Upgrade of Trigger and Data Acquisition Systems for the LHC Experiments Nicoletta Garelli CERN XXIII International Symposium on Nuclear Electronics and Computing, 12-19 September 2011, Varna, Bulgaria
Feb 25, 2016
Upgrade of Trigger and Data Acquisition Systems
for the LHC Experiments
Nicoletta GarelliCERN
XXIII International Symposium on Nuclear Electronics and Computing, 12-19 September 2011, Varna, Bulgaria
2
Acknowledgment & Disclaimer• I would like to thank David Francis, Benedetto Gorini,
Reiner Hauser, Frans Meijers, Andrea Negri, Niko Neufeld, Stefano Mersi, Stefan Stancu and all other colleagues for answering my questions and sharing ideas.
• My apologizes for any mistakes, misinterpretations and misunderstandings.
• This presentation is far to be a complete review of all the trigger and data acquisition related activities foreseen by the LHC experiments from 2013 to 2022.
• I will focus on the upgrade plans of ATLAS, CMS and LHCb only.
9/13/2011 N. Garelli (CERN). NEC'2011
3
Outline• Large Hadron Collider (LHC)
– today, design, beyond design• LHC experiments
– design– trigger & data acquisition systems– upgrade challenges
• Upgrade plans– ATLAS – CMS – LHCb
9/13/2011 N. Garelli (CERN). NEC'2011
N. Garelli (CERN). NEC'2011 4
LHC: a Discovery Machine
9/13/2011
SPS
PS
LHC
LHCb
Alice
ATLAS
CMS
Goal: explore TeV energy scale to find Higgs Boson & New Physics beyond Standard Model How: Large Hadron Collider (LHC) at CERN, with possibility of steady increase of luminosity large discovery range
LHC Project in brief• LEP tunnel: 27 km Ø, ~100 m
underground• pp collisions, center of mass E = 14 TeV • 4 interaction points 4 big detectors• Particles travel in bunches at ~ c• Bunches of O(1011) particles each • Bunch Crossing frequency: 40 MHz• Superconducting magnets cooled to 1.9 K
with 140 tons of liquid He. (Magnetic field strength ~ 8.4 T)
• Energy of one beam = 362 MJ (300x Tevatron)
N. Garelli (CERN). NEC'2011 5
Current Status Design Beyond Design
beam energy (TeV) 3.5 (½ design) 7 (7x Tevatron) -
bunch spacing (ns) 50 (½ design) 25 -
colliding bunches nb 1331 (~½ design) 2808 -
peak luminosity (cm-2s-1) 3.1 1033 (~30% design) 1034 (30x Tevatron) 5 1034 (leveled)
bunch intensity, protons/bunch (1011)
1.25 (>design) 1.15 1.7 3.4 (with 50 ns)
b* (m) 1 (~½ design) 0.55 0.15
LHC: Today, Design, Beyond Design
9/13/2011
b* = beam envelope at Interaction Point (IP), determined by magnets arrangements & powering. Smaller b* = Higher Luminosity
Interventions needed to reach design conditions
LHC can go further Higher
Luminosity
1
2
N. Garelli (CERN). NEC'2011 6
LHC Schedule Model
9/13/2011
Jan Feb Mar April May June July Aug Sept Oct Nov Dec
TS HWC Phys Phys Phys TS+MD
Phys Phys Phy TS+MD
Phys Phys TS & Ion
TS
Yearly Schedule• operating at unexplored conditions long way to reach design performance
need for commissioning & testing periods• one 2-month Technical Stop (TS). Best period for power saving: Dec-Jan• every ~2 months of physics a shorter TS followed by a Machine Development (MD)
period necessary• 1 month of heavy ion run (different physics program)
Every 3 years a 1 year long (at least) shutdown needed for major component upgrades… and the experiments?
