Commissioning Experience with the ATLAS Level1 Calorimeter Trigger

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Commissioning Experience with the ATLAS Level-1 Calorimeter Trigger System ATLAS Level-1 Calorimeter Trigger Collaboration

Commissioning Experience with the ATLAS Level-1 Calorimeter Trigger System ATLAS Level-1 Calorimeter Trigger Collaboration R. Achenbach 1, P. Adragna 2, V. Andrei 1, B. M. Barnett 3, B. Bauss 4, M. Bendel 4, C. Bohm 5, J. R. A. Booth 6, I. P. Brawn 3, D. G. Charlton 6, C. J. 6 3 2 6 Curtis , A. O. Davis , E. Eisenhandler , P. J. W. Faulkner , F. 1 3 1 Föhlisch , C. N. P. Gee , C. Geweniger , A. R. Gillman , P. Hanke , S. Hellman 5, A. Hidvégi 5, S. J. Hillier 6, M. Johansen 5, E. -E. Kluge 1, M. Landon 2, V. Lendermann 1, K. Mahboubi 1, G. Mahout 6, K. Meier 1, V. J. O. Perera 3, D. P. F. Prieur 3, W. Qian 3, S. Rieke 4, F. Rühr 1, D. P. C. 3 4 1 1 Sankey , U. Schäfer , K. Schmitt , H. -C. Schultz-Coulon , S. 5 6 1 4 Silverstein , R. J. Staley , R. Stamen , S. Tapprogge , J. P. Thomas 6, T. Trefzger 4, P. M. Watkins 6, A. Watson 6, P. Weber 1, E. -E. Woehrling 6 1 Kirchhoff-Institut für Physik, University of Heidelberg, Germany Department, Queen Mary, University of London, UK 3 CCLRC Rutherford Appleton Laboratory, Oxon, UK 4 Institut für Physik, University of Mainz, Germany 5 Fysikum, University of Stockholm, Sweden 6 School of Physics and Astronomy, University of Birmingham, UK 2 Physics Commissioning of ATLAS Level-1 Calorimeter Trigger, Stephen Hillier

Commissioning Experience with the ATLAS Level-1 Calorimeter Trigger System o Trigger Architecture o Challenge

Commissioning Experience with the ATLAS Level-1 Calorimeter Trigger System o Trigger Architecture o Challenge of Scale o o Rationale for architecture and size Implications for Installation Full scale crate tests Commissioning and Integration o o Integration into ATLAS Data Acquisition First signals from Calorimeters Commissioning of ATLAS Level-1 Calorimeter Trigger, Stephen Hillier

Level-1 triggering in ATLAS o o Muon Detectors Calorimeter Trigger Muon Trigger Three-stage triggering

Level-1 triggering in ATLAS o o Muon Detectors Calorimeter Trigger Muon Trigger Three-stage triggering system o o Calorimeters Level-1: custom built hardware, fixed latency – target rate 75 k. Hz Level-2: software, Ro. I based selection – target rate 1000 Hz Event Filter: software, full detector – target rate 200 Hz All data buffered at bunch-crossing rate of 40 MHz for 2. 5 ms Level-1 has three sub-systems: o o o Calorimeter Trigger Muon Trigger Central Trigger (CTP) e/γ tau jet ET ΣET Central Trigger Processor Trigger to Front-end Buffers μ Level-1 Trigger Regions of Interest (Ro. I) To Level-2 Commissioning of ATLAS Level-1 Calorimeter Trigger, Stephen Hillier

Calorimeter Trigger Architecture Digitized Energies Features: Realtime Path: Fixed Latency (~1μs) Analogue Calorimeter signals

Calorimeter Trigger Architecture Digitized Energies Features: Realtime Path: Fixed Latency (~1μs) Analogue Calorimeter signals (>7000) Preprocessor 124 modules Many stage processing Real-time Data Path Massive parallelism Dual purpose modules Heavily FPGA based Cluster Processor 56 modules Merging 8 modules Jet/Energy Processor 32 modules Merging 4 modules Readout Driver (ROD) 14 modules Readout Data Region of Interest ROD 6 modules Region of Interest Data Five Main Types of Custom 9 U Modules PPM CPM JEM Merged Results To CTP CMM ROD Commissioning of ATLAS Level-1 Calorimeter Trigger, Stephen Hillier

Compromise of Scale Main motivations leading to: Extensive Parallel System o Physical Size of

Compromise of Scale Main motivations leading to: Extensive Parallel System o Physical Size of Connectors o o o e. g. 496 inflexible analogue cables with large connectors Quantity of processing Power consumption Compact Integrated System o Latency o Fewer data transmission stages o Algorithm Environment o Sharing of information leads to extensive fanout/fanin Commissioning of ATLAS Level-1 Calorimeter Trigger, Stephen Hillier

