigger (HLT) system. The high rate of triggered events is exploited to make precise measurements of the position, size and orientation of the luminous region in near real-time, as these parameters change significantly even during a single data-taking run. We present the challenges, solutions and results for the online determination, monitoring and beam spot feedback system in ATLAS. A specially designed algorithm, which uses tracks registered in the silicon detectors to reconstruct event vertices, is executed on the HLT processor farm of several thousand CPU cores. Monitoring histograms from all the cores are sampled and aggregated across the farm every 60 seconds. The reconstructed beam values are corrected for detector resolution effects, measured in situ from the separation of vertices whose tracks have been split into two collections. Furthermore, measurements for individual ...

  17. A System for Monitoring and Tracking the LHC Beam Spot within the ATLAS High Level Trigger

    CERN Document Server

    Winklmeier, F; The ATLAS collaboration; Cogan, J; Salnikov, A; Strauss, E

    2012-01-01

    The parameters of the beam spot produced by the LHC in the ATLAS interaction region are computed online using the ATLAS High Level Trigger (HLT) system. The high rate of triggered events is exploited to make precise measurements of the position, size and orientation of the luminous region in near real-time, as these parameters change significantly even during a single data-taking run. We present the challenges, solutions and results for the online determination, monitoring and beam spot feedback system in ATLAS. A specially designed algorithm, which uses tracks registered in the silicon detectors to reconstruct event vertices, is executed on the HLT processor farm of several thousand CPU cores. Monitoring histograms from all the cores are sampled and aggregated across the farm every 60 seconds. The reconstructed beam values are corrected for detector resolution effects, measured in situ from the separation of vertices whose tracks have been split into two collections. Furthermore, measurements for individual ...

  18. An upgraded ATLAS Central Trigger for 2015 LHC luminosities

    CERN Document Server

    Ohm, C

    2014-01-01

    The LHC collides protons at a rate of 40 MHz and each collision produces $\\sim$1.5~MB of data from the ATLAS detector. The ATLAS trigger system is implemented in three levels and selects only the most interesting collision events to reduce the event storage rate to about 400 Hz. The first level is implemented in custom electronics and reduces the input rate to $\\sim$75 kHz with a decision latency of $\\sim$2.5 us. It is also responsible for initiating the read-out of data from all the sub-detectors in ATLAS. Based primarily on information from calorimeters and muon trigger detectors, the Central Trigger Processor (CTP) produces the Level-­1 trigger decision. After a very successful first run, the LHC is now being upgraded to operate with increased luminosity and a center-of-mass energy of up to 14 TeV. To cope with the higher luminosities, the Level-1 trigger system will have to perform a more refined selection in order to not lose interesting physics data while keeping the total Level-1 rate below 100~kHz. I...

  19. The ATLAS Local Trigger Processor (LTP) 018

    CERN Document Server

    Borrego-Amaral, P; Farthouat, Philippe; Gällnö, P; Pessoa-Lima, H; Maeno, T; Resurreccion-Arcas, I; De Seixas, J M; Schuler, G; Spiwoks, R; Torga-Teixeira, R; Wengler, T; 10th Workshop on Electronics for LHC and Future Experiments

    2004-01-01

    The Local Trigger Processor (LTP) receives timing and trigger signals from the Central Trigger Processor (CTP) and injects them into the Timing, Trigger and Control (TTC) system of a sub-detector front-end TTC partition. The LTP allows stand-alone running by using local timing and trigger signals or by generating them from memory. In addition, several LTPs of the same sub-detector can be daisy-chained. The LTP can thus be regarded as a switching element for timing and trigger signals with input from the CTP or the daisy-chain, from local input, or from the internal data generator, and with output to the daisy-chain, to the TTC partition, or to local output. Finally, in combined mode several LTPs can be connected together using their local outputs and local inputs to allow stand-alone running of combinations of different sub-detectors.

  20. Deployment of the ATLAS High-Level Triggers

    CERN Document Server

    Anjos, A; Baines, J T M; Beck, H P; Bee, C P; Biglietti, M; Bogaerts, J A C; Bosman, M; Burckhart, Doris; Caprini, M; Caron, B; Casado, M P; Cataldi, G; Cavalli, D; Ciobotaru, M; Comune, G; Conde, P; Corso-Radu, A; Crone, G; Damazio, D; De Santo, A; Díaz-Gómez, M; Di Mattia, A; Dobson, M; Ellis, Nick; Emeliyanov, D; Epp, B; Falciano, S; Ferrari, R; Francis, D; Gadomski, S; Gameiro, S; Garitaonandia, H; George, S; Ghete, V; Goncalo, R; Gorini, B; Gruwé, M; Haeberli, C; Haller, J; Joos, M; Kabana, S; Kazarov, A; Khomich, A; Kilvington, G; Kirk, J; Kolos, S; Konstantinidis, N P; Kootz, A; Lankford, A; Lehmann, G; Lowe, A; Luminari, L; Maeno, T; Masik, J; Meirosu, C; Meessen, C; Mello, A G; Moore, R; Morettini, P; Negri, A; Nikitin, N; Nisati, A; Osuna, C; Padilla, C; Panikashvili, N; Parodi, F; Pasqualucci, E; Pérez-Réale, V; Petersen, J; Pinfold, J L; Pinto, P; Qian, Z; Resconi, S; Rosati, S; Sánchez, C; Santamarina-Rios, C; Scannicchio, D A; Schiavi, C; Segura, E; Seixas, J M; Sivoklokov, S Yu; Sloper, J; Sobreira, A; Soloviev, I; Soluk, R A; Stancu, S; Stefanidis, E; Sushkov, S; Sutton, M; Tapprogge, S; Tarem, S; Thomas, E; Touchard, F; Tremblet, L; Ünel, G; Usai, G; Vandelli, Wainer R; Venda-Pinto, B; Ventura, A; Vercesi, V; Wengler, T; Werner, P; Wheeler, S J; Wickens, F J; Wiedenmann, W; Wielers, M; Wiesmann, M; Yasu, Y; Zobernig, G; 14th IEEE - NPSS Real Time Conference 2005 Nuclear Plasma Sciences Society

    2005-01-01

    The ATLAS combined test beam in the second half of 2004 saw the first deployment of the ATLAS High-Level Triggers (HLT). The next steps are deployment on the pre-series farms in the experimental area during 2005, commissioning and cosmics tests in 2006 and collisions in 2007. This paper reviews the experience gained in the test beam, describes the current status and discusses the further enhancements to be made. We address issues related to the dataflow, selection algorithms, testing, software distribution, installation and improvements.

  1. Instrumentation of a Level-1 Track Trigger at ATLAS with Double Buffer Front-End Architecture

    CERN Document Server

    Cooper, B; The ATLAS collaboration

    2012-01-01

    The increased collision rate and pile-up produced at the HLLHC requires a substantial upgrade of the ATLAS level-1 trigger in order to maintain a broad physics reach. We show that tracking information can be used to control trigger rates, and describe a proposal for how this information can be extracted within a two-stage level-1 trigger design that has become the baseline for the HLLHC upgrade. We demonstrate that, in terms of the communication between the external processing and the tracking detector frontends, a hardware solution is possible that fits within the latency constraints of level-1.

  2. L1Track: a fast Level 1 track trigger for the ATLAS High Luminosity Upgrade

    CERN Document Server

    Cerri, Alessandro

    2015-01-01

    With the planned high-luminosity upgrade of the LHC (HL-LHC), the ATLAS detector will see its collision rate increase by approximately a factor of 5 with respect to the current LHC operation. The earliest hardware based ATLAS trigger stage ("Level 1") will have to provide an higher rejection factor in a more difficult environment: a new improved Level 1 trigger architecture is under study, which includes the possibility of extracting with low latency and hight accuracy tracking information on time for the decision taking process. The expected trigger rates at HL-LHC and the available latency are the key ingredients that will drive the new design. The Level 1 track trigger (L1Track) design requires substantial modification of the ATLAS silicon detector readout philosophy: a precursor of the potential merging of detector and trigger architectures in the future silicon detectors at particle colliders. We will discuss potential approaches that are being actively considered to fulfil the demanding HL-LHC constrain...

  3. ATLAS Jet Trigger at 13 TeV

    CERN Document Server

    Grossi, Giulio Cornelio; The ATLAS collaboration

    2015-01-01

    The new Large Hadron Collider (LHC) centre of mass energy and expected high luminosity conditions impose more demanding constraints on the ATLAS online trigger than ever before. The immense rate of proton-proton collisions must be reduced from the bunch-crossing rate of 40 MHz to approximately 1 kHz before the data can be written on disk for offline analysis. The ATLAS Trigger System performs real-time reconstruction and selection of these events in order to achieve this reduction. The selection of events containing jets is uniquely challenging at a hadron collider where nearly every event contains significant hadronic activity. It is, however, of crucial importance for several physics analyses, including early searches for new physics in the new kinematic regime. Following the very successful first LHC run in 2010/12, the ATLAS Trigger was much improved, including a new hardware topological module and a restructured High Level Trigger system, merging two previous software-based processing levels. After summa...

  4. The ATLAS Jet Trigger for LHC Run 2

    CERN Document Server

    Anjos, Nuno

    2015-01-01

    The new centre of mass energy and high luminosity conditions expected for Run 2 at the Large Hadron Collider (LHC) impose more demanding constraints on the ATLAS online trigger than ever before. An immense rate of proton-proton collisions must be reduced from the bunchcrossing rate of 40 MHz to approximately 1 kHz before data can be written on disk for offline analysis. The ATLAS trigger system performs real-time reconstruction and selection of these events in order to achieve this reduction. The selection of events containing jets is uniquely challenging at a hadron collider where nearly every event contains significant hadronic activity. It is, however, of crucial importance to exploit the new data in many physics topics in the new kinematic regime, ranging from early Standard Model measurements to searches for New Physics. Following the very successful first LHC run in 2010/12, the ATLAS trigger was much improved, including a new hardware at Level 1 and the restructuring of the High Level Trigger system, w...

  5. The ATLAS Jet Trigger at 13 TeV

    CERN Document Server

    Grossi, Giulio Cornelio; The ATLAS collaboration

    2015-01-01

    he new Large Hadron Collider (LHC) center of mass energy and expected high luminosity conditions impose more demanding constraints on the ATLAS online trigger than ever before. The immense rate of proton-proton collisions must be reduced from the bunch-crossing rate of 40 MHz to approximately 1 kHz before the data can be written on disk for offline analysis. The ATLAS Trigger System performs real-time reconstruction and selection of these events in order to achieve this reduction. The selection of events containing jets is uniquely challenging at a hadron collider where nearly every event contains significant hadronic activity. It is, however, of crucial importance for several physics analyses, including early searches for new physics in the new kinematic regime. Following the very successful first LHC run in 2010/12, the ATLAS Trigger was much improved, including a new hardware topological module and a restructured High Level Trigger system, merging two previous software-based processing levels. After summar...

  6. The performance of the ATLAS Level-1 Calorimeter Trigger with LHC collision data

    CERN Document Server

    Bracinik, J

    2011-01-01

    The ATLAS first-level calorimeter trigger is a hardware-based system designed to identify high-E$_T$ jets, electron/photon and $ au$ candidates and to measure total and missing E$_T$ in the ATLAS calorimeters. After more than two years of commissioning in situ with calibration data and cosmic rays, the system has now been used extensively to select the most interesting proton-proton collision events. Fine tuning of timing and energy calibration has been carried out in 2010 to improve the trigger response to physics objects. In these proceedings, an analysis of the performance of the level-1 calorimeter trigger is presented, along with the techniques used to achieve these results.

  7. The Performance and Development of the Inner Detector Trigger Algorithms at ATLAS for LHC Run 2

    CERN Document Server

    Sowden, Benjamin Charles; The ATLAS collaboration

    2015-01-01

    A description of the design and performance of the newly reimplemented tracking algorithms for the ATLAS trigger for LHC Run 2, to commence in spring 2015, is provided. The ATLAS High Level Trigger (HLT) has been restructured to run as a more flexible single stage process, rather than the two separate Level 2 and Event Filter stages used during Run 1. To make optimal use of this new scenario, a new tracking strategy has been implemented for Run 2 for the HLT. This new strategy will use a Fast Track Finder (FTF) algorithm to directly seed the subsequent Precision Tracking, and will result in improved track parameter resolution and significantly faster execution times than achieved during Run 1 but with no significant reduction in efficiency. The performance and timing of the algorithms for numerous physics signatures in the trigger are presented. The profiling infrastructure, constructed to provide prompt feedback from the optimisation, is described, including the methods used to monitor the relative performan...

  8. The ATLAS FTK system: how to improve the physics potential with a tracking trigger

    CERN Document Server

    Iizawa, T; The ATLAS collaboration

    2014-01-01

    After a very successful data taking run, the ATLAS experiment is being upgraded to cope with the higher luminosity and higher center of mass energy that the Large Hadron Collider will provide in the next years. The Fast Tracker (FTK) trigger system, part of the ATLAS trigger upgrade program, is a highly parallel hardware device designed to operate at the level-1 trigger output rate. FTK is a dedicated processor based on a mixture of advanced technologies. Modern, powerful Field Programmable Gate Arrays (FPGAs) form an important part of the system architecture, and the large level of computing power required for pattern recognition is provided by incorporating standard-cell ASICs named Associative Memories (AM). FTK provides global track reconstruction in the full inner silicon detector, with resolution comparable to the offline algorithms, in approximately 100 microseconds, allowing a fast and precise detection of the primary and secondary vertex information. The track and vertex information is then used by t...

  9. A Trigger Data Serialize ASIC for the ATLAS Forward Muon Detector Upgrade

    CERN Document Server

    Wang, Jinhong; The ATLAS collaboration

    2016-01-01

    The small-strip Thin-Gap Chambers (sTGC) will be used as both trigger and precision tracking muon detectors for the Phase-I upgrade of the ATLAS New Small Wheel (NSW) muon detector. A Trigger data serializer (TDS) ASIC is required to prepare trigger data for both sTGC pad and strip detectors, perform pad-strip matching, and serializer trigger data to the circuits on the rim the rim of the NSW detector. The large number of input channels (128 differential input channels), short time available to prepare and transmit trigger data (<100 ns), high speed output data rate (4.8 Gbps), harsh radiation environment (about 300 kRad), and low power consumption (<1 W) all impose great challenges for the design of this ASIC using the IBM 130 nm CMOS process. We present our design and consderation of the TDS ASIC and the first prototype we built

  10. Missing Transverse Momentum Trigger Performance Studies for the ATLAS Calorimeter Trigger Upgrades

    Science.gov (United States)

    Stamas, Brianna; Parrish, Elliot; Lisi, Luc; Dudley, Christopher; Majewski, Stephanie

    2016-03-01

    The ATLAS Experiment is one of two general purpose detectors at the Large Hadron Collider at CERN in Geneva, Switzerland. In anticipation of discovering new physics, the detector will undergo numerous hardware upgrades including improvements to the Liquid Argon Calorimeter trigger electronics. For the upgrade, one component of the Level-1 trigger system will be the global feature extractor, gFEX, which will house three field programmable gate arrays (FPGAs). Specifically, in order to improve the missing transverse energy (ETmiss)trigger, an adapted topological clustering algorithm is being investigated for implementation on the FPGAs for reconstruction of proton-proton interactions in the ATLAS detector. Using simulated data, this study analyzes the performance of the adapted algorithm in software.

  11. Improving the ATLAS physics potential with the Fast Track Trigger System

    CERN Document Server

    Cavaliere, Viviana; The ATLAS collaboration

    2015-01-01

    The ATLAS Fast TracKer (FTK) is a custom electronics system that will operate at the full Level-1 accept rate, 100 kHz, to provide high quality tracks as input to the High-Level Trigger. The event reconstruction is performed in hardware, thanks to the massive parallelism of associative memories (AM) and FPGAs. We present the advantages for the physics goals of the ATLAS experiment and the recent results on the design, technological advancements and testing of some of the core components used in the processor.

  12. L1Track: a Fast Level 1 Track Trigger for the ATLAS High Luminosity Upgrade

    CERN Document Server

    Cerri, Alessandro; The ATLAS collaboration

    2015-01-01

    With the planned high-luminosity upgrade of the LHC, the ATLAS detector will see its collision rate increased by approximately a factor of 5 with respect to the current LHC design. Due to this the pile-up collisions will increase by a similar factor. The earliest, hardware based, ATLAS trigger stage ("Level 1") will have to provide an higher rejection factor in a more difficult environment. The Level 1 trigger architecture needs therefore to be improved. A new Level 1 trigger architecture is under study, which, in addition of the “regions of interest” identified by the calorimetry and the muon chambers, also includes the possibility of extracting tracking information and use it for the decision taking process. The expected trigger rates at HL-LHC and the available latency are the key ingredients that will drive the new design. A low-latency and accurate tracking trigger system is being developed in the context of this additional trigger refinement. The design results in a substantial modification of the A...

  13. Preparing the ATLAS Jet Trigger for High Luminosity

    CERN Document Server

    Kasieczka, G; The ATLAS collaboration

    2011-01-01

    Poster for PLHC 2011 Conference The performance of jet finding in the ATLAS trigger is presented. Results from early-2011 LHC runs are reviewed and enhancements aimed at improving performance are evaluated. The fast and precise measurement of hadronic jets with high transverse momenta in the trigger is essential to the physics goals of the ATLAS experiment. The ATLAS trigger finds jets in three stages with increasingly more complex algorithms and tighter selection criteria. Jets are found in the first stage, Level 1, from coarse granularity calorimeter towers using a sliding windows algorithm. Jets are reconstructed in the second stage, Level 2, from calorimeter cells with a cone algorithm seeded by the Level 1 jets. In the final stage - the Event Filter - topological clusters of calorimeter cells are input into the anti-kT algorithm for jet finding. This is similar to the methodology adopted by the offline analyses and improves the jet energy and angular resolution. The calorimeter is also read-out in a sing...

  14. The ATLAS trigger high-level trigger commissioning and operation during early data taking

    CERN Document Server

    Goncalo, R

    2008-01-01

    The ATLAS experiment is one of the two general-purpose experiments due to start operation soon at the Large Hadron Collider (LHC). The LHC will collide protons at a centre of mass energy of 14~TeV, with a bunch-crossing rate of 40~MHz. The ATLAS three-level trigger will reduce this input rate to match the foreseen offline storage capability of 100-200~Hz. After the Level 1 trigger, which is implemented in custom hardware, the High-Level Trigger (HLT) further reduces the rate from up to 100~kHz to the offline storage rate while retaining the most interesting physics. The HLT is implemented in software running in commercially available computer farms and consists of Level 2 and Event Filter. To reduce the network data traffic and the processing time to manageable levels, the HLT uses seeded, step-wise reconstruction, aiming at the earliest possible rejection. Data produced during LHC commissioning will be vital for calibrating and aligning sub-detectors, as well as for testing the ATLAS trigger and setting up t...

  15. Phase-I Trigger Readout Electronics Upgrade of the ATLAS Liquid-Argon Calorimeters

    CERN Document Server

    Mori, Tatsuya; The ATLAS collaboration

    2015-01-01

    The Large Hadron Collider (LHC) is foreseen to be upgraded during the shut-down period of 2018-2019 to deliver about 3 times the instantaneous design luminosity. Since the ATLAS trigger system, at that time, will not support such an increase of the trigger rate an improvement of the trigger system is required. The ATLAS LAr Calorimeter readout will therefore be modified and digital trigger signals with a higher spatial granularity will be provided to the trigger. The new trigger signals will be arranged in 34000 Super Cells which achieves a 5-10 better granularity than the trigger towers currently used and allows an improved background rejection. The Super Cell readout is composed of custom developed 12-bit combined SAR ADCs in 130 nm CMOS technology which will be installed on-detector in a radiation environment and digitizes the detector pulses at 40 MHz. The data will be transmitted to the back end using a custom serializer and optical converter applying 5.44 Gb/s optical links. These components are install...

  16. Hardware, firmware and software developments for the upgrade of the ATLAS Level-1 Central Trigger Processor

    CERN Document Server

    Ghibaudi, M; The ATLAS collaboration; Spiwoks, R; Anders, G; Bertelsen, H; Boisen, A; Childers, T; Dam, M; Ellis, N; Farthouat, P; Gabaldon Ruiz, C; Gorini, B; Kaneda, M; Ohm, C; Silva Oliveira, M; Pauly, T; Pottgen, R; Schmieden, K; Xella, S

    2013-01-01

    The Central Trigger Processor (CTP) is the final stage of the ATLAS first level trigger system which reduces the collision rate of 40 MHz to a Level-1 event rate of 100 kHz. An upgrade of the CTP is currently underway to significantly increase the number of trigger inputs and trigger combinations, allowing additional flexibility for the trigger menu.\

  17. Upgraded Trigger Readout Electronics for the ATLAS LAr Calorimeters for Future LHC Running

    CERN Document Server

    Ma, H; The ATLAS collaboration

    2015-01-01

    The ATLAS Liquid Argon (LAr) calorimeters produce almost 200K signals that are digitized and processed by the front-end and back-end electronics for every triggered event. Additionally, the front-end electronics sums analog signals to provide coarse-grained energy sums to the first- level (L1) trigger system. The current design was optimized for the nominal LHC luminosity of 10^34cm^−2s^−1. In order to retain the capability to trigger on low energy electrons and photons when the LHC is upgraded to higher luminosity, an improved LAr calorimeter trigger readout is proposed and being constructed. The new trigger readout system makes available the fine segmentation of the calorimeter at the L1 trigger with high precision in order to reduce the QCD jet background in electron, photon and tau triggers, and to improve jet and missing ET trigger performance. The new LAr Trigger Digitizer Board is designed to receive the higher granularity signals, digitize them on-detector and send them via fast optical links to a...

  18. Performance Analysis of the ATLAS Second Level Trigger Software

    CERN Document Server

    Bogaerts, J A C; Li, W; Middleton, R P; Werner, P; Wickens, F J; Zobernig, H

    2002-01-01

    Abstract--In this paper we analyse the performance of the prototype software developed for the ATLAS Second Level Trigger. The OO framework written in C++ has been used to implement a distributed system which collects (simulated) detector data on which it executes event selection algorithms. The software has been used on testbeds of up to 100 nodes with various interconnect technologies. The final system will have to sustain traffic of ~ 40 Gbits/s and require an estimated number of ~750 processors. Timing measurements are crucial for issues such as trigger decision latency, assessment of required CPU and network capacity, scalability, and load-balancing. In addition, final architectural and technological choices, code optimisation and system tuning require a detailed understanding of both CPU utilisation and trigger decision latency. In this paper we describe the instrumentation used to disentangle effects due to such factors as OS system intervention, blocking on interlocks (applications are multi-threaded)...

  19. Algorithms, performance, development of the ATLAS High-Level trigger

    International Nuclear Information System (INIS)

    The ATLAS trigger system has been used for the online event selection for three years of LHC data-taking and is preparing for the next run. The trigger system consists of a hardware level-1 and a software high-level trigger (HLT) which is implemented in a region-of-interest based level-2 stage and a event filter operating after event building with offline-like software. During the past three years, the luminosity and pile-up (number of collisions per beam crossing) has increased significantly placing escalating demands on the rejection and timing performance. The HLT algorithms advanced during this period to maintain and even improve performance. Also discussed is the work towards the merging of the two HLT levels in to a single level HLT.

  20. Performance of ATLAS RPC Level-1 muon trigger during the 2015 data taking

    CERN Document Server

    Corradi, Massimo; The ATLAS collaboration

    2016-01-01

    RPCs are used in the ATLAS experiment at the LHC for muon trigger in the barrel region, which corresponds to |eta|<1.05. The status of the barrel trigger system during the 2015 data taking is presented, including measurements of the RPC detector efficiencies and of the trigger performance. The RPC system has been active in more than 99.9% of the ATLAS data taking, showing very good reliability. The RPC detector efficiencies were close to Run-1 and to design value. The trigger efficiency for the high-pT thresholds used in single-muon triggers has been approximately 4% lower than in Run 1, mostly because of chambers disconnected from HV due to gas leaks. Two minor upgrades have been performed in preparation of Run 2 by adding the so-called feet and elevator chambers to increase the system acceptance. The feet chambers have been commissioned during 2015 and are included in the trigger since the last 2015 runs. Part of the elevator chambers are still in commissioning phase and will probably need a replacement ...

  1. Simulation of the High Performance Time to Digital Converter for the ATLAS Muon Spectrometer trigger upgrade

    Science.gov (United States)

    Meng, X. T.; Levin, D. S.; Chapman, J. W.; Zhou, B.

    2016-09-01

    The ATLAS Muon Spectrometer endcap thin-Resistive Plate Chamber trigger project compliments the New Small Wheel endcap Phase-1 upgrade for higher luminosity LHC operation. These new trigger chambers, located in a high rate region of ATLAS, will improve overall trigger acceptance and reduce the fake muon trigger incidence. These chambers must generate a low level muon trigger to be delivered to a remote high level processor within a stringent latency requirement of 43 bunch crossings (1075 ns). To help meet this requirement the High Performance Time to Digital Converter (HPTDC), a multi-channel ASIC designed by CERN Microelectronics group, has been proposed for the digitization of the fast front end detector signals. This paper investigates the HPTDC performance in the context of the overall muon trigger latency, employing detailed behavioral Verilog simulations in which the latency in triggerless mode is measured for a range of configurations and under realistic hit rate conditions. The simulation results show that various HPTDC operational configurations, including leading edge and pair measurement modes can provide high efficiency (>98%) to capture and digitize hits within a time interval satisfying the Phase-1 latency tolerance.

  2. Upgrade of the Trigger Readout System of the ATLAS Liquid Argon Calorimeters

    CERN Document Server

    Marino, CP; The ATLAS collaboration

    2013-01-01

    The ATLAS detector was designed and built to study proton-proton collisions produced at the LHC at centre-of-mass energies up to 14 TeV and instantaneous luminosities up to 10^34 cm^-2 s^-1. Liquid argon (LAr) sampling calorimeters are employed for all electromagnetic calorimetry in the pseudorapidity region |eta|<3.2, and for hadronic calorimetry in the region from |eta|=1.5 to |eta|=4.9. The ATLAS Liquid Argon (LAr) calorimeters produce a total of 182,486 signals which are digitizedand processed by the front-end and back-end electronics at every triggered event. In addition, the front-end electronics sums analog signals to provide coarsely grained energy sums, called trigger towers, to the first-level trigger system, which is optimized for nominal LHC luminosities. In 2018, an instantaneous luminosity of 2-3 x 10^34 cm^-2 s^-1 is expected, far beyond the nominal one for which the detector was designed. In order to cope with this increased trigger rate, an improved spatial granularity of the trigger primi...

  3. Upgrade of the Trigger System of the ATLAS Liquid Argon calorimeters

    CERN Document Server

    Kanaya, N; The ATLAS collaboration

    2014-01-01

    The ATLAS detector was designed and build to study proton-proton collisions produced at the LHC at centre-of-mass energies up to 14 TeV and instantaneous luminosities up to 1034 cm^-2s^-1. Liquid argon (LAr) sampling calorimeters are employed for all electromagnetic calorimetry in the pseudorapidity region |η| <3.2, and for hadronic calorimetry in the region from |η| = 1.5 to |η| = 4.9. The ATLAS Liquid Argon (LAr) calorimeters produce a total of 182,486 signals, which are digitized and processed by the front-end and back-end electronics for each triggered event. In addition, the front-end electronics sums analog signals to provide coarse-grained energy sums, called trigger towers, to the first-level trigger system, which is optimized for nominal LHC luminosities. In 2019, instantaneous luminosities of (2-3)×1034 cm^-2s^-1 are expected, far beyond that for which the detector was designed. In order to cope with this increased trigger rate, an improved spatial granularity of the trigger primitives is pro...

  4. Upgrade of the Trigger System of the ATLAS Liquid Argon calorimeters

    CERN Document Server

    Kanaya, N; The ATLAS collaboration

    2014-01-01

    ATLAS detector was designed and build to study proton-proton collisions produced at the LHC at centre-of-mass energies up to 14 TeV and instantaneous luminosities up to 1034 cm-2s-1. Liquid argon (LAr) sampling calorimeters are employed for all electromagnetic calorimetry in the pseudorapidity region |η| <3.2, and for hadronic calorimetry in the region from |η| = 1.5 to |η| = 4.9. The ATLAS Liquid Argon (LAr) calorimeters produce a total of 182,486 signals, which are digitized and processed by the front-end and back-end electronics for each triggered event. In addition, the front-end electronics sums analog signals to provide coarse-grained energy sums, called trigger towers, to the first-level trigger system, which is optimized for nominal LHC luminosities. In 2020, instantaneous luminosities of (2-3)×1034 cm-2s-1 are expected, far beyond that for which the detector was designed. In order to cope with this increased trigger rate, an improved spatial granularity of the trigger primitives is proposed, t...

  5. ATLAS Jet Trigger Update for the LHC Run II

    CERN Document Server

    Tavares Delgado, Ademar; The ATLAS collaboration

    2015-01-01

    The CERN Large Hadron Collider is the biggest and most powerful particle collider ever built. It produces up to 40 million proton-proton collisions per second at unprecedented energies to explore the fundamental laws and properties of Nature. The ATLAS experiment is one of the detectors that analyses and records these collisions. It generates dozens of GB/s of data that has to be reduced before it can be permanently stored, the event selection is made by the ATLAS trigger system, which reduces the data volume by a factor of 10^5 . The trigger system has to be highly configurable in order to adapt to changing running conditions and maximize the physics output whilst keeping the output rate under control. A particularly interesting pattern generated during collisions consists of a collimated spray of particles, known as a hadronic jet. To retain the interesting jets and efficiently reject the overwhelming background, optimal jet energy resolution is needed. Therefore the Jet trigger software requires CPU-intens...

  6. The ATLAS Hadronic Tau Trigger: Initial Run-2 Strategy and Performance

    CERN Document Server

    Pickering, Mark Andrew; The ATLAS collaboration

    2015-01-01

    As proton-proton collisions at the LHC reach instantaneous luminosities of over 10 34cm-2s-1, and a centre-of-mass energy of 13 TeV, the strategies for triggering have become more important than ever for physics analyses. In these conditions, single tau lepton triggers suffer from severe rate limitations, despite the sophisticated algorithms used in the tau identification. The development of further fast algorithms and the design of topological selections are the main challenges to allow a large program of physics analysis. The tau triggers provide many opportunities to study new physics beyond the Standard Model, and to get precise measurements of the properties of the Higgs boson decaying to tau-leptons. Presented here is the strategy for Run-2 data-taking and the initial performance of the ATLAS tau trigger with a dataset corresponding to an integrated luminosity of 78.3 pb-1 of 13TeV.

  7. Operation of the enhanced ATLAS First Level Calorimeter Trigger at the start of LHC Run-2

    CERN Document Server

    Palka, Marek; The ATLAS collaboration

    2015-01-01

    In 2015 the LHC is already operating with a higher center-of-mass energy and proton beams luminosity. To keep a high trigger efficiency against an increased event rate, part of ATLAS Level-1 Calorimeter Trigger electronics have been re-designed or newly introduced (Pre-Processors, Merging Modules and Topological Processors). Additionally, to achieve the best possible resolution for the reconstructed physics objects, complex calibration and monitoring systems are employed. Hit rates and energy spectra down to channel level, based on reconstructed events, are supervised with the calorimeter trigger hardware. In this paper the performance of the upgraded Level-1 Calorimeter Trigger at the beginning of LHC Run-2 is illustrated.

  8. Expected performance of the ATLAS experiment detector, trigger and physics

    CERN Document Server

    Aad, G; Abbott, B; Abdallah, J; Abdelalim, A A; Abdesselam, A; Abdinov, O; Abi, B; Abolins, M; Abramowicz, H; Acharya, B S; Adams, D L; Addy, T N; Adorisio, C; Adragna, P; Adye, T; Aguilar-Saavedra, J A; Aharrouche, M; Ahlen, S P; Ahles, F; Ahmad, A; Ahmed, H; Aielli, G; Akdogan, T; Åkesson, T P A; Akimoto, G; Alam, M A; Alam, S M; Albert, J; Albrand, S; Aleksa, M; Aleksandrov, I N; Alessandria, F; Alexa, C; Alexander, G; Alexandre, G; Alexopoulos, T; Alhroob, M; Alimonti, G; Alison, J; Aliyev, M; Allport, P P; Allwood-Spiers, S E; Aloisio, A; Alon, R; Alonso, A; Alonso, J; Alviggi, M G; Amako, K; Amaral, P; Amelung, C; Ammosov, V V; Amorim, A; Amorós, G; Amram, N; Anastopoulos, C; Anders, C F; Anderson, K J; Andreazza, A; Andrei, V; Andrieux, M L; Anduaga, X S; Anghinolfi, F; Antonaki, A; Antonelli, M; Antonelli, S; Antunovic, B; Anulli, F A; Arabidze, G; Aracena, I; Arai, Y; Arce, A T H; Archambault, J P; Arfaoui, S; Arguin, J F; Argyropoulos, T; Arik, E; Arik, M; Armbruster, A J; 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    2009-01-01

    A detailed study is presented of the expected performance of the ATLAS detector. The reconstruction of tracks, leptons, photons, missing energy and jets is investigated, together with the performance of b-tagging and the trigger. The physics potential for a variety of interesting physics processes, within the Standard Model and beyond, is examined. The study comprises a series of notes based on simulations of the detector and physics processes, with particular emphasis given to the data expected from the first years of operation of the LHC at CERN.

  9. Performance and development plans for the Inner Detector trigger algorithms at ATLAS

    CERN Document Server

    Martin-Haugh, S; The ATLAS collaboration

    2013-01-01

    We present a description of the algorithms and the performance of the ATLAS Inner Detector trigger for LHC Run 1, as well as prospects for a redesign of the tracking algorithms in Run 2. The Inner Detector trigger algorithms are vital for many trigger signatures at ATLAS. The performance of the algorithms for electrons is presented. The ATLAS trigger software will be restructured from two software levels into a single stage which poses a big challenge on the trigger algorithms in terms of execution time and maintaining the physics performance. Expected future improvements in the timing and efficiencies of the Inner Detector triggers are discussed, utilising the planned merging of the current two-stage software of the ATLAS trigger.

  10. Performance and development plans for the Inner Detector trigger algorithms at ATLAS

    CERN Document Server

    Martin-Haugh, S; The ATLAS collaboration

    2014-01-01

    We present a description of the algorithms and the performance of the ATLAS Inner Detector trigger for LHC Run 1, as well as prospects for a redesign of the tracking algorithms in Run 2. The Inner Detector trigger algorithms are vital for many trigger signatures at ATLAS. The performance of the algorithms for electrons is presented. The ATLAS trigger software will be restructured from two software levels into a single stage which poses a big challenge on the trigger algorithms in terms of execution time and maintaining the physics performance. Expected future improvements in the timing and efficiencies of the Inner Detector triggers are discussed, utilising the planned merging of the current two-stage software of the ATLAS trigger.

  11. Integration of the Trigger and Data Acquisition Systems in ATLAS

    Energy Technology Data Exchange (ETDEWEB)

    Abolins, M.; /Michigan State U.; Adragna, P.; /Queen Mary, U. of London; Aleksandrov, E.; /Dubna, JINR; Aleksandrov, I.; /Dubna, JINR; Amorim, A.; /Lisbon, LIFEP; Anderson, K.; /Chicago U., EFI; Anduaga, X.; /La Plata U.; Aracena, I.; /SLAC; Asquith, L.; /University Coll. London; Avolio, G.; /CERN; Backlund, S.; /CERN; Badescu, E.; /Bucharest, IFIN-HH; Baines, J.; /Rutherford; Barria, P.; /Rome U. /INFN, Rome; Bartoldus, R.; /SLAC; Batreanu, S.; /Bucharest, IFIN-HH /CERN; Beck, H.P.; /Bern U.; Bee, C.; /Marseille, CPPM; Bell, P.; /Manchester U.; Bell, W.H.; /Glasgow U.; Bellomo, M.; /Pavia U. /INFN, Pavia /Regina U. /CERN /Annecy, LAPP /Paris, IN2P3 /Royal Holloway, U. of London /Napoli Seconda U. /INFN, Naples /Argonne /CERN /UC, Irvine /Barcelona, Autonoma U. /CERN /Montreal U. /CERN /Glasgow U. /Michigan State U. /Bucharest, IFIN-HH /Napoli Seconda U. /INFN, Naples /New York U. /Barcelona, Autonoma U. /Salento U. /INFN, Lecce /Pisa U. /INFN, Pisa /Bucharest, IFIN-HH /UC, Irvine /CERN /Glasgow U. /Genoa U. /INFN, Genoa /Lisbon, LIFEP /Napoli Seconda U. /INFN, Naples /UC, Irvine /Valencia U. /Rio de Janeiro Federal U. /University Coll. London /New York U. /University Coll. London; /more authors..

    2011-11-09

    During 2006 and the first half of 2007, the installation, integration and commissioning of trigger and data acquisition (TDAQ) equipment in the ATLAS experimental area have progressed. There have been a series of technical runs using the final components of the system already installed in the experimental area. Various tests have been run including ones where level 1 preselected simulated proton-proton events have been processed in a loop mode through the trigger and dataflow chains. The system included the readout buffers containing the events, event building, level 2 and event filter trigger algorithms. The scalability of the system with respect to the number of event building nodes used has been studied and quantities critical for the final system, such as trigger rates and event processing times, have been measured using different trigger algorithms as well as different TDAQ components. This paper presents the TDAQ architecture, the current status of the installation and commissioning and highlights the main test results that validate the system.

  12. The evolution of the Trigger and Data Acquisition System in the ATLAS experiment

    CERN Document Server

    Krasznahorkay, A; The ATLAS collaboration

    2013-01-01

    The ATLAS experiment, aimed at recording the results of LHC proton-proton collisions, is upgrading its Trigger and Data Acquisition (TDAQ) system during the current LHC first long shutdown. The purpose of such upgrade is to add robustness and flexibility to the selection and the conveyance of the physics data, simplify the maintenance of the infrastructure, exploit new technologies and, overall, make ATLAS data-taking capable of dealing with increasing event rates. The TDAQ system used to date is organised in a three-level selection scheme, including a hardware-based first-level trigger and second- and third-level triggers implemented as separate software systems distributed on commodity hardware nodes. The second-level trigger operates over limited regions of the detector, the so-called Regions-of-Interest (RoI). The third-level trigger deals instead with complete events. While this architecture was successfully operated well beyond the original design goals, the accumulated experience stimulated interest to...

  13. Triggering On Hadronic Tau Decays: A challenge met by ATLAS

    Directory of Open Access Journals (Sweden)

    Morgenstern Marcus M.

    2012-06-01

    Full Text Available The ATLAS experiment at the Large Hadron Collider (LHC has been able to collect 5.25 fb−1 of data in 2011. For many physics analyses both in context of the Standard Model (SM and Beyond the Standard Model (BSM theories such as Higgs boson searches, tau leptons play an important role. Thus, triggering on hadronic tau decays is an essential ingredient for the success of those measurements. This contribution will summarize the developed efforts to meet this challenge. Efficiency measurements using data taken in 2011 at a center-of-mass energy of 7 TeV are described and results are presented. An outlook on further developments of the tau trigger algorithms, to match future requirements and higher instantaneous luminosities are summarised in the end.

