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Triggering CMS. Wesley H. Smith U. Wisconsin – Madison CMS Trigger Coordinator Seminar, Texas A&M April 20, 2011 Outline: Introduction to CMS Trigger Challenges & Architecture Level -1 Trigger Implementation & Performance Higher Level Trigger Algorithms & Performance - PowerPoint PPT Presentation

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Trigger Base Personnel

Triggering CMSWesley H. SmithU. Wisconsin MadisonCMS Trigger CoordinatorSeminar, Texas A&MApril 20, 2011

Outline:

Introduction to CMS Trigger Challenges & ArchitectureLevel -1 Trigger Implementation & PerformanceHigher Level Trigger Algorithms & PerformanceThe Future: SLHC TriggerWesley Smith, U. Wisconsin, April 20, 2011Texas A&M Seminar: Triggering CMS - #1LHC Collisions

with every bunch crossing23 Minimum Bias eventswith ~1725 particles producedWesley Smith, U. Wisconsin, April 20, 2011Texas A&M Seminar: Triggering CMS - #2LHC Physics & Event RatesAt design L = 1034cm-2s-123 pp events/25 ns xing~ 1 GHz input rateGood events contain ~ 20 bkg. events1 kHz W events10 Hz top events< 104 detectable Higgs decays/yearCan store ~ 300 Hz eventsSelect in stagesLevel-1 Triggers1 GHz to 100 kHzHigh Level Triggers100 kHz to 300 Hz

Wesley Smith, U. Wisconsin, April 20, 2011Texas A&M Seminar: Triggering CMS - #

Collisions (p-p) at LHCEvent size: ~1 MByte Processing Power: ~X TFlop

All charged tracks with pt > 2 GeV

Reconstructed tracks with pt > 25 GeVOperating conditions:one good event (e.g Higgs in 4 muons ) + ~20 minimum bias events)

Event rateWesley Smith, U. Wisconsin, April 20, 2011Texas A&M Seminar: Triggering CMS - #4

CMS Detector DesignMUON BARRELCALORIMETERS PixelsSilicon Microstrips210 m2 of silicon sensors9.6M channels

ECAL76k scintillating PbWO4 crystals Cathode Strip Chambers (CSC)Resistive Plate Chambers (RPC)Drift Tube Chambers (DT)Resistive Plate Chambers (RPC)Superconducting Coil, 4 TeslaIRON YOKETRACKERMUONENDCAPSHCALPlastic scintillator/brasssandwich Today:RPC || < 1.6 instead of 2.1 & 4th endcap layer missingLevel-1 Trigger OutputToday: 50 kHz(instead of 100)

Wesley Smith, U. Wisconsin, April 20, 2011Texas A&M Seminar: Triggering CMS - #5LHC Trigger & DAQ Challenges

Computing Services16 Million channels

Charge TimePattern40 MHz COLLISION RATE100 - 50 kHz 1 MB EVENT DATA 1 Terabit/s READOUT 50,000 data channels200 GB buffers ~ 400 Readout memories3 Gigacell buffers 500 Gigabit/s 5 TeraIPS ~ 400 CPU farmsGigabit/s SERVICE LANPetabyte ARCHIVE

EnergyTracks300 HzFILTERED EVENTEVENT BUILDER. A large switching network (400+400 ports) with total throughput ~ 400Gbit/s forms the interconnection between the sources (deep buffers) and the destinations (buffers before farm CPUs). EVENT FILTER. A set of high performance commercial processors organized into many farms convenient for on-line and off-line applications. SWITCH NETWORK

LEVEL-1TRIGGERDETECTOR CHANNELSChallenges:1 GHz of Input InteractionsBeam-crossing every 25 ns with ~ 23 interactions produces over 1 MB of dataArchival Storage at about 300 Hz of 1 MB eventsWesley Smith, U. Wisconsin, April 20, 2011Texas A&M Seminar: Triggering CMS - #6Level 1 Trigger Operation

Wesley Smith, U. Wisconsin, April 20, 2011Texas A&M Seminar: Triggering CMS - #7CMS Trigger Levels

