1,351 research outputs found
The CMS Level-1 Trigger Barrel Track Finder
No full textThe design and performance of the upgraded CMS Level-1 Trigger Barrel Muon Track Finder (BMTF) is presented. Monte Carlo simulation data as well as cosmic ray data from a CMS muon detector slice test have been used to study in detail the performance of the new track finder. The design architecture is based on twelve MP7 cards each of which uses a Xilinx Virtex-7 FPGA and can receive and transmit data at 10 Gbps from 72 input and 72 output fibers. According to the CMS Trigger Upgrade TDR the BMTF receives trigger primitive data which are computed using both RPC and DT data and transmits data from a number of muon candidates to the upgraded Global Muon Trigger. Results from detailed studies of comparisons between the BMTF algorithm results and the results of a C++ emulator are also presented. The new BMTF will be commissioned for data taking in 2016
The CMS Level-1 Trigger at LHC and Super-LHC
No full textThe Level-1 trigger of the CMS experiment at CERN has been designed to select proton-proton interactions whose final state includes signatures of new physics in the form of high transverse energy electrons, photons, jets, or high missing transverse energy. The Level-1 trigger system process data in a pipeline fashion at a rate of 40 MHz, has a design latency of 128 bunch crossings and an output rate of 100 KHz. The design of this system is presented with emphasis on the calorimeter triggers. After a long period of testing and validation of its performance the Level-1 trigger system has been installed and commissioned at the CMS experiment at CERN. Cosmic ray data and Monte Carlo events have been used to compare the actual performance of the trigger with expectations from off-line emulation models. Results from these studies are presented here. The limitations of this system to cope with future luminosity upgrades of the LHC, the Super-LHC, are discussed. The current CMS plan for a new CMS Level-1 trigger system at the Super-LHC is presented. The center point of the new system is a Level-1 tracking trigger which uses data from a new CMS silicon tracking detector
Performance studies of the CMS strip tracker before installation
No full textThis is the Pre-print version of the Article. The official published version can be accessed from the link below - Copyright @ 2009 IOPIn March 2007 the assembly of the Silicon Strip Tracker was completed at the Tracker Integration Facility at CERN. Nearly 15% of the detector was instrumented using cables, fiber optics, power supplies, and electronics intended for the operation at the LHC. A local chiller was used to circulate the coolant for low temperature operation. In order to understand the efficiency and alignment of the strip tracker modules, a cosmic ray trigger was implemented. From March through July 4.5 million triggers were recorded. This period, referred to as the Sector Test, provided practical experience with the operation of the Tracker, especially safety, data acquisition, power, and cooling systems. This paper describes the performance of the strip system during the Sector Test, which consisted of five distinct periods defined by the coolant temperature. Significant emphasis is placed on comparisons between the data and results from Monte Carlo studies.This work was supported by: the Austrian
Federal Ministry of Science and Research; the Belgium Fonds de la Recherche Scientifique and Fonds voorWetenschappelijk
Onderzoek; the Academy of Finland and Helsinki Institute of Physics; the Institut National de Physique Nucleaire et de Physique des Particules / CNRS, France; the Bundesministerium f¨ur Bildungund Forschung, Germany; the Istituto Nazionale di Fisica Nucleare, Italy; the Swiss Funding Agencies; the Science and Technology Facilities Council, UK; the US Department of Energy, and National Science Foundation. Individuals have received support from the Marie-Curie IEF program (European Union) and the A.P. Sloan Foundation
Observation of the Standard Model Higgs boson via lepton+jet Channel
No full textThe potential of observing the Standard Model Higgs boson with a mass below 150 GeVc^2 via the H -> tautau -> lepton+jet decay channel with Vector Boson Fusion production process has been evaluated using full simulation of the CMS detector. A number of background rejection methods based on the characteristics of the VBF process have been studied. It is shown that about 10 Higgs boson events are expected to be observed with a significance of 3.9 sigma (Higgs mass = 135 GeV/c^2) using an integrated luminosity of 30 fb^-1
The CMS Barrel Muon trigger upgrade
No full textThe increase of luminosity expected by LHC during Phase1 will impose tighter constraints for rate reduction in order to maintain high efficiency in the CMS Level1 trigger system. The TwinMux system is the early layer of the muon barrel region that concentrates the information from different subdetectors: Drift Tubes, Resistive Plate Chambers and Outer Hadron Calorimeter. It arranges the slow optical trigger links from the detector chambers into faster links (10 Gbps) that are sent in multiple copies to the track finders. Results from collision runs, that confirm the satisfactory operation of the trigger system up to the output of the barrel track finder, will be shown
Stacked Tracking for CMS at Super-LHC
No full textWe report recent work on the design of a pixel detector for CMS at the Super-LHC. This work builds on previous studies of a tracking detector capable of providing track stubs to be used in the Level-1 Trigger (L1T). We now focus on the use of two ‘superlayers’ of tracking; each comprising a pair of pixel sensors with 50×50×50μm3 pitch (z×φ×r) separated by a few millimetres. Preliminary work on track reconstruction in Field Programmable Gate Arrays (FPGAs) is also presented
Development of the read-out link and control board for the ATLAS Tile Calorimeter Upgrade [Elektronisk resurs]
No full textThe Phase-II upgrade plan for the ATLAS Hadronic Tile Calorimeter facing the High-Luminosity LHC (HL-LHC) era includes approximately 1000 radiation tolerant read-out link and control boards (Daughterboards) that will provide full-granularity digital data to a fully-digital trigger system off-detector through multi-Gbps optic fibres. Different Daughterboard (DB) revisions have been developed, each successively aiming to meet the demanding HL-LHC requirements. The DB communicates with the off-detector systems via four 9.6 Gbps uplinks and two 4.8 Gbps downlinks. The DB performs high-speed read-out of digitized Photomultiplier (PMT) samples, while receiving and distributing configuration, control and LHC-synchronous timing to the front-end system. The design aims to minimize radiation-induced errors and enhance data reliability by embracing a fully double redundant design using CERN radiation hard GBTx ASICs and Xilinx FPGAs, implementing Triple Mode Redundancy (TMR), adopting Soft Error Mitigation (SEM) to correct for configuration memory Single Event Upsets (SEU), and employing Cyclic Redundancy Check (CRC) and Forward Error Correction (FEC) in the data format of the uplink and downlink, respectively. Total Ionizing Dose (TID), Non-Ionizing Energy Losses (NIEL) and Single Event Effects (SEE) radiation tests have been performed in order to assess the radiation tolerance strategies followed in the design and to qualify the DB for the HL-LHC requirements according to the ATLAS policy on radiation tolerant electronics. This thesis presents the author's contribution to the development of the DB through the different revisions, the integration of the DB to the Demonstrator and the radiation tests performed aiming to demonstrate the readiness of the DB to withstand the radiation requirements imposed by the HL-LHC. Resulting of this document, the author proposes strategies to be used in the new DB design moving forward the final design to be produced and inserted in ATLAS during the 2024-2026 period.</p
- …