  14. The ATLAS Muon Trigger - Experience and Performance in the first 3 years of LHC pp runs

    CERN Document Server

    Ventura, A; The ATLAS collaboration

    2013-01-01

    The ATLAS experiment at CERN's Large Hadron Collider (LHC) deploys three-levels processing scheme for the trigger system. The level-1 muon trigger system gets its input from fast muon trigger detectors. Fast sector logic boards select muon candidates, which are passed via an interface board to the central trigger processor and then to the High Level Trigger (HLT). The muon HLT is purely software based and encompasses a level-2 trigger followed by an event filter for a staged trigger approach. It has access to the data of the precision muon detectors and other detector elements to refine the muon hypothesis. The ATLAS experiment has taken data with high efficiency continuously over entire running periods form 2010 to 2012, for which sophisticated triggers to guard the highest physics output while reducing effectively the event rate were mandatory. The ATLAS Muon trigger has successfully adapted to this changing environment. The selection strategy has been optimized for the various physics analysis involving mu...

  15. Upgrade of the Trigger Readout System of the ATLAS Liquid Argon Calorimeters

    CERN Document Server

    Marino, CP; The ATLAS collaboration

    2014-01-01

    The ATLAS detector was designed and built to study proton-proton collisions produced at the LHC at centre-of-mass energies up to 14 TeV and instantaneous luminosities up to $10^{34} \\rm{cm}^{-2} \\rm{s}^{-1}$. Liquid argon (LAr) sampling calorimeters are employed for all electromagnetic calorimetry in the pseudorapidity region $|\\eta|$ < 3.2, and for hadronic calorimetry in the region from $|\\eta|=$1.5 to $|\\eta|=$4.9. The ATLAS Liquid Argon (LAr) calorimeters produce a total of 182,486 signals which are digitized and processed by the front-end and back-end electronics at every triggered event. In addition, the front-end electronics sums analog signals to provide coarsely grained energy sums, called trigger towers, to the first-level trigger system, which is optimized for nominal LHC luminosities. In 2018, an instantaneous luminosity of 2-3 $\\times 10^{34} \\rm{cm}^{-2} \\rm{s}^{-1}$ is expected, far beyond the nominal one for which the detector was designed. In order to cope with this increased trigger rate,...

  16. Fast TracKer: A fast hardware track trigger for the ATLAS detector

    Science.gov (United States)

    Pandini, Carlo

    2016-07-01

    The trigger system at the ATLAS experiment is designed to lower the event rate occurring from the nominal bunch crossing rate of 40 MHz to about 1 kHz for a LHC luminosity of the order of 1034cm-2s-1. To achieve high background rejection while maintaining good efficiency for interesting physics signals, sophisticated algorithms are needed which require an extensive use of tracking information. The Fast TracKer (FTK) trigger system, part of the ATLAS trigger upgrade program, is a highly parallel hardware device designed to perform track-finding at 100 kHz. Modern, powerful Field Programmable Gate Arrays (FPGAs) form an important part of the system architecture, and the combinatorial problem of pattern recognition is solved by 8000 standard-cell ASICs used to implement an Associative Memory architecture. The availability of the tracking and subsequent vertex information within a short latency ensures robust selections and allows improved trigger performance for the most difficult signatures, such as b-jets and τ leptons.

  17. A Hardware Fast Tracker for the ATLAS Trigger: The Fast TracKer (FTK) Project.

    CERN Document Server

    Asbah, Nedaa; The ATLAS collaboration

    2015-01-01

    The trigger system of the ATLAS experiment is designed to reduce the event rate from the LHC nominal bunch crossing at 40 MHz to about 1 kHz, at the design luminosity of 10^{34} cm^{-2} s{-1}. After a successful period of data taking from 2010 to early 2013, the LHC is restarting in 2015 with much higher instantaneous luminosity and this will increase the load on High Level Trigger system, the second stage of the selection based on software algorithms. More sophisticated algorithms will be needed to achieve higher background rejection while maintaining good efficiency for interesting physics signals. The Fast TracKer is part of the ATLAS trigger upgrade project; it is a hardware processor that will provide, at every level-1 accept (100 kHz) and within 100 microseconds, full tracking information for tracks with momentum as low as 1 GeV. Providing fast extensive access to tracking information, with resolution comparable to the offline reconstruction, the Fast Tracker will for example help the High Level Trigger...

  18. The Muon Spectrometer Barrel Level-1 Trigger of the ATLAS Experiment at LHC

    CERN Document Server

    Aloisio, A; Conventi, F; De Asmundis, R; Izzo, V; Migliaccio, A; Ciapetti, G; Di Mattia, A; Luci, C; Luminari, L; Nisati, A; Pastore, F; Petrolo, E; Vari, R; Veneziano, Stefano; Salamon, A

    2006-01-01

    The proton-proton beam crossing at the LHC accelerator at CERN will have a rate of 40 MHz at the project luminosity. The ATLAS Trigger System has been designed in three levels in order to select only interesting physics events reducing from that rate of 40 MHz to the foreseen storage rate of about 200 Hz. The First Level reduces the output rate to about 100 kHz. The ATLAS Muon Spectrometer has been designed to perform stand-alone triggering and measurement of muon transverse momentum up to 1 TeV/c with good resolution (from 3% at 10 GeV/c up to 10% at 1 TeV/c). In the Barrel region of the Muon Spectrometer the Level-1 trigger is given by means of three layers of Resistive Plate Chamber detectors (RPC): a gaseous detector working in avalanche mode composed by two plates of high-resistivity bakelite and two orthogonal planes of read-out strips. The logic of the Level-1 barrel muon trigger is based on the search of patterns of RPC hits in the three layers consistent with a high transverse momentum muon track ori...

  19. B-Identifikation im Level 2 Trigger des ATLAS Experiments

    CERN Document Server

    AUTHOR|(CDS)2072780

    Zur Zeit wird am europäischen Forschungszentrum für Teilchenphysik CERN der neue Proton-Proton-Speicherring LHC und die zugehörigen vier Experimente gebaut. Ziele der Experimente sind unter anderem der Nachweis des Higgs-Bosons sowie detaillierte Studien des top-Quarks. Um möglichst reine Datensätze zu erhalten wäre es hilfreich, diese Ereignisse bereits während der Datennahme möglichst effizient zu selektieren. Dabei würde es helfen, wenn b-Quark-Jets auf Trigger-Niveau erkannt werden könnten. Ziel der Arbeit war die Entwicklung eines Algorithmus zur Identifikation von b-Quark-Jets, welcher die Anforderungen des Level 2 Triggers erfüllt. Das erste Kapitel der Arbeit gibt einen Einblick in die wesentlichen Bestandteile des Standardmodells der Teilchenphysik. In den folgenden zwei Kapiteln wird der Beschleuniger und der ATLAS Detektor sowie das ATLAS-Triggersystem beschrieben. Kapitel vier beschreibt die Möglichkeiten der B-Jet-Identifikation sowie einen Vertexalgorithmus auf Basis der Perigee-Pa...

  20. Studies for the development of the Inner Detector trigger algorithms at ATLAS

    CERN Document Server

    The ATLAS collaboration

    2013-01-01

    A description of the ATLAS Inner Detector (ID) sofware trigger algorithms running online on the high level trigger (HLT) processor farm is presented. The prospects for a redesign of the ID trigger afforded by the 2013-2014 long shutdown are discussed. The ID trigger HLT algorithms are essential for many trigger signatures within the ATLAS trigger. During the shutdown, the ATLAS HLT software will be restructured to run in a single stage rather than in the two distinct levels present during the Run I operation. This poses significant challenges for the trigger algorithms both in terms of execution time, and physics perfor- mance. Expected future improvements in the timing and efficiencies of the Inner Detector triggers within the new merged single stage architecture are also discussed. In addition, potential improvements in the algorithm performance resulting from the additional spacepoint information from the new Insertable B-Layer are also presented.

  1. A new scheme for ATLAS trigger simulation using legacy code

    International Nuclear Information System (INIS)

    Analyses at the LHC which search for rare physics processes or determine with high precision Standard Model parameters require accurate simulations of the detector response and the event selection processes. The accurate determination of the trigger response is crucial for the determination of overall selection efficiencies and signal sensitivities. For the generation and the reconstruction of simulated event data, the most recent software releases are usually used to ensure the best agreement between simulated data and real data. For the simulation of the trigger selection process, however, ideally the same software release that was deployed when the real data were taken should be used. This potentially requires running software dating many years back. Having a strategy for running old software in a modern environment thus becomes essential when data simulated for past years start to present a sizable fraction of the total. We examined the requirements and possibilities for such a simulation scheme within the ATLAS software framework and successfully implemented a proof-of-concept simulation chain. One of the greatest challenges was the choice of a data format which promises long term compatibility with old and new software releases. Over the time periods envisaged, data format incompatibilities are also likely to emerge in databases and other external support services. Software availability may become an issue, when e.g. the support for the underlying operating system might stop. In this paper we present the encountered problems and developed solutions, and discuss proposals for future development. Some ideas reach beyond the retrospective trigger simulation scheme in ATLAS as they also touch more generally aspects of data preservation.

  2. ATLAS Jet Trigger Performance in LHC Run I and Initial Run II Results

    CERN Document Server

    Shimizu, Shima; The ATLAS collaboration

    2015-01-01

    The immense rate of proton-proton collisions at the Large Hadron Collider (LHC) must be reduced from the nominal bunch-crossing rate of 40 MHz to approximately 1 kHz before the data can be written on disk offline. The ATLAS Trigger System performs real-time selection of these events in order to achieve this reduction. Dedicated selection of events containing jets is uniquely challenging at a hadron collider where nearly every event contains significant hadronic energy. Following the very successful first LHC run from 2010 to 2012, the ATLAS Trigger was much improved, including a new hardware topological module and a restructured High Level Trigger system, merging two previous software-based processing levels. This allowed the optimization of resources and a much greater re-use of the precise but costly offline software base. After summarising the overall performance of the jet trigger during the first LHC run, the software design choices and use of the topological module will be reviewed. The expected perform...

  3. Commissioning of the ATLAS high-level trigger with single beam and cosmic rays

    CERN Document Server

    Özcan, V Erkcan

    2010-01-01

    ATLAS is one of the two general-purpose detectors at the Large Hadron Collider (LHC). Using fast reconstruction algorithms, its trigger system needs to efficiently reject a huge rate of background events and still select potentially interesting ones with good efficiency. After a first processing level using custom electronics, the trigger selection is made by software running on two processor farms, designed to have a total of around two thousand multi-core machines. This system is known as the High Level Trigger (HLT). To reduce the network data traffic and the processing time to manageable levels, the HLT uses seeded, step-wise reconstruction, aiming at the earliest possible rejection of background events. The recent LHC startup and short single-beam run provided a "stress test" of the trigger. Following this period, ATLAS continued to collect cosmic-ray events for detector alignment and calibration purposes. These running periods allowed strict tests of the HLT reconstruction and selection algorithms as we...

  4. Upgraded readout and trigger electronics for the ATLAS liquid argon calorimeters for future LHC running

    CERN Document Server

    Yamanaka, T; The ATLAS collaboration

    2014-01-01

    The ATLAS Liquid Argon (LAr) calorimeters produce almost 200K signals that must be digitized and processed by the front-end and back-end electronics at every triggered event. Additionally, the front-end electronics sums analog signals to provide coarse-grained energy sums to the first-level (L1) trigger system. The current design was optimized for the nominal LHC luminosity of 10^34 cm^-2s^-1. However, in future higher-luminosity phases of LHC operation, the luminosity (and associated pile-up noise) will be 3-7 times higher. An improved spatial granularity of the trigger primitives is therefore proposed, in order to improve the trigger performance at high background rejection rates. For the first upgrade phase in 2018, new LAr Trigger Digitizer Boards are being designed to receive the higher granularity signals, digitize them on-detector and send them via fast optical links to a new digital processing system (DPS). This applies digital filtering and identifies significant energy depositions in each trigger ch...

  5. Upgraded readout and trigger electronics for the ATLAS liquid argon calorimeters for future LHC running

    CERN Document Server

    Ma, Hong; The ATLAS collaboration

    2014-01-01

    The ATLAS Liquid Argon (LAr) calorimeters produce almost 200K signals that must be digitized and processed by the front-end and back-end electronics for every triggered event. Additionally, the front-end electronics sums analog signals to provide coarse-grained energy sums to the first-level (L1) trigger system. The current design was optimized for the nominal LHC luminosity of 10^34/cm^2/s. However, in future higher-luminosity phases of LHC operation, the luminosity (and associated pile-up noise) will be 3-7 times higher. An improved spatial granularity of the trigger primitives is therefore proposed, in order to improve the trigger performance at high background rejection rates. For the first upgrade phase in 2018, new LAr Trigger Digitizer Boards are being designed to receive the higher granularity signals, digitize them on-detector and send them via fast optical links to a new digital processing system (DPS). This applies digital filtering and identifies significant energy depositions in each trigger chan...

  6. Upgrade readout and trigger electronics for the ATLAS liquid argon calorimeters for future LHC running

    CERN Document Server

    Yamanaka, T; The ATLAS collaboration

    2014-01-01

    The ATLAS Liquid Argon (LAr) calorimeters produce almost 200K signals that must be digitized and processed by the front-end and back-end electronics at every triggered event. Additionally, the front-end electronics sums analog signals to provide coarse-grained energy sums to the first-level (L1) trigger system. The current design was optimized for the nominal LHC luminosity of 10^34 cm^-2s^-1. However, in future higher-luminosity phases of LHC operation, the luminosity (and associated pile-up noise) will be 3-7 times higher. An improved spatial granularity of the trigger primitives is therefore proposed, in order to improve the trigger performance at high background rejection rates. For the first upgrade phase in 2018, new LAr Trigger Digitizer Boards are being designed to receive the higher granularity signals, digitize them on-detector and send them via fast optical links to a new digital processing system (DPS). This applies digital filtering and identifies significant energy depositions in each trigger ch...

  7. The Upgrade of the ATLAS First Level Calorimeter Trigger

    CERN Document Server

    Yamamoto, Shimpei; The ATLAS collaboration

    2015-01-01

    The Level-1 calorimeter trigger (L1Calo) operated successfully during the first data taking phase of the ATLAS experiment at the LHC. Based on the lessons learned, a series of upgrades is planned for L1Calo to face the new challenges posed by the upcoming increases of the LHC beam energy and luminosity. The initial upgrade phase in 2013-15 includes substantial improvements to the analogue and digital signal processing to cope with baseline shifts due to signal pile-up. Additionally a newly introduced system will receive real-time data from both the upgraded L1Calo and L1Muon trigger to perform trigger algorithms based on entire event topologies. During the second upgrade phase in 2018-19 major parts of L1Calo will be rebuilt in order to exploit a tenfold increase in the available calorimeter data granularity compared to that of the current system. In this contribution we present the lessons learned during the first period of LHC data taking. Based on these we discuss the expected performance improvements toge...

  8. Upgrade of the ATLAS Level-1 Calorimeter Trigger

    CERN Document Server

    Mueller, Felix; The ATLAS collaboration

    2014-01-01

    The Level-1 calorimeter trigger (L1Calo) operated successfully during the first data taking phase of the ATLAS experiment at the LHC. Facing the new challenges posed by the upcoming increases of the LHC beam energy and luminosity, and from the experience of the previous running, a series of upgrades is planned for L1Calo. The initial upgrade phase in 2013-14 includes substantial improvements to the analogue and digital signal processing to cope with baseline shifts due to signal pile-up. Additionally a newly introduced system will receive real-time data from both the upgraded L1Calo and L1Muon trigger to perform trigger algorithms based on entire event topologies. During the second upgrade phase in 2018-19 major parts of L1Calo will be rebuilt in order to exploit a tenfold increase in the available calorimeter data granularity compared to that of the current system. The contribution gives an overview of the existing system and the lessons learned during the first period of LHC data taking. Based on these, the...

  9. Upgrade of the ATLAS Level-1 Calorimeter Trigger

    CERN Document Server

    Mueller, Felix; The ATLAS collaboration

    2014-01-01

    The Level-1 calorimeter trigger (L1Calo) operated successfully during the first data taking phase of the ATLAS experiment at the LHC. Based on the lessons learned , a series of upgrades is planned for L1Calo to face the new challenges posed by the upcoming increases of the LHC beam energy and luminosity. The initial upgrade phase in 2013-14 includes substantial improvements to the analogue and digital signal processing to cope with baseline shifts due to signal pile-up. Additionally a newly introduced system will receive real-time data from both the upgraded L1Calo and L1Muon trigger to perform trigger algorithms based on entire event topologies. During the second upgrade phase in 2018-19 major parts of L1Calo will be rebuilt in order to exploit a tenfold increase in the available calorimeter data granularity compared to that of the current system. In this contribution we present the lessons learned during the first period of LHC data taking. Based on these we discuss the expected performance improvements tog...

  10. Upgrade of the ATLAS Level-1 Calorimeter Trigger

    CERN Document Server

    Wessels, M; The ATLAS collaboration

    2014-01-01

    The Level-1 Calorimeter Trigger (L1Calo) of the ATLAS experiment has been operating well since the start of LHC data taking, and played a major role in the Higgs boson discovery. To face the new challenges posed by the upcoming increases of the LHC proton beam energy and luminosity, a series of upgrades is planned for L1Calo. The initial upgrade phase in 2013-14 includes substantial improvements to the analogue and digital signal processing to allow more sophisticated digital filters for energy and timing measurement, as well as compensate for pile-up and baseline shifting effects. Two existing digital algorithm processor subsystems will receive substantial hardware and firmware upgrades to increase the real-time data path bandwidth, allowing topological information to be transmitted and processed at Level-1. An entirely new subsystem, the Level-1 Topological Processor, will receive real-time data from both the upgraded L1Calo and Level-1 Muon Trigger to perform trigger algorithms based on entire event topolo...

  11. The readiness of the ATLAS Trigger-DAQ system for the second LHC run

    CERN Document Server

    Rammensee, Michael; The ATLAS collaboration

    2015-01-01

    After its first shutdown, the Large Hadron Collider (LHC) will provide proton-proton collisions with increased luminosity and energy. In the ATLAS experiment~\\cite{Atlas}, the Trigger and Data Acquisition (TDAQ) system has been upgraded to deal with the increased event rates~\\cite{TDAQPhase1}. The updated system is radically different from the previous implementation, both in terms of architecture and expected performance. The main architecture has been reshaped in order to profit from the technological progress and to maximize the flexibility and efficiency of the data selection process. Design choices and the strategies employed to minimize the data-collection and the selection latency will be discussed. First results of tests done during the commissioning phase and the operational performance after the first months of data taking will be presented.

  12. Triggering on 7 TeV Collisions with the ATLAS High Level Trigger

    CERN Document Server

    Fedorko, W; The ATLAS collaboration

    2010-01-01

    In 2010 ATLAS has seen the first proton-proton collisions at 7 TeV. Later this year a collision rate of nearly 10 MHz is expected. Events of potential interest for physics analysis are selected by a three-level trigger system, with a final recording rate of about 200 Hz. The first level (L1) is implemented in customized hardware, the two levels of the high level trigger (HLT) are software triggers. The selection is described by the Trigger Configuration in the form of menus, each of which contains more than 500 signatures. Each signature corresponds to a chain of algorithms which reconstruct and refine specific event features. The HLT Steering receives information from the Configuration system, dynamically creates chains and controls the execution of algorithms and flow of information during event processing. The Steering tests each signature on L1-accepted events, and those satisfying one or more test are recorded for later analysis. To save execution time, the Steering has a facility to cache results, avoid...

  13. The readiness of ATLAS Trigger-DAQ system for the second LHC run

    CERN Document Server

    Rammensee, Michael; The ATLAS collaboration

    2015-01-01

    After its first shutdown, LHC will provide pp collisions with increased luminosity and energy. In the ATLAS experiment, the Trigger and Data Acquisition (TDAQ) system has been upgraded to deal with the increased event rates. The updated system is radically different from the previous implementation, both in terms of architecture and expected performance. The main architecture has been reshaped in order to profit from the technological progress and to maximize the flexibility and efficiency of the data selection process. The trigger system in ATLAS consists of a hardware Level-1 (L1) and a software based high-level trigger (HLT) that reduces the event rate from the design bunch-crossing rate of 40 MHz to an average recording rate of a few hundred Hz. The pre-existing two-level software filtering, known as L2 and the Event Filter, are now merged into a single process, performing incremental data collection and analysis. This design has many advantages, among which are: the radical simplification of the architec...

  14. Evolution of the ATLAS Trigger and Data Acquisition System

    CERN Document Server

    Pozo Astigarraga, M E; The ATLAS collaboration

    2014-01-01

    ATLAS is a Physics experiment that explores high-energy particle collisions at the Large Hadron Collider at CERN. It uses tens of millions of electronics channels to capture the outcome of the particle bunches crossing each other every 25 ns. Since reading out and storing the complete information is not feasible (~100 TB/s), ATLAS makes use of a complex and highly distributed Trigger and Data Acquisition (TDAQ) system, in charge of selecting only interesting data and transporting those to permanent mass storage (~1 GB/s) for later analysis. The data reduction is carried out in two stages: first, custom electronics performs an initial level of data rejection for each bunch crossing based on partial and localized information. Only data corresponding to collisions passing this stage of selection will be actually read-out from the on-detector electronics. Then, a large computer farm (~17 k cores) analyses these data in real-time and decides which ones are worth being stored for Physics analysis. A large network a...

  15. Evolution of the ATLAS Trigger and Data Acquisition System

    CERN Document Server

    Pozo Astigarraga, M E; The ATLAS collaboration

    2015-01-01

    ATLAS is a Physics experiment that explores high-energy particle collisions at the Large Hadron Collider at CERN. It uses tens of millions of electronics channels to capture the outcome of the particle bunches crossing each other every 25 ns. Since reading out and storing the complete information is not feasible (~100 TB/s), ATLAS makes use of a complex and highly distributed Trigger and Data Acquisition (TDAQ) system, in charge of selecting only interesting data and transporting those to permanent mass storage (~1 GB/s) for later analysis. The data reduction is carried out in two stages: first, custom electronics performs an initial level of data rejection for each bunch crossing based on partial and localized information. Only data corresponding to collisions passing this stage of selection will be actually read-out from the on-detector electronics. Then, a large computer farm (~17 k cores) analyses these data in real-time and decides which ones are worth being stored for Physics analysis. A large network a...

  16. The Resource utilization by ATLAS High Level Triggers. The contributed talk for the Technology and Instrumentation in Particle Physics 2011.

    CERN Document Server

    Ospanov, R; The ATLAS collaboration

    2011-01-01

    In 2010 the ATLAS experiment has successfully recorded data from LHC collisions with high efficiency and excellent data quality. ATLAS employs a three-level trigger system to select events of interest for physics analyses and detector commissioning. The trigger system consists of a custom-designed hardware trigger at level-1 (L1) and software algorithms executing on commodity servers at the two higher levels: second level trigger (L2) and event filter (EF). The corresponding trigger rates are 75~kHz, 3~kHz and 200~Hz. The L2 uses custom algorithms to examine a small fraction of data at full detector granularity in Regions of Interest selected by the L1. The EF employs offline algorithms and full detector data for more computationally intensive analysis. The trigger selection is defined by trigger menus which consist of more than 500 individual trigger signatures, such as electrons, muons, particle jets, etc. An execution of a trigger signature incurs computing and data storage costs. A composition of the depl...

  17. Verification and Diagnostics Framework in ATLAS Trigger/DAQ

    CERN Document Server

    Barczyk, M; Caprini, M; Da Silva-Conceicao, J; Dobson, M; Flammer, J; Jones, R; Kazarov, A; Kolos, S; Liko, D; Lucio, L; Mapelli, L; Soloviev, I; Hart, R; Amorim, A; Klose, D; Lima, J; Pedro, L; Wolters, H; Badescu, E; Alexandrov, I; Kotov, V; Mineev, M A; Ryabov, Yu; CHEP 2003 Computing in High Energy Physics

    2003-01-01

    Trigger and data acquisition (TDAQ) systems for modern HEP experiments are composed of thousands of hardware and software components depending on each other in a very complex manner. Typically, such systems are operated by non-expert shift operators, which are not aware of system functionality details. It is therefore necessary to help the operator to control the system and to minimize system down-time by providing knowledge-based facilities for automatic testing and verification of system components and also for error diagnostics and recovery. For this purpose, a verification and diagnostic framework was developed in the scope of ATLAS TDAQ. The verification functionality of the framework allows developers to configure simple low-level tests for any component in a TDAQ configuration. The test can be configured as one or more processes running on different hosts. The framework organizes tests in sequences, using knowledge about components hierarchy and dependencies, and allowing the operator to verify the fun...

  18. The Phase-1 Upgrade of the ATLAS First Level Calorimeter Trigger

    CERN Document Server

    Schwienhorst, Reinhard; The ATLAS collaboration

    2015-01-01

    The ATLAS level-1 calorimeter trigger pursues a series of upgrades in order to face the challenges posed by the upcoming increase of the LHC luminosity. The hardware built during the Phase-1 upgrade will be installed in 2018. The calorimeter data will be available with a tenfold increase of granularity which allows to employ more sophisticated identification algorithms. To cope with this increase of input data, an entirely new custom electronics processing system will be built exploiting the technological advances in the design of complex PCBs, powerful FPGAs, new crate technologies and high speed optical interconnects.

  19. The Phase-1 Upgrade of the ATLAS First Level Calorimeter Trigger

    CERN Document Server

    Schwienhorst, Reinhard; The ATLAS collaboration

    2015-01-01

    The ATLAS level-1 calorimeter trigger pursues a series of upgrades in order to face the challenges posed by the upcoming increase of the LHC beam energy and luminosity. The hardware built during the Phase-1 upgrade will be installed in 2018. The calorimeter data will be available with a tenfold increase of granularity which allows to employ more sophisticated identification algorithms. To cope with this increase of input data, an entirely new custom electronics processing system will be built exploiting the technological advances in the design of complex PCBs, powerful FPGAs, new crate technologies and high speed optical interconnects.

  20. Trigger Data Serializer ASIC chip for the ATLAS New Small Wheel sTGC Detector

    Science.gov (United States)

    Meng, Xiangting; Wang, Jinhong; Guan, Liang; Sang, Ziru; Chapman, John; Zhou, Bing; Zhu, Junjie

    2015-04-01

    The small-strip thin-gap chambers (sTGC) will be used as the trigger device for the Phase-I upgrade of the ATLAS new small wheel (nSW) muon detector. An Application-Specific Integrated Circuit (ASIC) chip is needed to collect digital signals from both pad and strip detectors and serialize the outputs to the circuitry located on the rim of the nSW. The large number of input channels (128 differential input channels), short time available to prepare and transmit trigger data (power consumption (<1 W) impose great challenges for the design of this ASIC chip using the IBM 130 nm CMOS process. We will present our design and test results based on the prototype chip we build.

  1. Evolution of the Trigger and Data Acquisition System for the ATLAS experiment

    CERN Document Server

    Negri, A; The ATLAS collaboration

    2012-01-01

    The ATLAS experiment at the Large Hadron Collider at CERN relies on a complex and highly distributed Trigger and Data Acquisition (TDAQ) system to gather and select particle collision data at unprecedented energy and rates. The TDAQ is composed of three levels which reduces the event rate from the design bunch-crossing rate of 40 MHz to an average event recording rate of about 200 Hz. The first part of this paper gives an overview of the operational performance of the DAQ system during 2011 and the first months of data taking in 2012. It describes how the flexibility inherent in the design of the system has be exploited to meet the changing needs of ATLAS data taking and in some cases push performance beyond the original design performance specification. The experience accumulated in the TDAQ system operation during these years stimulated also interest to explore possible evolutions, despite the success of the current design. One attractive direction is to merge three systems - the second trigger level (L2), ...

  2. Performance and development plans for the Inner Detector trigger algorithms at ATLAS

    Science.gov (United States)

    Martin-Haugh, Stewart

    2015-12-01

    A description of the design and performance of the newly re-implemented tracking algorithms for the ATLAS trigger for LHC Run 2, to commence in spring 2015, is presented. The ATLAS High Level Trigger (HLT) has been restructured to run as a more flexible single stage process, rather than the two separate Level 2 and Event Filter stages used during Run 1. To make optimal use of this new scenario, a new tracking strategy has been implemented for Run 2. This new strategy will use a FastTrackFinder algorithm to directly seed the subsequent Precision Tracking, and will result in improved track parameter resolution and significantly faster execution times than achieved during Run 1 and with better efficiency. The timings of the algorithms for electron and tau track triggers are presented. The profiling infrastructure, constructed to provide prompt feedback from the optimisation, is described, including the methods used to monitor the relative performance improvements as the code evolves. The online deployment and commissioning are also discussed.

  3. Performance and development plans for the Inner Detector trigger algorithms at ATLAS

    CERN Document Server

    Martin-haugh, Stewart; The ATLAS collaboration

    2015-01-01

    A description of the design and performance of the newly re-implemented tracking algorithms for the ATLAS trigger for LHC Run 2, to commence in spring 2015, is presented. The ATLAS High Level Trigger (HLT) has been restructured to run as a more flexible single stage process, rather than the two separate Level 2 and Event Filter stages used during Run 1. To make optimal use of this new scenario, a new tracking strategy has been implemented for Run 2. This new strategy will use a FastTrackFinder algorithm to directly seed the subsequent Precision Tracking, and will result in improved track parameter resolution and significantly faster execution times than achieved during Run 1 and with better efficiency. The timings of the algorithms for electron and tau track triggers are presented. The profiling infrastructure, constructed to provide prompt feedback from the optimisation, is described, including the methods used to monitor the relative performance improvements as the code evolves. The online deployment and co...

  4. Performance and development plans for the Inner Detector trigger algorithms at ATLAS

    CERN Document Server

    Martin-haugh, Stewart; The ATLAS collaboration

    2015-01-01

    A description of the design and performance of the newly re-implemented tracking algorithms for the ATLAS trigger for LHC Run 2, to commence in spring 2015, is presented. The ATLAS High Level Trigger (HLT) has been restructured to run as a more flexible single stage process, rather than the two separate Level 2 and Event Filter stages used during Run 1. To make optimal use of this new scenario, a new tracking strategy has been implemented for Run 2. This new strategy will use a Fast Track Finder (FTF) algorithm to directly seed the subsequent Precision Tracking, and will result in improved track parameter resolution and significantly faster execution times than achieved during Run 1 and with better efficiency. The performance and timing of the algorithms for electron and tau track triggers are presented. The profiling infrastructure, constructed to provide prompt feedback from the optimisation, is described, including the methods used to monitor the relative performance improvements as the code evolves. The o...

  5. The Performance and development of the ATLAS Inner Detector trigger at the LHC

    CERN Document Server

    Sutton, M; The ATLAS collaboration

    2013-01-01

    A description of the algorithms and performance of the ATLAS Inner Detector trigger for LHC Run 1, and the prospects for a redesign of the tracking algorithms for Run 2 are presented. The Inner Detector trigger algorithms are vital for many trigger signatures at ATLAS. The performance of the algorithms for electron reconstruction is presented. The upgrade of the LHC to 13-14 TeV centre-of-mass energy will present a significant challenge for the trigger algorithms in terms of the execution time and in order to maintain the physics performance. To deal the expected high rates, the ATLAS High Level Trigger software is being restructured from two software levels used in LHC Run 1 to run as a single stage for Run 2. Expected future improvements in the timing and efficiencies of the Inner Detector triggers are briefly discussed

  6. The Octant Module of the ATLAS Level-1 Muon to Central Trigger Processor Interface

    CERN Document Server

    Haas, Stefan; Berge, D; Ellis, Nick; Farthouat, P; Krasznahorkay, A; Pauly, T; Schuler, G; Spiwoks, R; Wengler, T

    2007-01-01

    The Muon to Central Trigger Processor Interface (MUCTPI) of the ATLAS Level-1 trigger receives data from the sector logic modules of the muon trigger at every bunch crossing and calculates the total multiplicity of muon candidates, which is then sent to the Central Trigger Processor where the final Level-1 decision is taken. The MUCTPI system consists of a 9U VME crate with a special backplane and 18 custom designed modules. We focus on the design and implementation of the octant module (MIOCT). Each of the 16 MIOCT modules processes the muon candidates from 13 sectors of one half-octant of the detector and forms the local muon candidate multiplicities for the trigger decision. It also resolves the overlaps between chambers in order to avoid double-counting of muon candidates that are detected in more than one sector. The handling of overlapping sectors is based on Look-Up-Tables (LUT) for maximum flexibility. The MIOCT also sends the information on the muon candidates over the custom backplane via the Readou...

  7. Using FTK tracks for particle flow reconstruction at the high-level trigger of ATLAS

    CERN Document Server

    Jaeger, Benjamin Paul

    2016-01-01

    The Fast Tracker (FTK) enables the ATLAS high-level trigger (HLT) to have early access to global tracking information. The project of my Summer Student Internship at CERN was to investigate the potential of using particle flow reconstruction with FTK tracks at the ATLAS HLT. This report shortly summarizes my studies, ranging from comparison of FTK tracks with offline tracks to more sophisticated analyses, such as assessing the jet resolution and trigger related properties.

  8. Optimisation of the level-1 calorimeter trigger at ATLAS for Run II

    Energy Technology Data Exchange (ETDEWEB)

    Suchek, Stanislav [Kirchhoff-Institute for Physics, Im Neuenheimer Feld 227, 69120 Heidelberg (Germany); Collaboration: ATLAS-Collaboration

    2015-07-01

    The Level-1 Calorimeter Trigger (L1Calo) is a central part of the ATLAS Level-1 Trigger system, designed to identify jet, electron, photon, and hadronic tau candidates, and to measure their transverse energies, as well total transverse energy and missing transverse energy. The optimisation of the jet energy resolution is an important part of the L1Calo upgrade for Run II. A Look-Up Table (LUT) is used to translate the electronic signal from each trigger tower to its transverse energy. By optimising the LUT calibration we can achieve better jet energy resolution and better performance of the jet transverse energy triggers, which are vital for many physics analyses. In addition, the improved energy calibration leads to significant improvements of the missing transverse energy resolution. A new Multi-Chip Module (MCM), as a part of the L1Calo upgrade, provides two separate LUTs for jets and electrons/photons/taus, allowing to optimise jet transverse energy and missing transverse energy separately from the electromagnetic objects. The optimisation is validated using jet transverse energy and missing transverse energy triggers turn-on curves and rates.

  9. Electronics Development for the ATLAS Liquid ArgonCalorimeter Trigger and Readout for Future LHC Running

    CERN Document Server

    Hopkins, Walter; The ATLAS collaboration

    2016-01-01

    The upgrade of the LHC will provide 7 times greater instantaneous and total luminosities than assumed in the original design of the ATLAS Liquid Argon (LAr) Calorimeters. Radiation tolerance criteria and an improved trigger system with higher acceptance rate and longer latency require an upgrade of the LAr readout electronics. In the first upgrade phase in 2019-2020, a trigger readout with up to 10 times higher granularity will be implemented. This allows an improved reconstruction of electromagnetic and hadronic showers and will reduce the background for electron, photon and energy-flow signals at the first trigger level. The analog and digital signal processing components are currently in their final design stages and a fully functional demonstrator system is operated and tested on the LAr Calorimeters. In a second upgrade stage in 2024-2026, the readout of all 183,000 LAr Calorimeter cells will be performed without trigger selection at 40 MHz sampling rate and 16 bit dynamic range. Calibrated energies of a...

  10. Electronics Development for the ATLAS Liquid Argon Calorimeter - Trigger and Readout for Future LHC Running -

    CERN Document Server

    Starz, Steffen; The ATLAS collaboration

    2016-01-01

    The upgrade of the LHC will provide up to 7.5 times greater instantaneous and total luminosities than assumed in the original design of the ATLAS Liquid Argon (LAr) Calorimeters. Radiation tolerance criteria and an improved trigger system with higher acceptance rate and longer latency require an upgrade of the LAr readout electronics. In the first upgrade phase in 2019-2020, a trigger-readout with up to 10 times higher granularity will be implemented. This allows an improved reconstruction of electromagnetic and hadronic showers and will reduce the background for electron, photon and energy-flow signals at the first trigger level. The analog and digital signal processing components are currently in their final design stages and a fully functional demonstrator system is operated and tested on the LAr Calorimeters. In a second upgrade stage in 2024-2026, the readout of all 183,000 LAr Calorimeter cells will be performed without trigger selection at 40 MHz sampling rate and 16 bit dynamic range. Calibrated energ...

  11. Electronics Development for the ATLAS Liquid Argon Calorimeter Trigger and Readout for Future LHC Running

    CERN Document Server

    Hopkins, Walter; The ATLAS collaboration

    2016-01-01

    The upgrade of the LHC will provide 7 times greater instantaneous and total luminosities than assumed in the original design of the ATLAS Liquid Argon (LAr) Calorimeters. Radiation tolerance criteria and an improved trigger system with higher acceptance rate and longer latency require an upgrade of the LAr readout electronics. In the first upgrade phase in 2019-2020, a trigger readout with up to 10 times higher granularity will be implemented. This allows an improved reconstruction of electromagnetic and hadronic showers and will reduce the background for electron, photon and energy-flow signals at the first trigger level. The analog and digital signal processing components are currently in their final design stages and a fully functional demonstrator system is operated and tested on the LAr Calorimeters. In a second upgrade stage in 2024-2026, the readout of all 183,000 LAr Calorimeter cells will be performed without trigger selection at 40 MHz sampling rate and 16 bit dynamic range. Calibrated energies of a...

  12. Simulation of the new topological processor in the ATLAS first level trigger

    International Nuclear Information System (INIS)

    The LHC will start again in May 2015 with proton-proton collisions at a center of mass energy of √(s)=13 TeV. This results in an increased rate of collisions and a new approach is needed in order to keep high efficiencies for processes of interest at the first level trigger stage. A new trigger module for the first level trigger stage of the ATLAS experiment has been developed in order to achieve this. This new trigger module, the topological processor, is able to make trigger decisions based on topological observables, for example angular correlations of trigger objects from the ATLAS calorimeter and muon system. This talk concentrates on the validation of the trigger decision and read-out of the topological processor by using a bit-wise simulation of the module. The basic strategy how the hardware is validated, and first results are presented.

  13. Operational Experience of the ATLAS High Level Trigger with Single-Beam and Cosmic Rays

    CERN Document Server

    Aracena, I; The ATLAS collaboration

    2009-01-01

    ATLAS is one of two general-purpose detectors at the LHC. Using fast reconstruction algorithms, the trigger system needs to efficiently reject a large rate of background events while keeping potentially interesting ones with high efficiency. After a first level trigger implemented in custom electronics, the trigger selection is made by software running on two processor farms (the High Level Trigger system), containing a total of around two thousand multi-core machines. To reduce the network data traffic and the processing time to manageable levels, the HLT uses seeded, step-wise event reconstruction, aiming at the earliest possible rejection of background events. The LHC start up and single-beam run periods in 2008 provided a "stress test" of the trigger system. Following this period, ATLAS continued to collect cosmic-ray events for detector alignment and calibration as well as for commissioning the trigger. These running periods allowed us to exercise the trigger system online, including its configuration an...

  14. FTK: A Hardware Real-Time Track Finder for the ATLAS Trigger System

    CERN Document Server

    ATLAS Collaboration; The ATLAS collaboration

    2016-01-01

    An overview of the ATLAS Fast Tracker processor will be presented, reporting the design of the system, its expected performance, and the current integration status. The Fast TracKer is an upgrade of the trigger system at the ATLAS experiment. This system is designed to lower the event rate from the proton-proton collisions occurring at 40 MHz to about 1 kHz for the expected LHC luminosity (2x1034cm-2s-1). To achieve this selection rate an intensive use of particle tracking must be exploited. For such a demanding application a dedicated hardware tracker was designed, the Fast TracKer processor. To achieve the required performance Fast TracKer uses a combination of custom designed VLSI chips and latest generation FPGAs, all embedded in custom designed boards, exploiting a fully parallel architecture. Fast TracKer provides track reconstruction based on the full silicon (inner) detector with resolution comparable to the offline reconstruction with a latency of approximately 100μs.

