Snowmass P. Le Dû Next generation of Trigger/DAQ Where are we today? Evolution On/off line boundaries What next ? LC’s Triggers Technologies What about standards? Technology transfer to others fields Patrick Le Dû -

Snowmass P. Le Dû General comments about Trigger/DAQ From the Physics: NO loss From the Detector : Deadtimeless From the Machine :use 100% from T/DAQ people: maximum efficiency and minimum maintenance Can we achieve the ultimate T/DAQ system ?

Snowmass P. Le Dû Tevatron selection scheme Level 3 Available time (sec) Production rate Hardwired processors ( FPGA) Level 1 Level 2 Recorded Events 7MHz QCD W,Z Top Higgs? 396/132ns 4 µsec  sec > Sec Standard PC’s Farm KHz 50Hz 1 KHz Coarse, dedicated data RISC Processors and DSPs optimized code “Off-line” code 6

Snowmass P. Le Dû L2 4.2 µs <50 Hz D0 Detector L1 Buffer Pipeline) L1 Trigger L3 Farm Mass Storage 10 KHz Accept Acce/rej < 1KHz 100 µs latency 7.6 MHz Xing rate 48 Input nodes 50 ms latency L2 Global Preprocessing Farm L2 Buffer & digitization

Snowmass P. Le Dû LHC Multilevels Selection scheme Available time (sec) Production rate Hardwired processors (ASIC, FPGA) Standard processor farms & Networks Level 1 Level 2 Level 3 # / sec QCD W,Z Top Higgs Z’ 25nsfew µsec ~ms > Sec Recorded Events HLTHLT

Snowmass P. Le Dû Evolution  LHC (ATLAS & CMS)  Two levels trigger –L1 = physics objects ( e/g,jet,m..) using dedicated data –L2 + L3 = High Levels « software » Triggers using « digitized data » Complex algorithms like displaced vertices are moving downstream –CDF/DO : L2 vertex trigger –LHCb/Btev : L0/L1 b trigger Use as much as possible comodity products (HLT) –No more « Physic » busses  VME,PCI.. –Off the shelf technology Processor farms Networks switches (ATM, GbE ) –Commonly OS and high level languages

Snowmass P. Le Dû “Logical Strategy” for event selection Prompt Trigger “Identification of objects” Prompt Trigger “Identification of objects” High Level Trigger Selection “L 1 objects “ confirm Particle signature Global Topology Trigger Menu High Level Trigger Selection “L 1 objects “ confirm Particle signature Global Topology Trigger Menu Event Filter On-line processing Event Filter On-line processing collision rate > KHz > Hz “off-line” Coarse dedicated data Final Digitized data optimised code Partial to full event “Off-line” code type Local identification of Energy cluster Track segment Missing energy Objects Classification of Physics/calibration Process Refine Et and Pt cut Detector matching Mass calculation VTX & Impact parameters... Full or partial reconstruction Calibration & monitoring “Hot stream” physics “Gold platted ”events Final formatting etc... Storage& analysis S1S2S3S4Sn Few µsec Few msec Few sec Data streams Logical steps MHz L1 L2 L3

Snowmass P. Le Dû On-off line boundaries Detectors are becoming more stable and less faulty On-line processing power is increasing and use similar hw/sw components (PC farms..) On-line calibration and correction of data possible More complex analysis is moving on-line –Filter event –Sort data streams… become flexible

Snowmass P. Le Dû Trigger strategy & Event Analysis hours days Sec. Temporary storage Monitoring Calibration Alignements Physics monitoring “Gold Platted“ events Physics samples On-Line Processing Database “Garbage” Final storage Candidates Storage Calibration Constant Sub-Detector performance Event Background Infos to the LHC “Analysis” farm Sample Prescale Compress Fast Analysis StreamPhysics streams ms hours days Sec. S1 S2 Sn Simple signatures Complex signatures Topology Others signatures Menu Event Candidate & classification Simple signatures : e/g, µ, taus,Jet Refine Et and Pt cut Detector matching Complex signatures : Missing Et, scalar Et Invariant and transverse mass separation … vertices, primary and displaced Selection: Thresholding Prescaling “Intelligent formatting “ HLT Algorithms Select « Physics tools » Select objects and compare to Menus HLT Partial/Full Event Building Reject 1-2 KHz 5-10KHz 100Hz

Snowmass P. Le Dû Summary of T/DAQ architecture evolution Today –Tree structure and partitions –Processing farms at very highest levels –Trigger and DAQ dataflow are merging Near future –Data and control networks centered –Processing farm already at L2 More complex are moving on line Boundaries between on-line and off-line are flexible Comodity components more towards L1 L1 L2 L3 HLT Pass1 Pass2 Analysis farm Pass2 hardware On-line Off-line

