CentOS Linux for the ATLAS MUCTPI Upgrade Spiwoks, R.; Armbruster, A.; Czodrowski, P. ...
IEEE transactions on nuclear science,
08/2021, Letnik:
68, Številka:
8
Journal Article
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A new Muon-to-Central-Trigger Processor Interface (MUCTPI) was built as part of the upgrade of the ATLAS Level-1 trigger system for the next Run of the Large Hadron Collider at CERN. The MUCTPI has ...208 high-speed optical serial links for receiving muon candidates from the muon trigger detectors. Three high-end field-programmable gate arrays (FPGAs) are used for real-time processing of the muon candidates, for sending trigger information to other parts of the trigger system, and for sending summary information to the data acquisition and monitoring system. A System-on-Chip (SoC) is used for the control, configuration, and monitoring of the hardware and the operation of the MUCTPI. The SoC consists of an FPGA part and a processor system (PS). The FPGA part provides communication with the processing FPGAs, while the PS runs software for communication with the run-control system of the ATLAS experiment. In this article, we will describe our experience with running CentOS Linux on the SoC. Cross-compilation together with the existing framework for building the ATLAS trigger and data acquisition (TDAQ) software is being used in order to allow the deployment of the TDAQ software directly on the SoC.
Abstract
The Muon-to-Central Trigger Processor Interface was completely redesigned as part of the ATLAS Level-1 trigger upgrade for Run 3 of the Large Hadron Collider. The new system is implemented ...as a single AdvancedTCA module, using three large state-of-the-art FPGAs and high-density fiber-optic modules. Trigger information from the muon trigger detectors are received through 208 high speed links, while 60 links are used to send processed trigger information to the L1 Topological Trigger Processor and the Central Trigger Processor. Extensive integration tests with all input and output systems have shown that the data transfer is stable and reliable. We present results from integration tests with connected sub-systems as well as commissioning of the Muon-to-Central Trigger Processor Interface in the ATLAS experiment.
Abstract
The ATLAS trigger system includes a Level-1 (L1) trigger based on custom electronics and firmware, and a high-level software trigger running on off-the-shelf hardware. The L1 trigger system ...uses information from the forward detectors, the calorimeters and the muon trigger detectors. Once information from all muon trigger sectors has been received, trigger candidate multiplicities are calculated by the Muon-to-Central-Trigger-Processor Interface (MUCTPI). Muon multiplicity information is sent to the Central-Trigger-Processor (CTP) and trigger objects are sent to the L1 Topological Trigger Processor (L1Topo). The CTP combines the information received from the MUCTPI with the trigger information from the forward detectors, the calorimeters and the L1Topo, and takes the L1 trigger decision. As part of the ATLAS L1 trigger system upgrade for Run-3 of the Large Hadron Collider (LHC) a new MUCTPI has been designed and commissioned. We discuss the commissioning and operation of the new MUCTPI used in ATLAS from the beginning of Run-3. In particular, we describe the integration tests which have been carried out for the commissioning and operation of the new MUCTPI.
A synthetic single crystal diamond sample has been prepared with graphitic in bulk electrodes by laser induced graphitisation of diamond. A geometry with an array of electrodes has been fabricated to ...demonstrate the functionality of a “3D diamond detector” for ionising radiation. The detection capability has been studied with synchrotron radiation.
•Prototype 3D diamond detector•Graphitic micro-wires by laser graphitisation•Detector response mapped with a synchrotron micro-beam
The ATLAS Level-1 Central Trigger Processor (CTP) combines information from calorimeter and muon trigger processors as well as other sources and makes the final Level-1 Accept (L1A) decision. Due to ...the increasing luminosity of the LHC and the growing demands of physics and monitoring placed on the ATLAS Level-1 trigger system, the current CTP has reached its design limits. Therefore and in order to provide some margin for future operation, the CTP will be upgraded during the LHC shutdown of 2013/14.
The ATLAS Trigger and data acquisition system has been designed to use more than 2000 CPUs. During the current development stage it is crucial to test the system on a number of CPUs of similar scale. ...A dedicated farm of this size is difficult to find, and can only be made available for short periods. On the other hand many large farms have become available recently as part of computing grids, leading to the idea of using them to test the TDAQ system of ATLAS. However the task of adapting the TDAQ system to run on the Grid is not trivial, as it requires full access to the computing resources it runs on and real-time interaction. Moreover the Grid virtualises the resources to present a common interface to the user. We will describe the implementation and first tests of a scheme that resolves these issues using a pilot job mechanism. The Tier2 cluster in Manchester was successfully used to run a full TDAQ system on 400 nodes using this implementation. Apart from the tests described above, this scheme also has great potential for other applications, like running Grid remote farms to perform detector calibration and monitoring in real-time, and automatic nightly testing of the TDAQ system.
Results from the CMS and ATLAS Collaborations are presented on angular distributions in top quark decays. The studies presented here are based on proton-proton collisions at a center of mass energy ...of 7 TeV collected by the two experiments at the LHC in 2011. The angular distributions of the top quark decay products are used to probe several fundamental properties of the top quark and its couplings. The polarization of produced top quarks is investigated as well as the correlation of the spin of pair-produced top and anti-top quarks. The polarization states of the W-boson originating from the decay of the top quark are determined and used to constrain possible contributions of new physics processes to the W tb vertex.
In early 2012, the Large Hadron Collider (LHC) reached instantaneous luminosities of 6.7 times 10 super(33) cm super(-2)s super(-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 collision rate of up to 40MHz when operating with design parameters to a manageable event storage rate of about 400 Hz without discarding those events considered interesting. The Level-1 trigger is the first rate-reducing step in the ATLAS trigger and 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 centre of mass energy of up to 14 TeV, compared to the current 8 TeV, and the luminosity will exceed 10 super(34) cm super(-2)s super(-1). 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 a maximum of 100 kHz. To provide this added functionality, the Central Trigger Processor will be upgraded during the planned LHC shutdown that begins in 2013.
The ATLAS detector at CERN's LHC will be exposed to proton-proton collisions at a rate of 40 MHz. To reduce the data rate, only potentially interesting events are selected by a three-level trigger ...system. The first level is implemented in custom-made electronics, with an output rate to less than 100 kHz. The second and third level are software triggers with a final output rate of 100 to 200 Hz. A system has been designed and implemented that holds and records the full configuration information of all three trigger levels at a centrally maintained location. This system provides fast access to consistent configuration information of the online trigger system for the purpose of data taking as well as to all parts of the offline trigger simulation. The use of relational database technology provides a means of reliable recording of the trigger configuration history over the lifetime of the experiment. In addition to the online system, tools for flexible browsing and manipulation of trigger configurations, and for their distribution across the ATLAS reconstruction sites have been developed. The usability of this design has been demonstrated in dedicated configuration tests of the ATLAS level-1 Central Trigger and of a 600-node software trigger computing farm. Further tests on a computing cluster which is part of the final high level trigger system were also successful.
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