• profit from LHC TS & shutdown periods for improvements & replacements
• LHC drives the schedule experiments schedule has to be flexible
N. Garelli (CERN). NEC'2011 7
LHC: Towards Design ConditionsDon’t forget that life is not always easy
Single Event Effects due to radiation Unidentified Falling Objects (UFO), fast beam losses
What LHC can do as it is today: with 50 ns spacing: nb = 1380, bunch intensity = 1.7 1011, b* = 1.0 m L = 5 1033 cm-2s-1 at 3.5 TeV
with 25 ns spacing: nb = 2808, bunch intensity = 1.2 1011, b* = 1.0 m L = 4 1033 cm-2s-1 at 3.5 TeV
Not possible to reach design performance today: 1) Beam Energy: joints between s/c magnets limits to 3.5 TeV/beam2) Beam Intensity: collimation limits luminosity to ~5 1033 cm-2s-1 with E =
3.5 TeV/beam
9/13/2011
N. Garelli (CERN). NEC'2011 8
LHC Draft Schedule – Consolidation
2013 CONSOLIDATION
Long Shut-Down
• fully repair joints between s/c magnets
• install magnet clamps
E = 6.5-7 TeVL = 1034 cm-2s-1
9/13/2011
• Electrical fault in bus between super conducting magnets caused 19.9.2008 accident limit E to 3.5 TeV
• After joints reparation 7 TeV will be reached, after dipole training: O(100) quench/sector O(month) hardware commissioning
Upgrade Phases
after Shut-Down
LCH activities
N. Garelli (CERN). NEC'2011 9
• fully repair joints between s/c magnets
• install magnet clamps
LHC Upgrade Draft Schedule – Phase1&2
Long Shut-Down
2013 E = 6.5-7 TeVL = 1034
9/13/2011
Upgrade Phases
after Shut-Down
LCH activities
2017 PHASE 1• collimation upgrade• injector upgrade (Linac4)
E = 7 TeVL = 2 1034cm-2s-1
2021 PHASE 2• new bigger quadrupoles
smaller b* • new RF Crab cavities
E = 7 TeVL = 5 1034cm-2s-1
CONSOLIDATION New collimation system necessary to be protected from high losses at higher luminosity
N. Garelli (CERN). NEC'2011 10
LHC Upgrade Draft Schedule
Long Shut-Down
• fully repair joints between s/c magnets
• install magnet clamps 2013 E = 6.5-7 TeV
L = 1034cm-2s-1
9/13/2011
Upgrade Phases
after Shut-Down
LCH activities
2017 PHASE 1• collimation upgrade• injector upgrade (Linac4)
E = 7 TeVL = 2 1034cm-2s-1
2021PHASE 2
The Super-LHC• new bigger quadrupoles
smaller b* • new RF Crab cavities
E = 7 TeVL = 5 1034 cm-2s-1
3000 fb-1 by the end of 2030x103 wrt today
CONSOLIDATION
N. Garelli (CERN). NEC'2011 11
LHC Experiments Design• LHC environment (design)
– spp inelastic ~ 70 mb Event Rate = 7 108 Hz
– Bunch Cross (BC) every 25 ns (40 MHz) ~ 22 interactions every “active” BC
– 1 interesting collision is rare & always hidden within ~22 minimum bias collisions = pile-up
• Stringent requirements− fast electronics response to resolve
individual bunch crossings− high granularity (= many electronics
channels) to avoid that a pile-up event(1) goes in the same detector element as the interesting event(1)
− radiation resistant
9/13/2011
(1) Event = snapshot of values of all front-end electronics elements containing particle signals from single BC
N. Garelli (CERN). NEC'2011 12
LHC Upgrade: Effects on Experiments
• Higher peak luminosity Higher pile-up – more complex trigger selection– higher detector granularity– radiation hard electronics
• Higher accumulated luminosity radiation damage: need to replace components – sensors: Inner Tracker in particular (~200 MCHF/experiment)– electronics? not guaranteed after 10 y use
9/13/2011
Challenge for experiments: LHC luminosity x10 higher than today after second long shutdown (phase 1)
20132014
20172018
20212022
N. Garelli (CERN). NEC'2011 13
Interesting Physics at LHCFl
uegg
e, G
. 199
4, F
utur
e Re
sear
ch in
Hig
h En
ergy
Ph
ysic
s, Te
ch. r
ep
11
)GeV 500(
10 1 100
pbmb
H
tot
ss
mbtot 100s Total (elastic, diffractive, inelastic) cross-section of proton-proton collision
pbH 1)GeV 500( s
Cross-section of SM Higgs Boson production
Find a needle …Higgs -> 4mDESIGN ~22 MinBias
9/13/2011
…in the haystack!
BEYOND DESIGN 5x bigger haystack
~100 MinBias
N. Garelli (CERN). NEC'2011 14
Trigger & Data Acquisition (DAQ) Systems
9/13/2011
• @ LHC nominal conditions O(10) TB/s of data produced– mostly useless data (min. bias events)– impossible to store them
• Trigger&DAQ: select & store interesting data for analysis at O(100) MB/s– TRIGGER: select interesting events (the
Higgs boson in the haystack)– DAQ: convey data to local mass storage– Network: the backbone, large Ethernet
networks with O(103) Gbit & 10-Gbit ports, O(102) switches
• Until now: high efficiency (>90%)
Local Storage
CERN Data Storage
40 MHz
O(10)TB/s
O(100)MB/s
Trigger & DAQ
N. Garelli (CERN). NEC'2011 15
Comparing LHC Experiments Today
9/13/2011
Experiment Read-out channels
Trigger Levels
Read-Out Links (type, out, #)
Level 0-1-2 Rate (Hz)
Event Size (B)
HLT Out (MB/s)
ATLAS ~90 106 3 S-link, 160 Mb/s~1600
L1 ~ 105
L2 ~ 3 1031.5 106 300
CMS ~90 106 2 S-link64, 400 Mb/s~500