  15. FTK: A HARDWARE REAL-TIME TRACK FINDER FOR THE ATLAS TRIGGER SYSTEM

    CERN Document Server

    Stabile, Alberto; The ATLAS collaboration

    2016-01-01

    An overview of the ATLAS Fast Tracker processor will be presented, reporting the design of the system, its expected performance, and the current integration status. The Fast TracKer is an upgrade of the trigger system at the ATLAS experiment. This system is designed to lower the event rate from the proton-proton collisions occurring at 40 MHz to about 1 kHz for the expected LHC luminosity (2x1034cm-2s-1). To achieve this selection rate an intensive use of particle tracking must be exploited. For such a demanding application a dedicated hardware tracker was designed, the Fast TracKer processor. To achieve the required performance Fast TracKer uses a combination of custom designed VLSI chips and latest generation FPGAs, all embedded in custom designed boards, exploiting a fully parallel architecture. Fast TracKer provides track reconstruction based on the full silicon (inner) detector with resolution comparable to the offline reconstruction with a latency of approximately 100μs.

  16. The ATLAS Trigger and Data Acquisition System during the 2002 combined testbeam run

    CERN Document Server

    Lehmann, G

    2004-01-01

    The Trigger and Data Acquisition System of the ATLAS experiment at CERN has undergone a series of design and prototyping phases, with the aim of studying different architectural and technological choices suited to sustaining the very high event rate and data size of this experiment: up to 100 kHz Level 1 trigger accept rate, with events of the order of 2 MB. The DAQ/EF-1 project, a vertical slice of the Data AcQuisition and Event Filter, is one of these prototypes. After the completion of its development and implementation, this prototype was reengineered for exploitation as a DAQ system for the ATLAS detectors in testing and calibration phase. During summer 2002 DAQ/EF-1 has been successfully integrated with several detectors. This paper presents an overview of DAQ/EF-1 the implementation of a PC based setup that has been prepared for the combined testbeam of the Pixel, the tile calorimeter and the MDT detectors, and the usage of the Event Filter during data taking. (7 refs).

  17. Triggering on Long-Lived Neutral Particles in the ATLAS Detector

    CERN Document Server

    Aad, G; Abdallah, J; Abdelalim, A A; Abdesselam, A; Abdinov, O; Abi, B; Abolins, M; Abramowicz, H; Acerbi, E; Acharya, B S; Adams, D L; Addy, T N; Adelman, J; Adorisio, C; Adragna, P; Adye, T; Aefsky, S; Aguilar Saavedra, J A; Aharrouche, M; Ahlen, S P; Ahles, F; Ahmad, A; Ahmed, H; Ahsan, M; Aielli, G; Akdogan, T; Akesson, T P A; Akimoto, G; Akimov, A V; Alam, M S; Alam, M A; Albert, J; Albrand, S; Aleksa, M; Aleksandrov, I N; Alexa, C; Alexander, G; Alexandre, G; Alexopoulos, T; Alhroob, M; Aliev, M; Alimonti, G; Alison, J; Aliyev, M; Allport, P P; Allwood-Spiers, S E; Aloisio, A; Alon, R; Alonso, A; Alviggi, M G; Amako, K; Amelung, C; Ammosov, V V; Amorim, A; Amorós, G; Amram, N; Anastopoulos, C; Anders, C F; Anderson, K J; Andreazza, A; Andrei, V; Anduaga, X S; Angerami, A; Anghinolfi, F; Anjos, N; Antonaki, A; Antonelli, M; Antonelli, S; Antunovic, B; Anulli, F; Arabidze, G; Aracena, I; Arai, Y; Arce, A T H; Archambault, J P; Arfaoui, S; Arguin, J-F; Argyropoulos, T; Arik, M; Armbruster, A J; Arnaez, O; Arnault, C; Artamonov, A; Arutinov, D; Asai, M; Asai, S; Asfandiyarov, R; Ask, S; Asman, B; Asner, D; Asquith, L; Assamagan, K; Astbury, A; Astvatsatourov, A; Atoian, G; Auerbach, B; Auge, E; Augsten, K; Aurousseau, M; Austin, N; Avolio, G; Avramidou, R; Axen, D; Ay, C; Azuelos, G; Azuma, Y; Baak, M A; Bacci, C; Bach, A; Bachacou, H; Bachas, K; Backes, M; Badescu, E; Bagnaia, P; Bai, Y; Bailey, D C; Bain, T; Baines, J T; Baker, O K; Baker, M D; Baltasar Dos Santos Pedrosa, F; Banas, E; Banerjee, P; Banerjee, S; Banfi, D; Bangert, A; Bansal, V; Baranov, S P; Baranov, S; Barashkou, A; Barber, T; Barberio, E L; Barberis, D; Barbero, M; Bardin, D Y; Barillari, T; Barisonzi, M; Barklow, T; Barlow, N; Barnett, B M; Barnett, R M; Baroncelli, A; Barr, A J; Barreiro, F; Barreiro Guimaraes da Costa, J; Barrillon, P; Barros, N; Bartoldus, R; Bartsch, D; Bastos, J; Bates, R L; Bathe, S; Batley, J R; Battaglia, A; Battistin, M; Bauer, F; Bazalova, M; Beare, B; Beauchemin, P H; Beccherle, R; Becerici, N; Bechtle, P; Beck, G A; Beck, H P; Beckingham, M; Becks, K H; Beddall, A J; Beddall, A; Bednyakov, V A; Bee, C; Begel, M; Behar Harpaz, S; Behera, P K; Beimforde, M; Belanger- Champagne, C; Bell, P J; Bell, W H; Bella, G; Bellagamba, L; Bellina, F; Bellomo, M; Belloni, A; Belotskiy, K; Beltramello, O; Ben Ami, S; Benary, O; Benchekroun, D; Bendel, M; Benedict, B H; Benekos, N; Benhammou, Y; Benincasa, G P; Benjamin, D P; Benoit, M; Bensinger, J R; Benslama, K; Bentvelsen, S; Beretta, M; Berge, D; Bergeaas Kuutmann, E; Berger, N; Berghaus, F; Berglund, E; Beringer, J; Bernardet, K; Bernat, P; Bernhard, R; Bernius, C; Berry, T; Bertin, A; Besson, N; Bethke, S; Bianchi, R M; Bianco, M; Biebel, O; Biesiada, J; Biglietti, M; Bilokon, H; Binet, S; Bingul, A; Bini, C; Biscarat, C; Bitenc, U; Black, K M; Blair, R E; Blanchot, G; Blocker, C; Blondel, A; Blum, W; Blumenschein, U; Bobbink, G J; Bocci, A; Boek, J; Boelaert, N; Boeser, S; Bogaerts, J A; Bogouch, A; Bohm, C; Bohm, J; Boisvert, V; Bold, T; Boldea, V; Boldyrev, A; Bondarenko, V G; Bondioli, M; Boonekamp, M; Borisov, A; Borissov, G; Borjanovic, I; Borroni, S; Bos, K; Boscherini, D; Bosman, M; Boterenbrood, H; Bouchami, J; Boudreau, J; Bouhova-Thacker, E V; Boulahouache, C; Bourdarios, C; Boyd, J; Boyko, I R; Bozovic-Jelisavcic, I; Bracinik, J; Braem, A; Branchini, P; Brandenburg, G W; Brandt, A; Brandt, G; Brandt, O; Bratzler, U; Brau, J E; Braun, H M; Brelier, B; Bremer, J; Brenner, R; Bressler, S; Breton, D; Britton, D; Brochu, F M; Brock, I; Brock, R; Brodet, E; Bromberg, C; Brooijmans, G; Brooks, W K; Brubaker, E; Bruckman de Renstrom, P A; Bruncko, D; Bruneliere, R; Brunet, S; Bruni, A; Bruni, G; Bruschi, M; Bucci, F; Buchanan, J; Buchholz, P; Buckley, A G; Budagov, I A; Budick, B; Buescher, V; Bugge, L; Bulekov, O; Bunse, M; Buran, T; Burckhart, H; Burdin, S; Burgess, T; Burke, S; Busato, E; Bussey, P; Buszello, C P; Butin, F; Butler, B; Butler, J M; Buttar, C M; Butterworth, J M; Byatt, T; Caballero-Bejar, J; Cabrera Urbán, S; Caforio, D; Cakir, O; Calafiura, P; Calderini, G; Calfayan, P; Calkins, R; Caloba, L P; Calvet, D; Camarri, P; Cameron, D; Campana, S; Campanelli, M; Canale, V; Canelli, F; Cantero, J; Capasso, L; Caprini, I; Caprini, M; Capua, M; Caputo, R; Caracinha, D; Caramarcu, C; Cardarelli, R; Carli, T; Carlino, G; Carminati, L; Caron, B; Caron, S; Carrillo Montoya, G D; Carron Montero, S; Carter, A A; Carter, J R; Carvalho, J; Casadei, D; Casado, M P; Cascella, M; Castaneda Hernadez, A M; Castaneda Miranda, E; Castillo Gimenez, V; Castro, N; Cataldi, G; Catinaccio, A; Catmore, J R; Cattai, A; Cattani, G; Caughron, S; Cauz, D; Cavalleri, P; Cavalli, D; Cavalli-Sforza, M; Cavasinni, V; Ceradini, F; Cerqueira, A S; Cerri, A; Cerrito, L; Cerutti, F; Cetin, S A; Cevenini, F; Chafaq, A; Chakraborty, D; Chan, K; Chapman, J D; Chapman, J W; Chareyre, E; Charlton, D G; Chatterjii, S; Cheatham, S; Chekanov, S; Chekulaev, S V; Chelkov, G A; Chen, H; Chen, S; Chen, X; Cheplakov, A; Chepurnov, V F; Cherkaoui El Moursli, R; Chernyatin, V; Chesneanu, D; Cheu, E; Cheung, S L; Chevalier, L; Chevallier, F; Chiarella, V; Chiefari, G; Chikovani, L; Childers, J T; Chilingarov, A; Chiodini, G; Chizhov, M; Chouridou, S; Christidi, I A; Christov, A; Chromek-Burckhart, D; Chu, M L; Chudoba, J; Ciapetti, G; Ciftci, A K; Ciftci, R; Cindro, V; Ciobotaru, M D; Ciocca, C; Ciocio, A; Cirilli, M; Citterio, M; Clark, A; Cleland, W; Clemens, J C; Clement, B; Clement, C; Clements, D; Coadou, Y; Cobal, M; Coccaro, A; Cochran, J; Coggeshall, J; Cogneras, E; Cole, B; Colijn, A P; Collard, C; Collins, N J; Collins-Tooth, C; Collot, J; Colon, G; Conde Muino, P; Coniavitis, E; Consonni, M; Constantinescu, S; Conta, C; Conventi, F; Cook, J; Cooke, M; Cooper, B D; Cooper-Sarkar, A M; Cooper-Smith, N J; Copic, K; Cornelissen, T; Corradi, M; Corriveau, F; Corso-Radu, A; Cortes-Gonzalez, A; Cortiana, G; Costa, G; Costa, M J; Costanzo, D; Costin, T; Cote, D; Coura Torres, R; Courneyea, L; 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Quayle, W B; Quinonez, F; Raas, M; Radeka, V; Radescu, V; Radics, B; Rador, T; Ragusa, F; Rahal, G; Rahimi, A M; Rahm, D; Rajagopalan, S; Rauscher, F; Rauter, E; Raymond, M; Read, A L; Rebuzzi, D M; Redelbach, A; Redlinger, G; Reece, R; Reeves, K; Reinherz, E; Reinsch, A; Reisinger, I; Reljic, D; Rembser, C; Ren, Z L; Renkel, P; Rescia, S; Rescigno, M; Resconi, S; Resende, B; Reznicek, P; Rezvani, R; Richards, A; Richards, R A; Richter, D; Richter, R; Richter-Was, E; Ridel, M; Rieke, S; Rijpstra, M; Rijssenbeek, M; Rimoldi, A; Rinaldi, L; Rios, R R; Riu, I; Rizatdinova, F; Rizvi, E R; Roa Romero, D A; Robertson, S H; Robichaud-Veronneau, A; Robinson, D; Robinson, M; Robson, A; Rocha de Lima, J G; Roda, C; Rodriguez, D; Rodriguez, Y; Roe, S; Rohne, O; Rojo, V; Rolli, S; Romaniouk, A; Romanov, V M; Romeo, G; Romero Maltrana, D; Roos, L; Ros, E; Rosati, M; Rosati, S; Rosenbaum, G A; Rosenberg, E I; Rosselet, L; Rossi, L P; Rotaru, M; Rothberg, J; Rottlaender, I; Rousseau, D; Royon, C R; Rozanov, A; Rozen, Y; Ruckert, B; Ruckstuhl, N; Rud, V I; Rudolph, G; Ruehr, F; Ruggieri, F; Ruiz-Martinez, A; Rumyantsev, L; Rusakovich, N A; Rutherfoord, J P; Ruwiedel, C; Ruzicka, P; Ryabov, Y F; Ryan, P; Rybin, A M; Rybkin, G; Rzaeva, S; Saavedra, A F; Sadrozinski, H F-W; Sadykov, R; Sakamoto, H; Salamanna, G; Salamon, A; Saleem, M; Salihagic, D; Salnikov, A; Salt, J; Salvachúa Ferrando, B M; Salvatore, D; Salvatore, F; Salvucci, A; Salzburger, A; Sampsonidis, D; Samset, B H; Sandaker, H; Sander, H G; Sandhoff, M; Sandstroem, R; Sandvoss, S; Sankey, D P C; Sanny, B; Sansoni, A; Santamarina Rios, C; Santoni, C; Santonico, R; Santos, D; Santos, J; Saraiva, J G; Sarangi, T; Saremi, S; Sarkisyan-Grinbaum, E; Sarri, F; Sasaki, O; Sasao, N; Satsounkevitch, I; Sauvage, G; Savard, P; Savine, A Y; Savinov, V; Sawyer, L; Saxon, D H; Says, L P; Sbarra, C; Sbrizzi, A; Scannicchio, D A; Schaarschmidt, J; Schacht, P; Schaefer, U; Schaetzel, S; Schaffer, A C; Schaile, D; Schamberger, R D; Schamov, A G; Schegelsky, V A; Schernau, M; Scherzer, M I; Schiavi, C; Schieck, J; Schioppa, M; Schlenker, S; Schmid, P; Schmitt, C; Schmitz, M; Schott, M; Schouten, D; Schovancova, J; Schram, M; Schreiner, A; Schroeder, C; Schroer, N; Schroers, M; Schultes, J; Schultz-Coulon, H-C; Schumacher, J; Schumacher, M; Schumm, B A; Schune, Ph; Schwanenberger, C; Schwartzman, A; Schwemling, Ph; Schwienhorst, R; Schwierz, R; Schwindling, J; Scott, W G; Searcy, J; Sedykh, E; Segura, E; Seidel, S C; Seiden, A; Seifert, F; Seixas, J M; Sekhniaidze, G; Seliverstov, D M; Sellden, B; Semprini-Cesari, N; Serfon, C; Serin, L; Seuster, R; Severini, H; Sevior, M E; Sfyrla, A; Shan, L Y; Shank, J T; Shao, Q T; Shapiro, M; Shatalov, P B; Shaw, K; Sherman, D; Sherwood, P; Shibata, A; Shimojima, M; Shin, T; Shmeleva, A; Shochet, M J; Shupe, M A; Sicho, P; Sidoti, A; Siegrist, J; Sijacki, Dj; Silbert, O; Silva, J; Silverstein, D; Silverstein, S B; Simak, V; Simic, Lj; Simion, S; Simmons, B; Simonyan, M; Sinervo, P; Sinev, N B; Sipica, V; Siragusa, G; Sisakyan, A N; Sivoklokov, S Yu; Sjoelin, J; Sjursen, T B; Skubic, P; Slater, M; Slavicek, T; Sliwa, K; Sloper, J; Sluka, T; Smakhtin, V; Smirnov, S Yu; Smirnov, Y; Smirnova, L N; Smirnova, O; Smith, B C; Smith, D; Smith, K M; Smizanska, M; Smolek, K; Snesarev, A A; Snow, S W; Snow, J; Snuverink, J; Snyder, S; Soares, M; Sobie, R; Sodomka, J; Soffer, A; Solans, C A; Solar, M; Solfaroli Camillocci, E; Solodkov, A A; Solovyanov, O V; Soluk, R; Sondericker, J; Sopko, V; Sopko, B; Sosebee, M; Sosnovtsev, V V; Soukharev, A; Spagnolo, S; Spano, F; Spencer, E; Spighi, R; Spigo, G; Spila, F; Spiwoks, R; Spousta, M; Spreitzer, T; Spurlock, B; Denis, R D; Stahl, T; Stamen, R; Stancu, S N; Stanecka, E; Stanek, R W; Stanescu, C; Stapnes, S; Starchenko, E A; Stark, J; Staroba, P; Stastny, J; Staude, A; Stavina, P; Steinbach, P; Steinberg, P; Stekl, I; Stelzer, B; Stelzer, H J; Stenzel, H; Stevenson, K; Stewart, G; Stockton, M C; Stoicea, G; Stonjek, S; Strachota, P; Stradling, A; Straessner, A; Strandberg, J; Strandberg, S; Strandlie, A; Strassler, M J; Strauss, M; Strizenec, P; Stroehmer, R; Strom, D M; Stroynowski, R; Stugu, B; Su, D A; Su, D; Suchkov, S I; Sugaya, Y; Sugimoto, T; Suhr, C; Sulin, V V; Sultansoy, S; Sun, X; Sundermann, J E; Suruliz, K; Sushkov, S; Susinno, G; Sutton, M R; Suzuki, T; Suzuki, Y; Sykora, I; Sykora, T; Szymocha, T; Sánchez, J; Ta, D; Taffard, A; Tafirout, R; Taga, A; Takahashi, Y; Takai, H; Takashima, R; Takeda, H; Takeshita, T; Talby, M; Talyshev, A; Tamsett, M C; Tanaka, J; Tanaka, R; Tanaka, S; Tanaka, S; Tapprogge, S; Tardif, D; Tarem, S; Tarrade, F; Tartarelli, G F; Tas, P; Tasevsky, M; Tassi, E; Taylor, C; Taylor, F E; Taylor, G N; Taylor, R P; Taylor, W; Teixeira-Dias, P; Ten Kate, H; Teng, P K; Terada, S; Terashi, K; Terron, J; Terwort, M; Testa, M; Teuscher, R J; Tevlin, C M; Thananuwong, R; Thioye, M; Thoma, S; Thomas, J P; Thomas, T L; Thompson, E N; Thompson, P D; Thompson, P D; Thompson, R J; Thompson, A S; Thomson, E; Thun, R P; Tic, T; Tikhomirov, V O; Tikhonov, Y A; Tipton, P; Tique Aires Viegas, F J; Tisserant, S; Toczek, B; Todorov, T; Todorova-Nova, S; Tojo, J; Tokar, S; Tokushuku, K; Tomasek, L; Tomasek, M; Tomasz, F; Tomoto, M; Tompkins, D; Tompkins, L; Toms, K; Tonoyan, A; Topfel, C; Topilin, N D; Torrence, E; Torro Pastor, E; Toth, J; Touchard, F; Tovey, D R; Tovey, S N; Trefzger, T; Tremblet, L; Tricoli, A; Trigger, I M; Trincaz-Duvoid, S; Tripiana, M F; Triplett, N; Trischuk, W; Trivedi, A; Trocme, B; Troncon, C; Trzupek, A; Tsarouchas, C; Tseng, J C-L; Tsiakiris, M; Tsiareshka, P V; Tsipolitis, G; Tsiskaridze, V; Tskhadadze, E G; Tsukerman, I I; Tsulaia, V; Tsuno, S; Turecek, D; Turk Cakir, I; Turlay, E; Tuts, P M; Twomey, M S; Tylmad, M; Tyndel, M; Tzanakos, G; Uchida, K; Ueda, I; Uhrmacher, M; Ukegawa, F; Unal, G; Underwood, D G; Undrus, A; Unel, G; Unno, Y; Urbaniec, D; Urkovsky, E; Urquijo, P; Urrejola, P; Usai, G; Vacavant, L; Vacek, V; Vachon, B; Vahsen, S; Valenta, J; Valente, P; Valentinetti, S; Valkar, S; Vallecorsa, S; Valls Ferrer, J A; van der Graaf, H; van der Kraaij, E; van der Poel, E; Van Der Ster, D; van Eldik, N; van Gemmeren, P; van Kesteren, Z; van Vulpen, I; VanBerg, R; Vandelli, W; Vaniachine, A; Vankov, P; Vannucci, F; Vari, R; Varnes, E W; Varouchas, D; Vartapetian, A; Varvell, K E; Vassilakopoulos, V I; Vassilieva, L; Vazeille, F; Veillet, J J; Vellidis, C; Veloso, F; Veneziano, S; Ventura, A; Ventura, D; Venturi, M; Venturi, N; Vercesi, V; Verducci, M; Verkerke, W; Vermeulen, J C; Vetterli, M C; Vichou, I; Vickey, T; Viehhauser, G H A; Villa, M; Villani, E G; Villaplana Perez, M; Villate, J; Vilucchi, E; Vincter, M G; Vinogradov, V B; Viret, S; Virzi, J; Vitale, A; Vitells, O V; Vivarelli, I; Vives Vaques, F; Vlachos, S; Vlasak, M; Vlasov, N; Vokac, P; Volpi, M; von der Schmitt, H; von Loeben, J; von Radziewski, H; von Toerne, E; Vorobel, V; Vorobiev, A P; Vorwerk, V; Vos, M; Voss, R; Voss, T T; Vossebeld, J H; Vranjes, N; Vranjes Milosavljevic, M; Vrba, V; Vreeswijk, M; Vu Anh, T; Vudragovic, D; Vuillermet, R; Vukotic, I; Wagner, P; Wahlen, H; Walbersloh, J; Walder, J; Walker, R; Walkowiak, W; Wall, R; Wang, C; Wang, J; Wang, S M; Ward, C P; Warsinsky, M; Watkins, P M; Watson, A T; Watts, G; Watts, S; Waugh, A T; Waugh, B M; Webel, M; Weber, J; Weber, M D; Weber, M; Weber, M S; Weber, P; Weidberg, A R; Weingarten, J; Weiser, C; Wellenstein, H; Wells, P S; Wemans, A; Wen, M; Wenaus, T; Wendler, S; Wengler, T; Wenig, S; Wermes, N; Werner, M; Werner, P; Werthenbach, U; Wessels, M; Whalen, K; Wheeler-Ellis, S J; White, A; White, M J; White, S; Whiteson, D; Whittington, D; Wicek, F; Wicke, D; Wickens, F J; Wiedenmann, W; Wielers, M; Wienemann, P; Wiglesworth, C; Wildauer, A; Wildt, M A; Wilkens, H G; Williams, E; Williams, H H; Willocq, S; Wilson, J A; Wilson, M G; Wilson, A; Wingerter-Seez, I; Winklmeier, F; Wittgen, M; Wolter, M W; Wolters, H; Wosiek, B K; Wotschack, J; Woudstra, M J; Wraight, K; Wright, C; Wright, D; Wrona, B; Wu, S L; Wu, X; Wulf, E; Xella, S; Xie, S; Xu, N; Yamada, M; Yamamoto, A; Yamamoto, S; Yamamura, T; Yamanaka, K; Yamaoka, J; Yamazaki, T; Yamazaki, Y; Yan, Z; Yang, H; Yang, U K; Yang, Z; Yao, W-M; Yao, Y; Yasu, Y; Ye, J; Ye, S; Yilmaz, M; Yoosoofmiya, R; Yorita, K; Yoshida, R; Young, C; Youssef, S P; Yu, D; Yu, J; Yuan, J; Yuan, L; Yurkewicz, A; Zaidan, R; Zaitsev, A M; Zajacova, Z; Zambrano, V; Zanello, L; Zarzhitsky, P; Zaytsev, A; Zeitnitz, C; Zeller, M; Zema, P F; Zemla, A; Zendler, C; Zenis, T; Zenonos, Z; Zenz, S; Zerwas, D; Zevi della Porta, G; Zhan, Z; Zhang, H; Zhang, J; Zhang, Q; Zhang, X; Zhao, L; Zhao, T; Zhao, Z; Zhemchugov, A; Zhong, J; Zhou, B; Zhou, N; Zhou, Y; Zhu, C G; Zhu, H; Zhu, Y; Zhuang, X; Zhuravlov, V; Zimmermann, R; Zimmermann, S; Ziolkowski, M; Zitoun, R; Zivkovic, L; Zobernig, G; Zoccoli, A; zur Nedden, M

    2009-01-01

    Neutral particles with long decay paths that decay to many-particle final states represent, from an experimental point of view, a challenge both for the trigger and for the reconstruction capabilities of the ATLAS apparatus. The Hidden Valley scenario serves as an excellent setting for the purpose of exploring the challenges to the trigger posed by long-lived particles.

  18. Frameworks to monitor and predict resource usage in the ATLAS High Level Trigger

    CERN Document Server

    Martin, Tim; The ATLAS collaboration

    2016-01-01

    The ATLAS High Level Trigger Farm consists of around 30,000 CPU cores which filter events at up to 100 kHz input rate. A costing framework is built into the high level trigger, this enables detailed monitoring of the system and allows for data-driven predictions to be made utilising specialist datasets. This talk will present an overview of how ATLAS collects in-situ monitoring data on both CPU usage and dataflow over the data-acquisition network during the trigger execution, and how these data are processed to yield both low level monitoring of individual selection-algorithms and high level data on the overall performance of the farm. For development and prediction purposes, ATLAS uses a special `Enhanced Bias' event selection. This mechanism will be explained along with how is used to profile expected resource usage and output event-rate of new physics selections, before they are executed on the actual high level trigger farm.

  19. Trigger Data Serializer ASIC chip for the ATLAS New Small Wheel sTGC Detector

    CERN Document Server

    Wang, Jinhong; The ATLAS collaboration

    2014-01-01

    The small-strip Thin-Gap Chambers (sTGC) will be used as both trigger and precision tracking muon detectors for the Phase-I upgrade of the ATLAS New Small Wheel (NSW) muon detector. Signals from both the sTGC pad and strip detectors will be first read out by the Amplifier-Shaper-Discriminator (ASD) chip designed by the Brookhaven National Laboratory, and then collected and transmitted by a Trigger Data Serializer (TDS) chip at a rate of 4.8 Gbps to other related circuits. The pad-TDS chip checks the presence of pad hits and sends the information together with Bunching Crossing ID to the pad-trigger logic to define roads of interest. The strip-TDS chip collects and buffers strip charge information and transmits a range of strips within the road of interest to the router board located on the rim of the NSW. The large number of input channels (128 differential input channels), short time available to prepare and transmit trigger data (<100 ns), high speed output data rate (4.8 Gbps), harsh radiation environme...

  20. Hardware-based Tracking at Trigger Level for ATLAS the Fast TracKer (FTK) Project

    CERN Document Server

    AUTHOR|(CDS)2078679

    2015-01-01

    Physics collisions at 13 TeV are expected at the LHC with an average of 40-50 proton-proton collisions per bunch crossing under nominal conditions. Tracking at trigger level is an essential tool to control the rate in high-pileup conditions while maintaining a good efficiency for relevant physics processes. The Fast TracKer is an integral part of the trigger upgrade for the ATLAS detector. For every event passing the Level-1 trigger (at a maximum rate of 100 kHz) the FTK receives data from all the channels of the silicon detectors, providing tracking information to the High Level Trigger in order to ensure a selection robust against pile-up. The FTK performs a hardware-based track reconstruction, using associative memory that is based on the use of a custom chip, designed to perform pattern matching at very high speed. It finds track candidates at low resolution (roads) that seed a full-resolution track fitting done by FPGAs. An overview of the FTK system with focus on the pattern matching procedure will be p...

  1. Hardware-based tracking at trigger level for ATLAS: The Fast Tracker (FTK) Project

    CERN Document Server

    Gramling, Johanna; The ATLAS collaboration

    2015-01-01

    Physics collisions at 13 TeV are expected at the LHC with an average of 40-50 proton-proton collisions per bunch crossing. Tracking at trigger level is an essential tool to control the rate in high-pileup conditions while maintaining a good efficiency for relevant physics processes. The Fast TracKer (FTK) is an integral part of the trigger upgrade for the ATLAS detector. For every event passing the Level 1 trigger (at a maximum rate of 100 kHz) the FTK receives data from the 80 million channels of the silicon detectors, providing tracking information to the High Level Trigger in order to ensure a selection robust against pile-up. The FTK performs a hardware-based track reconstruction, using associative memory (AM) that is based on the use of a custom chip, designed to perform pattern matching at very high speed. It finds track candidates at low resolution (roads) that seed a full-resolution track fitting done by FPGAs. Narrow roads permit a fast track fitting but need many patterns stored in the AM to ensure ...

  2. Hardware-based Tracking at Trigger Level for ATLAS: The Fast TracKer (FTK) Project

    CERN Document Server

    Gramling, Johanna; The ATLAS collaboration

    2015-01-01

    Physics collisions at 13 TeV are expected at the LHC with an average of 40-50 proton-proton collisions per bunch crossing. Tracking at trigger level is an essential tool to control the rate in high-pileup conditions while maintaining a good efficiency for relevant physics processes. The Fast TracKer (FTK) is an integral part of the trigger upgrade for the ATLAS detector. For every event passing the Level 1 trigger (at a maximum rate of 100 kHz) the FTK receives data from the 80 million channels of the silicon detectors, providing tracking information to the High Level Trigger in order to ensure a selection robust against pile-up. The FTK performs a hardware- based track reconstruction, using associative memory (AM) that is based on the use of a custom chip, designed to perform pattern matching at very high speed. It finds track candidates at low resolution (roads) that seed a full-resolution track fitting done by FPGAs. Narrow roads permit a fast track fitting but need many patterns stored in the AM to ensure...

  3. ATLAS TDAQ System Administration: evolution and re-design

    Science.gov (United States)

    Ballestrero, S.; Bogdanchikov, A.; Brasolin, F.; Contescu, C.; Dubrov, S.; Fazio, D.; Korol, A.; Lee, C. J.; Scannicchio, D. A.; Twomey, M. S.

    2015-12-01

    The ATLAS Trigger and Data Acquisition system is responsible for the online processing of live data, streaming from the ATLAS experiment at the Large Hadron Collider at CERN. The online farm is composed of ∼3000 servers, processing the data read out from ∼100 million detector channels through multiple trigger levels. During the two years of the first Long Shutdown there has been a tremendous amount of work done by the ATLAS Trigger and Data Acquisition System Administrators, implementing numerous new software applications, upgrading the OS and the hardware, changing some design philosophies and exploiting the High- Level Trigger farm with different purposes. The OS version has been upgraded to SLC6; for the largest part of the farm, which is composed of net booted nodes, this required a completely new design of the net booting system. In parallel, the migration to Puppet of the Configuration Management systems has been completed for both net booted and local booted hosts; the Post-Boot Scripts system and Quattor have been consequently dismissed. Virtual Machine usage has been investigated and tested and many of the core servers are now running on Virtual Machines. Virtualisation has also been used to adapt the High-Level Trigger farm as a batch system, which has been used for running Monte Carlo production jobs that are mostly CPU and not I/O bound. Finally, monitoring the health and the status of ∼3000 machines in the experimental area is obviously of the utmost importance, so the obsolete Nagios v2 has been replaced with Icinga, complemented by Ganglia as a performance data provider. This paper serves for reporting of the actions taken by the Systems Administrators in order to improve and produce a system capable of performing for the next three years of ATLAS data taking.

  4. Trigger monitoring and rate predictions using Enhanced Bias data from the ATLAS Detector at the LHC

    CERN Document Server

    The ATLAS collaboration

    2016-01-01

    A data-driven method for performing offline rate and CPU usage predictions for any algorithmic selection in the ATLAS High Level Trigger at the Large Hadron Collider is described. To assure statistical sensitivity in the most relevant kinematic regions, a mix of events is selected by the Level 1 trigger system that emphasises higher energies and object multiplicities. This sample, referred to as `enhanced bias', is constructed in such a way that the selection bias is removable with event weights. The use of enhanced bias data to calculate the rates of HLT trigger chains along with complex combinations such as group rates, the total rate and unique rates is described, along with methods for performing extrapolations of rates to different instantaneous luminosities and for performing predictions of trigger CPU usage. The process by which ATLAS collects and processes monitoring data in the High Level Trigger is outlined, this allows for CPU and readout system resource utilisation within the trigger to be studied...

  5. The Upgrade of the ATLAS Electron and Photon Triggers towards LHC Run 2 and their Performance

    CERN Document Server

    Kahn, Sebastien Jonathan

    2015-01-01

    Electron and photon triggers are essential for a wide variety of ATLAS physics analyses. For example, final states including leptons and photons had key role in the discovery and measurement of the Higgs particle properties. Dedicated triggers are also used for calibration, efficiency and fake rate measurements. The ATLAS trigger system is divided in a hardware-based (L1) and a software-based High Level Trigger (HLT). Both were upgraded during the long shutdown of the LHC in preparation for data taking in 2015 to cope with the increasing luminosity, the more challenging pile-up conditions and higher center-of-mass energy. The trigger selection has also been optimised to further control the rates while keeping efficiencies high. Performance of the the run~2 triggers measured with early run~2 data are shown.

  6. ATLAS Central Trigger Processor Input Module (CTPIN) Firmware Upgrade

    CERN Document Server

    Fountas, Petros

    2013-01-01

    The upgraded CTPIN firmware is designed to receive its inputs at twice the design speed. A constraint is that the CTPIN hardware will not be changed, so the upgrade is constrained to the firmware of the Pipeline FPGA and the Monitoring FPGA. The Pipeline FPGA is configured to latch in DDR registers the 32 XSDP input signals at 80 MHz and then decode and latch them internally in 64 registers operating at 40 MHz. After synchronization and alignment these 64 trigger signals are encoded and exported in 31 output lines, using Double-Data-Rate (DDR) registers. Again in the Monitoring module the 31 input trigger signals are decoded and latched in 62 internal signals, using DDR registers. The Pipeline FPGA and Monitoring FPGA firmware have been successfully verified in timing simulation, which shows that an upgrade of the CTPIN without redesigning the hardware is feasible.

  7. TileCal Trigger Tower studies considering additional segmentation on the ATLAS upgrade for high luminosity at LHC

    CERN Document Server

    March, L; The ATLAS collaboration

    2013-01-01

    The Tile Calorimeter (TileCal) is the hadronic calorimeter covering the most central region of the ATLAS experiment at LHC. The TileCal readout consists of about 10000 channels and provides a compact information, called trigger towers (around 2000 signals), to the ATLAS first level online event selection system. The ATLAS upgrade program is divided in three phases: Phase 0 occurs during 2013- 2014 and prepares the LHC to reach peak luminosities of 10^34 cm2s-1; Phase 1, foreseen for 2018-1019, prepares the LHC for peak luminosity up to 2-3 x 10^34 cm2s-1, corresponding to 55 to 80 interactions per bunch-crossing with 25 ns bunch interval; and Phase 2 is foreseen for 2022-2023, whereafter the peak luminosity will reach 5-7 x 1034 cm2s-1 (HL-LHC). The ATLAS experiment is operating very well since 2009 providing large amount of data for physics analysis. The online event selection system (trigger system) was designed to reject the huge amount of background noise generated at LHC and is one of the main systems re...

  8. The Evolution of the Trigger and Data Acquisition System in the ATLAS Experiment

    CERN Document Server

    Garelli, N; The ATLAS collaboration

    2014-01-01

    The ATLAS experiment, aimed at recording the results of LHC proton-proton collisions, is upgrading its Trigger and Data Acquisition (TDAQ) system during the current LHC first long shutdown. The purpose of such upgrade is to add robustness and flexibility to the selection and the conveyance of the physics data, simplify the maintenance of the infrastructure, exploit new technologies and, overall, make ATLAS data-taking capable of dealing with increasing event rates. \

  9. ATLAS TDAQ System Administration: evolution and re-design

    CERN Document Server

    Ballestrero, Sergio; The ATLAS collaboration; Brasolin, Franco; Contescu, Alexandru Cristian; Dubrov, Sergei; Fazio, Daniel; Korol, Aleksandr; Lee, Christopher Jon; Scannicchio, Diana; Twomey, Matthew Shaun

    2015-01-01

    The ATLAS Trigger and Data Acquisition (TDAQ) system is responsible for the online processing of live data, streaming from the ATLAS experiment at the Large Hadron Collider (LHC) at CERN. The online farm is composed of $\\sim 3000$ servers, processing the data readout from $\\sim 100$ million detector channels through multiple trigger levels. During the two years of the first Long Shutdown (LS1) there has been a tremendous amount of work done by the ATLAS TDAQ System Administrators, implementing numerous new software applications, upgrading the OS and the hardware, changing some design philosophies and exploiting the High Level Trigger farm with different purposes. The OS version has been upgraded to SLC6; for the largest part of the farm, which is composed by net booted nodes, this required a completely new design of the net booting system. In parallel, the migration to Puppet of the Configuration Management systems has been completed for both net booted and local booted hosts; the Post-Boot Scripts system and...

  10. An FPGA based demonstrator for a topological processor in the,future ATLAS L1-Calo trigger (“GOLD”)

    CERN Document Server

    "Bauss, B"; The ATLAS collaboration; "Degele, R"; "Ebling, A"; "Ji, W"; "Meyer, C"; "Moritz, S"; "Schaefer, U"; "Simioni, E"; "Tapprogge, S"; "Wenzel, V"

    2011-01-01

    The existing ATLAS trigger consists of three levels. The level 1 (L1) is an FPGAs based custom designed trigger, while the second and third levels are software based. The LHC machine plans to bring the beam energy to the nominal value of 7 TeV and to increase the luminosity in the coming years. The current L1 trigger system is therefore seriously challenged. To cope with the resulting higher event rate, as part of the ATLAS trigger upgrade, a new electronics module is foreseen to be added in the L1-Calo electronics chain: the topological processor. Such processor is provided with fast optical I/O and large bandwidth capability, in order to use the information on the cluster position in space (i.e. jets in the calorimeters or muons in the muon detectors) and improve the purity of the L1 triggers streams by applying topological cuts within the latency budget. In this talk, an overview of the adopted tecnological solutions and the R&D activities on the demonstrator (“GOLD”) are presented.

  11. A Scalable and Reliable Message Transport Service for the ATLAS Trigger and Data Acquisition System

    CERN Document Server

    Kazarov, A; The ATLAS collaboration; Kolos, S; Lehmann Miotto, G; Soloviev, I

    2014-01-01

    The ATLAS Trigger and Data Acquisition (TDAQ) is a large distributed computing system composed of several thousands of interconnected computers and tens of thousands applications. During a run, TDAQ applications produce a lot of control and information messages with variable rates, addressed to TDAQ operators or to other applications. Reliable, fast and accurate delivery of the messages is important for the functioning of the whole TDAQ system. The Message Transport Service (MTS) provides facilities for the reliable transport, the filtering and the routing of the messages, basing on publish-subscribe-notify communication pattern with content-based message filtering. During the ongoing LHC shutdown, the MTS was re-implemented, taking into account important requirements like reliability, scalability and performance, handling of slow subscribers case and also simplicity of the design and the implementation. MTS uses CORBA middleware, a common layer for TDAQ infrastructure, and provides sending/subscribing APIs i...

