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تسجيل مستخدم جديدThe ATLAS Trigger System Commissioning and Performance
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A. Hamilton
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The ATLAS trigger has been used very successfully to collect collision data during 2009 and 2010 LHC running at centre of mass energies of 900 GeV, 2.36 TeV, and 7 TeV. This paper presents the ongoing work to commission the ATLAS trigger with proton collisions, including an overview of the performance of the trigger based on extensive online running. We describe how the trigger has evolved with increasing LHC luminosity and give a brief overview of plans for forthcoming LHC running.
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Since the start-up of the LHC end of 2009, the trigger commissioning is in full swing. The ATLAS trigger system is divided into three levels: the hardware-based first level trigger, and the software-based second level trigger and Event Filter, collec
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The ATLAS detector at CERNs Large Hadron Collider will be exposed to proton-proton collisions from beams crossing at 40 MHz that have to be reduced to the few 100 Hz allowed by the storage systems. A three-level trigger system has been designed to ac
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larity readout using a new system of Feature EXtractors (FEX), which each reconstruct different physics objects for the trigger selection. The jet FEX (jFEX) system is conceived to provide jet identification (including large area jets) and measurements of global variables within a latency budget of less then 400ns. It consists of 6 modules. A single jFEX module is an ATCA board with 4 large FPGAs of the Xilinx Ultrascale+ family, that can digest a total input data rate of ~3.6 Tb/s using up to 120 Multi Gigabit Transceiver (MGT), 24 electrical optical devices, board control and power on the mezzanines to allow flexibility in upgrading controls functions and components without affecting the main board. The 24-layers stack-up was carefully designed to preserve the signal integrity in a very densely populated high speed signal board selecting MEGTRON6 as the most suitable PCB material. This contribution reports on the design challenges and the test results of the jFEX prototypes. In particular the fully assembled final prototype has been tested up to 12.8 Gb/s in house and in integrated tests at CERN. The full jFEX system will be produced by the end of 2018 to allow for installation and commissioning to be completed before LHC restarts in March 2021.
This article documents the characteristics of the high voltage (HV) system of the hadronic calorimeter TileCal of the ATLAS experiment. Such a system is suitable to supply reliable power distribution into particles physics detectors using a large num
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The MEG experiment at the Paul Scherrer Institut (PSI) represents the state of the art in the search for the charged Lepton Flavour Violating (cLFV) $mu^+ rightarrow e^+ gamma$ decay. With the phase 1, MEG set the new world best upper limit on the $m
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