February 19th 2009AlbaNova Instrumentation Seminar1 Christian Bohm Instrumentation Physics, SU Upgrading the ATLAS detector Overview Motivation The current design and why Why upgrade How Planning the short range development

February 19th 2009AlbaNova Instrumentation Seminar2 Motivation Accelerator upgrades will increase the luminosity above the design value cm -2 s -1 Phase II Bunch Crossing (BC) rate may change 25->50 ns

February 19th 2009AlbaNova Instrumentation Seminar3 Design criteria/considerations for an ATLAS type detector Higher energies to study new phenomena Large luminosity to study rare events – many events to reach 5 

February 19th 2009AlbaNova Instrumentation Seminar4 Design criteria/considerations for an ATLAS type detector Higher energies to study new phenomena Large luminosity to study rare events – many events to reach 5  Tracker near beam pipe to determine the source position Magnet around beam pipe for momentum information Large E/M calorimeter to stop and measure energy of electrons and photons – not too large to stop hadrons as well

February 19th 2009AlbaNova Instrumentation Seminar5 Design criteria/considerations for an ATLAS type detector Higher energies to study new phenomena Large luminosity to study rare events – many events to reach 5  Tracker near beam pipe to determine the source position Magnet around beam pipe for momentum information Large E/M calorimeter to stop and measure energy of electrons and photons – not too large to stop hadrons as well Large hadron calorimeter to stop and measure energy of hadrons Minimize matter in front of calorimeters to improve resolution Should the magnet be inside or outside the calorimeters Large muon detector with strong magnetic field to measure muon energies with high precision.

February 19th 2009AlbaNova Instrumentation Seminar6 Design criteria/considerations for the on-detector electronics Radian tolerance and reliability main problems Long design cycles -> problems with obsolescence Paradigm shifts during long development processes

February 19th 2009AlbaNova Instrumentation Seminar7 Design criteria/considerations for the on-detector electronics Radiation tolerance and reliability main problems Long design cycles -> problems with obsolescence Paradigm shifts during long development processes Radiation tolerance achievable – bandwidth expensive On-detector logic and memories – transfer only if necessary Radiation tolerance expensive – bandwidth achievable Minimize on-detector electronics – transfer as soon as possible Radiation tolerance achievable – bandwidth achievable On-detector logic OK but minimize for reliability – protect for transient errors

February 19th 2009AlbaNova Instrumentation Seminar8 Design criteria/considerations for the on-detector electronics Radian tolerance and reliability main problems Long design cycles -> problems with obsolescence Paradigm shifts during long development processes Radiation tolerance achievable – bandwidth expensive On-detector logic and memories – transfer only if necessary Radiation tolerance expensive – bandwidth achievable Minimize on-detector electronics – transfer as soon as possible Radiation tolerance achievable – bandwidth achievable On-detector logic OK but minimize for reliability – protect for transient errors ASICs -> FPGAs (sometimes even on-detector) Another change: During phase 0 LHC projects were often driving technology development Now it is telecom

February 19th 2009AlbaNova Instrumentation Seminar9 Current design ATLAS

February 19th 2009AlbaNova Instrumentation Seminar10 Current design ATLAS data Flow 40M Hz LHC physics looks for rare events – 1 in  High event rates and  High selectivity new data every 25 ns About 100 million channels

February 19th 2009AlbaNova Instrumentation Seminar11 Current design ATLAS data Flow 40M Hz 1 event in 400 new data every 25 ns Since all data must be stored while waiting for the L1 decision the L1 processing must be quick – <2.5ns Data from entire detector but with low spatial resolution and reduced dynamic range from calorimeters and muon detector About 100 million channels 75 kHz The high granularity data is merged into roughly 64x64 trigger towers each.1x.1 in  and  where  = log  Design requirement

February 19th 2009AlbaNova Instrumentation Seminar12 Current design ATLAS data Flow 2 kHz 40M Hz new data every 25 ns About 100 million channels 1 event in 100 Data from ROIs with high spatial resolution and full dynamic range from all subdetectors 75 kHz