  12. The ATLAS transverse momentum trigger evolution at the LHC towards Run II

    CERN Document Server

    Strubig, Antonia; The ATLAS collaboration

    2015-01-01

    The missing transverse momentum triggers of the ATLAS experiment at the CERN Large Hadron Collider (LHC) are designed to select collision events with non-interacting particles passing through the detector. Such events provide an interesting probe for new physics interactions beyond the Standard Model, but also provide the basis for precise measurements of Standard Model parameters such as the Higgs couplings. The transverse momentum used in the trigger system is calculated from calorimeter-based global energy sums and supplemented with information from the muon detection system. The trigger operated successfully during the first running period of the LHC. With the start-up in 2015, the LHC is now operating at a higher centre-of-mass energy and increased luminosity, both making it challenging to improve on the Run I performance. A brief summary of the Run I performance studies will be presented, together with the Run II software and hardware-based improvements as well as some of the first results from the Run ...

  13. L1Track: A fast Level 1 track trigger for the ATLAS high luminosity upgrade

    Science.gov (United States)

    Cerri, Alessandro

    2016-07-01

    With the planned high-luminosity upgrade of the LHC (HL-LHC), the ATLAS detector will see its collision rate increase by approximately a factor of 5 with respect to the current LHC operation. The earliest hardware-based ATLAS trigger stage ("Level 1") will have to provide a higher rejection factor in a more difficult environment: a new improved Level 1 trigger architecture is under study, which includes the possibility of extracting with low latency and high accuracy tracking information in time for the decision taking process. In this context, the feasibility of potential approaches aimed at providing low-latency high-quality tracking at Level 1 is discussed.

  14. Operational performance of the ATLAS trigger and data acquisition system and its possible evolution

    CERN Document Server

    Negri, A; The ATLAS collaboration

    2012-01-01

    The experience accumulated in the ATLAS DAQ/HLT system operation during these years stimulated interest to explore possible evolutions, despite the success of the current design. One attractive direction is to merge three systems - the second trigger level (L2), the Event Builder (EB), and the Event Filter (EF) - within a single homogeneous one in which each HLT node executes all the steps required by the trigger and data acquisition process. Each L1 event is assigned to an available HLT node which executes the L2 algorithms using a subset of the event data and, upon positive selection, builds the event, which is further processed by the EF algorithms. Appealing aspects of this design are: a simplification of the software architecture and of its configuration, a better exploitation of the computing resources, the caching of fragments already collected for L2 processing, the automated load balancing between L2 and EF selection steps, the sharing of code and services on HLT nodes. Furthermore, the full treatmen...

  15. The ATLAS barrel level-1 Muon Trigger Sector-Logic/RX off-detector trigger and acquisition board

    CERN Document Server

    Chiodi, G; Petrolo, E; Pastore, F; Salamon, A; Vari, R; Veneziano, S

    2007-01-01

    The ATLAS experiment uses a system of three concentric layers of Resistive Plate Chambers (RPC) detector for the Level-1 Muon Trigger in the air-core barrel toroid region. The trigger algorithm looks for hit coincidences within different detector layers inside the programmable geometrical road which defines the transverse momentum cut. The on-detector electronics that provides the trigger and detector readout functionalities collects input signals coming from the RPC front-end. Trigger and readout data are then sent via optical fibres to the off-detector electronics. Six or seven optical fibres from one of the 64 trigger sectors go to one Sector-Logic/RX module, that later elaborates the collected trigger and readout data, and sends data respectively to the Read-Out Driver modules and to the Central Level-1 Trigger. We present the functionality and the implementation of the VME Sector-Logic/RX module, and the configuration of the system for the first cosmic ray data collected using this module.

  16. Commissioning and Initial LHC Run-2 operation of the ATLAS minimum bias trigger scintillators

    Science.gov (United States)

    Hoffmann, M.

    2016-07-01

    The Minimum Bias Trigger Scintillators (MBTS) are sub-detectors in ATLAS delivering the primary trigger for selecting events from low luminosity proton-proton, lead-lead and lead-proton collisions with the smallest possible bias. The MBTS have undergone a complete replacement before LHC Run-2 and several improvements have been implemented in the layout. Since 2014 the MBTS have been commissioned with cosmic rays and first LHC Run-2 beam splash events. We summarise the outcome of the commissioning.

  17. Physics performances with the new ATLAS Level-1 Topological trigger in Run 2

    CERN Document Server

    Artz, Sebastian; The ATLAS collaboration

    2016-01-01

    The ATLAS trigger system aims at reducing the 40 MHz proton-proton collision event rate to a manageable event storage rate of 1 kHz, preserving events valuable for physics analysis. The Level-1 trigger is the first rate-reducing step in the ATLAS trigger system, with an output rate of 100 kHz and decision latency of less than 2.5 micro seconds. It is composed of the calorimeter trigger, muon trigger and central trigger processor. During the last upgrade, a new electronics element was introduced to Level-1: The Topological Processor System. It will make it possible to use detailed realtime information from the Level-1 calorimeter and muon triggers, processed in individual state of the art FPGA processors to determine angles between jets and/or leptons and calculate kinematic variables based on lists of selected/sorted objects. More than one hundred VHDL algorithms are producing trigger outputs to be incorporated into the central trigger processor. This information will be essential to improve background reject...

  18. Design studies for the Double Chooz trigger

    Energy Technology Data Exchange (ETDEWEB)

    Cucoanes, Andi Sebastian

    2009-07-24

    The main characteristic of the neutrino mixing effect is assumed to be the coupling between the flavor and the mass eigenstates. Three mixing angles ({theta}{sub 12}, {theta}{sub 23}, {theta}{sub 13}) are describing the magnitude of this effect. Still unknown, {theta}{sub 13} is considered very small, based on the measurement done by the CHOOZ experiment. A leading experiment will be Double Chooz, placed in the Ardennes region, on the same site as used by CHOOZ. The Double Chooz goal is the exploration of {proportional_to}80% from the currently allowed {theta}{sub 13} region, by searching the disappearance of reactor antineutrinos. Double Chooz will use two similar detectors, located at different distances from the reactor cores: a near one at {proportional_to}150 m where no oscillations are expected and a far one at 1.05 km distance, close to the first minimum of the survival probability function. The measurement foresees a precise comparison of neutrino rates and spectra between both detectors. The detection mechanism is based on the inverse {beta}-decay. The Double Chooz detectors have been designed to minimize the rate of random background. In a simplified view, two optically separated regions are considered. The target, filled with Gd-doped liquid scintillator, is the main antineutrino interaction volume. Surrounding the target, the inner veto region aims to tag the cosmogenic muon background which hits the detector. Both regions are viewed by photomultipliers. The Double Chooz trigger system has to be highly efficient for antineutrino events as well as for several types of background. The trigger analyzes discriminated signals from the central region and the inner veto photomultipliers. The trigger logic is fully programmable and can combine the input signals. The trigger conditions are based on the total energy released in event and on the PMT groups multiplicity. For redundancy, two independent trigger boards will be used for the central region, each of

  19. Design studies for the Double Chooz trigger

    International Nuclear Information System (INIS)

    The main characteristic of the neutrino mixing effect is assumed to be the coupling between the flavor and the mass eigenstates. Three mixing angles (θ12, θ23, θ13) are describing the magnitude of this effect. Still unknown, θ13 is considered very small, based on the measurement done by the CHOOZ experiment. A leading experiment will be Double Chooz, placed in the Ardennes region, on the same site as used by CHOOZ. The Double Chooz goal is the exploration of ∝80% from the currently allowed θ13 region, by searching the disappearance of reactor antineutrinos. Double Chooz will use two similar detectors, located at different distances from the reactor cores: a near one at ∝150 m where no oscillations are expected and a far one at 1.05 km distance, close to the first minimum of the survival probability function. The measurement foresees a precise comparison of neutrino rates and spectra between both detectors. The detection mechanism is based on the inverse β-decay. The Double Chooz detectors have been designed to minimize the rate of random background. In a simplified view, two optically separated regions are considered. The target, filled with Gd-doped liquid scintillator, is the main antineutrino interaction volume. Surrounding the target, the inner veto region aims to tag the cosmogenic muon background which hits the detector. Both regions are viewed by photomultipliers. The Double Chooz trigger system has to be highly efficient for antineutrino events as well as for several types of background. The trigger analyzes discriminated signals from the central region and the inner veto photomultipliers. The trigger logic is fully programmable and can combine the input signals. The trigger conditions are based on the total energy released in event and on the PMT groups multiplicity. For redundancy, two independent trigger boards will be used for the central region, each of them receiving signals from half of the photomultipliers. A third trigger board will

  20. Instrumentation of a Level-1 Track Trigger at ATLAS with Double Buffer Front-End Architecture

    CERN Document Server

    Cooper, B; The ATLAS collaboration

    2012-01-01

    Around 2021 the Large Hadron Collider will be upgraded to provide instantaneous luminosities 5x10^34, leading to excessive rates from the ATLAS Level-1 trigger. We describe a double-buffer front-end architecture for the ATLAS tracker replacement which should enable tracking information to be used in the Level-1 decision. This will allow Level-1 rates to be controlled whilst preserving high efficiency for single lepton triggers at relatively low transverse momentum thresholds pT ~25 GeV, enabling ATLAS to remain sensitive to physics at the electroweak scale. In particular, a potential hardware solution for the communication between the upgraded silicon barrel strip detectors and the external processing within this architecture will be described, and discrete event simulations used to demonstrate that this fits within the tight latency constraints.

  1. The Upgrade and Performance of the ATLAS Electron and Photon Triggers towards Run II

    CERN Document Server

    Reichert, Joseph; The ATLAS collaboration

    2015-01-01

    Electron and photon triggers are essential for signal selection in a wide variety of ATLAS physics analyses to study Standard Model processes and to search for new phenomena. Final states including leptons and photons had, for example, an important role in the discovery and measurement of the Higgs particle. Dedicated triggers are also used for the collection of J/ψ →e+ e− , W→ eν and QCD background samples for calibration, efficiency and fake rate measurements. The ATLAS trigger system is divided in a hardware-based (Level 1) and a software based high level trigger, both of which were upgraded during the long shutdown of the LHC in preparation for data taking in 2015. The increasing luminosity and more challenging pile-up conditions as well as the planned higher centre-of-mass energy demanded the optimisation of the trigger selections at each level to control the rates and keep efficiencies high. The evolution of the ATLAS electron and photon triggers and their performance will be presented, includin...

  2. The Upgrade and Performance of the ATLAS Electron and Photon Triggers Towards Run 2

    CERN Document Server

    Reichert, Joseph; The ATLAS collaboration

    2015-01-01

    Electron and photon triggers are essential for signal selection in a wide variety of ATLAS physics analyses to study Standard Model processes and to search for new phenomena. Final states in- cluding leptons and photons had, for example, an essential role in the discovery and measurement of the Higgs particle. Dedicated triggers are also used for the collection of J/ψ →ee, W →eν, and QCD background samples for calibration, efficiency, and fake rate measurements. The ATLAS trigger system is divided in a hardware-based (Level 1) and a software-based high level trigger, both of which were upgraded during the long shutdown of the LHC in preparation for data tak- ing in 2015. The increasing luminosity and more challenging pile-up conditions as well as the planned higher center-of-mass energy demanded the optimisation of the trigger selections at each level to control the rates and keep efficiencies high. The evolution of the ATLAS electron and photon triggers and their performance will be presented, includin...

  3. The Upgrade of the ATLAS Electron and Photon Triggers towards LHC Run 2 and their Performance

    CERN Document Server

    Kahn, Sebastien Jonathan; The ATLAS collaboration

    2015-01-01

    Electron and photon triggers covering transverse energies from 5 GeV to several TeV are essential for signal selection in a wide variety of ATLAS physics analyses to study Standard Model processes and to search for new phenomena. Final states including leptons and photons had, for example, an important role in the discovery and measurement of the Higgs particle. Dedicated triggers are also used to collect data for calibration, efficiency and fake rate measurements. The ATLAS trigger system is divided in a hardware-based (Level 1) and a software based high level trigger, both of which were upgraded during the long shutdown of the LHC in preparation for data taking in 2015. The increasing luminosity and more challenging pile-up conditions as well as the planned higher center-of-mass energy demanded the optimisation of the trigger selections at each level to control the rates and keep efficiencies high. The evolution of the ATLAS electron and photon triggers and their performance will be presented, including ini...

  4. The use of low-cost SMPs in the Atlas level-2 trigger

    CERN Document Server

    Bock, R; Ermolin, Y; Kugel, A; Lay, R; Werner, P

    2000-01-01

    Low-cost SMP (Symmetric Multi-Processor) systems have become generallyavailable since 1998; they provide substantial CPU and I/O capacity along with a memory that is shared by all processors. We have investigated two areas of application in the Atlas level-2 trigger.

  5. A Highly Selective First-Level Muon Trigger With MDT Chamber Data for ATLAS at HL-LHC

    CERN Document Server

    Nowak, Sebastian; The ATLAS collaboration

    2015-01-01

    Highly selective triggers are essential for the physics programme of the ATLAS experiment at HL-LHC where the instantaneous luminosity will be about an order of magnitude larger than the LHC design luminosity. The Level-1 muon trigger rate is dominated by low momentum muons below the nominal trigger threshold due to the limited momentum resolution of the Resistive Plate and Thin Gap trigger chambers. The resulting high trigger rates at HL-LHC can be sufficient reduced by using the data of the precision Muon Drift Tube chambers for the trigger decision. This requires the implementation of a fast MDT read-out chain and of a fast MDT track reconstruction algorithm with a latency of at most 6~$\\mu$s. A hardware demonstrator of the fast read-out chain has been successfully tested at the high HL-LHC background rates at the CERN Gamma Irradiation Facility. The fast track reconstruction algorithm has been implemented on a fas trigger processor.

  6. The ATLAS Muon Trigger Performance : Run 1 and initial Run 2.

    CERN Document Server

    Kasahara, Kota; The ATLAS collaboration

    2015-01-01

    The ATLAS Muon Trigger Performance: Run 1 and Initial Run 2 Performance

Events with muons in the final state are an important signature for many physics topics at the Large Hadron Collider (LHC). An efficient trigger on muons and a detailed understanding of its performance are required. In 2012, the last year of Run 1, the instantaneous luminosity of the LHC reached 7.7x10^33 cm -2s-1 and the average number of events that occur in a same bunch crossing was 25. The ATLAS Muon trigger has successfully adapted to this changing environment by making use of isolation requirements, combined trigger signatures with electron and jet trigger objects, and by using so-called full-scan triggers, which make use of the full event information to search for di-lepton signatures, seeded by single lepton objects. A stable and highly efficient muon trigger was vital in the discovery of Higgs boson in 2012 and for many searches for new physics. 
The performance of muon triggers during the LHC Run 1 data-taking campaigns i...

  7. A Level-2 trigger algorithm for the identification of muons in the ATLAS Muon Spectrometer

    CERN Document Server

    Di Mattia, A; Dos Anjos, A; Baines, J T M; Bee, C P; Biglietti, M; Bogaerts, J A C; Boisvert, V; Bosman, M; Caron, B; Casado, M P; Cataldi, G; Cavalli, D; Cervetto, M; Comune, G; Conde-Muíño, P; De Santo, A; Díaz-Gómez, M; Dosil, M; Ellis, Nick; Emeliyanov, D; Epp, B; Falciano, S; Farilla, A; George, S; Ghete, V M; González, S; Grothe, M; Kabana, S; Khomich, A; Kilvington, G; Konstantinidis, N P; Kootz, A; Lowe, A; Luminari, L; Maeno, T; Masik, J; Meessen, C; Mello, A G; Merino, G; Moore, R; Morettini, P; Negri, A; Nikitin, N V; Nisati, A; Padilla, C; Panikashvili, N; Parodi, F; Pasqualucci, E; Pérez-Réale, V; Pinfold, J L; Pinto, P; Qian, Z; Resconi, S; Rosati, S; Sánchez, C; Santamarina-Rios, C; Scannicchio, D A; Schiavi, C; Segura, E; De Seixas, J M; Sivoklokov, S Yu; Soluk, R A; Stefanidis, E; Sushkov, S S; Sutton, M; Tapprogge, Stefan; Thomas, E; Touchard, F; Venda-Pinto, B; Vercesi, V; Werner, P; Wheeler, S; Wickens, F J; Wiedenmann, W; Wielers, M; Zobernig, G; Computing In High Energy Physics

    2005-01-01

    The ATLAS Level-2 trigger provides a software-based event selection after the initial Level-1 hardware trigger. For the muon events, the selection is decomposed in a number of broad steps: first, the Muon Spectrometer data are processed to give physics quantities associated to the muon track (standalone feature extraction) then, other detector data are used to refine the extracted features. The “µFast” algorithm performs the standalone feature extraction, providing a first reduction of the muon event rate from Level-1. It confirms muon track candidates with a precise measurement of the muon momentum. The algorithm is designed to be both conceptually simple and fast so as to be readily implemented in the demanding online environment in which the Level-2 selection code will run. Never-the-less its physics performance approaches, in some cases, that of the offline reconstruction algorithms. This paper describes the implemented algorithm together with the software techniques employed to increase its timing p...

  8. Boosted object hardware trigger development and testing for the Phase I upgrade of the ATLAS Experiment

    Science.gov (United States)

    Stark, Giordon; Atlas Collaboration

    2015-04-01

    The Global Feature Extraction (gFEX) module is a Level 1 jet trigger system planned for installation in ATLAS during the Phase 1 upgrade in 2018. The gFEX selects large-radius jets for capturing Lorentz-boosted objects by means of wide-area jet algorithms refined by subjet information. The architecture of the gFEX permits event-by-event local pile-up suppression for these jets using the same subtraction techniques developed for offline analyses. The gFEX architecture is also suitable for other global event algorithms such as missing transverse energy (MET), centrality for heavy ion collisions, and ``jets without jets.'' The gFEX will use 4 processor FPGAs to perform calculations on the incoming data and a Hybrid APU-FPGA for slow control of the module. The gFEX is unique in both design and implementation and substantially enhance the selectivity of the L1 trigger and increases sensitivity to key physics channels.

  9. Boosted object hardware trigger development and testing for the Phase I upgrade of the ATLAS Experiment

    CERN Document Server

    Stark, Giordon Holtsberg; The ATLAS collaboration

    2015-01-01

    The Global Feature Extraction (gFEX) module is a Level 1 jet trigger system planned for installation in ATLAS during the Phase 1 upgrade in 2018. The gFEX selects large-radius jets for capturing Lorentz-boosted objects by means of wide-area jet algorithms refined by subjet information. The architecture of the gFEX permits event-by-event local pile-up suppression for these jets using the same subtraction techniques developed for offline analyses. The gFEX architecture is also suitable for other global event algorithms such as missing transverse energy (MET), centrality for heavy ion collisions, and "jets without jets". The gFEX will use 4 processor FPGAs to perform calculations on the incoming data and a Hybrid APU-FPGA for slow control of the module. The gFEX is unique in both design and implementation and substantially enhance the selectivity of the L1 trigger and increases sensitivity to key physics channels.

  10. ATLAS Electron and Photon Trigger Performance in Run 1 and Developments toward Run 2

    CERN Document Server

    Ezhilov, A; The ATLAS collaboration

    2014-01-01

    Electron and photon triggers are essential for signal selection in a wide variety of ATLAS physics analyses to study Standard Model processes and to search for new phenomena. Final states including leptons and photons had, for example, an important role in the discovery and measurement of the Higgs particle. Dedicated triggers are also used for the collection of J/ψ →e+ e− , W→ eν and QCD background samples for calibration, efficiency and fake rate measurements. The ATLAS trigger system is divided in a hardware-based (Level 1) and two software stages (Level 2 and Event-Filter). During the LHC Run1 proton-proton data-taking period, the increasing luminosity and the more challenging pile-up conditions demanded the optimization of the trigger selections at each level to control rates and keep efficiencies high. The evolution and performance of the ATLAS electron and photon triggers in Run1 will be discussed, updates and plans for the operation during Run 2 starting in 2015 will be presented.

  11. Balancing the resources of the High Level Trigger farm of the ATLAS experiment

    CERN Document Server

    Garelli, N; The ATLAS collaboration; Vandelli, W

    2012-01-01

    The ATLAS High Level Trigger (HLT) is organized in two trigger levels running different selection algorithms on heterogeneous farms composed of off-the-shelf processing units. The processing units have varying computing power and network connectivities. The ATLAS working conditions are changing due to the continuous optimization of the LHC operations and the consequent trigger adjustment. In addition, the rolling expansion and replacement of the HLT hardware changes the HLT farm composition. Therefore, balancing the available resources is essential for optimizing the HLT farm exploitation. In this paper, a tool for managing the HLT resources will be presented. The tool allows for showing, modifying and generating the HLT farm configuration, keeping the resource balance, in terms of computing power and bandwidth, across the farms under control.

  12. The ATLAS FTK system: how to improve the physics potential with a tracking trigger

    CERN Document Server

    Iizawa, T; The ATLAS collaboration

    2014-01-01

    After a very successful data taking run, the ATLAS experiment [1] is being upgraded to cope with the higher luminosity and higher center of mass energy that the Large Hadron Collider (LHC) will provide in the next years. The Fast Tracker (FTK) trigger system, part of the ATLAS trigger upgrade program, is a highly parallel hardware device processor based on a mixture of advanced technologies. Modern, powerful Field Programmable Gate Arrays (FPGAs) form an important part of the system architecture, and the large level of computing power required for pattern recognition is provided by incorporating standard-cell ASICs named Associative Memory (AM). FTK provides global track reconstruction in the full inner silicon detector, with resolution comparable to the offline algorithms, in approximately 100 microseconds, allowing a fast and precise detection of the primary and secondary vertex information. The track and vertex information is then used by the high-level trigger (HLT) algorithms, allowing highly improved tr...

  13. The evolution of the trigger and data acquisition system in the ATLAS experiment (CHEP2013: 20. international conference on computing in high energy and nuclear physics)

    International Nuclear Information System (INIS)

    The ATLAS experiment, which records the results of LHC proton-proton collisions, is upgrading its Trigger and Data Acquisition (TDAQ) system during the current LHC first long shutdown. The purpose of this upgrade is to add robustness and flexibility to the selection and the conveyance of the physics data, simplify the maintenance of the infrastructure, exploit new technologies and, overall, make ATLAS data-taking capable of dealing with increasing event rates. While the TDAQ system successfully operated well beyond the original design goals, the accumulated experience stimulated interest to explore possible evolutions. With higher luminosities, the required number and complexity of Level-1 triggers will increase in order to satisfy the physics goals of ATLAS, while keeping the total Level-1 rates at or below 100 kHz. The Central Trigger Processor will be upgraded to increase the number ofmanageable inputs and accommodate additional hardware for improved performance, and a new Topological Processor will be included. A single homogeneous high level trigger system will be deployed. The current second and third trigger levels will be executed together on a unique hardware node. This design has many advantages: the radical simplification of the architecture, the flexible and automatically balanced distribution of the computing resources, the sharing of code and services on nodes. In this paper, we report on the design and the development status of the upgraded TDAQ system, with particular attention to the tests currently on-going to identify the required performance and to spot its possible limitations.

  14. Performance of ATLAS RPC Level-1 Muon trigger during the 2015 data taking

    CERN Document Server

    Corradi, Massimo; The ATLAS collaboration

    2016-01-01

    The Level-1 Muon Barrel Trigger is one of the main elements of the event selection of the ATLAS experiment at the Large Hadron Collider. Its input stage consists of an array of processors receiving the full granularity of data from Resistive Plate Chambers in the central area of the ATLAS detector ("Barrel"). The trigger efficiency and the level of synchronisation of its elements with the rest of ATLAS and the LHC clock are crucial figures of this system: many parameters of the constituent RPC detector and the trigger electronics have to be constantly and carefully checked to assure a correct functioning of the Level-1 selection. Notwithstanding the complexity of such a large array of integrated RPC detectors, the ATLAS Level-1 system has resumed operations successfully after the past 2 year shutdown, with levels similar to those of Run 1. We present the inclusive monitoring of the RPC+L1 system that we have developed to characterise the behaviour of the system, using reconstructed muons in events selected by...

  15. A low-latency, low-overhead encoder for data transmission in the ATLAS Liquid Argon Calorimeter trigger upgrade

    Science.gov (United States)

    Xiao, Le; Li, Xiaoting; Gong, Datao; Chen, Jinghong; Deng, Binwei; Fan, Qingjun; Feng, Yulang; Guo, Di; He, Huiqin; Hou, Suen; Huang, Guangming; Liu, Chonghan; Liu, Tiankuan; Sun, Xiangming; Tang, Yuxuan; Teng, Ping-Kun; Vosooghi, Bozorgmehr; Xiang, Annie C.; Ye, Jingbo; You, Yang; Zuo, Zhiheng

    2016-09-01

    In this paper, we present the design and test results of an encoder integrated circuit for the ATLAS Liquid Argon Calorimeter trigger upgrade. The encoder implements a low-latency and low-overhead line code called LOCic. The encoder operates at 320 MHz with a latency of no greater than 21 ns. The overhead of the encoder is 14.3%. The encoder is an important block of the transmitter ASIC LOCx2, which is prototyped with a commercial 0.25 μm Silicon-on-Sapphire CMOS technology and packaged in a 100-pin QFN package.

  16. The Second Level Trigger of the ATLAS Experiment at CERN's LHC

    CERN Document Server

    Dos Anjos, A; Armstrong, S; Baines, J T M; Barisonzi, M; Beck, H P; Bee, C P; Beretta, M; Biglietti, M; Blair, R; Bogaerts, A; Boisvert, V; Bosman, M; Boterenbrood, H; Botterill, David R; Brandt, S; Caron, B; Casado, M P; Cataldi, G; Cavalli, D; Cervetto, M; Ciobotaru, M; Comune, G; Corso-Radu, A; Palencia-Cortezon, E; Cranfield, R; Crone, G J; Dawson, J; Di Girolamo, B; Di Mattia, A; Díaz-Gómez, M; Dobinson, Robert W; Drohan, J; Ellis, Nick; Elsing, M; Epp, B; Ermoline, Y; Etienne, F; Falciano, S; Farilla, A; Ferrer, M L; Francis, D; Gadomski, S; Gameiro, S; George, S; Ghete, V M; Golonka, P; González, S; Gorini, B; Green, B; Grothe, M; Gruwé, M; Haas, S; Haeberli, C; Hasegawa, Y; Hauser, R; Hinkelbein, C; Hughes-Jones, R E; Jansweijer, P; Joos, M; Kaczmarska, A; Karr, K M; Khomich, A; Kieft, G; Knezo, E; Konstantinidis, N P; Korcyl, K; Krasny, W; Kugel, A; Lankford, A; Lehmann, G; Le Vine, M J; Li, W; Liu, W; Lowe, A; Luminari, L; Maeno, T; Losada, M; Mapelli, L; Martin, B; McLaren, R; Meessen, C; Meirosu, C; Mello, A G; Merino, G; Misiejuk, A; Mommsen, R K; Morettini, P; Mornacchi, Giuseppe; Moyse, E; Müller, M; Nagasaka, Y; Nairz, A; Nakayoshi, K; Negri, A; Nikitin, N V; Nisati, A; Padilla, C; Papadopoulos, I M; Parodi, F; Pérez-Réale, V; Petersen, J; Pinfold, J L; Pinto, P; Polesello, G; Pope, B; Prigent, D; Qian, Z; Resconi, S; Rosati, S; Scannicchio, D A; Schiavi, C; Schlereth, J L; Schörner-Sadenius, T; Segura, E; De Seixas, J M; Shears, T G; Shimojima, M; Sivoklokov, S Yu; Smizanska, M; Soluk, R A; Spiwoks, R; Stancu, S; Stanescu, C; Strong, J; Tapprogge, Stefan; Tremblet, L; Touchard, F; Vercesi, V; Vermeulen, J C; Watson, A; Wengler, T; Werner, P; Wheeler, S; Wickens, F J; Wiedenmann, W; Wielers, M; Yasu, Y; Yu, M; Zobernig, G; Zurek, M; IEEE Nuclear Science Symposium and Medical Imaging Conference, Part 1

    2003-01-01

    The Trigger System of the ATLAS experiment reduces the rate of events produced by proton-proton collisions at CERN's Large Hadron Collider (LHC) in three successive steps from 40 MHz to ~ 100, 1 and 0.2 kHz respectively. The ATLAS Second Level Trigger is original in several ways. It makes use of information provided by the First Level Trigger which identifies Regions of Interest (RoI) indicating where the most significant activity has occurred within the detector. Accessing detector data in RoIs only reduces the estimated 100 Gbytes/s data rate by a factor 100. Appart from a custom interface to acquire the RoI information, the Second Level Trigger is implemented in software. Another cost saving approach is the development of Trigger Selection software in an offline environment using a common framework for the High Level Trigger and Reconstruction Software. Consequently, the Second Level Trigger draws on software developed in two largely independant domains: real time oriented dataflow software combined with o...

  17. Monitoring the pre-processor system of the ATLAS level-1 calorimeter trigger

    International Nuclear Information System (INIS)

    The Pre-Processor (PPr) System of the ATLAS Level-1 Calorimeter Trigger is a highly parallel system, with hard-wired algorithms implemented in ASICs, to receive, digitise and process over 7000 analogue trigger tower signals from the entire ATLAS Calorimetry, and to transmit the determined transverse energy deposits to the object-finding processors of the calorimeter trigger: Cluster Processor and Jet/Energy-sum Processor. The PPr System consists of 8 crates, each of which being equipped with 16 Preprocessor Modules, that can each receive and process 64 analogue input signals. The Preprocessor System provides facilities to monitor the operation and performance of both its individual components and the Level-1 Calorimeter Trigger: pipelined readout of event based monitoring data to the DAQ System, in order to document the Level-1 Trigger decision, diagnostic features implemented in PPrASIC to establish rate maps and energy spectra per trigger tower, and output interface to the crate controller CPU. Monitoring software for trigger-specific applications is developed and presented in this talk. (orig.)

  18. ATLAS Level-1 Jet Trigger Rates and study of the ATLAS discovery potential of the neutral MSSM Higgs bosons in b-jet decay channels

    OpenAIRE

    Mahboubi, Kambiz

    2001-01-01

    The response of the ATLAS calorimeters to electrons, photons and hadrons, in terms of the longitudinal and lateral shower development, is parameterized using the GEANT package and a detailed detector description (DICE). The parameterizations are implemented in the ATLAS Level-1 (LVL1) Calorimeter Trigger fast simulation package which, based on an average detector geometry, simulates the complete chain of the LVL1 calorimeter trigger system. In addition, pile-up effects due to multiple p...

  19. Upgraded Readout and Trigger Electronics for the ATLAS Liquid Argon Calorimeter at the LHC at the Horizons 2018-2022

    CERN Document Server

    Oliveira Damazio, Denis; The ATLAS collaboration

    2013-01-01

    The ATLAS Liquid Argon (LAr) calorimeters produce a total of 182,486 signals which are digitized and processed by the front-end and back-end electronics at every triggered event. In addition, the front-end electronics is summing analog signals to provide coarsely grained energy sums, called trigger towers, to the first-level trigger system, which is optimized for nominal LHC luminosities. However, the pile-up noise expected during the High Luminosity phases of LHC will be increased by factors of 3 to 7. An improved spatial granularity of the trigger primitives is therefore proposed in order to improve the identification performance for trigger signatures, like electrons, photons, tau leptons, jets, total and missing energy, at high background rejection rates. For the first upgrade phase in 2018, new LAr Trigger Digitizer Board (LTDB) are being designed to receive higher granularity signals, digitize them on detector and send them via fast optical links to a new digital processing system (DPS). The DPS applies...

  20. Software framework developed for the slice test of the ATLAS endcap muon trigger system

    CERN Document Server

    Komatsu, S; Ishida, Y; Tanaka, K; Hasuko, K; Kano, H; Matsumoto, Y; Yakamura, Y; Sakamoto, H; Ikeno, M; Nakayoshi, K; Sasaki, O; Yasu, Y; Hasegawa, Y; Totsuka, M; Tsuji, S; Maeno, T; Ichimiya, R; Kurashige, H

    2002-01-01

    A sliced system test of the ATLAS end cap muon level 1 trigger system has been done in 2001 and 2002 separately. We have developed an own software framework for property and run controls for the slice test in 2001. The system is described in C++ throughout. The multi-PC control system is accomplished using the CORBA system. We have then restructured the software system on top of the ATLAS online software framework, and used this one for the slice test in 2002. In this report we discuss two systems in detail with emphasizing the module property configuration and run control. (8 refs).

  1. ATLAS High-Level Trigger Algorithms for Run-2 Data Taking

    CERN Document Server

    Schiavi, Carlo; The ATLAS collaboration

    2015-01-01

    Following the successful Run-1 LHC data-taking, the long shutdown gave the opportunity for significant improvements in the ATLAS trigger capabilities, as a result of the introduction of new or improved Level-1 trigger hardware and significant restructuring of the DAQ infrastructure. To make use of these new capabilities, the High-Level trigger (HLT) software has been to a large extent rewritten, introducing in its turn a plethora of new features and improved algorithms for object reconstruction. The HLT algorithms rely heavily on the offline reconstruction algorithms with the aim to have an even larger efficiency for accepted events than in Run-1. A summary of the HLT algorithms for object reconstruction will be given with the focus on new and improved algorithms together with an outline of the strategy to combine them into a trigger menu. In addition, we will show examples of impressive code speedups and the expected trigger performance for Run-2 data-taking.

  2. ATLAS High-Level Trigger algorithms for Run-2 data-taking

    CERN Document Server

    Schiavi, Carlo; The ATLAS collaboration

    2015-01-01

    Following the successful Run-1 LHC data-taking, the long shutdown gave the opportunity for significant improvements in the ATLAS trigger capabilities, as a result of the introduction of new or improved Level-1 trigger hardware and significant restructuring of the DAQ infrastructure. To make use of these new capabilities, the High-Level trigger (HLT) software has been to a large extent rewritten, introducing in its turn a plethora of new features and improved algorithms for object reconstruction. The HLT algorithms rely heavily on the offline reconstruction algorithms with the aim to have an even larger efficiency for accepted events than in Run-1. A summary of the HLT algorithms for object reconstruction will be given with the focus on new and improved algorithms together with an outline of the strategy to combine them into a trigger menu. In addition, we will show examples of impressive code speedups and the expected trigger performance for Run-2 data-taking.

  3. The Trigger and Data Acquisition System of the ATLAS experiment in preparation for Run 2

    CERN Document Server

    Heinrich, Lukas; The ATLAS collaboration

    2014-01-01

    After its first shutdown, LHC will provide pp collisions with increased luminosity and energy. In the ATLAS experiment, aimed at recording these collisions, the Trigger and Data Acquisition (TDAQ) system is upgrading to deal with increased event rates. A new trigger strategy is deployed, exploiting new methods and technologies that will further increase robustness and flexibility. The first stage of the trigger, hardware based, will increase the number and complexity of the input signals, while accommodating new hardware for improved performance. The high-level trigger, software based, will become more flexible in operating over both limited regions of the detector, the so-called Regions-of-Interest (RoI), or complete events. Higher rejection power is achieved by incorporating more elements of the offline reconstruction in the trigger. The data-acquisition architecture is simplified, with a single network for automatically balanced distribution of the computing resources and a single node execution of the sof...

  4. Beam Test of the ATLAS Level-1 Calorimeter Trigger System

    CERN Document Server

    Garvey, J; Mahout, G; Moye, T H; Staley, R J; Thomas, J P; Typaldos, D; Watkins, P M; Watson, A; Achenbach, R; Föhlisch, F; Geweniger, C; Hanke, P; Kluge, E E; Mahboubi, K; Meier, K; Meshkov, P; Rühr, F; Schmitt, K; Schultz-Coulon, H C; Ay, C; Bauss, B; Belkin, A; Rieke, S; Schäfer, U; Tapprogge, T; Trefzger, T; Weber, GA; Eisenhandler, E F; Landon, M; Apostologlou, P; Barnett, B M; Brawn, I P; Davis, A O; Edwards, J; Gee, C N P; Gillman, A R; Mirea, A; Perera, V J O; Qian, W; Sankey, D P C; Bohm, C; Hellman, S; Hidvegi, A; Silverstein, S

    2005-01-01

    The Level-1 Calorimter Trigger consists of a Preprocessor (PP), a Cluster Processor (CP), and a Jet/Energy-sum Processor (JEP). The CP and JEP receive digitised trigger-tower data from the Preprocessor and produce Region-of-Interest (RoIs) and trigger multiplicities. The latter are sent in real time to the Central Trigger Processor (CTP) where the Level-1 decision is made. On receipt of a Level-1 Accept, Readout Driver Modules (RODs), provide intermediate results to the data acquisition (DAQ) system for monitoring and diagnostic purpose. RoI information is sent to the RoI builder (RoIB) to help reduce the amount of data required for the Level-2 Trigger The Level-1 Calorimeter Trigger System at the test beam consisted of 1 Preprocessor module, 1 Cluster Processor Module, 1 Jet/Energy Module and 2 Common Merger Modules. Calorimeter energies were sucessfully handled thourghout the chain and trigger object sent to the CTP. Level-1 Accepts were sucessfully produced and used to drive the readout path. Online diagno...

  5. The ATLAS Trigger Core Configuration and Execution System in Light of the ATLAS Upgrade for LHC Run 2

    CERN Document Server

    Heinrich, Lukas; The ATLAS collaboration

    2015-01-01

    During the 2013/14 shutdown of the Large Hadron Collider (LHC) the ATLAS first level trigger (L1T) and the data acquisition system (DAQ) were substantially upgraded to cope with the increase in luminosity and collision multiplicity, expected to be delivered by the LHC in 2015. To name a few, the L1T was extended on the calorimeter side (L1Calo) to better cope with pile-up and apply better-tuned isolation criteria on electron, photon, and jet candidates. The central trigger (CT) was widened to analyze twice as many inputs, provide more trigger lines, and serve multiple sub-detectors in parallel during calibration periods. A new FPGA-based trigger, capable of analyzing event topologies at 40 MHz, was added to provide further input to forming the level 1 trigger decision (L1Topo). On the DAQ side the dataflow was completely remodeled, merging the two previously existing stages of the software-based high level trigger into one. Partially because of these changes, partially because of the new trigger paradigm to h...

  6. A new Scheme for ATLAS Trigger Simulation using Legacy Code

    CERN Document Server

    Galster, G; The ATLAS collaboration; Wiedenmann, W

    2014-01-01

    An accurate simulation of the trigger response is necessary for high quality data analyses. This poses a challenge. For event generation and simulated data reconstruction the latest software is used to be in best agreement with the reconstructed data. Contrary the trigger response simulation needs to be in agreement with when the data was taken. The approach we follow is to use trigger software and conditions data that matches the simulated data-taking period potentially dating many years back. Having a strategy for running old software in a modern environment thus becomes essential when data simulated for past years start to present a sizable fraction of the total.\

  7. FTK status and track triggers in ATLAS at HL-LHC

    CERN Document Server

    ATLAS Collaboration; The ATLAS collaboration

    2016-01-01

    The expected instantaneous luminosities delivered by the Large Hadron Collider will place continually increasing burdens on the trigger systems of the ATLAS detector. The use of tracking information is key to maintaining a manageable trigger rate while keeping a high efficiency. At the same time, however, track finding is one of the more resource-intensive tasks in the software-based processing farms of the high level trigger system. To support the trigger, ATLAS is building and currently installing the Fast TracK Finder (FTK), a hardware-based system that uses massively parallel pattern recognition in Associative Memory to reconstruct tracks above transverse momenta of 1 GeV across the entire detector at 100 kHz with a latency of ~100 microseconds. In the first-stage of track finding, FTK compares hits in ATLAS silicon detectors against ~1 billion pre-computed track pattern candidates. Track parameters for these candidates, including goodness-of-fit tests, are calculated in FPGAs using a linear approximation...