Wesley Smith, U. Wisconsin, April 20, 2011Texas A&M Seminar: Triggering CMS - #8

L1 Trigger LocationsUnderground Counting RoomCentral rows of racks fortriggerConnections via high-speed copper links to adjacent rows of ECAL & HCAL readout racks with trigger primitive circuitryConnections via opticalfiber to muon trigger primitive generatorson the detectorOptical fibersconnected viatunnels to detector(~90m fiber lengths)Rows of Racks containing trigger & readout electronics7m thickshieldingwallUSC55Wesley Smith, U. Wisconsin, April 20, 2011Texas A&M Seminar: Triggering CMS - #9CMS Level-1 Trigger & DAQOverall Trigger & DAQ Architecture: 2 Levels:Level-1 Trigger:25 ns input3.2 s latencyInteraction rate: 1 GHzBunch Crossing rate: 40 MHzLevel 1 Output: 100 kHz (50 initial)Output to Storage: 100 HzAverage Event Size: 1 MBData production 1 TB/day

UXCUSCWesley Smith, U. Wisconsin, April 20, 2011Texas A&M Seminar: Triggering CMS - #10

CMS Calorimeter GeometryEB, EE, HB, HE map to 18 RCT cratesProvide e/ and jet, , ET triggers1 trigger tower (.087 .087) = 5 5 ECAL xtals = 1 HCAL tower2 HF calorimeters map on to 18 RCT cratesTrigger towers: = = 0.087Wesley Smith, U. Wisconsin, April 20, 2011Texas A&M Seminar: Triggering CMS - #11

ECAL Endcap GeometryMap non-projective x-y trigger crystal geometry onto projective trigger towers:Individualcrystal5 x 5 ECAL xtals 1 HCAL tower in detail+ZEndcap-ZEndcapWesley Smith, U. Wisconsin, April 20, 2011Texas A&M Seminar: Triggering CMS - #12Calorimeter Trig. ProcessingTrigger Tower25 Xtals (TT)TCC(LLR)

CCS(CERN)SRP(CEADAPNIA)DCC(LIP)TCSTTCTrigger primitives @800 Mbits/sODDAQ@100 kHzL1 Global TRIGGERRegionalCaloTRIGGERTrigger Tower Flags (TTF)Selective Readout Flags (SRF)SLB (LIP)Data path@100KHz (Xtal Datas)Trigger Concentrator CardSynchronisation & Link BoardClock & Control SystemSelective Readout ProcessorData Concentrator CardTiming, Trigger & ControlTrigger Control System

Level 1 Trigger (L1A)From : R. Alemany LIPWesley Smith, U. Wisconsin, April 20, 2011Texas A&M Seminar: Triggering CMS - #13Calorimeter Trig.Overview(located in underground counting room)CalorimeterElectronicsInterfaceRegionalCalorimeterTrigger

ReceiverElectron IsolationJet/SummaryGlobal Cal. TriggerSorting, ETMiss, ETGlobalTriggerProcessorGlobal Muon TriggerIso Mu MinIon TagLumi-nosity Info.4K 1.2 Gbaud serial links w/2 x (8 bits E/H/FCAL Energy+ fine grain structure bit) + 5 bits error detection codeper 25 ns crossingUS CMS HCAL:BU/FNAL/Maryland/PrincetonCMS ECAL:Lisbon/PalaiseauUS CMS:WisconsinBristol/CERN/Imperial/LANLCMS:Vienna72 60 H/ECALTowers (.087 .087 for < 2.2 & .174-.195, >2.2)HF: 2(12 12 )Copper 80 MHz Parallel4 Highest ET:Isolated & non-isol. e/Central, forward, jets,Ex, Ey from each crateMinIon & QuietTags for each 4 4 regionGCT Matrix + Q bitsIC/LANL/UWWesley Smith, U. Wisconsin, April 20, 2011Texas A&M Seminar: Triggering CMS - #14ECAL Trigger Primitives

Test beam results (45 MeV per xtal):Wesley Smith, U. Wisconsin, April 20, 2011Texas A&M Seminar: Triggering CMS - #15CMS Electron/Photon Algorithm