Influence of ‘Sliding’ Algorithm o o Processor input is a matrix of tower energies

Influence of ‘Sliding’ Algorithm o o Processor input is a matrix of tower energies (up to 50 x 64) Physics algorithms use 4 x 4 grid o o Sliding by 1 tower in each direction To process each location, an outer environment is required Commissioning of ATLAS Level-1 Calorimeter Trigger, Stephen Hillier

Core and Environment o o Each processor (module, crate) has a core of towers

Core and Environment o o Each processor (module, crate) has a core of towers processed Jet/Energy Module Core Algorithm Environment Requires extra ‘enviroment’ input o Achieved by fanout 32 Core cells o Ratio of core: environment dependant on size o o Smaller (more parallel) system requires more fanout Sub-dividing makes connectivity more difficult 45 Environment cells Jet/Energy Module (4 x 8) 32: 45 Cluster Module (4 x 16) 64: 69 Commissioning of ATLAS Level-1 Calorimeter Trigger, Stephen Hillier

Solution and implications o Entirely Parallel Preprocessor o o Size governed by input cabling

Solution and implications o Entirely Parallel Preprocessor o o Size governed by input cabling Eight 9 U VME crates High bandwidth digital cabling ‘spaghetti’ to: Parallel Processor o o o Preprocessor crate Four 9 U VME crates for e/gamma trigger Two 9 U VME crates for jet/energy trigger High speed digital links Necessary fanout performed via: o o Digital cables to processors (~30%) Custom backplane in processor (~75%) Processor crate Commissioning of ATLAS Level-1 Calorimeter Trigger, Stephen Hillier LVDS @ 480 Mbit/s

Installation Reality Check: Input Analogue Cables 496 cables into 8 crates Four cables just

Installation Reality Check: Input Analogue Cables 496 cables into 8 crates Four cables just fit front of one 9 U module Commissioning of ATLAS Level-1 Calorimeter Trigger, Stephen Hillier

Installation Reality Check: Digital Cabling into Processor Crates Up to 1400 individual LVDS signals

Installation Reality Check: Digital Cabling into Processor Crates Up to 1400 individual LVDS signals into one crate More than 500 Gbit/s data input Commissioning of ATLAS Level-1 Calorimeter Trigger, Stephen Hillier

Full Scale Crate Tests o o o Comprehensive tests performed with all subsystems Performance

Full Scale Crate Tests o o o Comprehensive tests performed with all subsystems Performance scaled well One new hardware problem: o Processor backplane Preprocessor Jet/Energy Processor Cluster Processor Commissioning of ATLAS Level-1 Calorimeter Trigger, Stephen Hillier

Backplane Problems and Status o Dense, high bandwidth backplane o o No problems in

Backplane Problems and Status o Dense, high bandwidth backplane o o No problems in prototyping In production, pins had problems at about 0. 01% level o o o Up to 1150 pins per slot About 20, 000 pins in all ie about 1 -2 per backplane! Pins bent during insertion of connectors All backplanes being studied for faults o Bad connectors to be replaced Commissioning of ATLAS Level-1 Calorimeter Trigger, Stephen Hillier

Integration into ATLAS Data Acquisition o Tests of output to all downstream hardware performed

Integration into ATLAS Data Acquisition o Tests of output to all downstream hardware performed in situ o o o Simple setups for the moment Links to Readout System and Region of Interest Builder showed no data corruption Some problems with links to Central Trigger Processor o o Poor cable quality Minor firmware bugs Cluster Processor Modules Level-1 Calorimeter Readout Driver Region of Interest Builder Level-1 Calorimeter Readout Ro. IB Readout Compare Commissioning of ATLAS Level-1 Calorimeter Trigger, Stephen Hillier

First Signals from Calorimeters Installation at ATLAS means: First opportunity to see calorimeter signals

First Signals from Calorimeters Installation at ATLAS means: First opportunity to see calorimeter signals since test-beam in 2004 Means to check channel connectivity, signal quality, and tower calibrations (Using calibration systems) Maximum pulse height per input tower Phi (radians) FADC counts Input pulse as seen by Preprocessor FADC Timeslice Number Pseudorapidity Commissioning of ATLAS Level-1 Calorimeter Trigger, Stephen Hillier

Future Plans o More integrations o o Connect up full scale subsystems More calorimeter

Future Plans o More integrations o o Connect up full scale subsystems More calorimeter tests o o o More channels Different parts of detectors Join ATLAS combined runs o o Commissioning runs Cosmic runs o Majority of hardware installed by mid 2007 o Will require much work to fully understand system Commissioning of ATLAS Level-1 Calorimeter Trigger, Stephen Hillier