  8. Performance and development for the Inner Detector Trigger algorithms at ATLAS

    CERN Document Server

    Penc, O; The ATLAS collaboration

    2014-01-01

    The performance of the ATLAS Inner Detector (ID) Trigger algorithms being developed for running on the ATLAS High Level Trigger (HLT) processor farm during Run 2 of the LHC are presented. During the 2013-14 LHC long shutdown modifications are being carried out to the LHC accelerator to increase both the beam energy and luminosity. These modifications will pose significant challenges for the ID Trigger algorithms, both in terms execution time and physics performance. To meet these challenges, the ATLAS HLT software is being restructured to run as a more flexible single stage HLT, instead of two separate stages (Level2 and Event Filter) as in Run 1. This will reduce the overall data volume that needs to be requested by the HLT system, since data will no longer need to be requested for each of the two separate processing stages. Development of the ID Trigger algorithms for Run 2, currently expected to be ready for detector commissioning near the end of 2014, is progressing well and the current efforts towards op...

  9. The ATLAS Tau Trigger Performance during LHC Run1 and Prospects for Run2

    CERN Document Server

    Mitani, T; The ATLAS collaboration

    2014-01-01

    Triggering on hadronic tau decays at ATLAS is essential for a wide variety of analyses of interesting physics processes at ATLAS. Among those are the measurement of the Higgs boson in the di-tau final state and multiple searches for physics beyond the Standard Model. The ATLAS tau trigger combines information from the tracking detectors and calorimeters to identify the signature of hadronically decaying tau leptons. In 2015 the trigger strategies will become more important than ever for physics analyses. Under the demanding high luminosity scenario of the LHC Run 2, with instantaneous luminosities up to 2x10^34 cm^-2s^-1, one of the major challenges will be to sustain high efficiencies and background rejection in events with up to 50 overlapping interactions. In this environment single-tau triggers suffer from severe rate limitations, despite the sophisticated algorithms that are used in the tau identification. Hence, new algorithms with improved resolution, multi-variate selection techniques, and new topolog...

  10. Instrumentation of the upgraded ATLAS tracker with a double buffer front-end architecture for track triggering

    CERN Document Server

    Wardrope, DR; The ATLAS collaboration

    2012-01-01

    The Large Hadron Collider will be upgraded to provide instantaneous luminosity $L=5\\times10^{34}\\,\\mbox{cm}^{-2}\\mbox{s}^{-1}$, leading to excessive rates from the ATLAS Level-1 trigger. A double buffer front-end architecture for the ATLAS tracker replacement is proposed, that will enable the use of track information in trigger decisions within 20$\\,\\mu$s in order to reduce the high trigger rates. Analysis of ATLAS simulations have found that using track information will enable the use of single lepton triggers with transverse momentum thresholds of $p_{T}\\sim25\\,$GeV, which will be of great benefit to the future physics programme of ATLAS

  11. Optimisation of Level 1 Topological Trigger Cuts for B-physics in ATLAS Detector

    CERN Document Server

    Ng Chi, Wing

    2015-01-01

    Triggers are important in detector systems as they select the most interesting events to be investigated from the huge amount of data coming out every second. In the ATLAS detector, the rate of events occuring was 20MHz in Run 1 data taking, while in Run 2, the rate will be increased to 40MHz. This imposes a great pressure on the trigger system as the time needed to process one event is roughly constant in the Data Acquisition (DAQ) System. More eective triggering conditions have to be imposed in order to reduce the rate of events passing the rst level of the triggering system. In this project, the main goal is to nd out the most eective set of triggering conditions, in order to build a suitable menu for a wide range of B-physics anlayses to be performed in Run2. The organisation of the report is as follows: the ATLAS trigger system and data/MC samples are discussed in Section 2 and 3 respectively. Then the analysis for 1-dimensional topological cuts is described and the corresponding result is presented in S...

  12. Framework for data intercommunication and control of ATLAS High Level Trigger algorithms

    CERN Document Server

    Ospanov, Rustem; The ATLAS collaboration

    2016-01-01

    The ATLAS experiment at the LHC is equipped with a sophisticated trigger system capable of reducing the 40 MHz LHC collision rate to the 70 kHz rate at the Level 1 hardware trigger and to the average 400 Hz rate at the High Level Trigger (HLT) during the Run 1 data taking in 2010-2012. In the HLT, the Steering Framework manages a few hundred of trigger algorithms: it evaluates every collision event and makes an accept/reject decision using as few resources as possible. Communication among algorithms is facilitated by a data navigation structure, implemented as a directed acyclic graph structure, that allows HLT algorithms fast discovery of detector regions containing interesting physics objects, as well as selecting an optimal way to build and traverse the event graph structure. For ATLAS running after the 2013-2014 shutdown (Run 2), more detailed trigger information is given to physics analysis users thus improving capabilities of trigger aware analyses. To reduce size of event data stored for physics analys...

  13. Installation and Test of the ATLAS Muon Endcap Trigger Chamber Electronics

    CERN Document Server

    Nomoto, Hiroshi; Kuwabara, T; Ishino, M; Sakamoto, H; Fukunaga, C; Kagawa, S; Ikeno, M; Sasaki, O; Yasu, Y; Hasegawa, Y; Sugaya, Y; Sugimoto, T; Tomoto, M; Kurashige, H; Ogata, T

    2007-01-01

    For the detector commissioning planned in 2007, a sector assembly of the ATLAS muon endcap trigger chambers is being progressed in CERN. Final technical test of the electronics mounted on a sector must be made at this stage. For systematic test of the electronics (sector test), we have developed a DAQ system on top of the ATLAS online software framework. The system is not dedicated only for this test, but can be used also for the front-end detector part of the overall ATLAS DAQ system. In the presentation, the procedure, meaning and results of the sector test are discussed after brief introduction of the TGC electronics and the sector structure as a construction unit. We introduce plans of further detailed and elaborated tests for the whole system using cosmic ray and single halo muons when all the TGC sub-detector part is completed as concluding remark.

  14. The PC—Based ATLAS Event Filter Prototype:Supervision Design,Implementation and Tests

    Institute of Scientific and Technical Information of China (English)

    C.P.Bee; F.Etienne; 等

    2001-01-01

    The studies undertaken to prepare the Technical Design Report of the ATLAS 3rd Level Trigger(Event Filter)are performed on different prototypes based on different technologies.we present here the most recent results obtained for the supervision of the prototype based on conventional,off-the-shelf PC machines and Java Moblie agent technology.

  15. The data path of the ATLAS level-1 calorimeter trigger preprocessor

    Energy Technology Data Exchange (ETDEWEB)

    Andrei, George Victor

    2010-10-27

    The PreProcessor of the ATLAS Level-1 Calorimeter Trigger provides digital values of transverse energy in real-time to the subsequent object-finding processors. The input comprises more than 7000 analogue signals of reduced granularity from the calorimeters of the ATLAS detector. The Level-1 trigger decision must be verified. For this, the PreProcessor transmits copies of the real-time digital data to the Data Acquisition (DAQ) system. In addition, the PreProcessor system provides a standard VMEbus interface to the computing infrastructure of the experiment, on which configuration data is loaded and control or monitoring data are read out. A dedicated system that ensures both the transfer of event data to storage in ATLAS and the data transfer over the VME was implemented on the 124 modules of the PreProcessor system in the form of a ''Readout Manager''. The ''Field Programmable Gate Array'' (FPGA) is located on each module. The rst part of this work describes the algorithms developed to meet the functionality of the Readout Manager. The second part deals with the tests that were carried out to ensure the proper functionality of the modules before they were installed at CERN in the ATLAS cavern. (orig.)

  16. The data path of the ATLAS level-1 calorimeter trigger preprocessor

    International Nuclear Information System (INIS)

    The PreProcessor of the ATLAS Level-1 Calorimeter Trigger provides digital values of transverse energy in real-time to the subsequent object-finding processors. The input comprises more than 7000 analogue signals of reduced granularity from the calorimeters of the ATLAS detector. The Level-1 trigger decision must be verified. For this, the PreProcessor transmits copies of the real-time digital data to the Data Acquisition (DAQ) system. In addition, the PreProcessor system provides a standard VMEbus interface to the computing infrastructure of the experiment, on which configuration data is loaded and control or monitoring data are read out. A dedicated system that ensures both the transfer of event data to storage in ATLAS and the data transfer over the VME was implemented on the 124 modules of the PreProcessor system in the form of a ''Readout Manager''. The ''Field Programmable Gate Array'' (FPGA) is located on each module. The rst part of this work describes the algorithms developed to meet the functionality of the Readout Manager. The second part deals with the tests that were carried out to ensure the proper functionality of the modules before they were installed at CERN in the ATLAS cavern. (orig.)

  17. The performance and development for the Inner Detector Trigger algorithms at ATLAS

    CERN Document Server

    Penc, O; The ATLAS collaboration

    2015-01-01

    A redesign of the tracking algorithms for the ATLAS trigger for LHC's Run 2 starting in 2015 is in progress. The ATLAS HLT software has been restructured to run as a more flexible single stage HLT, instead of two separate stages (Level 2 and Event Filter) as in Run 1. The new tracking strategy employed for Run 2 will use a Fast Track Finder (FTF) algorithm to seed subsequent Precision Tracking, and will result in improved track parameter resolution and faster execution times than achieved during Run 1. The performance of the new algorithms has been evaluated to identify those aspects where code optimisation would be most beneficial. The performance and timing of the algorithms for electron and muon reconstruction in the trigger are presented. The profiling infrastructure, constructed to provide prompt feedback from the optimisation, is described, including the methods used to monitor the relative performance improvements as the code evolves.

  18. Performance and development for the Inner Detector Trigger Algorithms at ATLAS

    CERN Document Server

    Penc, Ondrej; The ATLAS collaboration

    2015-01-01

    A redesign of the tracking algorithms for the ATLAS trigger for Run 2 starting in spring 2015 is in progress. The ATLAS HLT software has been restructured to run as a more flexible single stage HLT, instead of two separate stages (Level 2 and Event Filter) as in Run 1. The new tracking strategy employed for Run 2 will use a Fast Track Finder (FTF) algorithm to seed subsequent Precision Tracking, and will result in improved track parameter resolution and faster execution times than achieved during Run 1. The performance of the new algorithms has been evaluated to identify those aspects where code optimisation would be most beneficial. The performance and timing of the algorithms for electron and muon reconstruction in the trigger are presented. The profiling infrastructure, constructed to provide prompt feedback from the optimisation, is described, including the methods used to monitor the relative performance improvements as the code evolves.

  19. A Novel Highly Ionizing Particle Trigger using the ATLAS Transition Radiation Tracker

    CERN Document Server

    Penwell, J; The ATLAS collaboration

    2011-01-01

    The ATLAS Transition Radiation Tracker (TRT) is an important part of the experiment’s charged particle tracking system. It also provides the ability to discriminate electrons from pions efficiently using large signal amplitudes induced in the TRT straw tubes by transition radiation. This amplitude information can also be used to identify heavily ionizing particles, such as monopoles, or Q-balls, that traverse the straws. Because of their large ionization losses, these particles can range out before they reach the ATLAS calorimeter, making them difficult to identify by the experiment’s first level trigger. Much of this inefficiency could be regained by making use of a feature of the TRT electronics that allows fast access to information on whether large-amplitude signals were produced in regions of the detector. A modest upgrade to existing electronics could allow triggers sensitive to heavily ionizing particles at level-1 to be constructed by counting such large-amplitude signals in roads corresponding to...

  20. Monitoring the tracking performance of the ATLAS trigger for electrons in Z->ee decays

    CERN Document Server

    Langford, Jonathon

    2016-01-01

    This project was carried out to develop an algorithm which monitors the performance of the tracking system in the ATLAS trigger. The algorithm uses tag and probe methods to measure the efficiency of the tracking for electrons by looking at Z → ee candidates. Once this method is validated, the ultimate goal is to implement the algorithm into the High-Level-Trigger (HLT) of ATLAS whilst online. The advantage of this technique over traditional offline monitoring is continuous feedback during data taking and higher available statistics. In this report the results of an offline analysis are presented, showing electron tracking efficiencies between 96% and 99% across almost all regions of the inner detector (run 306278).

  1. The ATLAS Tier-3 in Geneva and the Trigger Development Facility

    CERN Document Server

    Gadomski, S; The ATLAS collaboration; Pasche, P; Baud, J-P

    2010-01-01

    The ATLAS Tier-3 farm at the University of Geneva provides storage and processing power for analysis of ATLAS data. In addition the facility is used for development, validation and commissioning of the High Level Trigger of ATLAS. The latter purpose leads to additional requirements on the availability of latest software and data, which will be presented. The farm is also a part of the WLCG, and is available to all members of the ATLAS Virtual Organization. The farm currently provides 268 CPU cores and 177 TB of storage space. A grid Storage Element, implemented with the Disk Pool Manager software, is available and integrated with the ATLAS Distributed Data Management system. The batch system can be used directly by local users, or with a grid interface provided by NorduGrid ARC middleware. In this article we will present the use cases that we support, as well as the experience with the software and the hardware we are using. Results of I/O benchmarking tests, which were done for our DPM Storage Element and fo...

  2. The ATLAS Tier-3 in Geneva and the Trigger Development Facility

    CERN Document Server

    Gadomski, S; The ATLAS collaboration; Meunier, Y; Pasche, P

    2011-01-01

    The ATLAS Tier-3 farm at the University of Geneva provides storage and processing power for analysis of ATLAS data. In addition the facility is used for development, validation and commissioning of the High Level Trigger of ATLAS. The latter purpose leads to additional requirements on the availability of latest software and data, which will be presented. The farm is also a part of the WLCG, and is available to all members of the ATLAS Virtual Organization. The farm currently provides 268 CPU cores and 177 TB of storage space. A grid Storage Element, implemented with the Disk Pool Manager software, is available and integrated with the ATLAS Distributed Data Management system. The batch system can be used directly by local users, or with a grid interface provided by NorduGrid ARC middleware. In this article we will present the use cases that we support, as well as the experience with the software and the hardware we are using. Results of I/O benchmarking tests, which were done for our DPM Storage Element and fo...

  3. SOFTWARE RELEASES MANAGEMENT IN THE TRIGGER AND DATA ACQUISITION OF ATLAS EXPERIMENT

    CERN Document Server

    Kazarov, A; The ATLAS collaboration; Hauser, R; Soloviev, I

    2011-01-01

    ATLAS is a general-purpose experiment in high-energy physics at Large Hadron Collider at CERN. ATLAS Trigger and Data Acquisition (TDAQ) system is a distributed computing system which is responsible for transferring and filtering the physics data from the experiment to mass-storage. TDAQ software is developed since 1998 by a team of few dozens developers. It is used for integration of all ATLAS subsystem participating in data-taking, providing framework and API for building the s/w pieces of TDAQ system. It is currently composed of more then 200 s/w packages which are available for ATLAS users in form of regular software releases. The s/w is available for development on a shared filesystem, on test beds and it is deployed to the ATLAS pit where it is used for data-taking. The paper describes the working model, the policies and the tools which are used by s/w developers and s/w librarians in order to develop, release, deploy and maintain the TDAQ s/w for the long period of development, commissioning and runnin...

  4. Expected performance for displaced Lepton Jets: ATLAS trigger and reconstruction efficiency in LHC 2015 run.

    CERN Document Server

    Del Gaudio, Michela; The ATLAS collaboration; Policicchio, Antonio; Testa, Marianna; Giagu, Stefano; Verducci, Monica; Ciapetti, Guido; Diamond, Miriam; Les, Robert

    2016-01-01

    Several models of physics beyond the Standard Model predict neutral particles that decay to final states consisting of collimated jets of light leptons and hadrons (so-called ``Lepton Jets''). These particles can also have a decay length comparable to, or even larger than, the LHC detectors' linear dimensions. This note presents the 2015 ATLAS trigger and reconstruction efficiencies expected for simulated displaced Lepton Jets, based on the Falkowsky-Ruderman-Volansky-Zupan BSM Higgs decay models.

  5. Development of the Trigger Readout System for the Phase-I Upgrade of the ATLAS Liquid Argon Calorimeters

    CERN Document Server

    Xu, Hao; The ATLAS collaboration

    2015-01-01

    The ATLAS Liquid Argon (LAr) Calorimeters were designed and built to measure electromagnetic and hadronic energy in proton-proton collisions produced at the LHC at centre-of-mass energies up to 14 TeV and at instantaneous luminosities up to 1034cm-2s-1. An LHC upgrade is planned to enhance the luminosities to 2-3 x 1034cm-2s-1 and to deliver an integrated luminosity of about 300 fb-1 during Run 3 from 2019 through 2021. In order to improve the identification performance for electrons, photons, taus, jets, missing energy at high background rejection rates, an improved spatial granularity of the trigger primitives has been proposed. Therefore, a new trigger readout system is being designed to digitize and process the signals with higher spatial granularity. A demonstrator system has been developed and installed on the ATLAS detector to evaluate the technical and performance aspects. Analog signal parameters including noise and cross-talk have been analyzed. The performance of the new demonstrator system in the ...

  6. Development of the Trigger Readout System for Phase-I Upgrade of the ATLAS Liquid Argon Calorimeters

    CERN Document Server

    Xu, Hao; The ATLAS collaboration

    2015-01-01

    The ATLAS Liquid Argon (LAr) Calorimeters were designed and built to measure electromagnetic and hadronic energy in proton-proton collisions produced at the LHC at centre-of-mass energies up to 14 TeV and at instantaneous luminosities up to 10^34 cm^-2s^-1. An LHC upgrade is planned to enhance the luminosities to 2-3 x 10^34 cm^-2 s^-1 and to deliver an integrated luminosity of about 300 fb^-1 during Run 3 from 2019 through 2021. In order to improve the identification performance for electrons, photons, taus, jets, missing energy at high background rejection rates, an improved spatial granularity of the trigger primitives has been proposed. Therefore, a new trigger readout system is being designed to digitize and process the signals with higher spatial granularity. A demonstrator system has been developed and installed on the ATLAS detector to evaluate the technical and performance aspects. Analog signal parameters including noise and cross-talk have been analyzed. The performance of the new readout system is...

  7. The ATLAS fast tracker processor design

    CERN Document Server

    Volpi, Guido; Albicocco, Pietro; Alison, John; Ancu, Lucian Stefan; Anderson, James; Andari, Nansi; Andreani, Alessandro; Andreazza, Attilio; Annovi, Alberto; Antonelli, Mario; Asbah, Needa; Atkinson, Markus; Baines, J; Barberio, Elisabetta; Beccherle, Roberto; Beretta, Matteo; Biesuz, Nicolo Vladi; Blair, R E; Bogdan, Mircea; Boveia, Antonio; Britzger, Daniel; Bryant, Partick; Burghgrave, Blake; Calderini, Giovanni; Camplani, Alessandra; Cavaliere, Viviana; Cavasinni, Vincenzo; Chakraborty, Dhiman; Chang, Philip; Cheng, Yangyang; Citraro, Saverio; Citterio, Mauro; Crescioli, Francesco; Dawe, Noel; Dell'Orso, Mauro; Donati, Simone; Dondero, Paolo; Drake, G; Gadomski, Szymon; Gatta, Mauro; Gentsos, Christos; Giannetti, Paola; Gkaitatzis, Stamatios; Gramling, Johanna; Howarth, James William; Iizawa, Tomoya; Ilic, Nikolina; Jiang, Zihao; Kaji, Toshiaki; Kasten, Michael; Kawaguchi, Yoshimasa; Kim, Young Kee; Kimura, Naoki; Klimkovich, Tatsiana; Kolb, Mathis; Kordas, K; Krizka, Karol; Kubota, T; Lanza, Agostino; Li, Ho Ling; Liberali, Valentino; Lisovyi, Mykhailo; Liu, Lulu; Love, Jeremy; Luciano, Pierluigi; Luongo, Carmela; Magalotti, Daniel; Maznas, Ioannis; Meroni, Chiara; Mitani, Takashi; Nasimi, Hikmat; Negri, Andrea; Neroutsos, Panos; Neubauer, Mark; Nikolaidis, Spiridon; Okumura, Y; Pandini, Carlo; Petridou, Chariclia; Piendibene, Marco; Proudfoot, James; Rados, Petar Kevin; Roda, Chiara; Rossi, Enrico; Sakurai, Yuki; Sampsonidis, Dimitrios; Saxon, James; Schmitt, Stefan; Schoening, Andre; Shochet, Mel; Shoijaii, Jafar; Soltveit, Hans Kristian; Sotiropoulou, Calliope-Louisa; Stabile, Alberto; Swiatlowski, Maximilian J; Tang, Fukun; Taylor, Pierre Thor Elliot; Testa, Marianna; Tompkins, Lauren; Vercesi, V; Wang, Rui; Watari, Ryutaro; Zhang, Jianhong; Zeng, Jian Cong; Zou, Rui; Bertolucci, Federico

    2015-01-01

    The extended use of tracking information at the trigger level in the LHC is crucial for the trigger and data acquisition (TDAQ) system to fulfill its task. Precise and fast tracking is important to identify specific decay products of the Higgs boson or new phenomena, as well as to distinguish the contributions coming from the many collisions that occur at every bunch crossing. However, track reconstruction is among the most demanding tasks performed by the TDAQ computing farm; in fact, complete reconstruction at full Level-1 trigger accept rate (100 kHz) is not possible. In order to overcome this limitation, the ATLAS experiment is planning the installation of a dedicated processor, the Fast Tracker (FTK), which is aimed at achieving this goal. The FTK is a pipeline of high performance electronics, based on custom and commercial devices, which is expected to reconstruct, with high resolution, the trajectories of charged-particle tracks with a transverse momentum above 1 GeV, using the ATLAS inner tracker info...

  8. The Trigger Readout Electronics for the Phase-I Upgrade of the ATLAS Liquid Argon Calorimeters

    CERN Document Server

    Xu, Hao; The ATLAS collaboration

    2016-01-01

    For the Phase-I luminosity upgrade of the LHC a higher granularity trigger readout of the ATLAS Liquid Argon (LAr) Calorimeters is foreseen to enhance the trigger feature extraction and background rejection. The new readout system digitizes the detector signals, grouped into 34000 so-called Super Cells, with 12bit precision at 40MHz and transfers the data on optical links to the digital processing system, which computes the Super Cell transverse energies. In this paper, development and test results of the new readout system are presented.

  9. Simulation of dynamic pile-up corrections in the ATLAS level-1 calorimeter trigger

    Energy Technology Data Exchange (ETDEWEB)

    Narrias-Villar, Daniel; Wessels, Martin; Brandt, Oleg [Heidelberg University, Heidelberg (Germany)

    2015-07-01

    The Level-1 Calorimeter Trigger is a crucial part of the ATLAS trigger effort to select only relevant physics events out of the large number of interactions at the LHC. In Run II, in which the LHC will double the centre-of-mass energy and further increase the instantaneous luminosity, pile-up is a limiting key factor for triggering and reconstruction of relevant events. The upgraded L1Calo Multi-Chip-Modules (nMCM) will address this problem by applying dynamic pile-up corrections in real-time, of which a precise simulation is crucial for physics analysis. Therefore pile-up effects are studied in order to provide a predictable parametrised baseline correction for the Monte Carlo simulation. Physics validation plots, such as trigger rates and turn-on curves are laid out.

  10. The Upgrade of the ATLAS Electron and Photon Triggers towards LHC Run 2 and their Performance

    CERN Document Server

    White, Ryan Mackenzie; The ATLAS collaboration

    2015-01-01

    Electron and photon triggers covering transverse energies from 5 GeV to several TeV are essential for signal selection in a wide variety of ATLAS physics analyses to study Standard Model processes and to search for new phenomena. Final states including leptons and photons had, for example, an important role in the discovery and measurement of the Higgs particle. Dedicated triggers are also used to collect data for calibration, efficiency and fake rate measurements. The ATLAS trigger system is divided in a hardware-based (Level 1) and a software based high level trigger (HLT), both of which were upgraded during the long shutdown of the LHC in preparation for data taking in 2015. The increasing luminosity and more challenging pile-up conditions as well as the planned higher center-of-mass energy demanded the optimisation of the trigger selections at each level, to control the rates and keep efficiencies high. To improve the performance multivariate analysis techniques are introduced at the HLT. The evolution of...

  11. The Upgrade of the ATLAS Electron and Photon Triggers towards LHC Run 2 and their Performance

    CERN Document Server

    Pasztor, Gabriella

    2015-01-01

    Electron and photon triggers covering transverse energies from 5 GeV to several TeV are essential for signal selection in a wide variety of ATLAS physics analyses to study Standard Model processes and to search for new phenomena. Final states including leptons and photons had, for example, an important role in the discovery and measurement of the Higgs particle. Dedicated triggers are also used to collect data for calibration, efficiency and fake rate measurements. The ATLAS trigger system is divided in a hardware-based (Level 1) and a software based High-Level Trigger (HLT), both of which were upgraded during the long shutdown of the LHC in preparation for data taking in 2015. The increasing luminosity and more chal- lenging pile-up conditions as well as the higher center-of-mass energy demanded the optimisation of the trigger selections at each level, to control the rates and keep efficiencies high. To improve the performance, multivariate analysis techniques were introduced at the HLT. The evolution of the...

  12. The Upgrade of the ATLAS Electron and Photon Triggers for LHC Run 2 and their Performance

    CERN Document Server

    Monticelli, Fernando; The ATLAS collaboration

    2016-01-01

    Electron and photon triggers covering transverse energies from 5 GeV to several TeV are essential for signal selection in a wide variety of ATLAS physics analyses to study Standard Model processes and to search for new phenomena. Final states including leptons and photons had, for example, an important role in the discovery and measurement of the Higgs particle. Dedicated triggers are also used to collect data for calibration, efficiency and fake rate measurements. The ATLAS trigger system is divided in a hardware-based (Level 1) and a software based high level trigger (HLT), both of which were upgraded during the long shutdown of the LHC in preparation for data taking at $\\sqrt{s}$ = 13TeV. The increasing luminosity and more challenging pile-up conditions as well as the planned higher center-of-mass energy demanded the optimisation of the trigger selections at each level, to control the rates and keep efficiencies high. To improve the performance multivariate analysis techniques are introduced at the HLT. Th...

  13. The Upgrade of the ATLAS $e/\\gamma$ Triggers for Run2 and their Performance

    CERN Document Server

    ATLAS Collaboration; The ATLAS collaboration

    2016-01-01

    Electron and photon triggers covering transverse energies from 5 GeV to several TeV are essential for signal selection in a wide variety of ATLAS physics analyses to study Standard Model processes and to search for new phenomena. Final states including leptons and photons had, for example, an important role in the discovery and measurement of the Higgs particle. Dedicated triggers are also used to collect data for calibration, efficiency and fake rate measurements. The ATLAS trigger system is divided in a hardware-based (Level 1) and a software based high level trigger (HLT), both of which were upgraded during the long shutdown of the LHC in preparation for data taking at $\\sqrt{s} = $ 13TeV . The increasing luminosity and more challenging pile-up conditions as well as the planned higher center-of-mass energy demanded the optimisation of the trigger selections at each level, to control the rates and keep efficiencies high. To improve the performance multivariate analysis techniques are introduced at the HLT. ...

  14. Testing the PreProcessor modules of the ATLAS level-1 calorimeter Trigger

    International Nuclear Information System (INIS)

    The PreProcessor (PPr) System of the ATLAS Level-1 Calorimeter Trigger is a highly parallel system which receives, digitises and processes about 7200 analogue calorimeter trigger signals from the entire ATLAS Calorimetry. Its key component is a custom build ASIC which determines the transverse energy deposits and transmits them to the object-finding processors of the calorimeter trigger: Cluster Processor and Jet/Energy-Sum Processor. The PPr System consists of 124 identical 9U VME PreProcessor Modules (PPMs), which fit into 8 crates. Each module receives and processes 64 analogue calorimeter trigger signals. Before the modules are installed in the electronic cavern of the experiment, their proper operation has to be ensured. An extensive test procedure has been developed to establish all functions of the PPM in short and long periods of operation. The modules are tested both individually as well as in a crate configuration similar to that of the final system. The transmission of the real-time data over 15m long LVDS cables and the readout are checked with a dedicated VME based system, which emulates both the processors of the calorimeter trigger and a DAQ readout module. Additionally, periodic monitoring of the temperatures and voltages across each board is performed during tests to verify the operating conditions of the modules

  15. A fast hardware tracker for the ATLAS trigger system

    International Nuclear Information System (INIS)

    The Fast Tracker (FTK) processor is an approved ATLAS upgrade that will reconstruct tracks using the full silicon tracker at Level-1 rate (up to 100 KHz). FTK uses a completely parallel approach to read the silicon tracker information, execute the pattern matching and reconstruct the tracks. This approach, according to detailed simulation results, allows full tracking with nearly offline resolution within an execution time of 100μs. A central component of the system is the associative memories (AM); these special devices reduce the pattern matching combinatoric problem, providing identification of coarse resolution track candidates. The system consists of a pipeline of several components with the goal to organize and filter the data for the AM, then to reconstruct and filter the final tracks. This document presents an overview of the system and reports the status of the different elements of the system

  16. Performance of the ATLAS Calorimeter High-Level Trigger in the LHC Run 1 Data Taking period

    CERN Document Server

    Oliveira Damazio, D; The ATLAS collaboration

    2013-01-01

    The ATLAS detector operated very successfully at the LHC Run 1 data taking period collecting a large number of events used for the discovery of the Higgs boson as well as for the search for beyond the Standard Model physics. In the main search channels related to the finding of the Higgs, the ATLAS calorimeter system played a major role in measuring the energy of photons, electrons, jets, taus as well as global missing transverse energy. The ATLAS trigger system selects the physics of interest from the huge amount of events produced every second, those few that must be recorded for analysis (less than one out of 40 thousand can be kept). The selection process is performed in three levels. The first one uses hardware based algorithms to select events using information with coarse granularity from the detectors. The next levels are designed in software. The Level 2 (L2) works only in the regions that caused the first level to fire, the so called Regions Of Interest (RoI), calculating special features like the e...

  17. TRIGGER

    CERN Multimedia

    R. Carlin with contributions from D. Acosta

    2012-01-01

    Level-1 Trigger Data-taking continues at cruising speed, with high availability of all components of the Level-1 trigger. We have operated the trigger up to a luminosity of 7.6E33, where we approached 100 kHz using the 7E33 prescale column.  Recently, the pause without triggers in case of an automatic "RESYNC" signal (the "settle" and "recover" time) was reduced in order to minimise the overall dead-time. This may become very important when the LHC comes back with higher energy and luminosity after LS1. We are also preparing for data-taking in the proton-lead run in early 2013. The CASTOR detector will make its comeback into CMS and triggering capabilities are being prepared for this. Steps to be taken include improved cooperation with the TOTEM trigger system and using the LHC clock during the injection and ramp phases of LHC. Studies are being finalised that will have a bearing on the Trigger Technical Design Report (TDR), which is to be rea...

  18. The operational performance of the ATLAS trigger and data acquisition system and its possible evolution

    CERN Document Server

    CERN. Geneva

    2012-01-01

    The first part of this presentation will give an overview of the operational performance of the DAQ system during 2011 and the first months of data taking in 2012. It will describe how the flexibility inherent in the design of the system has be exploited to meet the changing needs of ATLAS data taking and in some cases push performance beyond the original design performance specification. The experience accumulated in the ATLAS DAQ/HLT system operation during these years stimulated also interest to explore possible evolutions, despite the success of the current design. One attractive direction is to merge three systems - the se...

  19. Development of the ATLAS High-Level Trigger Steering and Inclusive Searches for Supersymmetry

    CERN Document Server

    Eifert, T

    2009-01-01

    The presented thesis is divided into two distinct parts. The subject of the first part is the ATLAS high-level trigger (HLT), in particular the development of the HLT Steering, and the trigger user-interface. The second part presents a study of inclusive supersymmetry searches, including a novel background estimation method for the relevant Standard Model (SM) processes. The trigger system of the ATLAS experiment at the Large Hadron Collider (LHC) performs the on-line physics selection in three stages: level-1 (LVL1), level-2 (LVL2), and the event filter (EF). LVL2 and EF together form the HLT. The HLT receives events containing detector data from high-energy proton (or heavy ion) collisions, which pass the LVL1 selection at a maximum rate of 75 kHz. It must reduce this rate to ~200 Hz, while retaining the most interesting physics. The HLT is a software trigger and runs on a large computing farm. At the heart of the HLT is the Steering software. The HLT Steering must reach a decision whether or not to accept ...

  20. The ATLAS Muon Trigger Performance in pp collisions at $\\sqrt s$ = 8 TeV

    CERN Document Server

    Klinger, J; The ATLAS collaboration

    2013-01-01

    Events with muons in the final state are an important signature for many physics topics at the Large Hadron Collider (LHC), for instance searches for muonic Higgs boson decays or new phenomena, or measurements of the standard model (SM) processes like top-quark, W-boson, and Z-boson production. The use of efficient trigger muon selections during data taking and a good understanding of their performance is crucial for these physics studies. At the LHC high rejection power against the large SM backgrounds, while simulatneously maintaining high efficiency for rare signal events, is required at the online trigger stage. The ATLAS experiment employs a multi-level trigger architecture that selects the events in three sequential steps of increasing complexity and accuracy to cope with this challenging task. This presentation reports about efficiency, resolution, and general performance of the ATLAS muon trigger for proton-proton collision data at $\\sqrt s$ = 8TeV collected in year 2012.

  1. Preliminary performance studies for the ATLAS Muon Trigger during initial Run 2

    CERN Document Server

    Reale, Marilea; The ATLAS collaboration

    2015-01-01

    The physics program of the ATLAS experiment at CERN's Large Hadron Collider (LHC) includes the search for the Higgs Boson and the measurements of its properties, searches for new physics and precision measurements of the Standard Model. Events with high momentum muons in the final state are an important signature of many of these physics topics, then an efficient muon trigger and a deep understanding of its performance are crucial. During Run 1 the ATLAS muon trigger was successfully adapted to the challenging environment, thus reaching an excellent performance. During Run 2 ~100 pb-1 of data with 50 ns bunch spacing have been already collected, while the collection of data with 25 ns bunch spacing is currently ongoing. As the data taking proceeds, the muon trigger performance is being constantly monitored. The muon trigger efficiency, studied both with respect to offline muon reconstruction and with Tag&Probe method applied to the Z decays in muon pairs, is presented here as a function of different kinem...

  2. Real time algorithms in the ATLAS tau trigger system at 7 TeV center of mass energy

    DEFF Research Database (Denmark)

    Kadlecik, Peter

    2012-01-01

    The ATLAS hadronic tau trigger plays an important role in many analyses. Among these analyses are searches for H 0 , H ± , W ' , and Z ' in the tau decay channel. In order to achieve the needed sensitivity in these measurement it is important to reduce the QCD background, but at the same time to ...... keep the signal efficiency high. Furthermore it is important to understand the trigger efficiency in real data. This paper summarizes the performance of the tau trigger in data collected by the ATLAS detector in 2011....

  3. Error detection, handling and recovery at the High Level Trigger of the ATLAS experiment at the LHC

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00223972; The ATLAS collaboration

    2016-01-01

    The complexity of the ATLAS High Level Trigger (HLT) requires a robust system for error detection and handling during online data-taking; it also requires an offline system for the recovery of events where no trigger decision could be made online. The error detection and handling ensure smooth operation of the trigger system and provide debugging information necessary for offline analysis and diagnosis. In this presentation, we give an overview of the error detection, handling and recovery of problematic events at the HLT of ATLAS.

  4. Demonstrator System for the Phase-I Upgrade of the Trigger Readout Electronics of the ATLAS Liquid Argon Calorimeters

    CERN Document Server

    FRAGNAUD, J; The ATLAS collaboration

    2014-01-01

    The trigger readout electronics of the ATLAS LAr Calorimeters will be improved for the Phase-I luminosity upgrade of the LHC to enhance the trigger feature extraction. Signals with higher spatial granularity will be digitized and processed by newly developed front-end and back-end components. In order to evaluate technical and performance aspects, a demonstrator system is being set up which is planned to be installed on the ATLAS detector during the upcoming LHC run. Results from system tests of the analog signal treatment, the trigger digitizer, the optical signal transmission and the FPGA-based back-end are reported.

  5. The ATLAS Muon Trigger Performance in Run I and Initial Run II Performance

    CERN Document Server

    Bielski, Rafal; The ATLAS collaboration

    2015-01-01

    Events with muons in the final state are an important signature for many physics topics at the Large Hadron Collider (LHC). An efficient trigger on muons and a detailed understanding of its performance are required. In 2012, the last year of Run I, the instantaneous luminosity of the LHC reached 7.7x1033 cm-2s-1 and the average number of events that occur in a same bunch crossing was 25. The ATLAS Muon trigger has successfully adapted to this changing environment by making use of isolation requirements, combined trigger signatures with electron and jet trigger objects, and by using so-called full-scan triggers, which make use of the full event information to search for di-lepton signatures, seeded by single lepton objects. A stable and highly efficient muon trigger was vital in the discovery of Higgs boson in 2012 and for many searches for new physics. The performance of muon triggers during the LHC Run 1 data-taking campaigns is presented, together with an overview and preliminary results of the new muon str...

  6. The ATLAS Muon Trigger Performance in Run I and Initial Run II Performance

    CERN Document Server

    Bielski, Rafal; The ATLAS collaboration

    2015-01-01

    Events with muons in the final state are an important signature for many physics topics at the Large Hadron Collider. An efficient trigger on muons and a detailed understanding of its performance are required. In 2012, the last year of Run I, the instantaneous luminosity reached $7.7\\times10^{33}$ cm$^{-2}$s$^{-1}$ and the average number of interactions that occur in the same bunch crossing was 25. The ATLAS muon trigger has successfully adapted to this challenging environment by making use of isolation requirements, combined trigger signatures with electron and jet trigger objects, and by using so-called full-scan triggers, which make use of the full event information to search for di-lepton signatures, seeded by single lepton objects. A stable and highly efficient muon trigger was vital in the discovery of the Higgs boson in 2012 and for many searches for new physics. The performance of muon triggers during the Large Hadron Collider Run I data-taking campaigns is presented, together with an overview and pre...

  7. The ATLAS Muon Trigger Performance : Run 1 and initial Run 2.

    CERN Document Server

    Kasahara, Kota; The ATLAS collaboration

    2015-01-01

    Events with muons in the final state are an important signature for many physics topics at the Large Hadron Collider (LHC). An efficient trigger on muons and a detailed understanding of its performance are required. In 2012, the last year of Run 1, the instantaneous luminosity of the LHC reached 7.7x10^33 cm -2s-1 and the average number of events that occur in a same bunch crossing was 25. The ATLAS Muon trigger has successfully adapted to this changing environment by making use of isolation requirements, combined trigger signatures with electron and jet trigger objects, and by using so-called full-scan triggers, which make use of the full event information to search for di-lepton signatures, seeded by single lepton objects. A stable and highly efficient muon trigger was vital in the discovery of Higgs boson in 2012 and for many searches for new physics. 
The performance of muon triggers during the LHC Run 1 data-taking campaigns is presented, together with an overview and preliminary results of the new muo...