Wesley Smith, U. Wisconsin, April 20, 2011Texas A&M Seminar: Triggering CMS - #CMS / Jet Algorithm

Wesley Smith, U. Wisconsin, April 20, 2011Texas A&M Seminar: Triggering CMS - #

L1 Cal. Trigger SynchronizationBX ID Efficiency e/ & JetsSample of min bias events, triggered by BSC coincidence, with good vertex and no scraping

Fraction of candidates that are in time with bunch-crossing (BPTX) trigger as function of L1 assigned ET

Anomalous signals from ECAL, HF removed

Noise pollutes BX ID efficiency at low ET valuese/ Jet/ Forward Jet Wesley Smith, U. Wisconsin, April 20, 2011Texas A&M Seminar: Triggering CMS - #

L1 efficiency for electronsSample of ECAL Activity HLT triggers (seeded by L1 ZeroBias)Anomalous ECAL signals removed using standard cutsEG trigger efficiency for electrons from conversionsStandard loose electron isolation & IDConversion ID (inverse of conversion rejection cuts) to select electron-like objectsEfficiency shown w.r.t ET of the electron supercluster, for L1 threshold of 5 GeV (top), 8 GeV (bottom)Two ranges shown: Barrel (black), endcaps (red)

L1_EG5L1_EG8With RCT CorrectionWesley Smith, U. Wisconsin, April 20, 2011Texas A&M Seminar: Triggering CMS - #Jet Trigger Efficiency

minimum-bias triggerjet energy correction: online / offline matchturn-on curves steeperWesley Smith, U. Wisconsin, April 20, 2011Texas A&M Seminar: Triggering CMS - #

Reduced RE system|| < 1.61.6ME4/1MB1MB2MB3MB4ME1ME2ME3*Double Layer*RPCSingle LayerCMS Muon ChambersWesley Smith, U. Wisconsin, April 20, 2011Texas A&M Seminar: Triggering CMS - #21Muon Trigger Overview

|| < 1.2|| < 2.40.8 < || || < 2.1|| < 1.6 in 2009Cavern: UXC55Counting Room: USC55Wesley Smith, U. Wisconsin, April 20, 2011Texas A&M Seminar: Triggering CMS - #22CMS Muon Trigger Primitives

Memory to store patternsFast logic for matchingFPGAs are idealWesley Smith, U. Wisconsin, April 20, 2011Texas A&M Seminar: Triggering CMS - #23CMS Muon TriggerTrack FindersMemory to store patternsFast logic for matchingFPGAs are ideal

Sort based on PT, Quality - keep loc.Combine at next level - matchSort again - Isolate?Top 4 highest PT and quality muons with location coord.Match with RPCImprove efficiency and qualityWesley Smith, U. Wisconsin, April 20, 2011Texas A&M Seminar: Triggering CMS - #24

DT

L1 Muon Trigger SynchronizationBX ID Efficiency CSC, DT, RPCAll muon trigger timing within 2 ns, most better & being improved

RPC CSC

Log PlotWesley Smith, U. Wisconsin, April 20, 2011Texas A&M Seminar: Triggering CMS - #L1 Muon Efficiency vs. pT

01/04/2011

BarrelEndCapOverLap

L1_Mu7L1_Mu10L1_Mu12L1_Mu20Wesley Smith, U. Wisconsin, April 20, 2011Texas A&M Seminar: Triggering CMS - #CMS Global Trigger

Wesley Smith, U. Wisconsin, April 20, 2011Texas A&M Seminar: Triggering CMS - #27Global L1 Trigger Algorithms

Wesley Smith, U. Wisconsin, April 20, 2011Texas A&M Seminar: Triggering CMS - #28elta or correlation conditionsUnique Topological Capability of CMS L1 Triggerseparate objects in & : 2 hardware indices: 20 .. 40 degreesPresent Use:e / jet separation to avoid triggering twice on the same object in a correlation triggerobjects to be separated by one empty sector (20 degrees)

Wesley Smith, U. Wisconsin, April 20, 2011Texas A&M Seminar: Triggering CMS - #High Level Trigger Strategy

Wesley Smith, U. Wisconsin, April 20, 2011Texas A&amp

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