1. 1 1 Rapid recent developments in Phase I L1Calo Weakly 25 Jul 2011 Norman Gee

2. 25-Jul-2011N Gee - L1Calo Weekly - Upgrade 2 2 Background Phase-I Task Force set up to recommend contents of Phase-I upgrade By July had met 5 times since Dec 2010 Before last week, draft text from TDAQ – mainly level-1, concentrating on latency and known planned changes in L1Calo, L1Muon and CTP Some emphasis low threshold leptons –Including nMCM, CMX, L1Topo Suddenly, meetings 8,12,14,19 July + “pre-meetings” Detailed draft from LAr on 19 Jul at 10:30 for 13:00 pre-meeting!! –Baseline plan is fully replaced TBB. New TBB gives existing Analogue + 4 digitised depth samples; AND could provide lateral granularity –Tile would change only in 2021 –4 x 4 area to be instrumented in both calorimeters for tests

3. 25-Jul-2011N Gee - L1Calo Weekly - Upgrade 3 3 Background Coincided with Stockholm follow-up meeting (organised by DF+CB, with SH, ML, SS invited but travelling, NK, NG) Discussion on L1Calo response… agreed to prepare diagrams & list functions (NG) + thoughts on no of connections (ML) –Several ad-hoc, undemocratic discussions in a frenetic week at CERN, diagrams become obsolete before drawing was complete, etc Meeting organised to discuss evolution in Simulation results post-Stockholm between Alan (using L1Calo granularity) and Denis Damazio & Steve Sekula (using L2 environment) –Conclusion: significant risk that ATLAS may be limited in trig capability, joint R&D on new TBB L1Calo should continue This went into Ph-I TF draft recommendations, was reported to USC, seems to have been accepted (full report being assembled this week) Need to do work on architecture. Current diagrams follow:

4. 25-Jul-2011N Gee - L1Calo Weekly - Upgrade 4 4 Possible Phase I Level-1 Trigger Scheme shown to Ph-1 TF on 9 June

5. 25-Jul-2011N Gee - L1Calo Weekly - Upgrade 5 20 July

6. 25-Jul-2011N Gee - L1Calo Weekly - Upgrade 6 Comments Approximate size of system – from ML count of links in a depth-only system – roughly 8 digital Preprocessor modules + 1-2 “Depth Processors” –Could all fit in 1-2 crates, not a large/expensive/complex system Thinking: –Need to preserve all outputs provided by present L1Calo –We can’t delay L1Calo signals (needed by L1Topo for muon isolation) –New TBB signals are probably much later than PPR outputs (? 10 ticks) –Can’t get new TBB e.m. signals into existing system –Very hard to get old Tile etc had signals into new system would have to immediately expand to several crates – 3600 signals on grey cables: needs duplicate signals or entirely replace L1Calo –New parallel system is an incremental upgrade, not a replacement –Could be a prototype for Ph-II, Level-0

7. 25-Jul-2011N Gee - L1Calo Weekly - Upgrade 7 More 20 July

8. 25-Jul-2011N Gee - L1Calo Weekly - Upgrade 8 Functions of boxes on diagram Name change – Depth Processor becomes Feature Extractor Digital Preprocessor (individual channel-based) –Receive signals optically from from digital TBB, convert to 40 MHz, handle data reception errors; –Adjust timing to common phase and common clock; –BCID filtering, energy calibration, + other functions, e.g. rate metering; –Read out to DAQ (Slink or...) –Remap signals and transmit on fibres, providing duplicates as needed Depth processor (sliding window based) –Receive signals from digital preprocessor –Perform magic depth/granular algorithms –Either (a) send results to L1Topo, or – (b) send results to CMX, or – (c) get RoIs from CMX, match to depth data, send results to CTP and/or L1Topo. Both to provide DAQ/RoI readout as needed

9. 25-Jul-2011N Gee - L1Calo Weekly - Upgrade 9 Next Steps Algorithms, connectivity, partitioning, modularity, latency, simulation, infrastructure, readout, rack space, fibre routing, …