  8. The evolution of the Trigger and Data Acquisition System in the ATLAS experiment (ACAT2013: 15. international workshop on advanced computing and analysis techniques in physics research)

    International Nuclear Information System (INIS)

    The ATLAS experiment, aimed at recording the results of LHC proton-proton collisions, is upgrading its Trigger and Data Acquisition (TDAQ) system during the current LHC first long shutdown. The purpose of the upgrade is to add robustness and flexibility to the selection and the conveyance of the physics data, simplify the maintenance of the infrastructure, exploit new technologies and, overall, make ATLAS data-taking capable of dealing with increasing event rates. The TDAQ system used to date is organised in a three-level selection scheme, including a hardware-based first-level trigger and second- and third-level triggers implemented as separate software systems distributed on separate, commodity hardware nodes. While this architecture was successfully operated well beyond the original design goals, the accumulated experience stimulated interest to explore possible evolutions. We will also be upgrading the hardware of the TDAQ system by introducing new elements to it. For the high-level trigger, the current plan is to deploy a single homogeneous system, which merges the execution of the second and third trigger levels, still separated, on a unique hardware node. Prototyping efforts already demonstrated many benefits to the simplified design. In this paper we report on the design and the development status of this new system

  9. The DataFlow System of the ATLAS Trigger and DAQ

    CERN Document Server

    Lehmann, G; Dos Anjos, A; Barisonzi, M; Beck, H P; Beretta, M; Blair, R; Bogaerts, J A C; Boterenbrood, H; Botterill, David R; Ciobotaru, M; Palencia-Cortezon, E; Cranfield, R; Crone, R; Dawson, J; Di Girolamo, B; Dobinson, Robert W; Ermoline, Y; Ferrer, M L; Francis, D; Gadomski, S; Gameiro, S; Golonka, P; Gorini, B; Green, B; Gruwé, M; Haas, S; Haeberli, C; Hasegawa, Y; Hauser, R; Hinkelbein, C; Hughes-Jones, R E; Jansweijer, P; Joos, M; Kaczmarska, A; Knezo, E; Kieft, G; Korcyl, K; Kugel, A; Lankford, A; Le Vine, M J; Liuf, W; Maeno, T; Losada-Maia, L; Mapelli, L; Martin, B; McLaren, R; Meirosuh, C; Misiejuk, A; Mommsen, R K; Mornacchi, Giuseppe; Müller, M; Nagasaka, Y; Nakayoshi, K; Papadopoulos, I M; Petersen, J; De Matos-Lopes-Pinto, P; Prigent, D; Pérez-Réale, V; Schlereth, J L; Shimojima, M; Spiwoks, R; Stancu, S; Strong, J; Tremblet, L J; Vermeulen, J C; Werner, P; Wickens, F J; Yasu, Y; Yu, M; Zobernig, H; Zurek, M; CHEP 2003 Computing in High Energy Physics

    2003-01-01

    The baseline design and implementation of the DataFlow system, to be documented in the ATLAS DAQ/HLT Technical Design Report in summer 2003, will be presented. Empahsis will be placed on the system performance and scalability based on the results from prototyping studies which have maximised the use of commercially available hardware.

  10. Maps and atlases of cancer mortality: a review of a useful tool to trigger new questions.

    Science.gov (United States)

    d'Onofrio, Alberto; Mazzetta, Chiara; Robertson, Chris; Smans, Michel; Boyle, Peter; Boniol, Mathieu

    2016-01-01

    In this review we illustrate our view on the epidemiological relevance of geographically mapping cancer mortality. In the first part of this work, after delineating the history of cancer mapping with a view on interpretation of Cancer Mortality Atlases, we briefly illustrate the 'art' of cancer mapping. Later we summarise in a non-mathematical way basic methods of spatial statistics. In the second part of this paper, we employ the 'Atlas of Cancer Mortality in the European Union and the European Economic Area 1993-1997' in order to illustrate spatial aspects of cancer mortality in Europe. In particular, we focus on the cancer related to tobacco and alcohol epidemics and on breast cancer which is of particular interest in cancer mapping. Here we suggest and reiterate two key concepts. The first is that a cancer atlas is not only a visual tool, but it also contain appropriate spatial statistical analyses that quantify the qualitative visual impressions to the readers even though at times revealing fallacy. The second is that a cancer atlas is by no means a book where answers to questions can be found. On the contrary, it ought to be considered as a tool to trigger new questions. PMID:27610196

  11. RT2016 Phase-I Trigger Readout Electronics Upgrade for the ATLAS Liquid-Argon Calorimeters

    CERN Document Server

    AUTHOR|(SzGeCERN)478829; The ATLAS collaboration

    2016-01-01

    For the Phase-I luminosity upgrade of the LHC, a higher granularity trigger readout of the ATLAS LAr Calorimeters is foreseen in order to enhance the trigger feature extraction and background rejection. The new readout system digitizes the detector signals, which are grouped into 34000 so-called Super Cells, with 12-bit precision at 40 MHz. The data is transferred via optical links to a digital processing system which extracts the Super Cell energies. A demonstrator version of the complete system has now been installed and operated on the ATLAS detector. The talk will give an overview of the Phase-I Upgrade of the ATLAS LAr Calorimeter readout and present the custom developed hardware including their role in real-time data processing and fast data transfer. This contribution will also report on the performance of the newly developed ASICs including their radiation tolerance and on the performance of the prototype boards in the demonstrator system based on various measurements with the 13 TeV collision data. R...

  12. Electronics and Trigger developments for the Diffractive Physics Proposal at 220 m from LHC-ATLAS

    CERN Document Server

    Le Dû, P; Kepka, O; Kupco, A; Royon, Christophe; Tic, T; Vrba, Vaclav

    2007-01-01

    The instrumentation consists of two sets of Roman Pots installed respectively at 216 and 224m on both sides from the ATLAS IP to measure with precision the position (< 10 micrometers) and the timing (< 5ps) of the two back to back diffracted protons tracks. Each Roman Pot is equipped with several planes of Silicon strips detectors read out by a new version of the ATLAS Silicon tracker ABCD readout chip with a longer latency (6.4 microseconds) and fast OR outputs defining a track segment. Theses inputs are to be combined in time with the ATLAS level 1 trigger accept signal. In addition, these tracks are time filtered with a very fast timing detector (MCP-PMT) allowing to constraint further at the level 2 the position of the IP within a one millimetre precision., The description of the electronics and trigger system as well as the various technical issues associated with such challenging experiments (clocks, cabling,, time monitoring) will be presented.

  13. Development, Validation and Integration of the ATLAS Trigger System Software in Run 2

    CERN Document Server

    Keyes, Robert; The ATLAS collaboration

    2016-01-01

    The trigger system of the ATLAS detector at the LHC is a combination of hardware, firmware and software, associated to various sub-detectors that must seamlessly cooperate in order to select 1 collision of interest out of every 40,000 delivered by the LHC every millisecond. This talk will discuss the challenges, workflow and organization of the ongoing trigger software development, validation and deployment. This development, from the top level integration and configuration to the individual components responsible for each sub system, is done to ensure that the most up to date algorithms are used to optimize the performance of the experiment. This optimization hinges on the reliability and predictability of the software performance, which is why validation is of the utmost importance. The software adheres to a hierarchical release structure, with newly validated releases propagating upwards. Integration tests are carried out on a daily basis to ensure that the releases deployed to the online trigger farm duri...

  14. Performance and Operational Experience with the Heterogeneous Farm of the ATLAS Trigger and Data Acquisition System

    CERN Document Server

    Garelli, N; The ATLAS collaboration; Vandelli, W

    2011-01-01

    The ATLAS trigger and data acquisition (TDAQ) is a distributed, multi trigger level, data-acquisition system, mostly made of off-the-shelf processing units organized in a farm. In its final configuration the system will account more than 2000 nodes, sporting heterogeneous capabilities and network connections, due to the TDAQ program for rolling expansions and upgrades. In this paper we present how we dealt with the farm heterogeneity during the proton-proton collisions of 2010 and 2011: a period characterized by changing working conditions, and constantly increasing LHC instantaneous luminosity. We describe a graphical tool to balance the computing-power and bandwidth sharing across the trigger farms, a data-flow monitoring daemon that provides high-level resource-aware data-flow operational information and the evolution of data-flow communication protocols.

  15. Performance and operational experience with the heterogeneous farm of the ATLAS Trigger and Data Acquisition system.

    CERN Document Server

    Garelli, N; The ATLAS collaboration; Vandelli, W

    2011-01-01

    The ATLAS trigger and data acquisition (TDAQ) is a distributed, multi trigger level, data-acquisition system, mostly made of off-the-shelf processing units organized in a farm. In its final configuration the system will account more than 2000 nodes, sporting heterogeneous capabilities and network connectivities, due to the TDAQ program for rolling expansions and upgrades. In this paper we will present how we dealt with the farm heterogeneity during the proton-proton collisions of 2010 and 2011: a period characterized by changing working conditions, and constantly increasing LHC instantaneous luminosity. We will describe a graphical tool to show, control, modify and balance the computing-power and bandwidth sharing across the trigger farms, a data-flow monitoring daemon which provides a high-level resource-aware data-flow operational information, and the evolution of data-flow communication protocols.

  16. LHCP Poster : “Triggering on Hadronic Signatures with the ATLAS Detector"

    CERN Document Server

    Burr, Jonathan Thomas Peter; The ATLAS collaboration

    2016-01-01

    Hadronic signatures are from the most promising in the high energy physics analysis program, broadly used for both Standard Model measurements and searches for new physics. These signatures include generic quark and gluon jets as well as jets originating from b-quarks or tau leptons decaying hadronically. Additionally missing transverse momentum from non-interacting particles provide an interesting probe to search for new physics interactions beyond the Standard Model. Developing trigger selections that target on these signatures is a huge challenge in the hadron colliders, due to the enormous rates these signatures contribute. This talk presents an overview of how we trigger on hadronic signatures on the ATLAS experiment of the LHC, outlying the challenges of hadronic object trigger reconstruction and describing the improvements performed for the Run-2 LHC data-taking. The performance in Run-2 data is shown. We also discuss further critical developments envisaged for the rest for the Run-2 data taking. These...

  17. The base-line DataFlow system of the ATLAS Trigger and DAQ

    CERN Document Server

    Beck, H P; Dos Anjos, A; Barisonzi, M; Beretta, M; Blair, R; Bogaerts, A; Boterenbrood, H; Botterill, David R; Ciobotaru, M; Cortezon, E; Cranfield, R; Crone, G J; Dawson, J; Di Girolamo, B; Dobinson, Robert W; Ermoline, Y; Ferrer, M; Francis, D; Gadomski, S; Gameiro, S; Golonka, P; Gorini, B; Green, B; Gruwé, M; Haas, S; Haeberli, C; Hasegawa, Y; Hauser, R; Hinkelbein, C; Hughes-Jones, R E; Knezo, E; Jansweijer, P; Joos, M; Kaczmarska, A; Kieft, G; Korcyl, K; Kugel, A; Lankford, A; Lehmann, G; Le Vine, M J; Liu, W; Maeno, T; Maia, M; Mapelli, L; Martin, L; McLaren, R; Meirosu, C; Misiejuk, A; Mommsen, R K; Mornacchi, Giuseppe; Müller, M; Nagasaka, Y; Nakayoshi, Y; Papadopoulos, I M; Petersen, J; Pinto, P; Prigent, D; Pérez-Réale, V; Schlereth, J L; Shimojima, M; Spiwoks, R; Stancu, S; Strong, J; Tremblet, L J; Vermeulen, J C; Werner, P; Wickens, F J; Yasu, Y; Yu, M; Zobernig, H; Zurek, M

    2004-01-01

    The base-line design and implementation of the ATLAS DAQ DataFlow system is described. The main components realizing the DataFlow system, their interactions, bandwidths and rates are being discussed and performance measurements on a 10% scale prototype for the final Atlas TDAQ DataFlow system are presented. This prototype is a combination of custom design components and of multi-threaded software applications implemented in C++ and running in a Linux environment on commercially available PCs interconnected by a fully switched gigabit Ethernet network.

  18. RPCs as trigger detector for the ATLAS experiment performances, simulation and application to the level-1 di-muon trigger

    CERN Document Server

    Di Simone, A; Di Ciaccio, A

    2005-01-01

    In the muon spectrometer different detectors are used to provide trigger functionality and precision momentum measurements. In the pseudorapidity range |eta|<1 the first level muon trigger is based on Resistive Plate Chambers, gas ionization detectors which are characterized by a fast response and an excellent time resolution (<1.5ns). The working principles of the Resistive Plate Chambers will be illustrated in chapter 3. Given the long time of operation expected for the ATLAS experiment (~10 years), ageing phenomena have been carefully studied, in order to ensure stable long-term operation of all the subdetectors. Concerning Resistive Plate Chambers, a very extensive ageing test has been performed at CERN's Gamma Irradiation Facility on three production chambers. The results of this test are presented in chapter 4. One of the most commonly used gases in RPCs operation is C2H2F4, which during the gas discharge can produce fluorine ions. Being F one of the most aggressive elements in nature, the presenc...

  19. ATLAS level-1 calorimeter trigger hardware: initial timing and energy calibration

    International Nuclear Information System (INIS)

    The ATLAS Level-1 Calorimeter Trigger identifies high-pT objects in the Liquid Argon and Tile Calorimeters with a fixed latency of up to 2.5μs using a hardware-based, pipelined system built with custom electronics. The Preprocessor Module conditions and digitizes about 7200 pre-summed analogue signals from the calorimeters at the LHC bunch-crossing frequency of 40 MHz, and performs bunch-crossing identification (BCID) and deposited energy measurement for each input signal. This information is passed to further processors for object classification and total energy calculation, and the results are used to make the Level-1 trigger decision for the ATLAS detector. The BCID and energy measurement in the trigger depend on precise timing adjustments to achieve correct sampling of the input signal peak. Test pulses from the calorimeters were analysed to derive the initial timing and energy calibration, and first data from the LHC restart in autumn 2009 and early 2010 were used for validation and further optimization. The results from these calibration measurements are presented.

  20. An evaluation of GPUs for use in an upgraded ATLAS High Level Trigger

    CERN Document Server

    Tavares Delgado, Ademar; The ATLAS collaboration; Pastore, Francesca; Conde Muino, Patricia; Augusto, Jose; Kama, Sami; Negrini, Matteo; Sidoti, Antonio; Rinaldi, Lorenzo; Tupputi, Salvatore; Baines, John; Bauce, Matteo; Messina, Andrea; Emeliyanov, Dmitry; Elliott, Aaron Kyle; Greenwood Jr, Dick; Laosooksathit, Supada

    2015-01-01

    ATLAS is a general purpose particle physics experiment located on the LHC collider at CERN. The ATLAS Trigger system consists of two levels, the first level (L1) implemented in hardware and the High Level Trigger (HLT) implemented in software running on a farm of commodity CPU. The HLT reduces the trigger rate from the 100 kHz L1 accept rate to 1 kHz for recording requiring an average per-event processing time of ~250 ms for this task. The HLT selection is based on reconstructing tracks in the Inner Detector and Muon Spectrometer and clusters of energy deposited in the Calorimeter. Performing this reconstruction within the available HLT farm resources presents a significant challenge that will increase significantly after future LHC upgrades resulting in higher detector occupancies. General purpose Graphics Processor Units (GPGPU) are being evaluated for possible future inclusion in an upgraded HLT farm. We report on a demonstrator that has been developed consisting of GPGPU implementations of the Calorimeter...

  1. An evaluation of the potential of GPUs to accelerate tracking algorithms for the ATLAS trigger

    CERN Document Server

    Baines, JTM; The ATLAS collaboration; Emeliyanov, D; Howard, JR; Kama, S; Washbrook, AJ; Wynne, BM

    2014-01-01

    The potential of GPUs has been evaluated as a possible way to accelerate trigger algorithms for the ATLAS experiment located at the Large Hadron Collider (LHC). During LHC Run-1 ATLAS employed a three-level trigger system to progressively reduce the LHC collision rate of 20 MHz to a storage rate of about 600 Hz for offline processing. Reconstruction of charged particles trajectories through the Inner Detector (ID) was performed at the second (L2) and third (EF) trigger levels. The ID contains pixel, silicon strip (SCT) and straw-tube technologies. Prior to tracking, data-preparation algorithms processed the ID raw data producing measurements of the track position at each detector layer. The data-preparation and tracking consumed almost three-quarters of the total L2 CPU resources during 2012 data-taking. Detailed performance studies of a CUDA™ implementation of the L2 pixel and SCT data-preparation and tracking algorithms running on a Nvidia® Tesla C2050 GPU have shown a speed-up by a factor of 12 for the ...

  2. TRIGGER

    CERN Multimedia

    W. Smith

    2011-01-01

    Level-1 Trigger Hardware and Software Overall the L1 trigger hardware has been running very smoothly during the last months of proton running. Modifications for the heavy-ion run have been made where necessary. The maximal design rate of 100 kHz can be sustained without problems. All L1 latencies have been rechecked. The recently installed Forward Scintillating Counters (FSC) are being used in the heavy ion run. The ZDC scintillators have been dismantled, but the calorimeter itself remains. We now send the L1 accept signal and other control signals to TOTEM. Trigger cables from TOTEM to CMS will be installed during the Christmas shutdown, so that the TOTEM data can be fully integrated within the CMS readout. New beam gas triggers have been developed, since the BSC-based trigger is no longer usable at high luminosities. In particular, a special BPTX signal is used after a quiet period with no collisions. There is an ongoing campaign to provide enough spare modules for the different subsystems. For example...

  3. Simulation of the upgraded Phase-1 Trigger Readout Electronics of the Liquid-Argon Calorimeter of the ATLAS Detector at the LHC

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00338138

    In the context of an intensive upgrade plan for the LHC in order to provide proton beams of increased luminosity, a revision of the data readout electronics of the Liquid-Argon-Calorimeter of the ATLAS detector is scheduled. This is required to retain the efficiency of the trigger at increased event rates despite its fixed bandwidth. The focus lies on the early digitization and finer segmentation of the data provided to the trigger. Furthermore, there is the possibility to implement new energy reconstruction algorithms which are adapted to the specific requirements of the trigger. In order to constitute crucial design decisions, such as the digitization scale or the choice of digital signal processing algorithms, comprehensive simulations are required. High trigger efficiencies are decisive at it for the successful continuation of the measurements of rare Standard Model processes as well as for a high sensitivity to new physics beyond the established theories. It can be shown that a significantly improved res...

  4. Multi­-Threaded Algorithms for General purpose Graphics Processor Units in the ATLAS High Level Trigger

    CERN Document Server

    Conde Mui\\~no, Patricia; The ATLAS collaboration

    2016-01-01

    General purpose Graphics Processor Units (GPGPU) are being evaluated for possible future inclusion in an upgraded ATLAS High Level Trigger farm. We have developed a demonstrator including GPGPU implementations of Inner Detector and Muon tracking and Calorimeter clustering within the ATLAS software framework. ATLAS is a general purpose particle physics experiment located on the LHC collider at CERN. The ATLAS Trigger system consists of two levels, with level 1 implemented in hardware and the High Level Trigger implemented in software running on a farm of commodity CPU. The High Level Trigger reduces the trigger rate from the 100 kHz level 1 acceptance rate to 1 kHz for recording, requiring an average per­-event processing time of ~250 ms for this task. The selection in the high level trigger is based on reconstructing tracks in the Inner Detector and Muon Spectrometer and clusters of energy deposited in the Calorimeter. Performing this reconstruction within the available farm resources presents a significant ...

  5. A Scheme of Read-Out Organization for the ATLAS High-Level Triggers and DAQ based on ROB Complexes

    CERN Document Server

    Calvet, D; Huet, M; Mandjavidze, I D

    1999-01-01

    This paper describes a possible organization of the ATLAS High-LevelTriggers and DAQ read-out system downstream the Read-Out Drivers. Itis based on the ROB Complex concept which assumes that each read-outunit is formed by several input buffer modules sharing a networkinterface to a common Trigger/DAQ data collection network. Animplementation of such ROB Complex based on PCI bus to connectread-out buffers, a control processor and a network interface cardis presented. The total number of ROB Complexes required for ATLAS,as well as the number of CompactPCI crates housing them are estimated.The results obtained from measurements on a ROB Complex prototypeintegrated in the ATLAS Level 2 Trigger ATM Testbed are given. Thefeasibility of some data preprocessing within a ROB Complex is shown.

  6. The ATLAS Dataflow System in Run-2: Design and Performance

    CERN Document Server

    Rifki, Othmane; The ATLAS collaboration

    2016-01-01

    The ATLAS Dataflow system is composed of distributed hardware and software responsible for buffering and transporting event data from the Readout system to the High Level Trigger and to the event storage. By building on the experience gained during the successful first run of the LHC, the ATLAS Data Acquisition (DAQ) system has been simplified and upgraded to take advantage of state of the art technologies resulting in a maximized efficiency and improved performance. This proceeding describes the new architecture of the ATLAS DAQ system and highlights its performance during Run-2 of the LHC.

  7. Commissioning of real time algorithms in the ATLAS tau trigger system

    CERN Document Server

    Kadlecik, Peter; The ATLAS collaboration

    2011-01-01

    A significant part of the Standard Model particles involve tau leptons in their decay chains. For this reason it is very important to precisely measure the properties of taus. Given the fact, that the average decay length of the tau leptons is short (cτ = 87.11 μm), they can be studied only via their decay products, such as electrons, muons or pions. The ATLAS tau trigger system is dedicated to select tau decays involving hadrons, while rejecting a significant fraction of background events, such as QCD jets. In order to achieve this, a sophisticated three-level trigger system is used, which is tuned to be sensitive to the typical signature of taus: isolated narrow jets with low track multiplicity.

  8. Online Measurement of LHC Beam Parameters with the ATLAS High Level Trigger

    CERN Document Server

    Bartoldus, R; The ATLAS collaboration; Winklmeier, F

    2010-01-01

    We present the results of the first online measurement in ATLAS of the LHC beam position and size at sqrt(s)=900 GeV in 2009 and sqrt(s)=7 TeV in spring 2010. A dedicated algorithm, implemented in the ATLAS level 2 trigger, takes fully reconstructed tracks in the inner detector as input to a fast vertex fitter in order to reconstruct vertices on an event-by-event basis. The 3-dimensional distribution of primary vertices carries information of the LHC luminous region at the ATLAS interaction point and is used to extract its position, size and tilt angles. The luminous region parameters are monitored in real time and sent as online feedback to the LHC. With this method, we observe changes in the transverse centroid position that mirror IP-orbit drifts as well as longitudinal shifts arising from RF phase changes. Also, variations in the transverse widths, and an expected increase in the longitudinal spot size over the course of a fill were seen. In addition, the measured beam spot is used to track significant ch...

  9. Fast Tracker (FTK): A Hardware Track Finder for the ATLAS Trigger

    CERN Document Server

    Mitani, Takashi; The ATLAS collaboration

    2015-01-01

    During the 2010-2012 run of Large Hadron Collider experiment, the ATLAS trigger system was successfully operated and it contributed to several important results such as observation of Higgs boson with a mass of about 125 GeV. From 2015, collision energy will increase to 13-14 TeV and its instantaneous luminosity will reach $1$-$2\\times10^{34}$cm$^{-2}$s$^{-1}$ with a 25 ns bunch crossing period. Due to the energy increase, the cross sections for SM processes are expected to get much larger. Additionally, the number of overlapping proton-proton interactions per bunch crossing, which is refereed to as pile-up, is expected to increase significantly up to about 80. Therefore it will be challenging to control trigger rates while keeping good efficiency for interesting physics events. This document summarizes the development of Fast Tracker and its tracking performance for the ATLAS experiment. The Fast Tracker is a custom electronics system that will operate at the full Level 1 accepted rate of 100 kHz and provide...

  10. A rule-based verification and control framework in ATLAS Trigger-DAQ

    CERN Document Server

    Kazarov, A; Lehmann-Miotto, G; Sloper, J E; Ryabov, Yu; Computing In High Energy and Nuclear Physics

    2007-01-01

    In order to meet the requirements of ATLAS data taking, the ATLAS Trigger-DAQ system is composed of O(1000) of applications running on more than 2600 computers in a network. With such system size, s/w and h/w failures are quite often. To minimize system downtime, the Trigger-DAQ control system shall include advanced verification and diagnostics facilities. The operator should use tests and expertise of the TDAQ and detectors developers in order to diagnose and recover from errors, if possible automatically. The TDAQ control system is built as a distributed tree of controllers, where behavior of each controller is defined in a rule-based language allowing easy customization. The control system also includes verification framework which allow users to develop and configure tests for any component in the system with different levels of complexity. It can be used as a stand-alone test facility for a small detector installation, as part of the general TDAQ initialization procedure, and for diagnosing the problems ...

  11. Algorithms, performance, and development of the ATLAS High-level Trigger

    CERN Document Server

    Nagano, K; The ATLAS collaboration

    2013-01-01

    The ATLAS trigger system has been used for the online event selection for three years of LHC data-taking and is preparing for the next run. The trig- ger system consists of a hardware level-1 (L1) and a software high-level trigger (HLT). The high-level trigger is currently implemented in a region-of-interest based level-2 (L2) stage and a event filter (EF) operating after even building with offline-like software. During the past three years, the luminosity and pile- up (number of collisions per beam crossing) has increased significantly placing escalating demands on the rejection and timing performace. The HLT algo- rithms advanced during this period to maintain and even improve performance. For the next run, the boundary between the L2 and EF will be removed, so that there is only one high-level trigger which can operate either on regions of interest or on the full event depending on the objects found in the event either by the L1 or by the HLT itself. This talk will discuss the algorithms, performance and o...

  12. The ATLAS High Level Trigger Configuration and Steering Software: Experience with 7 TeV Collisions

    CERN Document Server

    George, S; The ATLAS collaboration

    2010-01-01

    In 2010 ATLAS has seen the first proton-proton collisions at 7 TeV. Later this year a collision rate of nearly 10 MHz is expected. Events of potential interest for physics analysis are selected by a three-level trigger system, with a final recording rate of about 200 Hz. The first level (L1) is implemented in customized hardware, the two levels of the high level trigger (HLT) are software triggers. The selection is described by the Trigger Configuration in the form of menus, each of which contains more than 500 signatures. Each signature corresponds to a chain of algorithms which reconstruct and refine specific event features. The HLT Steering receives information from the Configuration system, dynamically creates chains and controls the execution of algorithms and flow of information during event processing. The Steering tests each signature on L1-accepted events, and those satisfying one or more test are recorded for later analysis. To save execution time, the Steering has a facility to cache results, avoid...

  13. The Phase-1 Upgrade of the ATLAS First Level Calorimeter Trigger

    CERN Document Server

    Hristova, I; The ATLAS collaboration

    2014-01-01

    The level-1 calorimeter trigger (L1Calo) of the ATLAS experiment has been operating effectively since the start of LHC data taking, and has played a major role in the discovery of the Higgs boson. To face the new challenges posed by the upcoming increases of the LHC proton beam energy and luminosity, a series of upgrades is planned for L1Calo. An initial upgrade (Phase-0) is scheduled to be ready for the start of the second LHC run in 2015, and a further more substantial upgrade (Phase-1) is planned to be installed during the LHC shutdown expected in 2018. The calorimeter trigger aims to identify electrons, photons, taus and hadronic jets. It also determines total and missing transverse energy and can further analyse the event topology using a dedicated system incorporating information from both calorimeter and muon triggers. This paper presents the Phase-1 hardware trigger developments which exploit a tenf old increase in the available calorimeter data granularity when compared to that of the current system....

  14. The Phase-I Upgrade of the ATLAS First Level Calorimeter Trigger

    CERN Document Server

    Hristova, I; The ATLAS collaboration

    2014-01-01

    The level-1 calorimeter trigger (L1Calo) of the ATLAS experiment has been operating effectively since the start of LHC data taking, and has played a major role in the discovery of the Higgs boson. To face the new challenges posed by the upcoming increases of the LHC proton beam energy and luminosity, a series of upgrades is planned for L1Calo. An initial upgrade (Pre-Phase-I) is scheduled to be ready for the start of the second LHC run in 2015, and a further more substantial upgrade (Phase-1) is planned to be installed during the LHC shutdown expected in 2018. The calorimeter trigger aims to identify electrons, photons, taus and hadronic jets. It also determines total and missing transverse energy and can further analyse the event topology using a dedicated system incorporating information from both calorimeter and muon triggers. This paper presents the Phase-1 hardware trigger developments which exploit a tenfold increase in the available calorimeter data granularity when compared to that of the current syst...

  15. Production of configuration tables for the Input Mezzanine and Data Formatter components in the ATLAS Fast Tracker Trigger System

    CERN Document Server

    Poudroux, Jean-Michael

    2014-01-01

    The project revolve around developing configuration tables for two components in the Fast Tracker (FTK) trigger system used in the ATLAS trigger system. These components are Input Mezzanine cards and the Data Formatter. The tables give easy access to different ID's which identify which module the data is originating from and also which tower and what detector-region the data is being processed in.

  16. Physics performances with the new ATLAS Level-1 Topological trigger in the LHC High-Luminosity Era

    CERN Document Server

    Artz, Sebastian; The ATLAS collaboration

    2016-01-01

    The ATLAS trigger system aim at reducing the 40 MHz protons collision event rate to a manageable event storage rate of 1 kHz, preserving events with valuable physics meaning. The Level-1 trigger is the first rate-reducing step in the ATLAS trigger system, with an output rate of 100 kHz and decision latency of less than 2.5 micro seconds. It is composed of the calorimeter trigger, muon trigger and central trigger processor. During the last upgrade, a new electronics element was introduced to Level-1: L1Topo, the Topological Processor System. It will make it possible to use detailed realtime information from the Level-1 calorimeter and muon triggers, processed in individual state of the art FPGA processors to determine angles between jets and/or leptons and calculate kinematic variables based on lists of selected/sorted objects. Over hundred VHDL algorithms are producing trigger outputs to be incorporated into the central trigger processor. Such information will be essential to improve background rejection and ...

  17. Software design of the ATLAS Muon Cathode Strip Chamber ROD

    Science.gov (United States)

    Murillo, R.; Huffer, M.; Claus, R.; Herbst, R.; Lankford, A.; Schernau, M.; Panetta, J.; Sapozhnikov, L.; Eschrich, I.; Deng, J.

    2012-12-01

    The ATLAS Cathode Strip Chamber system consists of two end-caps with 16 chambers each. The CSC Readout Drivers (RODs) are purpose-built boards encapsulating 13 DSPs and around 40 FPGAs. The principal responsibility of each ROD is for the extraction of data from two chambers at a maximum trigger rate of 75 KHz. In addition, each ROD is in charge of the setup, control and monitoring of the on-detector electronics. This paper introduces the design of the CSC ROD software. The main features of this design include an event flow schema that decentralizes the different dataflow streams, which can thus operate asynchronously at its own natural rate; an event building mechanism that associates data transferred by the asynchronous streams belonging to the same event; and a sparcification algorithm that discards uninteresting events and thus reduces the data occupancy volume. The time constraints imposed by the trigger rate have made paramount the use of optimization techniques such as the curiously recurrent template pattern and the programming of critical code in assembly language. The behaviour of the CSC RODs has been characterized in order to validate its performance.

  18. Online measurement of LHC beam parameters with the ATLAS High Level Trigger

    CERN Document Server

    Strauss, E; The ATLAS collaboration

    2011-01-01

    We present an online measurement of the LHC beam parameters in ATLAS using the High Level Trigger (HLT). When a significant change is detected in the measured beamspot, it is distributed to the HLT. There, trigger algorithms like b-tagging which calculate impact parameters or decay lengths benefit from a precise,up-to-date set of beamspot parameters. Additionally, online feedback is sent to the LHC operators in real time. The measurement is performed by an algorithm running on the Level 2 trigger farm, leveraging the high rate of usable events. Dedicated algorithms perform a full scan of the silicon detector to reconstruct event vertices from registered tracks. The distribution of these vertices is aggregated across the farm and their shape is extracted through fits every 60 seconds to determine the beamspot position, size, and tilt. The reconstructed beam values are corrected for detector resolution effects, measured in situ using the separation of vertices whose tracks have been split into two collections. ...

  19. Online Measurement of LHC Beam Parameters with the ATLAS High Level Trigger

    CERN Document Server

    Strauss, E; The ATLAS collaboration

    2011-01-01

    We present an online measurement of the LHC beam parameters in ATLAS using the High Level Trigger (HLT). When a significant change is detected in the measured beamspot, it is distributed to the HLT. There, trigger algorithms like b-tagging which calculate impact parameters or decay lengths benefit from a precise, up-to-date set of beamspot parameters. Additionally, online feedback is sent to the LHC operators in real time. The measurement is performed by an algorithm running on the Level 2 trigger farm, leveraging the high rate of usable events. Dedicated algorithms perform a full scan of the silicon detector to reconstruct event vertices from registered tracks. The distribution of these vertices is aggregated across the farm and their shape is extracted through fits every 60 seconds to determine the beamspot position, size, and tilt. The reconstructed beam values are corrected for detector resolution effects, measured in situ using the separation of vertices whose tracks have been split into two collections....

  20. The Level-1 Calorimeter Global Feature Extractor (gFEX) Boosted Object Trigger for the Phase-I Upgrade of the ATLAS Experiment

    CERN Document Server

    Camacho Toro, Reina; The ATLAS collaboration

    2016-01-01

    The Global Feature Extractor (gFEX) module is a planned component of the Level 1 online trigger system for the ATLAS experiment planned for installation during the Phase I upgrade in 2018. This unique single electronics board with multiple high speed processors will receive coarse-granularity information from all the ATLAS calorimeters enabling the identification in real time of large-radius jets for capturing Lorentz-boosted objects such as top quarks, Higgs, $Z$ and $W$ bosons. The gFEX architecture also facilitates the calculation of global event variables such as missing transverse energy, centrality for heavy ion collisions, and event-by-event pile-up energy density. Details of the electronics architecture that provides these capabilities are presented, along with results of tests of the prototype systems now available. The status of the firmware algorithm design and implementation as well as monitoring capabilities are also presented.

  1. Data Quality Monitoring for the ATLAS trigger System during the first data taking period of the Large Hadron Collider

    CERN Document Server

    Damazio, D O; The ATLAS collaboration

    2013-01-01

    The first long period of data taking of the Large Hadron Collider was finished after 2 years of data in February 2013. The increase of the instantaneous luminosity by more than six orders of magnitude documents impressively the extraordinary success of this running period enabling the ATLAS experiment to collect data of very high quality. However, to ensure a constant and reliable monitoring and data quality assessment of the trigger's point of view, a highly flexible and powerful software framework is essential, covering many different aspects. Aside from drastically changing beam conditions as e.g. increasing pile up, the monitoring frame work has to follow up immediately and flexible all developments of the TDAQ system. The TDAQ monitoring system of ATLAS covers very different aspects as rate measurements, trigger configuration and software tests, data quality assessment and handling of events where the trigger decision has failed. Especially the data quality assessment must be made coherent at the online ...

  2. Data Quality Monitoring for the ATLAS trigger System during the first data taking period of the Large Hadron Collider

    CERN Document Server

    Oliveira Damazio, Denis; The ATLAS collaboration

    2013-01-01

    The first long period of data taking of the Large Hadron Collider was finished after 3 years of work in February 2013. The increase of the instantaneous luminosity by more than six orders of magnitude documents impressively the extraordinary success of this running period enabling the ATLAS experiment to collect very high quality data. However, to ensure a constant and reliable monitoring and data quality assessment from the trigger's point of view, a highly flexible and powerful software framework is essential, covering many different aspects. Aside from drastically changing beam conditions as e.g. increasing pile up, the monitoring frame work has to follow up immediately and in a flexible manner all developments of the TDAQ system. The TDAQ monitoring system of ATLAS covers very different aspects as rate measurements, trigger configuration and software tests, data quality assessment and handling of events where the trigger decision has failed. Especially the data quality assessment must be made coherent at ...

  3. Testing and calibrating analogue inputs to the ATLAS Level-1 Calorimeter Trigger

    CERN Document Server

    Achenbach, R; Aharrouche, M; Andrei, V; Åsman, B; Barnett, B M; Bauss, B; Bendel, M; Bohm, C; Booth, J R A; Bracinik, J; Brawn, I P; Charlton, D G; Childers, J T; Collins, N J; Curtis, C J; Davis, A O; Eckweiler, S; Eisenhandler, E F; Faulkner, P J W; Fleckner, J; Föhlisch, F; Gee, C N P; Gillman, A R; Goringer, C; Groll, M; Hadley, D R; Hanke, P; Hellman, S; Hidvegi, A; Hillier, S J; Johansen, M; Kluge, E E; Kühl, T; Landon, M; Lendermann, V; Lilley, J N; Mahboubi, K; Mahout, G; Meier, K; Middleton, R P; Moa, T; Morris, J D; Müller, F; Neusiedl, A; Ohm, C; Oltmann, B; Perera, V J O; Prieur, D P F; Qian, W; Rieke, S; Rühr, F; Sankey, D P C; Schäfer, U; Schmitt, K; Schultz-Coulon, H C; Seidler, P; Silverstein, S; Sjölin, J; Staley, R J; Stamen, R; Stockton, M C; Tan, C L A; Tapprogge, S; Thomas, J P; Thompson, P D; Watkins, P M; Watson, A; Weber, P; Wessels, M; Wildt, M

    2008-01-01

    The ATLAS Level-1 Calorimeter Trigger is a hardwarebased system which aims to identify objects with high transverse momentum within an overall latency of 2.5 μs. It is composed of a PreProcessor system (PPr) which digitises 7200 analogue input channels, determines the bunch crossing of the interaction, applies a digital noise filter, and provides a fine calibration; and two subsequent digital processors. The PreProcessor system needs various channel dependent parameters to be set in order to provide digital signals which are aligned in time and have proper energy calibration. The different techniques which are used to derive these parameters are described along with the quality tests of the analogue input signals.

  4. The upgrade of the ATLAS High Level Trigger and Data Acquisition systems and their integration

    CERN Document Server

    Abreu, R; The ATLAS collaboration

    2014-01-01

    The Data Acquisition (DAQ) and High Level Trigger (HLT) systems that served the ATLAS experiment during LHC's first run are being upgraded in the first long LHC shutdown period, from 2013 to 2015. This contribution describes the elements that are vital for the new interaction between the two systems. The central architectural enhancement is the fusion of the once separate Level 2, Event Building (EB), and Event Filter steps. Through the factorization of previously disperse functionality and better exploitation of caching mechanisms, the inherent simplification carries with it an increase in performance. Flexibility to different running conditions is improved by an automatic balance of formerly separate tasks. Incremental EB is the principle of the new Data Collection, whereby the HLT farm avoids duplicate requests to the detector Read-Out System (ROS) by preserving and reusing previously obtained data. Moreover, requests are packed and fetched together to avoid redundant trips to the ROS. Anticipated EB is ac...

  5. The new inter process communication middle-ware for the ATLAS Trigger and Data Acquisition system

    CERN Document Server

    Kolos, Serguei; The ATLAS collaboration

    2016-01-01

    The ATLAS Trigger & Data Acquisition (TDAQ) project was started almost twenty years ago with the aim of providing scalable distributed data collection system for the experiment. While the software dealing with physics data flow was implemented by directly using the low-level communication protocols, like TCP and UDP, the control and monitoring infrastructure services for the TDAQ system were implemented on top of the CORBA communication middle-ware. CORBA provides a high-level object oriented abstraction for the inter process communication, hiding communication complexity from the developers. This approach speeds up and simplifies development of communication services but incurs some extra cost in terms of performance and resources overhead. Our experience of using CORBA for control and monitoring data exchange in the distributed TDAQ system was very successful, mostly due to the outstanding quality of the CORBA brokers, which have been used in the project: omniORB for C++ and JacORB for Java. However, du...