Snowmass P. Le Dû What next ? Next generation of machines –LC (Tesla,NLC,JLC) Concept of « software trigger » –VLHC : like LHC –CLIC : < ns sec collision time! – Mu collider : Not invetigated yet! Next generation of detectors : –Pixels trackers : ex 800 M Ch (Tesla) –Si-W calorimeters: 32 M Ch. (Tesla) Very high luminosity > 10**34 High or continuous collision rate (< ns) multimillion Si read-out channels Challenges

Snowmass P. Le Dû LC beam structure Relatively long time between bunch trains 199 ms Rather long time between bunches: 337 ns Rather long bunch trains ( same order as detector rerad-out time: 1ms Relatively long time between bunch trains (same order as read- out time): 6.6 ms Very short time between bunches: 2.8 ns Rather short pulses : 238 ns TESLA JLC (NLC)  // / 199 ms 1ms 2820 bunches 5 Hz150 Hz / 85 bunches 6.6 ms 238 ns

Snowmass P. Le Dû LC basic trigger concept : NO hardware trigger Read-out and store front end digitized data of a complete bunch train into buffers –Deadtime free -- no data loss DAQ triggered by every train crossing –build the event and perform zero suppression and/or data compression –full event data information of complete bunch train available Software selection between train : software trigger –using « off-line » algorithms Classify events according – physics, calibration and machine needs Store events : –partial or everything!

Snowmass P. Le Dû Advantages Flexible –fully programmable –unforeseen backgrounds and physics rates easily accomodated –Machine people can adjust the beam using background events Easy maintenance and cost effective –Commodity products : Off the shelf technology (memory,switches, procsessors) –Commonly OS and high level languages –on-line computing ressources usable for « off-line » Scalable : –modular system

Snowmass P. Le Dû Consequences on detector concept Constraints on detector read-out technology –TESLA: Read 1ms continuously VTX: digitizing during pulse to keep VTX occupancy small TPC : no active gating –JLC/NLC : 7 ms pulse separation –detector read out in 5 ms –veto trains 3 ns bunch separation –off line bunch tagging Efficient/cheap read-out of million of front end channels should be developped –silicon detectors ( VTX and SiWcalorimeters)

Snowmass P. Le Dû Conclusion about LC triggers Software trigger concept remains the ‘ baseline ’ –T/DAQ for the LC is NOT an issue ! Looks like the ‘ ultimate trigger ’ –satisfy everybody : no loss and fully programmable Feasible - (almost) today and affordable –Less demanding than LHC Consequence on the detector design –constraint on detectors read-out electronics (trackers) Consequence on the sofware environment: –on and off-line are merging : need to develop a complete integrated computing model with common ressources from calibration, selection (algorithms and filter) and analysis /processing paths….

Snowmass P. Le Dû Technology forecast ( ) Fast logic & hardware triggering (L1) Move to digital & programmable ASICS not anymore developped FPGA’s is growing and can embed complex algorithms

Snowmass P. Le Dû Technology forecast ( ) (Software trigger) Processors and memories –Continuous increasing of the computing power More’s law still true until 2010!  x 64 Then double every 3years  –Memory size quasi illimited ! Today: 64 Mbytes 2004 : 256 MB 2010 : > 1 GB Networks:Commercial telecom/computer standards –Multi (10-100) GBEthernet –But : Software overhead will limit the performance… x 256 by 2016 Systematic use of : Off the Shelves comodity products

Snowmass P. Le Dû About standards Evolution of standards : no more HEP! –HEP : NIM (60s) CAMAC (70s), FASTBUS (80s), –Commercial OTS : VME (90s), PCI (2000)  CPCI? Looking ahead: today commercial technologies –No wide parallel data buses in crates –Backplanes used for power distribution,serial I/O, special functions –High speeGb/s fiber & copper serial data links –Wireless data link emerging –Higher densities for micros,memories standards commercial part –Hundred of pin packages

Snowmass P. Le Dû Transfer to other fields Last year IEEE NSS-MIC Conference shows a great interest and a common interest Medical Imaging as similar requirement as us for diagnostic TEP –Large data movment and on-line treatment –Fast selection and reconstruction

Snowmass P. Le Dû Final Conclusions Trigger/should not be an issue for the next generation of machines like LCs Fully commercial OTS comodity components Programmable & software triggers On-line and Off-line boundaries become very flexible: need a new « computing model » Challenges for 2020 –Very high luminosity > 10**34 –High or continuous collision rate (< ns)