February 19th 2009AlbaNova Instrumentation Seminar13 Current design ATLAS data Flow new data every 25 ns 200 Hz 2 kHz 75 kHz 40M Hz About 100 million channels 1 event in 100 Entire detector with high spatial resolution and full dynamic range from all subdetectors To Grid

February 19th 2009AlbaNova Instrumentation Seminar14 Current design L1 Trigger algorithms Look for isolated particles e/   /had Simplistically regard the L1 processor as consisting of 4096 parallel processors – one for each.1x.1 trigger tower Count the number different threshold combinations in the central trigger processor (CTP)

February 19th 2009AlbaNova Instrumentation Seminar15 Current design L1 Trigger algorithms Look for JETs 0.4 x x x 0.8 n ROI Identification u Identify 0.4 x 0.4 windows that are local maxima n Jet Identification u Apply thresholds to 0.4, 0.6, or 0.8 clusters around the local maxima u 8 Jet definitions available, each with selectable energy threshold and cluster size Simplistically regard the L1 processor as consisting of 1024 parallel processors – one for each.2x.2 trigger tower Count the number different threshold combinations in the CTP

February 19th 2009AlbaNova Instrumentation Seminar16 The x3 increased luminosity will lead to increased radiation levels and more pile-up Phase I upgrade, 6 months The inner layer of the inner detector must be replaced due to radiation damage

February 19th 2009AlbaNova Instrumentation Seminar17 The phase I upgrade Since the innermost layer cannot be replaced a new layer (IBL) is inserted closer to the beam pipe -> smaller beam pipe Another detector part that may need replacement is the FCAL electronics Increased luminosity ->more events Unrealistic to change level 2 rate -> Improve L1 rejection One way is to increase thresholds Another way is to improve L1 trigger by bringing some L2 processing down to L1

February 19th 2009AlbaNova Instrumentation Seminar18 The phase I upgrade Topological algorithms can be introduced in the L1 calorimeter trigger Use the ROI position information Takes additional time to determine in L1Calo and to evaluate in the L1 CTP The latency margin seem to suffice The main part of L1Calo stays inserting a new layer between L1Calo and CTP and a new CTP

February 19th 2009AlbaNova Instrumentation Seminar19 The x10 increased luminosity will lead to more increased radiation levels and still worse pile-up Phase II upgrade, 1.5 years All the on detector electronics has reached its designed life time

February 19th 2009AlbaNova Instrumentation Seminar20 Phase II upgrade Completely new inner detector The rest of the detector more or less OK New calorimeter on-detector and off-detector electronics Increased luminosity ->new electronics Increased luminosity ->more events->more logic Level 2 rate fixed?! Completely new L1 trigger

February 19th 2009AlbaNova Instrumentation Seminar21 Phase II upgrade Increased luminosity -> increased L1 trigger efficiency -> more information to L1 High granularity, depth segmented info from calorimeters Higher thresholds not enough more info from muon detector? or a Track trigger? Simulations needed

February 19th 2009AlbaNova Instrumentation Seminar22 Calorimeter ideas Full readout Minimize on-detector electronics Massive data transfers Preprocessor delivers tower info with flags e.g. high granularity or depth flags

February 19th 2009AlbaNova Instrumentation Seminar23 Track trigger ideas High Pt trigger Supply track info on demand -> much longer latencies L 1.5 track trigger Very challenging

February 19th 2009AlbaNova Instrumentation Seminar24 Practical planning Less work than phase 0 Financing Long lead times Radiation tolerance testing SIMULATIONS NEEDED Experience from running ATLAS (radiation damage) Coordination with machine, CMS,… Organize installation Organizational structures: USGs, UPOs, ATLAS weeks, meetings, meetings,…. Schedule Phase I (2013) and phase II (2017) – mostly controlled by machine development which is not primarily affected by the delay, the schedule may thus not slide with the startup delay. Atlas upgrade LoI 2009, IBL TDR 2009, upgrade TP 2010 (maybe with options), upgrade TDR 2011 We are already late compared to phase 0!