  6. ATLAS

    CERN Multimedia

    2002-01-01

    Barrel and END-CAP Toroids In order to produce a powerful magnetic field to bend the paths of the muons, the ATLAS detector uses an exceptionally large system of air-core toroids arranged outside the calorimeter volumes. The large volume magnetic field has a wide angular coverage and strengths of up to 4.7tesla. The toroids system contains over 100km of superconducting wire and has a design current of 20 500 amperes. (ATLAS brochure: The Technical Challenges)

  7. Development of a Concept for the Muon Trigger of the ATLAS Detector at the HL-LHC

    CERN Document Server

    Gadow, Paul Philipp

    Highly selective first level triggers are essential to exploit the full physics potential of the ATLAS experiment at the High Luminosity-Large Hadron Collider, where the instantaneous luminosity will exceed the LHC Run 1 instantaneous luminosity by almost an order of magnitude. The ATLAS experiment plans to increase the rate of the first trigger level to 1 MHz at 6 µs latency. The momentum resolution of the existing first level muon trigger is limited by the moderate position resolution of the trigger chambers. Including the data of the precision Monitored Drift Tube (MDT) chambers in the first level muon trigger decision will increase the selectivity of the first level muon trigger substantially. Run 1 LHC data with a centre-of-mass energy of $\\sqrt{s} = 8\\, \\textrm{TeV}$ and a bunch spacing of 25 ns was used to study the achievable selectivity of a muon trigger making use of the MDT data. It could be shown that it is not necessary to fully reconstruct the muon trajectory. The position and direction informa...

  8. TRIGGER

    CERN Multimedia

    Wesley Smith

    Level-1 Trigger Hardware and Software The hardware of the trigger components has been mostly finished. The ECAL Endcap Trigger Concentrator Cards (TCC) are in production while Barrel TCC firmware has been upgraded, and the Trigger Primitives can now be stored by the Data Concentrator Card for readout by the DAQ. The Regional Calorimeter Trigger (RCT) system is complete, and the timing is being finalized. All 502 HCAL trigger links to RCT run without error. The HCAL muon trigger timing has been equalized with DT, RPC, CSC and ECAL. The hardware and firmware for the Global Calorimeter Trigger (GCT) jet triggers are being commissioned and data from these triggers is available for readout. The GCT energy sums from rings of trigger towers around the beam pipe beam have been changed to include two rings from both sides. The firmware for Drift Tube Track Finder, Barrel Sorter and Wedge Sorter has been upgraded, and the synchronization of the DT trigger is satisfactory. The CSC local trigger has operated flawlessly u...

  9. Upgraded Readout and Trigger Electronics for the ATLAS Liquid-Argon Calorimeters at the LHC at the Horizons 2018-2022

    CERN Document Server

    Damazio, D O; The ATLAS collaboration

    2013-01-01

    The ATLAS Liquid Argon (LAr) calorimeters produce a total of 182,486 signals which are digitized and processed by the front-end and back-end electronics at every triggered event. In addition, the front-end electronics is summing analog signals to provide coarsely grained energy sums, called trigger towers, to the first-level trigger system, which is optimized for nominal LHC luminosities. However, the pile-up noise expected during the High Luminosity phases of LHC will be increased by factors of 3 to 7. An improved spatial granularity of the trigger primitives is therefore proposed in order to improve the identification performance for trigger signatures, like electrons, photons, tau leptons, jets, total and missing energy, at high background rejection rates. For the first upgrade phase in 2018, new LAr Trigger Digitizer Board (LTDB) are being designed to receive higher granularity signals, digitize them on detector and send them via fast optical links to a new digital processing system (DPS). The DPS applies...

  10. TRIGGER

    CERN Multimedia

    Roberta Arcidiacono

    2013-01-01

    Trigger Studies Group (TSG) The Trigger Studies Group has just concluded its third 2013 workshop, where all POGs presented the improvements to the physics object reconstruction, and all PAGs have shown their plans for Trigger development aimed at the 2015 High Level Trigger (HLT) menu. The Strategy for Trigger Evolution And Monitoring (STEAM) group is responsible for Trigger menu development, path timing, Trigger performance studies coordination, HLT offline DQM as well as HLT release, menu and conditions validation – this last task in collaboration with PdmV (Physics Data and Monte Carlo Validation group). In the last months the group has delivered several HLT rate estimates and comparisons, using the available data and Monte Carlo samples. The studies were presented at the Trigger workshops in September and December, and STEAM has contacted POGs and PAGs to understand the origin of the discrepancies observed between 8 TeV data and Monte Carlo simulations. The most recent results show what the...

  11. Development and deployment of an inner detector minimum bias trigger and analysis of minimum bias data of the ATLAS experiment at the large hadron collider

    Energy Technology Data Exchange (ETDEWEB)

    Kwee, Regina Esther

    2012-01-13

    Soft inelastic QCD processes are the dominant proton-proton interaction type at the LHC. More than 20 of such collisions pile up within a single bunch-crossing at ATLAS, when the LHC is operated at design luminosity of L=10{sup 34} cm{sup -2}s{sup -1} colliding proton bunches with an energy of {radical}(s)=14 TeV. Inelastic interactions are characterised by a small transverse momentum transfer and can only be approximated by phenomenological models that need experimental data as input. The initial phase of LHC beam operation in 2009, with luminosities ranging from L=10{sup 27} to 10{sup 31} cm{sup -2}s{sup -1}, offered an ideal period to select single proton-proton interactions and study general aspects of their properties. As first part of this thesis, a Minimum Bias trigger was developed and used for data-taking in ATLAS. This trigger, mbSpTrk, processes signals of the silicon tracking detectors of ATLAS and was designed to fulfill efficiently reject empty events, while possible biases in the selection of proton-proton collisions is reduced to a minimum. The trigger is flexible enough to cope also with changing background conditions allowing to retain low-p{sub T} events while machine background is highly suppressed. As second part, measurements of inelastic charged particles were performed in two phase-space regions. Centrally produced charged particles were considered with a pseudorapidity smaller than 0.8 and a transverse momentum of at least 0.5 or 1 GeV. Four characteristic distributions were measured at two centre-of-mass energies of {radical}(s)=0.9 and 7 TeV. The results are presented with minimal model dependency to compare them to predictions of different Monte Carlo models for soft particle production. This analysis represents also the ATLAS contribution for the first common LHC analysis to which the ATLAS, CMS and ALICE collaborations agreed. The pseudorapidity distributions for both energies and phase-space regions are compared to the respective

  12. Development and deployment of an inner detector minimum bias trigger and analysis of minimum bias data of the ATLAS experiment at the large hadron collider

    International Nuclear Information System (INIS)

    Soft inelastic QCD processes are the dominant proton-proton interaction type at the LHC. More than 20 of such collisions pile up within a single bunch-crossing at ATLAS, when the LHC is operated at design luminosity of L=1034 cm-2s-1 colliding proton bunches with an energy of √(s)=14 TeV. Inelastic interactions are characterised by a small transverse momentum transfer and can only be approximated by phenomenological models that need experimental data as input. The initial phase of LHC beam operation in 2009, with luminosities ranging from L=1027 to 1031 cm-2s-1, offered an ideal period to select single proton-proton interactions and study general aspects of their properties. As first part of this thesis, a Minimum Bias trigger was developed and used for data-taking in ATLAS. This trigger, mbSpTrk, processes signals of the silicon tracking detectors of ATLAS and was designed to fulfill efficiently reject empty events, while possible biases in the selection of proton-proton collisions is reduced to a minimum. The trigger is flexible enough to cope also with changing background conditions allowing to retain low-pT events while machine background is highly suppressed. As second part, measurements of inelastic charged particles were performed in two phase-space regions. Centrally produced charged particles were considered with a pseudorapidity smaller than 0.8 and a transverse momentum of at least 0.5 or 1 GeV. Four characteristic distributions were measured at two centre-of-mass energies of √(s)=0.9 and 7 TeV. The results are presented with minimal model dependency to compare them to predictions of different Monte Carlo models for soft particle production. This analysis represents also the ATLAS contribution for the first common LHC analysis to which the ATLAS, CMS and ALICE collaborations agreed. The pseudorapidity distributions for both energies and phase-space regions are compared to the respective results of ALICE and CMS.

  13. Muon Identification with the ATLAS Tile Calorimeter Read-Out Driver for Level-2 Trigger Purposes

    CERN Document Server

    Ruiz-Martinez, A

    2008-01-01

    The Hadronic Tile Calorimeter (TileCal) at the ATLAS experiment is a detector made out of iron as passive medium and plastic scintillating tiles as active medium. The light produced by the particles is converted to electrical signals which are digitized in the front-end electronics and sent to the back-end system. The main element of the back-end electronics are the VME 9U Read-Out Driver (ROD) boards, responsible of data management, processing and transmission. A total of 32 ROD boards, placed in the data acquisition chain between Level-1 and Level-2 trigger, are needed to read out the whole calorimeter. They are equipped with fixed-point Digital Signal Processors (DSPs) that apply online algorithms on the incoming raw data. Although the main purpose of TileCal is to measure the energy and direction of the hadronic jets, taking advantage of its projective segmentation soft muons not triggered at Level-1 (with pT<5 GeV) can be recovered. A TileCal standalone muon identification algorithm is presented and i...

  14. The coincidence matrix ASIC of the level-1 muon barrel trigger of the ATLAS experiment

    CERN Document Server

    Bocci, V; Salamon, A; Vari, R; Veneziano, Stefano

    2003-01-01

    The ATLAS barrel level-1 muon trigger processes hit information from the resistive plate chamber detector, identifying candidate muon tracks and assigning them to a programmable p/sub T/ range and to a unique bunch crossing number. The trigger system uses up to seven detector layers and seeks hit patterns compatible with muon tracks in the bending and nonbending projection. The basic principle of the algorithm is to demand a coincidence of hits in the different chamber layers within a path. The width of the road is related to the p/sub T / threshold to be applied. The system is split into an on-detector and an off-detector part. The on-detector electronics reduces the information from about 350 k channels to about 400 32-bit data words sent via optical fiber to the so-called sector logic (SL). The off- detector SL electronics collects muon candidates and associates them to detector regions-of-interest of Delta eta * Delta Phi of 0.1*0.1. The core of the on-detector electronics is the coincidence matrix ASIC (...

  15. Online Determination of the LHC Luminous Region with the ATLAS High-Level Trigger

    CERN Document Server

    Bartoldus, R

    2012-01-01

    During stable-beams operations of the LHC, the ATLAS High Level Trigger (HLT) offers the fastest and most precise online measurement available of the position, size and orientation of the luminous region at the interaction point. Taking advantage of the high rate of triggered events, a dedicated algorithm is executed on the HLT processor farm of several hundred nodes that uses tracks registered in the silicon detectors to reconstruct event vertices. The distribution of these vertices is aggregated across the farm and its shape is extracted through fits every 60 seconds. A correction is applied online to adjust for the intrinsic vertex resolution by examining the apparent separation of split vertices. The location, widths and tilts of the luminosity distribution are fed back to the LHC operators in real time. The transverse luminous centroid mirrors variations in the IP orbit, while its position along the beam axis is sensitive to the relative RF phase of the two beams. The time evolution of the luminous width...

  16. Studies with Muons in ATLAS: TileCal Level-2 Trigger and MSSM Higgs Discovery Reach

    CERN Document Server

    Ruiz Martínez, A; Valls Ferrer, J A

    2009-01-01

    This thesis was carried out in the years previous to the LHC start-up, i.e. during the ATLAS detector commissioning phase. It contains an introductory part about the detector and its expected physics performance and two main parts about the development of a Level-2 trigger for muons and a study of the MSSM Higgs discovery reach with simulated data, which are briefly described below. The first part of the thesis is devoted to TileMuId, the muon identication algorithm based on TileCal whose main goal is to be used as a Level-2 trigger of low-$p_{\\text{T}}$ muons. A second version of TileMuId (ROD-based) has been implemented to run in the TileCal ROD DSPs. This involved developments in the DSP firmware and in the Athena framework, described in the document. In addition, studies of the algorithm performance in terms of efficiency and fraction of fakes have been done. Developments and studies to match the TileCal muon candidates with the Inner Detector tracks (provided by ID reconstruction algorithms) have been pe...

  17. Online Determination of the LHC Luminous Region with the ATLAS High-Level Trigger

    CERN Document Server

    Bartoldus, R; The ATLAS collaboration

    2011-01-01

    During stable-beams operations of the LHC, the ATLAS High Level Trigger (HLT) offers the fastest and most precise online measurement available of the position, size and orientation of the luminous region at the interaction point. Taking advantage of the high rate of triggered events, a dedicated algorithm is executed on the HLT processor farm of several hundred nodes that uses tracks registered in the silicon detectors to reconstruct event vertices. The distribution of these vertices is aggregated across the farm and its shape is extracted through fits every 60 seconds. A correction is applied online to adjust for the intrinsic vertex resolution by examining the displacement of split vertices. The location, widths and tilts of the luminosity distribution are fed back to the LHC operators in real time. The transverse luminous centroid mirrors variations in the IP orbit, while its position along the beam axis is sensitive to the relative RF phase of the two beams. The time evolution of the luminous width tracks...

  18. The ATLAS High Level Trigger Configuration and Steering, Experience with the First 7 TeV Collisions

    CERN Document Server

    Stelzer, J; The ATLAS collaboration

    2011-01-01

    In March 2010 the four LHC experiments saw the first proton-proton collisions at a center-of-mass energy of 7 TeV. Still within the year a collision rate of nearly 10 MHz was expected. At ATLAS, events of potential physics interest for are selected by a three-level trigger system, with a final recording rate of about 200 Hz. The first level (L1) is implemented in customized hardware, the two levels of the high level trigger (HLT) are software triggers. For the ATLAS physics program more than 500 trigger signatures are defined. The HLT tests each signature on each L1-accepted event, the test outcome is recorded for later analysis. The HLT-Steering is responsible for this. It foremost ensures the independence of each signature test and an unbiased trigger decisions. Yet, to minimize data readout and execution time, cached detector data and once-calculated trigger objects are reused to form the decision. Some signature tests are performed only on a scaled-down fraction of candidate events, in order to reduce the...

  19. A new Highly Selective First Level ATLAS Muon Trigger With MDT Chamber Data for HL-LHC

    CERN Document Server

    Nowak, Sebastian; The ATLAS collaboration

    2015-01-01

    Highly selective first level triggers are essential for the physics programme of the ATLAS experiment at the HL-LHC where the instantaneous luminosity will exceed the LHC's instantaneous luminosity by almost an order of magnitude. The ATLAS first level muon trigger rate is dominated by low momentum sub-trigger threshold muons due to the poor momentum resolution at trigger level caused by the moderate spatial resolution of the resistive plate and thin gap trigger chambers. This limitation can be overcome by including the data of the precision muon drift tube chambers in the first level trigger decision. This requires the implementation of a fast MDT read-out chain and a fast MDT track reconstruction. A hardware demonstrator of the fast read-out chain was successfully tested under HL-LHC operating conditions at CERN's Gamma Irradiation Facility. It could be shown that the data provided by the demonstrator can be processed with a fast track reconstruction algorithm on an ARM CPU within the 6 microseconds latency...

  20. TRIGGER

    CERN Multimedia

    Wesley Smith

    Level-1 Trigger Hardware and Software The trigger synchronization procedures for running with cosmic muons and operating with the LHC were reviewed during the May electronics week. Firmware maintenance issues were also reviewed. Link tests between the new ECAL endcap trigger concentrator cards (TCC48) and the Regional Calorimeter Trigger have been performed. Firmware for the energy sum triggers and an upgraded tau trigger of the Global Calorimeter Triggers has been developed and is under test. The optical fiber receiver boards for the Track-Finder trigger theta links of the DT chambers are now all installed. The RPC trigger is being made more robust by additional chamber and cable shielding and also by firmware upgrades. For the CSC’s the front-end and trigger motherboard firmware have been updated. New RPC patterns and DT/CSC lookup tables taking into account phi asymmetries in the magnetic field configuration are under study. The motherboard for the new pipeline synchronizer of the Global Trigg...

  1. TRIGGER

    CERN Multimedia

    W. Smith

    2012-01-01

      Level-1 Trigger The Level-1 Trigger group is ready to deploy improvements to the L1 Trigger algorithms for 2012. These include new high-PT patterns for the RPC endcap, an improved CSC PT assignment, a new PT-matching algorithm for the Global Muon Trigger, and new calibrations for ECAL, HCAL, and the Regional Calorimeter Trigger. These should improve the efficiency, rate, and stability of the L1 Trigger. The L1 Trigger group also is migrating the online systems to SLC5. To make the data transfer from the Global Calorimeter Trigger to the Global Trigger more reliable and also to allow checking the data integrity online, a new optical link system has been developed by the GCT and GT groups and successfully tested at the CMS electronics integration facility in building 904. This new system is now undergoing further tests at Point 5 before being deployed for data-taking this year. New L1 trigger menus have recently been studied and proposed by Emmanuelle Perez and the L1 Detector Performance Group...

  2. TRIGGER

    CERN Multimedia

    W. Smith

    At the March meeting, the CMS trigger group reported on progress in production, tests in the Electronics Integration Center (EIC) in Prevessin 904, progress on trigger installation in the underground counting room at point 5, USC55, the program of trigger pattern tests and vertical slice tests and planning for the Global Runs starting this summer. The trigger group is engaged in the final stages of production testing, systems integration, and software and firmware development. Most systems are delivering final tested electronics to CERN. The installation in USC55 is underway and integration testing is in full swing. A program of orderly connection and checkout with subsystems and central systems has been developed. This program includes a series of vertical subsystem slice tests providing validation of a portion of each subsystem from front-end electronics through the trigger and DAQ to data captured and stored. After full checkout, trigger subsystems will be then operated in the CMS Global Runs. Continuous...

  3. TRIGGER

    CERN Multimedia

    by Wesley Smith

    2010-01-01

    Level-1 Trigger Hardware and Software The overall status of the L1 trigger has been excellent and the running efficiency has been high during physics fills. The timing is good to about 1%. The fine-tuning of the time synchronization of muon triggers is ongoing and will be completed after more than 10 nb-1 of data have been recorded. The CSC trigger primitive and RPC trigger timing have been refined. A new configuration for the CSC Track Finder featured modified beam halo cuts and improved ghost cancellation logic. More direct control was provided for the DT opto-receivers. New RPC Cosmic Trigger (RBC/TTU) trigger algorithms were enabled for collision runs. There is further work planned during the next technical stop to investigate a few of the links from the ECAL to the Regional Calorimeter Trigger (RCT). New firmware and a new configuration to handle trigger rate spikes in the ECAL barrel are also being tested. A board newly developed by the tracker group (ReTRI) has been installed and activated to block re...

  4. TRIGGER

    CERN Multimedia

    Wesley Smith

    Level-1 Trigger Hardware and Software The production of the trigger hardware is now basically finished, and in time for the turn-on of the LHC. The last boards produced are the Trigger Concentrator Cards for the ECAL Endcaps (TCC-EE). After the recent installation of the four EE Dees, the TCC-EE prototypes were used for their commissioning. Production boards are arriving and are being tested continuously, with the last ones expected in November. The Regional Calorimeter Trigger hardware is fully integrated after installation of the last EE cables. Pattern tests from the HCAL up to the GCT have been performed successfully. The HCAL triggers are fully operational, including the connection of the HCAL-outer and forward-HCAL (HO/HF) technical triggers to the Global Trigger. The HCAL Trigger and Readout (HTR) board firmware has been updated to permit recording of the tower “feature bit” in the data. The Global Calorimeter Trigger hardware is installed, but some firmware developments are still n...

  5. FELIX: a PCIe based high-throughput approach for interfacing front-end and trigger electronics in the ATLAS Upgrade framework

    CERN Document Server

    Anderson, John Thomas; The ATLAS collaboration

    2016-01-01

    The ATLAS Phase-I upgrade (2018) requires a Trigger and Data Acquisition (TDAQ) system able to trigger and record data from up to three times the nominal LHC instantaneous luminosity. The Front-End LInk eXchange (FELIX) system provides an infrastructure to achieve this in a scalable, detector agnostic and easily upgradeable way. It is a PC-based gateway, interfacing custom radiation tolerant optical links from front-end electronics, via FPGA PCIe Gen3 cards, to a commodity switched Ethernet or InfiniBand network. FELIX enables reducing custom electronics in favour of software running on commercial servers. The FELIX system, the design of the PCIe prototype card and the integration test results are presented in this paper.

  6. Anthropogenic triggers for Late Holocene soil erosion in the Jebel Toubkal, High Atlas, Morocco

    Science.gov (United States)

    Fletcher, William; Hughes, Philip

    2016-04-01

    The Assif n'Imserdane valley, located in the Jebel Toubkal area of the High Atlas, Morocco, is a highly dynamic geomorphological setting. The valley was glaciated during the Late Pleistocene, and subsequently experienced a catastrophic rock avalanche leading to the formation of one of the largest mass movement landforms in North Africa. Recent research (Hughes et al., GSA Bulletin 126: 1093-1104) has dated the formation of the rock avalanche to the mid-Holocene at 4.5 ± 0.5 ka. Here, we examine the sedimentological (organic matter content, magnetic susceptibility, particle size and XRF) and palaeoecological (pollen and spores, non-pollen palynomorphs (NPPs), microcharcoal and conifer tracheid fragments) record of a small infilled basin located adjacent to a Late Pleistocene moraine and close to the rock avalanche in the Arroumd sector. The deposits, primarily fine-grained and minerogenic with a low concentration of organic microfossils including pollen, coprophilous ascospores, wood and charcoal microfragments, are enriched in fine silts and ferrimagnetic minerals, consistent with erosional sources from surrounding slope soils. Two radiocarbon dates on fine charcoal recovered from the deposit indicate that the infill event occurred during the first millennium AD (after 430 - 640 AD). As such, the deposits point to a phase of slope instability and erosion that is not linked to either deglaciation processes or to the mid-Holocene rock avalanche. Instead, the nature and timing suggest that an anthropogenic trigger of degradation to the natural vegetation cover may be implicated. The record casts light on a previously undocumented phase of landscape instability in the dynamic setting of the Assif n'Imserdane valley, and highlights the potential for further exploration of small infilled basins in the High Atlas to illuminate the geoecological history of this semi-arid mountain region.

  7. A Simulation of the Front End Signal Digitization for the ATLAS Muon Spectrometer thin RPC trigger upgrade project

    Science.gov (United States)

    Meng, Xiangting; Chapman, John; Levin, Daniel; Dai, Tiesheng; Zhu, Junjie; Zhou, Bing; Um Atlas Group Team

    2016-03-01

    The ATLAS Muon Spectrometer Phase-I (and Phase-II) upgrade includes the BIS78 muon trigger detector project: two sets of eight very thin Resistive Place Chambers (tRPCs) combined with small Monitored Drift Tube (MDT) chambers in the pseudorapidity region 1conducted detailed HPTDC latency simulations using the Behavioral Verilog code from the CERN group. We will report the results of these simulations run for the anticipated detector operating environment and for various HPTDC configurations.

  8. TRIGGER

    CERN Multimedia

    W. Smith

    2010-01-01

    Level-1 Trigger Hardware and Software The Level-1 Trigger hardware has performed well during both the recent proton-proton and heavy ion running. Efforts were made to improve the visibility and handling of alarms and warnings. The tracker ReTRI boards that prevent fixed frequencies of Level-1 Triggers are now configured through the Trigger Supervisor. The Global Calorimeter Trigger (GCT) team has introduced a buffer cleanup procedure at stops and a reset of the QPLL during configuring to ensure recalibration in case of a switch from the LHC clock to the local clock. A device to test the cables between the Regional Calorimeter Trigger and the GCT has been manufactured. A wrong charge bit was fixed in the CSC Trigger. The ECAL group is improving crystal masking and spike suppression in the trigger primitives. New firmware for the Drift Tube Track Finder (DTTF) sorters was developed to improve fake track tagging and sorting. Zero suppression was implemented in the DT Sector Collector readout. The track finder b...

  9. TRIGGER

    CERN Multimedia

    Wesley Smith

    Trigger Hardware The status of the trigger components was presented during the September CMS Week and Annual Review and at the monthly trigger meetings in October and November. Procedures for cold and warm starts (e.g. refreshing of trigger parameters stored in registers) of the trigger subsystems have been studied. Reviews of parts of the Global Calorimeter Trigger (GCT) and the Global Trigger (GT) have taken place in October and November. The CERN group summarized the status of the Trigger Timing and Control (TTC) system. All TTC crates and boards are installed in the underground counting room, USC55. The central clock system will be upgraded in December (after the Global Run at the end of November GREN) to the new RF2TTC LHC machine interface timing module. Migration of subsystem's TTC PCs to SLC4/ XDAQ 3.12 is being prepared. Work is on going to unify the access to Local Timing Control (LTC) and TTC CMS interface module (TTCci) via SOAP (Simple Object Access Protocol, a lightweight XML-based messaging ...

  10. Upgrade of the First Level Muon Trigger in the End-Cap New Small Wheel Region of the ATLAS Detector

    CERN Document Server

    Munwes, Y; The ATLAS collaboration

    2013-01-01

    The luminosity levels foreseen at the LHC after the 2018 LHC upgrade will tighten the demands on the ATLAS first level muon trigger system. Some of the present Muon Spectrometer components will fail to cope with these high rates and will have to be replaced. The introduction of new detectors in the small wheel region of the end-cap muon spectrometer will allow to refine the current trigger selection, allowing to increase the rejection power for tracks not coming from the interaction point, thus to and candidate muon tracks within 1 mrad angular resolution and within the 500 ns available latency.

  11. TRIGGER

    CERN Multimedia

    W. Smith from contributions of C. Leonidopoulos

    2010-01-01

    Level-1 Trigger Hardware and Software Since nearly all of the Level-1 (L1) Trigger hardware at Point 5 has been commissioned, activities during the past months focused on the fine-tuning of synchronization, particularly for the ECAL and the CSC systems, on firmware upgrades and on improving trigger operation and monitoring. Periodic resynchronizations or hard resets and a shortened luminosity section interval of 23 seconds were implemented. For the DT sector collectors, an automatic power-off was installed in case of high temperatures, and the monitoring capabilities of the opto-receivers and the mini-crates were enhanced. The DTTF and the CSCTF now have improved memory lookup tables. The HCAL trigger primitive logic implemented a new algorithm providing better stability of the energy measurement in the presence of any phase misalignment. For the Global Calorimeter Trigger, additional Source Cards have been manufactured and tested. Testing of the new tau, missing ET and missing HT algorithms is underw...

  12. Design, Results, Evolution and Status of the ATLAS Simulation at Point1 Project

    CERN Document Server

    Brasolin, Franco; The ATLAS collaboration; Ballestrero, Sergio; Contescu, Alexandru Cristian; Fazio, Daniel; Di Girolamo, Alessandro; Lee, Christopher Jon; Pozo Astigarraga, Mikel Eukeni; Scannicchio, Diana; Sedov, Alexey; Twomey, Matthew Shaun; Wang, Fuquan; Zaytsev, Alexander

    2015-01-01

    Abstract. During the LHC Long Shutdown 1 period (LS1), that started in 2013, the Simulation at Point1 (Sim@P1) Project takes advantage, in an opportunistic way, of the TDAQ (Trigger and Data Acquisition) HLT (High Level Trigger) farm of the ATLAS experiment. This farm provides more than 1300 compute nodes, which are particularly suited for running event generation and Monte Carlo production jobs that are mostly CPU and not I/O bound. It is capable of running up to 2700 virtual machines (VMs) provided with 8 CPU cores each, for a total of up to 22000 parallel running jobs. This contribution gives a review of the design, the results, and the evolution of the Sim@P1 Project; operating a large scale OpenStack based virtualized platform deployed on top of the ATLAS TDAQ HLT farm computing resources. During LS1, Sim@P1 was one of the most productive ATLAS sites: it delivered more than 50 million CPU-hours and it generated more than 1.7 billion Monte Carlo events to various analysis communities. The design aspects a...

  13. TRIGGER

    CERN Multimedia

    Wesley Smith

    Level-1 Trigger Hardware and Software The final parts of the Level-1 trigger hardware are now being put in place. For the ECAL endcaps, more than half of the Trigger Concentrator Cards for the ECAL Endcap (TCC-EE) are now available at CERN, such that one complete endcap can be covered. The Global Trigger now correctly handles ECAL calibration sequences, without being influenced by backpressure. The Regional Calorimeter Trigger (RCT) hardware is complete and working in USC55. Intra-crate tests of all 18 RCT crates and the Global Calorimeter Trigger (GCT) are regularly taking place. Pattern tests have successfully captured data from HCAL through RCT to the GCT Source Cards. HB/HE trigger data are being compared with emulator results to track down the very few remaining hardware problems. The treatment of hot and dead cells, including their recording in the database, has been defined. For the GCT, excellent agreement between the emulator and data has been achieved for jets and HF ET sums. There is still som...

  14. TRIGGER

    CERN Multimedia

    W. Smith

    Level-1 Trigger Hardware and Software The trigger system has been constantly in use in cosmic and commissioning data taking periods. During CRAFT running it delivered 300 million muon and calorimeter triggers to CMS. It has performed stably and reliably. During the abort gaps it has also provided laser and other calibration triggers. Timing issues, namely synchronization and latency issues, have been solved. About half of the Trigger Concentrator Cards for the ECAL Endcap (TCC-EE) are installed, and the firmware is being worked on. The production of the other half has started. The HCAL Trigger and Readout (HTR) card firmware has been updated, and new features such as fast parallel zero-suppression have been included. Repairs of drift tube (DT) trigger mini-crates, optical links and receivers of sector collectors are under way and have been completed on YB0. New firmware for the optical receivers of the theta links to the drift tube track finder is being installed. In parallel, tests with new eta track finde...

  15. TRIGGER

    CERN Multimedia

    W. Smith

    At the December meeting, the CMS trigger group reported on progress in production, tests in the Electronics Integration Center (EIC) in Prevessin 904, progress on trigger installation in the underground counting room at point 5, USC55, and results from the Magnet Test and Cosmic Challenge (MTCC) phase II. The trigger group is engaged in the final stages of production testing, systems integration, and software and firmware development. Most systems are delivering final tested electronics to CERN. The installation in USC55 is underway and moving towards integration testing. A program of orderly connection and checkout with subsystems and central systems has been developed. This program includes a series of vertical subsystem slice tests providing validation of a portion of each subsystem from front-end electronics through the trigger and DAQ to data captured and stored. This is combined with operations and testing without beam that will continue until startup. The plans for start-up, pilot and early running tri...

  16. TRIGGER

    CERN Multimedia

    W. Smith, from contributions of D. Acosta

    2012-01-01

      The L1 Trigger group deployed several major improvements this year. Compared to 2011, the single-muon trigger rate has been reduced by a factor of 2 and the η coverage has been restored to 2.4, with high efficiency. During the current technical stop, a higher jet seed threshold will be applied in the Global Calorimeter Trigger in order to significantly reduce the strong pile-up dependence of the HT and multi-jet triggers. The currently deployed L1 menu, with the “6E33” prescales, has a total rate of less than 100 kHz and operates with detector readout dead time of less than 3% for luminosities up to 6.5 × 1033 cm–2s–1. Further prescale sets have been created for 7 and 8 × 1033 cm–2s–1 luminosities. The L1 DPG is evaluating the performance of the Trigger for upcoming conferences and publication. Progress on the Trigger upgrade was reviewed during the May Upgrade Week. We are investigating scenarios for stagin...

  17. TRIGGER

    CERN Multimedia

    W. Smith from contributions of C. Leonidopoulos, I. Mikulec, J. Varela and C. Wulz.

    Level-1 Trigger Hardware and Software Over the past few months, the Level-1 trigger has successfully recorded data with cosmic rays over long continuous stretches as well as LHC splash events, beam halo, and collision events. The L1 trigger hardware, firmware, synchronization, performance and readiness for beam operation were reviewed in October. All L1 trigger hardware is now installed at Point 5, and most of it is completely commissioned. While the barrel ECAL Trigger Concentrator Cards are fully operational, the recently delivered endcap ECAL TCC system is still being commissioned. For most systems there is a sufficient number of spares available, but for a few systems additional reserve modules are needed. It was decided to increase the overall L1 latency by three bunch crossings to increase the safety margin for trigger timing adjustments. In order for CMS to continue data taking during LHC frequency ramps, the clock distribution tree needs to be reset. The procedures for this have been tested. A repl...

  18. TRIGGER

    CERN Multimedia

    W. Smith

    Level-1 Trigger Hardware and Software The road map for the final commissioning of the level-1 trigger system has been set. The software for the trigger subsystems is being upgraded to run under CERN Scientific Linux 4 (SLC4). There is also a new release for the Trigger Supervisor (TS 1.4), which implies upgrade work by the subsystems. As reported by the CERN group, a campaign to tidy the Trigger Timing and Control (TTC) racks has begun. The machine interface was upgraded by installing the new RF2TTC module, which receives RF signals from LHC Point 4. Two Beam Synchronous Timing (BST) signals, one for each beam, can now be received in CMS. The machine group will define the exact format of the information content shortly. The margin on the locking range of the CMS QPLL is planned for study for different subsystems in the next Global Runs, using a function generator. The TTC software has been successfully tested on SLC4. Some TTC subsystems have already been upgraded to SLC4. The TTCci Trigger Supervisor ...

  19. TRIGGER

    CERN Multimedia

    Wesley Smith

    2011-01-01

    Level-1 Trigger Hardware and Software New Forward Scintillating Counters (FSC) for rapidity gap measurements have been installed and integrated into the Trigger recently. For the Global Muon Trigger, tuning of quality criteria has led to improvements in muon trigger efficiencies. Several subsystems have started campaigns to increase spares by recovering boards or producing new ones. The barrel muon sector collector test system has been reactivated, new η track finder boards are in production, and φ track finder boards are under revision. In the CSC track finder, an η asymmetry problem has been corrected. New pT look-up tables have also improved efficiency. RPC patterns were changed from four out of six coincident layers to three out of six in the barrel, which led to a significant increase in efficiency. A new PAC firmware to trigger on heavy stable charged particles allows looking for chamber hit coincidences in two consecutive bunch-crossings. The redesign of the L1 Trigger Emulator...

  20. TRIGGER

    CERN Multimedia

    R. Arcidiacono

    2013-01-01

      In 2013 the Trigger Studies Group (TSG) has been restructured in three sub-groups: STEAM, for the development of new HLT menus and monitoring their performance; STORM, for the development of HLT tools, code and actual configurations; and FOG, responsible for the online operations of the High Level Trigger. The Strategy for Trigger Evolution And Monitoring (STEAM) group is responsible for Trigger Menu development, path timing, trigger performance studies coordination, HLT offline DQM as well as HLT release, menu and conditions validation – in collaboration and with the technical support of the PdmV group. Since the end of proton-proton data taking, the group has started preparing for 2015 data taking, with collisions at 13 TeV and 25 ns bunch spacing. The reliability of the extrapolation to higher energy is being evaluated comparing the trigger rates on 7 and 8 TeV Monte Carlo samples with the data taken in the past two years. The effect of 25 ns bunch spacing is being studied on the d...

  1. Persistent Back End for the ATLAS Information Service of Trigger and Data Acquisition

    CERN Document Server

    Sicoe, Alexandru

    ATLAS is the largest of several experiments built along the Large Hadron Collider at CERN, Geneva. Its aim is to measure particle production when protons collide at a very high center of mass energy, thus reproducing the behavior of matter a few instants after the big bang. The detecting techniques used for this purpose are very sophisticated and the amount of digitized data created by the sensing elements requires a very large data acquisition system, based on thousands of interconnected computers. The experiment is successfully taking data since the end of 2008 and the trigger and data acquisition are now in a production stage.The main development eorts are guided towards adding easy to use and intuitive tools to aid experts monitor dierent components or subsystems. P BEAST is an example of such a tool. It facilitates the storage of vast amounts of operational information which is otherwise lost. With this data at hand, long term analysis can be made and issues discovered. The project has reached deployment...

  2. The ATLAS Data Acquisition and High Level Trigger Systems: Experience and Upgrade Plans

    CERN Document Server

    Hauser, R; The ATLAS collaboration

    2012-01-01

    The ATLAS DAQ/HLT system reduces the Level 1 rate of 75 kHz to a few kHz event build rate after Level 2 and a few hundred Hz out output rate to disk. It has operated with an average data taking efficiency of about 94% during the recent years. The performance has far exceeded the initial requirements, with about 5 kHz event building rate and 500 Hz of output rate in 2012, driven mostly by physics requirements. Several improvements and upgrades are foreseen in the upcoming long shutdowns, both to simplify the existing architecture and improve the performance. On the network side new core switches will be deployed and possible use of 10GBit Ethernet links for critical areas is foreseen. An improved read-out system to replace the existing solution based on PCI is under development. A major evolution of the high level trigger system foresees a merging of the Level 2 and Event Filter functionality on a single node, including the event building. This will represent a big simplification of the existing system, while ...

  3. Design of the Track Correlator for the DTBX Trigger

    CERN Document Server

    Martinelli, Roberto; Zotto, Pierluigi

    1999-01-01

    The fully reviewed design of the Track Correlator ( TRACO) developed for the muon barrel drift tubes first level trigger is presented. Details of the project and a study of the expected performance of the device, based on a full GEANT simulation using the CMS113 version of the detector, are given.

  4. Concepts, Design and Implementation of the ATLAS New Tracking (NEWT)

    CERN Document Server

    Cornelissen, T; Fleischmann, S; Liebig, W; Moyse, E; Salzburger, A

    2007-01-01

    The track reconstruction of modern high energy physics experiments is a very complex task that puts stringent requirements onto the software realisation. The ATLAS track reconstruction software has been in the past dominated by a collection of individual packages, each of which incorporating a different intrinsic event data model, different data flow sequences and calibration data. Invoked by the Final Report of the Reconstruction Task Force, the ATLAS track reconstruction has undergone a major design revolution to ensure maintainability during the long lifetime of the ATLAS experiment and the flexibility needed for the startup phase. The entire software chain has been re-organised in modular components and a common Event Data Model has been deployed during the last three years. A complete new track reconstruction that concentrates on common tools aimed to be used by both ATLAS tracking devices, the Inner Detector and the Muon System, has been established. It has been already used during many large scale test...

  5. The Data-Logging System of the Trigger and Data Acquisition for the ATLAS Experiment at CERN

    CERN Document Server

    Battaglia, A; Dobson, M; Gadomski, S; Kordas, K; Vandelli, W; 2007 IEEE Nuclear Science Symposium and Medical Imaging Conference

    2007-01-01

    The ATLAS experiment is getting ready to observe collisions between protons at a centre of mass energy of 14 TeV. These will be the highest energy collisions in a controlled environment to-date, to be provided by the Large Hadron Collider at CERN by mid 2008. The ATLAS Trigger and Data Acquisition (TDAQ) system selects events online in a three level trigger system in order to keep those events promising to unveil new physics at a budgeted rate of ~200 Hz for an event size of ~1.5 MB. This corresponds to a reduction of O(10^5) from the initial bunch-crossing rate of 40 MHz at nominal operating conditions. This paper focuses on the data-logging system on the TDAQ side, the so-called "Sub-Farm Output" (SFO) system. It takes data from the Event Filter farm, which is the third level trigger, and it streams and indexes the events into different files, according to each event's trigger path. The data files are moved to CASTOR, the central mass storage facility at CERN. The final TDAQ data-logging system has been ins...

  6. The ATLAS Muon Trigger Performance in pp Collisions at sqrt(s)=8 TeV in Year 2012 Runs

    CERN Document Server

    Nobe, T; The ATLAS collaboration

    2012-01-01

    Events with muons in the final state are an important signature for many physics topics at Large Hadron Collider (LHC), for instance, searches for Higgs boson production or new phenomena, measurements on the standard model processes like top-quark, W, Z production. Thus, efficient trigger on muons in data taking and understanding its performance are crucial to perform these physics studies. At LHC high rejection power against large backgrounds, while maintaining high efficiency for rare signal events, is required for online selection at the trigger level. The ATLAS experiment employs a multi-level trigger architecture that selects the events in three sequential steps of increasing complexity and accuracy to cope with this challenging task. The L1 muon trigger system gets its input from fast muon trigger detectors. Fast sector logic boards select muon candidates, which are passed via an interface board to the central trigger processor and then to the High Level Trigger (HLT). The Muon HLT is purely software ba...

  7. The ATLAS muon trigger performance in pp collisions at sqrt(s) = 8 TeV in year 2012 runs

    CERN Document Server

    Nobe, T; The ATLAS collaboration

    2012-01-01

    Events with muons in the final state are an important signature for many physics topics at Large Hadron Collider (LHC), for instance, searches for Higgs boson production or new phenomena, measurements on the standard model processes like top-quark, W, Z production. Thus, efficient trigger on muons in data taking and understanding its performance are crucial to perform these physics studies. At LHC high rejection power against large backgrounds, while maintaining high efficiency for rare signal events, is required for online selection at the trigger level. The ATLAS experiment employs a multi-level trigger architecture that selects the events in three sequential steps of increasing complexity and accuracy to cope with this challenging task. The L1 muon trigger system gets its input from fast muon trigger detectors. Fast sector logic boards select muon candidates, which are passed via an interface board to the central trigger processor and then to the High Level Trigger (HLT). The Muon HLT is purely software ba...

  8. A Highly Selective First-Level Muon Trigger With MDT Chamber Data for ATLAS at HL-LHC

    CERN Document Server

    Kroha, H

    2016-01-01

    Highly selective triggers are essential for the physics programme of the ATLAS experiment at HL-LHC where the instantaneous luminosity will be about an order of magnitude larger than the LHC instantaneous luminosity in Run 1. The first level muon trigger rate is dominated by low momentum muons below the nominal trigger threshold due to the moderate momentum resolution of the Resistive Plate and Thin Gap trigger chambers. The resulting high trigger rates at HL-LHC can be su?ciently reduced by using the data of the precision Muon Drift Tube chambers for the trigger decision. This requires the implementation of a fast MDT read-out chain and of a fast MDT track reconstruction algorithm with a latency of at most 6 microseconds. A hardware demonstrator of the fast read-out chain has been successfully tested at the HL-LHC operating conditions at the CERN Gamma Irradiation Facility. The fast track reconstruction algorithm has been implemented on a fast trigger processor.

  9. A highly selective first-level muon trigger with MDT chamber data for ATLAS at HL-LHC

    Science.gov (United States)

    Nowak, S.; Kroha, H.

    2016-07-01

    Highly selective triggers are essential for the physics programme of the ATLAS experiment at HL-LHC where the instantaneous luminosity will be about an order of magnitude larger than the LHC instantaneous luminosity in Run 1. The first level muon trigger rate is dominated by low momentum muons below the nominal trigger threshold due to the moderate momentum resolution of the Resistive Plate and Thin Gap trigger chambers. The resulting high trigger rates at HL-LHC can be sufficiently reduced by using the data of the precision Muon Drift Tube chambers for the trigger decision. This requires the implementation of a fast MDT read-out chain and of a fast MDT track reconstruction algorithm with a latency of at most 6 μs. A hardware demonstrator of the fast read-out chain has been successfully tested at the HL-LHC operating conditions at the CERN Gamma Irradiation Facility. The fast track reconstruction algorithm has been implemented on a fast trigger processor.

  10. Atlas based kinematic optimum design of the Stewart parallel manipulator

    Science.gov (United States)

    Shao, Zhufeng; Tang, Xiaoqiang; Wang, Liping; Sun, Dengfeng

    2015-01-01

    Optimum design is a key approach to make full use of potential advantages of a parallel manipulator. The optimum design of multi-parameter parallel manipulators(more than three design parameters), such as Stewart manipulator, relies on analysis based and algorithm based optimum design methods, which fall to be accurate or intuitive. To solve this problem and achieve both accurate and intuition, atlas based optimum design of a general Stewart parallel manipulator is established, with rational selection of design parameters. Based on the defined spherical usable workspace(SUW), primary kinematic performance indices of the Stewart manipulator, involving workspace and condition number are introduced and analyzed. Then, corresponding performance atlases are drawn with the established non-dimensional design space, and impact of joint distribution angles on the manipulator performance is analyzed and illustrated. At last, an example on atlas based optimum design of the Stewart manipulator is accomplished to illustrate the optimum design process, considering the end-effector posture. Deduced atlases can be flexibly applied to both quantitative and qualitative analysis to get the desired optimal design for the Stewart manipulator with respect to related performance requirements. Besides, the established optimum design method can be further applied to other multi-parameter parallel manipulators.

  11. Atlas Based Kinematic Optimum Design of the Stewart Parallel Manipulator

    Institute of Scientific and Technical Information of China (English)

    SHAO Zhufeng; TANG Xiaoqiang; WANG Liping; SUN Dengfeng

    2015-01-01

    Optimum design is a key approach to make full use of potential advantages of a parallel manipulator. The optimum design of multi-parameter parallel manipulators(more than three design parameters), such as Stewart manipulator, relies on analysis based and algorithm based optimum design methods, which fall to be accurate or intuitive. To solve this problem and achieve both accurate and intuition, atlas based optimum design of a general Stewart parallel manipulator is established, with rational selection of design parameters. Based on the defined spherical usable workspace(SUW), primary kinematic performance indices of the Stewart manipulator, involving workspace and condition number are introduced and analyzed. Then, corresponding performance atlases are drawn with the established non-dimensional design space, and impact of joint distribution angles on the manipulator performance is analyzed and illustrated. At last, an example on atlas based optimum design of the Stewart manipulator is accomplished to illustrate the optimum design process, considering the end-effector posture. Deduced atlases can be flexibly applied to both quantitative and qualitative analysis to get the desired optimal design for the Stewart manipulator with respect to related performance requirements. Besides, the established optimum design method can be further applied to other multi-parameter parallel manipulators.

  12. TRIGGER

    CERN Multimedia

    J. Alimena

    2013-01-01

    Trigger Strategy Group The Strategy for Trigger Evolution And Monitoring (STEAM) group is responsible for the development of future High-Level Trigger menus, as well as of its DQM and validation, in collaboration and with the technical support of the PdmV group. Taking into account the beam energy and luminosity expected in 2015, a rough estimate of the trigger rates indicates a factor four increase with respect to 2012 conditions. Assuming that a factor two can be tolerated thanks to the increase in offline storage and processing capabilities, a toy menu has been developed using the new OpenHLT workflow to estimate the transverse energy/momentum thresholds that would halve the current trigger rates. The CPU time needed to run the HLT has been compared between data taken with 25 ns and 50 ns bunch spacing, for equivalent pile-up: no significant difference was observed on the global time per event distribution at the only available data point, corresponding to a pile-up of about 10 interactions. Using th...

  13. TRIGGER

    CERN Multimedia

    by Wesley Smith

    2011-01-01

    Level-1 Trigger Hardware and Software After the winter shutdown minor hardware problems in several subsystems appeared and were corrected. A reassessment of the overall latency has been made. In the TTC system shorter cables between TTCci and TTCex have been installed, which saved one bunch crossing, but which may have required an adjustment of the RPC timing. In order to tackle Pixel out-of-syncs without influencing other subsystems, a special hardware/firmware re-sync protocol has been introduced in the Global Trigger. The link between the Global Calorimeter Trigger and the Global Trigger with the new optical Global Trigger Interface and optical receiver daughterboards has been successfully tested in the Electronics Integration Centre in building 904. New firmware in the GCT now allows a setting to remove the HF towers from energy sums. The HF sleeves have been replaced, which should lead to reduced rates of anomalous signals, which may allow their inclusion after this is validated. For ECAL, improvements i...

  14. Design, Results, Evolution and Status of the ATLAS Simulation at Point1 Project

    Science.gov (United States)

    Ballestrero, S.; Batraneanu, S. M.; Brasolin, F.; Contescu, C.; Fazio, D.; Di Girolamo, A.; Lee, C. J.; Pozo Astigarraga, M. E.; Scannicchio, D. A.; Sedov, A.; Twomey, M. S.; Wang, F.; Zaytsev, A.

    2015-12-01

    During the LHC Long Shutdown 1 (LSI) period, that started in 2013, the Simulation at Point1 (Sim@P1) project takes advantage, in an opportunistic way, of the TDAQ (Trigger and Data Acquisition) HLT (High-Level Trigger) farm of the ATLAS experiment. This farm provides more than 1300 compute nodes, which are particularly suited for running event generation and Monte Carlo production jobs that are mostly CPU and not I/O bound. It is capable of running up to 2700 Virtual Machines (VMs) each with 8 CPU cores, for a total of up to 22000 parallel jobs. This contribution gives a review of the design, the results, and the evolution of the Sim@P1 project, operating a large scale OpenStack based virtualized platform deployed on top of the ATLAS TDAQ HLT farm computing resources. During LS1, Sim@P1 was one of the most productive ATLAS sites: it delivered more than 33 million CPU-hours and it generated more than 1.1 billion Monte Carlo events. The design aspects are presented: the virtualization platform exploited by Sim@P1 avoids interferences with TDAQ operations and it guarantees the security and the usability of the ATLAS private network. The cloud mechanism allows the separation of the needed support on both infrastructural (hardware, virtualization layer) and logical (Grid site support) levels. This paper focuses on the operational aspects of such a large system during the upcoming LHC Run 2 period: simple, reliable, and efficient tools are needed to quickly switch from Sim@P1 to TDAQ mode and back, to exploit the resources when they are not used for the data acquisition, even for short periods. The evolution of the central OpenStack infrastructure is described, as it was upgraded from Folsom to the Icehouse release, including the scalability issues addressed.

  15. The ATLAS Hadronic Tau Trigger Initial Run-2 Strategy and Performance

    CERN Document Server

    Pickering, Mark Andrew; The ATLAS collaboration

    2015-01-01

    As proton-proton collisions at the LHC reach instantaneous luminosities of over 10^34cm^ -2s-1, the strategies for triggering have become more important than ever for physics analyses. In these conditions single tau lepton triggers suffer from severe rate limitations, despite the sophisticated algorithms used in the tau identification. The development of further fast algorithms and the design of topological selections are the main challenges to allow a large program of physics analysis. The tau triggers provide many opportunities to study new physics beyond the Standard Model, and to get precise measurements of the properties of the Higgs boson decaying to tau-leptons. One of the major challenges is to sustain high efficiencies in events with multiple interactions. To do this we utilised faster tracking methods, multivariate selection techniques. In Run II topological criteria can now be applied already at the first trigger level, due to the addition of the L1 topological. This makes it possible to use detail...

  16. TRIGGER

    CERN Multimedia

    W. Smith

    Level-1 Trigger Hardware The CERN group is working on the TTC system. Seven out of nine sub-detector TTC VME crates with all fibers cabled are installed in USC55. 17 Local Trigger Controller (LTC) boards have been received from production and are in the process of being tested. The RF2TTC module replacing the TTCmi machine interface has been delivered and will replace the TTCci module used to mimic the LHC clock. 11 out of 12 crates housing the barrel ECAL off-detector electronics have been installed in USC55 after commissioning at the Electronics Integration Centre in building 904. The cabling to the Regional Calorimeter Trigger (RCT) is terminated. The Lisbon group has completed the Synchronization and Link mezzanine board (SLB) production. The Palaiseau group has fully tested and installed 33 out of 40 Trigger Concentrator Cards (TCC). The seven remaining boards are being remade. The barrel TCC boards have been tested at the H4 test beam, and good agreement with emulator predictions were found. The cons...

  17. Upgrade of the First Level Muon Trigger in the End-Cap New Small Wheel Region of the ATLAS Detector

    CERN Document Server

    Munwes, Y; The ATLAS collaboration

    2013-01-01

    The luminosity levels foreseen at the LHC after the 2018 LHC upgrade will tighten the demands on the ATLAS first level muon trigger system. A finer muon selection will be required to cope with the increased background and to keep the trigger rate for 20GeV/c pT muons as before. The introduction of new detectors in the small wheel region of the end-cap muon spectrometer will allow to refine the current trigger selection, allowing to increase the rejection power for tracks not coming from the interaction point, thus to find candidate muon tracks within 1 mrad angular resolution and within the 500 ns available latency. The on-detector trigger logic will require a coincidence of eight layers of sTGC detector pads to determine the trigger regions-of-interest. The charge information from the detector strips of the selected regions-of-interest will be sent to the off-detector trigger logic, which will calculate the strip centroids and extrapolate the muon tracks. The muon tracks information will be finally sent to t...

  18. Implementation and Performance of the High Level Trigger Electron and Photon Selection for the ATLAS Experiment at the LHC

    CERN Document Server

    Schiavi, C; Dos Anjos, A; Baines, J T M; Bee, C P; Biglietti, M; Bogaerts, J A C; Boisvert, V; Bosman, M; Caron, B; Casado, M P; Cataldi, G; Cavalli, D; Cervetto, M; Comune, G; Conde-Muíño, P; De Santo, A; Díaz-Gómez, M; Dosil, M; Ellis, Nick; Emeliyanov, D; Epp, B; Falciano, S; Farilla, A; George, S; Ghete, V M; González, S; Grothe, M; Kabana, S; Khomich, A; Kilvington, G; Konstantinidis, N P; Kootz, A; Lowe, A; Luminari, L; Maeno, T; Masik, J; Di Mattia, A; Meessen, C; Mello, A G; Merino, G; Moore, R; Morettini, P; Negri, A; Nikitin, N; Nisati, A; Padilla, C; Panikashvili, N; Parodi, F; Pérez-Réale, V; Pinfold, J L; Pinto, P; Qiand, Z; Resconi, S; Rosati, S; Sánchez, C; Santamarina-Rios, C; Scannicchio, D A; Segura, E; De Seixas, J M; Sivoklokov, S Yu; Soluk, R A; Stefanidis, E; Sushkov, S; Sutton, M; Tapprogge, S; Thomas, E; Touchard, F; Venda-Pinto, B; Ventura, A; Vercesi, V; Werner, P; Wheeler, S; Wickens, F J; Wiedenmann, W; Wielers, M; Zobernig, G; 2004 IEEE Nuclear Science Symposium And Medical Imaging Conference

    2005-01-01

    The ATLAS experiment at the Large Hadron Collider (LHC) will face the challenge of efficiently selecting interesting candidate events in pp collisions at 14 TeV center of mass energy, while rejecting the enormous number of background events, stemming from an interaction rate of up to 10^9 Hz. The First Level trigger will reduce this rate to around O(100 kHz). Subsequently, the High Level Trigger (HLT), which is comprised of the Second Level trigger and the Event Filter, will need to further reduce this rate by a factor of O(10^3). The HLT selection is software based and will be implemented on commercial CPUs, using a common framework built on the standard ATLAS object oriented software architecture. In this paper an overview of the current implementation of the selection for electrons and photons in the HLT is given. The performance of this implementation has been evaluated using Monte Carlo simulations in terms of the efficiency for the signal channels, rate expected for the selection, data preparation times...

  19. Laser-trigger system design for PBFA II

    International Nuclear Information System (INIS)

    A revolutionary design for triggering a multitude of high-voltage gas switches is in the process of being implemented and tested at Sandia National Laboratories. This new laser triggering system for PBFA II consists of five major subsystems. The first subsystem is a KrF laser which injects as much as 4 J of uv radiation into the optical train. The second subsystem is the optical train consisting of over 300 optical components that split the laser beam into 36 equal uv beamlets which are respectively directed into the trigger section of the PBFA-II gas switches. The third, the alignment system, provides a convenient, reliable, low-cost method of sensing the degree of alignment of the KrF laser with respect to the high-voltage switches. The fourth subsystem is the mechanical assembly supporting and containing the optical components in a low vibration, environmentally controlled manner. The fifth subsystem is control and diagnostics. These five subsystems act in concert to provide a low-maintenance triggering system which is reliable, repeatable, repeatable in performance, and will fire the 36, 5.5-MW, PBFA-II switches with a total firing spread first to last of 4 ns

  20. ATLAS

    CERN Multimedia

    Akhnazarov, V; Canepa, A; Bremer, J; Burckhart, H; Cattai, A; Voss, R; Hervas, L; Kaplon, J; Nessi, M; Werner, P; Ten kate, H; Tyrvainen, H; Vandelli, W; Krasznahorkay, A; Gray, H; Alvarez gonzalez, B; Eifert, T F; Rolando, G; Oide, H; Barak, L; Glatzer, J; Backhaus, M; Schaefer, D M; Maciejewski, J P; Milic, A; Jin, S; Von torne, E; Limbach, C; Medinnis, M J; Gregor, I; Levonian, S; Schmitt, S; Waananen, A; Monnier, E; Muanza, S G; Pralavorio, P; Talby, M; Tiouchichine, E; Tocut, V M; Rybkin, G; Wang, S; Lacour, D; Laforge, B; Ocariz, J H; Bertoli, W; Malaescu, B; Sbarra, C; Yamamoto, A; Sasaki, O; Koriki, T; Hara, K; Da silva gomes, A; Carvalho maneira, J; Marcalo da palma, A; Chekulaev, S; Tikhomirov, V; Snesarev, A; Buzykaev, A; Maslennikov, A; Peleganchuk, S; Sukharev, A; Kaplan, B E; Swiatlowski, M J; Nef, P D; Schnoor, U; Oakham, G F; Ueno, R; Orr, R S; Abouzeid, O; Haug, S; Peng, H; Kus, V; Vitek, M; Temming, K K; Dang, N P; Meier, K; Schultz-coulon, H; Geisler, M P; Sander, H; 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Ferrari, A; Abdinov, O; Akhoundov, A; Hashimov, R; Shelkov, G; Khubua, J; Ladygin, E; Lazarev, A; Glagolev, V; Dedovich, D; Lykasov, G; Zhemchugov, A; Zolnikov, Y; Ryabenko, M; Sivoklokov, S; Vasilyev, I; Shalimov, A; Lobanov, M; Paramoshkina, E; Mosidze, M; Bingul, A; Nodulman, L J; Guarino, V J; Yoshida, R; Drake, G R; Calafiura, P; Haber, C; Quarrie, D R; Alonso, J R; Anderson, C; Evans, H; Lammers, S W; Baubock, M; Anderson, K; Petti, R; Suhr, C A; Linnemann, J T; Richards, R A; Tollefson, K A; Holzbauer, J L; Stoker, D P; Pier, S; Nelson, A J; Isakov, V; Martin, A J; Adelman, J A; Paganini, M; Gutierrez, P; Snow, J M; Pearson, B L; Cleland, W E; Savinov, V; Wong, W; Goodson, J J; Li, H; Lacey, R A; Gordeev, A; Gordon, H; Lanni, F; Nevski, P; Rescia, S; Kierstead, J A; Liu, Z; Yu, W W H; Bensinger, J; Hashemi, K S; Bogavac, D; Cindro, V; Hoeferkamp, M R; Coelli, S; Iodice, M; Piegaia, R N; Alonso, F; Wahlberg, H P; Barberio, E L; Limosani, A; Rodd, N L; Jennens, D T; Hill, E C; Pospisil, S; 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Shupe, M A; Wolin, S; Oshita, H; Gaudio, G; Das, R; Konig, A C; Croft, V A; Harvey, A; Maaroufi, F; Melo, I; Greenwood jr, Z D; Shabalina, E; Mchedlidze, G; Drechsler, E; Rieger, J K; Blackston, M; Colombo, T

    2002-01-01

    % ATLAS \\\\ \\\\ ATLAS is a general-purpose experiment for recording proton-proton collisions at LHC. The ATLAS collaboration consists of 144 participating institutions (June 1998) with more than 1750~physicists and engineers (700 from non-Member States). The detector design has been optimized to cover the largest possible range of LHC physics: searches for Higgs bosons and alternative schemes for the spontaneous symmetry-breaking mechanism; searches for supersymmetric particles, new gauge bosons, leptoquarks, and quark and lepton compositeness indicating extensions to the Standard Model and new physics beyond it; studies of the origin of CP violation via high-precision measurements of CP-violating B-decays; high-precision measurements of the third quark family such as the top-quark mass and decay properties, rare decays of B-hadrons, spectroscopy of rare B-hadrons, and $ B ^0 _{s} $-mixing. \\\\ \\\\The ATLAS dectector, shown in the Figure includes an inner tracking detector inside a 2~T~solenoid providing an axial...

  1. Design and Performance of the Virtualization Platform for Offline computing on the ATLAS TDAQ Farm

    CERN Document Server

    Ballestrero, S; The ATLAS collaboration; Brasolin, F; Contescu, C; Di Girolamo, A; Lee, C J; Pozo Astigarraga, M E; Scannicchio, D A; Twomey, M S; Zaytsev, A

    2014-01-01

    With the LHC collider at CERN currently going through the period of Long Shutdown 1 (LS1) there is a remarkable opportunity to use the computing resources of the large trigger farms of the experiments for other data processing activities. In the case of ATLAS experiment the TDAQ farm, consisting of more than 1500 compute nodes, is particularly suitable for running Monte Carlo production jobs that are mostly CPU and not I/O bound. This contribution gives a thorough review of all the stages of Sim@P1 project dedicated to the design and deployment of a virtualized platform running on the ATLAS TDAQ computing resources and using it to run the large groups of CernVM based virtual machines operating as a single CERN-P1 WLCG site. This platform has been designed to avoid interference with TDAQ usage of the farm and to guarantee the security and the usability of the ATLAS private network; Openstack has been chosen to provide a cloud management layer. The approaches to organizing support for the sustained operation of...

  2. Design and Performance of the Virtualization Platform for Offline computing on the ATLAS TDAQ Farm

    CERN Document Server

    Ballestrero, S; The ATLAS collaboration; Brasolin, F; Contescu, C; Di Girolamo, A; Lee, C J; Pozo Astigarraga, M E; Scannicchio, D A; Twomey, M S; Zaytsev, A

    2013-01-01

    With the LHC collider at CERN currently going through the period of Long Shutdown 1 (LS1) there is a remarkable opportunity to use the computing resources of the large trigger farms of the experiments for other data processing activities. In the case of ATLAS experiment the TDAQ farm, consisting of more than 1500 compute nodes, is particularly suitable for running Monte Carlo production jobs that are mostly CPU and not I/O bound. This contribution gives a thorough review of all the stages of Sim@P1 project dedicated to the design and deployment of a virtualized platform running on the ATLAS TDAQ computing resources and using it to run the large groups of CernVM based virtual machines operating as a single CERN-P1 WLCG site. This platform has been designed to avoid interference with TDAQ usage of the farm and to guarantee the security and the usability of the ATLAS private network; Openstack has been chosen to provide a cloud management layer. The approaches to organizing support for the sustained operation of...

  3. Design and performance of the virtualization platform for offline computing on the ATLAS TDAQ Farm

    Science.gov (United States)

    Ballestrero, S.; Batraneanu, S. M.; Brasolin, F.; Contescu, C.; Di Girolamo, A.; Lee, C. J.; Pozo Astigarraga, M. E.; Scannicchio, D. A.; Twomey, M. S.; Zaytsev, A.

    2014-06-01

    With the LHC collider at CERN currently going through the period of Long Shutdown 1 there is an opportunity to use the computing resources of the experiments' large trigger farms for other data processing activities. In the case of the ATLAS experiment, the TDAQ farm, consisting of more than 1500 compute nodes, is suitable for running Monte Carlo (MC) production jobs that are mostly CPU and not I/O bound. This contribution gives a thorough review of the design and deployment of a virtualized platform running on this computing resource and of its use to run large groups of CernVM based virtual machines operating as a single CERN-P1 WLCG site. This platform has been designed to guarantee the security and the usability of the ATLAS private network, and to minimize interference with TDAQ's usage of the farm. Openstack has been chosen to provide a cloud management layer. The experience gained in the last 3.5 months shows that the use of the TDAQ farm for the MC simulation contributes to the ATLAS data processing at the level of a large Tier-1 WLCG site, despite the opportunistic nature of the underlying computing resources being used.

  4. Design, Results, Evolution and Status of the ATLAS simulation in Point1 project.

    CERN Document Server

    Ballestrero, Sergio; The ATLAS collaboration; Brasolin, Franco; Contescu, Alexandru Cristian; Fazio, Daniel; Di Girolamo, Alessandro; Lee, Christopher Jon; Pozo Astigarraga, Mikel Eukeni; Scannicchio, Diana; Sedov, Alexey; Twomey, Matthew Shaun; Wang, Fuquan; Zaytsev, Alexander

    2015-01-01

    During the LHC long shutdown period (LS1), that started in 2013, the simulation in Point1 (Sim@P1) project takes advantage in an opportunistic way of the trigger and data acquisition (TDAQ) farm of the ATLAS experiment. The farm provides more than 1500 computer nodes, and they are particularly suitable for running event generation and Monte Carlo production jobs that are mostly CPU and not I/O bound. It is capable of running up to 2500 virtual machines (VM) provided with 8 CPU cores each, for a total of up to 20000 parallel running jobs. This contribution gives a thorough review of the design, the results and the evolution of the Sim@P1 project operating a large scale Openstack based virtualized platform deployed on top of the ATLAS TDAQ farm computing resources. During LS1, Sim@P1 was one of the most productive GRID sites: it delivered more than 50 million CPU-hours and it generated more than 1.7 billion Monte Carlo events to various analysis communities within the ATLAS collaboration. The particular design ...

  5. A compact pre-processor system for the ATLAS level-1 calorimeter trigger

    CERN Document Server

    Pfeiffer, U

    1999-01-01

    This thesis describ es the researc h whose aim is to dev elop a compact Pre-Pro cessor system for the A TLAS Lev el-1 Calorimeter T rigger. Con tributions to the p erformance and the arc hitecture of the Pre-Pro cessor w ere made. A demonstrator Multi-Chip Mo dule (PPrD- MCM) w as dev elop ed and assem bled whic h p erforms most of the prepro cessing of four analogue trigger-to w er signals. The prepro cessing includes digitisation to 8-bit precision, iden ti cation of the corresp onding bunc h-crossing in time (BCID), calibration of the transv erse energy , readout of ra w trigger data, and high-sp eed serial data transmission to the trigger pro cessors. The demonstrator Multi-Chip Mo dule has a size of 15.9 cm 2 and it consists of 9 dies. The MCM w as designed with a smallest feature size of 100 m and it w as fabricated in a laminated MCM-L pro cess o ered b yW urth Elektronik. A Flip-Chip in terconnection ASIC (Finco) w as dev elop ed for the PPrD-MCM and fabricated in a 0.8 m BiCMOS- pro cess o ered b ...

  6. Use of expert system and data analysis technologies in automation of error detection, diagnosis and recovery for ATLAS Trigger-DAQ Controls framework

    CERN Document Server

    Kazarov, A; The ATLAS collaboration; Magnoni, L; Lehmann Miotto, G

    2012-01-01

    Trigger and DAQ (Data AQuisition) System of the ATLAS experiment on LHC at CERN is a very complex distributed computing system, composed of O(10000) applications running on a farm of commodity CPUs. The system is being designed and developed by dozens of software engineers and physicists since end of 1990's and it will be maintained in operational mode during the lifetime of the experiment. The TDAQ system is controlled by the Controls framework, which includes a set of software components and tools used for system configuration, distributed processes handling, synchronization of Run Control state transitions etc. The huge flow of operational monitoring data produced is constantly monitored by operators and experts in order to detect problems or misbehaviour. Given the scale of the system and the rates of data to be analyzed, the automation of the Controls framework functionality in the areas of operational monitoring, system verification, error detection and recovery is a strong requirement. The paper descri...

  7. Performance of the Demonstrator System for the Phase-I Upgrade of the Trigger Readout Electronics of the ATLAS Liquid Argon Calorimeters

    International Nuclear Information System (INIS)

    For the Phase-I luminosity upgrade of the LHC a higher granularity trigger readout of the ATLAS LAr Calorimeters is foreseen to enhance the trigger feature extraction and background rejection. The new readout system digitizes the detector signals, which are grouped into 34000 so-called Super Cells, with 12 bit precision at 40 MHz and transfers the data on optical links to the digital processing system, which extracts the Super Cell energies. A demonstrator version of the complete system has now been installed and operated on the ATLAS detector. Results from the commissioning and performance measurements are reported

  8. Performance of the ATLAS muon trigger in pp collisions at $\\sqrt{s}=$8 TeV

    CERN Document Server

    Aad, Georges; Abdallah, Jalal; Abdel Khalek, Samah; Abdinov, Ovsat; Aben, Rosemarie; Abi, Babak; Abolins, Maris; AbouZeid, Ossama; Abramowicz, Halina; Abreu, Henso; Abreu, Ricardo; Abulaiti, Yiming; Acharya, Bobby Samir; Adamczyk, Leszek; Adams, David; Adelman, Jahred; Adomeit, Stefanie; Adye, Tim; Agatonovic-Jovin, Tatjana; Aguilar-Saavedra, Juan Antonio; Agustoni, Marco; Ahlen, Steven; Ahmadov, Faig; Aielli, Giulio; Akerstedt, Henrik; Åkesson, Torsten Paul Ake; Akimoto, Ginga; Akimov, Andrei; Alberghi, Gian Luigi; Albert, Justin; Albrand, Solveig; Alconada Verzini, Maria Josefina; Aleksa, Martin; Aleksandrov, Igor; Alexa, Calin; Alexander, Gideon; Alexandre, Gauthier; Alexopoulos, Theodoros; Alhroob, Muhammad; Alimonti, Gianluca; Alio, Lion; Alison, John; Allbrooke, Benedict; Allison, Lee John; Allport, Phillip; Almond, John; Aloisio, Alberto; Alonso, Alejandro; Alonso, Francisco; Alpigiani, Cristiano; Altheimer, Andrew David; Alvarez Gonzalez, Barbara; Alviggi, Mariagrazia; Amako, Katsuya; Amaral Coutinho, Yara; Amelung, Christoph; Amidei, Dante; Amor Dos Santos, Susana Patricia; Amorim, Antonio; Amoroso, Simone; Amram, Nir; Amundsen, Glenn; Anastopoulos, Christos; Ancu, Lucian Stefan; Andari, Nansi; Andeen, Timothy; Anders, Christoph Falk; Anders, Gabriel; Anderson, Kelby; Andreazza, Attilio; Andrei, George Victor; Anduaga, Xabier; Angelidakis, Stylianos; Angelozzi, Ivan; Anger, Philipp; Angerami, Aaron; Anghinolfi, Francis; Anisenkov, Alexey; Anjos, Nuno; Annovi, Alberto; Antonaki, Ariadni; Antonelli, Mario; Antonov, Alexey; Antos, Jaroslav; Anulli, Fabio; Aoki, Masato; Aperio Bella, Ludovica; Apolle, Rudi; Arabidze, Giorgi; Aracena, Ignacio; Arai, Yasuo; Araque, Juan Pedro; Arce, Ayana; Arguin, Jean-Francois; Argyropoulos, Spyridon; Arik, Metin; Armbruster, Aaron James; Arnaez, Olivier; Arnal, Vanessa; Arnold, Hannah; Arratia, Miguel; Arslan, Ozan; Artamonov, Andrei; Artoni, Giacomo; Asai, Shoji; Asbah, Nedaa; Ashkenazi, Adi; Åsman, Barbro; Asquith, Lily; Assamagan, Ketevi; Astalos, Robert; Atkinson, Markus; Atlay, Naim Bora; Auerbach, Benjamin; Augsten, Kamil; Aurousseau, Mathieu; Avolio, Giuseppe; Azuelos, Georges; Azuma, Yuya; Baak, Max; Bacci, Cesare; Bachacou, Henri; Bachas, Konstantinos; Backes, Moritz; Backhaus, Malte; Backus Mayes, John; Badescu, Elisabeta; Bagiacchi, Paolo; Bagnaia, Paolo; Bai, Yu; Bain, Travis; Baines, John; Baker, Oliver Keith; Baker, Sarah; Balek, Petr; Balli, Fabrice; Banas, Elzbieta; Banerjee, Swagato; Bannoura, Arwa A E; Bansal, Vikas; Bansil, Hardeep Singh; Barak, Liron; Baranov, Sergei; Barberio, Elisabetta Luigia; Barberis, Dario; Barbero, Marlon; Barillari, Teresa; Barisonzi, Marcello; Barklow, Timothy; Barlow, Nick; Barnett, Bruce; Barnett, Michael; Barnovska, Zuzana; Baroncelli, Antonio; Barone, Gaetano; Barr, Alan; Barreiro, Fernando; Barreiro Guimarães da Costa, João; Bartoldus, Rainer; Barton, Adam Edward; Bartos, Pavol; Bartsch, Valeria; Bassalat, Ahmed; Basye, Austin; Bates, Richard; Batkova, Lucia; Batley, Richard; Battaglia, Marco; Battistin, Michele; Bauer, Florian; Bawa, Harinder Singh; Beau, Tristan; Beauchemin, Pierre-Hugues; Beccherle, Roberto; Bechtle, Philip; Beck, Hans Peter; Becker, Anne Kathrin; Becker, Sebastian; Beckingham, Matthew; Becot, Cyril; Beddall, Andrew; Beddall, Ayda; Bedikian, Sourpouhi; Bednyakov, Vadim; Bee, Christopher; Beemster, Lars; Beermann, Thomas; Begel, Michael; Behr, Katharina; Belanger-Champagne, Camille; Bell, Paul; Bell, William; Bella, Gideon; Bellagamba, Lorenzo; Bellerive, Alain; Bellomo, Massimiliano; Belotskiy, Konstantin; Beltramello, Olga; Benary, Odette; Benchekroun, Driss; Bendtz, Katarina; Benekos, Nektarios; Benhammou, Yan; Benhar Noccioli, Eleonora; Benitez Garcia, Jorge-Armando; Benjamin, Douglas; Bensinger, James; Benslama, Kamal; Bentvelsen, Stan; Berge, David; Bergeaas Kuutmann, Elin; Berger, Nicolas; Berghaus, Frank; Berglund, Elina; Beringer, Jürg; Bernard, Clare; Bernat, Pauline; Bernius, Catrin; Bernlochner, Florian Urs; Berry, Tracey; Berta, Peter; Bertella, Claudia; Bertoli, Gabriele; Bertolucci, Federico; Bertsche, David; Besana, Maria Ilaria; Besjes, Geert-Jan; Bessidskaia, Olga; Bessner, Martin Florian; Besson, Nathalie; Betancourt, Christopher; Bethke, Siegfried; Bhimji, Wahid; Bianchi, Riccardo-Maria; Bianchini, Louis; Bianco, Michele; Biebel, Otmar; Bieniek, Stephen Paul; Bierwagen, Katharina; Biesiada, Jed; Biglietti, Michela; Bilbao De Mendizabal, Javier; Bilokon, Halina; Bindi, Marcello; Binet, Sebastien; Bingul, Ahmet; Bini, Cesare; Black, Curtis; Black, James; Black, Kevin; Blackburn, Daniel; Blair, Robert; Blanchard, Jean-Baptiste; Blazek, Tomas; Bloch, Ingo; Blocker, Craig; Blum, Walter; Blumenschein, Ulrike; Bobbink, Gerjan; Bobrovnikov, Victor; Bocchetta, Simona Serena; Bocci, Andrea; Bock, Christopher; Boddy, Christopher Richard; Boehler, Michael; Boek, Jennifer; Boek, Thorsten Tobias; Bogaerts, Joannes Andreas; Bogdanchikov, Alexander; Bogouch, Andrei; Bohm, Christian; Bohm, Jan; Boisvert, Veronique; Bold, Tomasz; Boldea, Venera; Boldyrev, Alexey; Bomben, Marco; Bona, Marcella; Boonekamp, Maarten; Borisov, Anatoly; Borissov, Guennadi; Borri, Marcello; Borroni, Sara; Bortfeldt, Jonathan; Bortolotto, Valerio; Bos, Kors; Boscherini, Davide; Bosman, Martine; Boterenbrood, Hendrik; Boudreau, Joseph; Bouffard, Julian; Bouhova-Thacker, Evelina Vassileva; Boumediene, Djamel Eddine; Bourdarios, Claire; Bousson, Nicolas; Boutouil, Sara; Boveia, Antonio; Boyd, James; Boyko, Igor; Bozovic-Jelisavcic, Ivanka; Bracinik, Juraj; Brandt, Andrew; Brandt, Gerhard; Brandt, Oleg; Bratzler, Uwe; Brau, Benjamin; Brau, James; Braun, Helmut; Brazzale, Simone Federico; Brelier, Bertrand; Brendlinger, Kurt; Brennan, Amelia Jean; Brenner, Richard; Bressler, Shikma; Bristow, Kieran; Bristow, Timothy Michael; Britton, Dave; Brochu, Frederic; Brock, Ian; Brock, Raymond; Bromberg, Carl; Bronner, Johanna; Brooijmans, Gustaaf; Brooks, Timothy; Brooks, William; Brosamer, Jacquelyn; Brost, Elizabeth; Brown, Gareth; Brown, Jonathan; Bruckman de Renstrom, Pawel; Bruncko, Dusan; Bruneliere, Renaud; Brunet, Sylvie; Bruni, Alessia; Bruni, Graziano; Bruschi, Marco; Bryngemark, Lene; Buanes, Trygve; Buat, Quentin; Bucci, Francesca; Buchholz, Peter; Buckingham, Ryan; Buckley, Andrew; Buda, Stelian Ioan; Budagov, Ioulian; Buehrer, Felix; Bugge, Lars; Bugge, Magnar Kopangen; Bulekov, Oleg; Bundock, Aaron Colin; Burckhart, Helfried; Burdin, Sergey; Burghgrave, Blake; Burke, Stephen; Burmeister, Ingo; Busato, Emmanuel; Büscher, Daniel; Büscher, Volker; Bussey, Peter; Buszello, Claus-Peter; Butler, Bart; Butler, John; Butt, Aatif Imtiaz; Buttar, Craig; Butterworth, Jonathan; Butti, Pierfrancesco; Buttinger, William; Buzatu, Adrian; Byszewski, Marcin; Cabrera Urbán, Susana; Caforio, Davide; Cakir, Orhan; Calafiura, Paolo; Calandri, Alessandro; Calderini, Giovanni; Calfayan, Philippe; Calkins, Robert; Caloba, Luiz; Calvet, David; Calvet, Samuel; Camacho Toro, Reina; Camarda, Stefano; Cameron, David; Caminada, Lea Michaela; Caminal Armadans, Roger; Campana, Simone; Campanelli, Mario; Campoverde, Angel; Canale, Vincenzo; Canepa, Anadi; Cano Bret, Marc; Cantero, Josu; Cantrill, Robert; Cao, Tingting; Capeans Garrido, Maria Del Mar; Caprini, Irinel; Caprini, Mihai; Capua, Marcella; Caputo, Regina; Cardarelli, Roberto; Carli, Tancredi; Carlino, Gianpaolo; Carminati, Leonardo; Caron, Sascha; Carquin, Edson; Carrillo-Montoya, German D; Carter, Janet; Carvalho, João; Casadei, Diego; Casado, Maria Pilar; Casolino, Mirkoantonio; Castaneda-Miranda, Elizabeth; Castelli, Angelantonio; Castillo Gimenez, Victoria; Castro, Nuno Filipe; Catastini