L1 ~ 105 106 600
LHCb ~1 106 2 G-link, 200 Mb/s~400
L0 ~ 106 5.5 104 70
ATLAS: partial & on-demand read-out @L2CMS & LHCb: read-out everything @L1
Similar read-out links
ATLAS
CMS
LHCb
N. Garelli (CERN). NEC'2011 16
ATLAS Trigger & DAQ (today)
9/13/2011
ATLAS Data
Calo/Muon Detectors
Data-Flow
ATLAS Event 1.5 MB/25 ns
Trigger DAQ
High Level Trigger
ROI data(~2%)
ROI Requests
~4 sec
EF Accept ~200 Hz
~ 200 Hz
~ 3 kHz
Event Filter
Level 2
L2 Accept~3 kHz
SubFarmOutput
SubFarmInput
~4.5 GB/s
~ 300 MB/s
Detector Read-Out
Level 1
FE FE FE
<2.5 ms Other Detectors
Regions Of Interest
L1 Accept 75 (100) kHz
40 MHz40 MHz
75 kHz
~40 ms112 GB/s
Trigger Info
CERN Data Storage
Event Builder
ROD ROD ROD
Event Filter Network
ReadOut System
Data Collection Network
N. Garelli (CERN). NEC'2011 17
CMS Trigger & DAQ (today)
9/13/2011
• LV1 trigger HW:– custom electronics– rate from 40 MHz to 100 kHz
• Event Building– 1st stage based on Myrinet
technology: FED-builder– 2nd stage based on TCP/IP over
GBE: RU-builder– 8 independent identical DAQ slices– 100 GB/s throughput
• HLT: PC farm– event driven– rate from 100 kHz to O(100) Hz
Detectors
Front-End pipelines
Read-out buffers
Processors farms
O(ms)
O(s)
40 MHz
100 kHz
100 Hz
High Level Trigger
Level 1Trigger
Mass storage
Switching Networks
N. Garelli (CERN). NEC'2011 18
Experiments Challenges Beyond Design
• Beyond design new working point to be established• Higher pile-up increase pattern recognition problems• Impossible to change calorimeter detectors (budget, time, manpower)• Necessary to change inner tracker
– current damaged by radiation – needs for more granularity
• Level-1 @ higher pile-up select all interesting physics– simple increase of thresholds in pT not possible: lot of physics will be lost– more sophisticated decision criteria needed
• move software algorithms into electronics• muon chambers better resolution for trigger required• add inner tracker information to Level-1
• Longer Level-1 decision time longer latency• More complex reconstruction in HLT
– more computing power required
9/13/2011
N. Garelli (CERN). NEC'2011 19
DAQ Challenges
• Problem:– which read-out ?– at which bandwidth?– which electronics?
• Higher detector granularity higher number of read-out channels increased event size
• Longer latency for Level-1 decisions possible changes in all sub-detector read-out systems
• Larger amount of data to be treated by network & DAQ– higher data rate network upgrade to accommodate higher bandwidth needs– need for increased local data storage
• Possibly higher HLT output rate if increased global data storage (Grid) allows
9/13/2011
N. Garelli (CERN). NEC'2011 20
As of Today: Difficult Planning• Hard to plan
– while maintaining running experiments– with uncertain schedule
• Upgrade plans driven by – Trigger: guarantee good & flexible selection– DAQ: guarantee high data taking efficiency
• New technologies might be needed– Trigger: new L1 trigger & more powerful HLT– DAQ: read-out links, electronics &network
• To be considered– replacing some components may damage others – new architecture must be compatible with existing components in case of
partial upgrade
9/13/2011
N. Garelli (CERN). NEC'2011 21
ATLASA Toroidal LHC ApparatuS
9/13/2011
22
ATLAS Draft Schedule – Consolidation
Long Shut-Down
TDAQ farms & networks consolidation
Sub-detector read-out upgrades to enable Level-1 output of 100 kHz
Current innermost pixel layer will have significant radiation
damage, largely reduced detector efficiency
replacement needed by 2015 Insertable B-Layer (IBL) built
around a new beam-pipe & slipped inside the current detector
2013
9/13/2011 N. Garelli (CERN). NEC'2011
Upgrade Phases
after Shut-Down
ATLAS Activities
TDAQ related
CONSOLIDATIONE = 6.5-7 TeVL = 1034 cm-2s-1
N. Garelli (CERN). NEC'2011 23
Evolution of TDAQ Farm• Today: architecture with many farms & network domains:
– cpu&network resources balancing on 3 different farms (L2, EB, EF) requires expertise
– 2 trigger steering instances (L2, EF)– 2 separate networks (DC & EF)– huge configuration
• Proposal: merge L2, EB, EF within a single homogeneous system– each node can perform the whole HLT selection steps
• L2 processing & data collection based on ROIs • event building• event filter processing on the full event
– automatic system balance– a single HLT instance
9/13/2011
To be approved
N. Garelli (CERN). NEC'2011 24
TDAQ Network Proposal
9/13/2011
• Current network architecture:– system working well– EF core router: single point of
failure– new technologies
• 2013: replacement of cores mandatory (exceeded life-time)
SV
ROSROSROS
XPUXPUXPUXPUXPUXPU
EFEFEF
SFI
SFO
DC
EF• Proposal: merge DC&EF
networks OK with new chassis some cost reductionperfect for TDAQ farms evolutionmixing functionalitiesreduce scaling potential with actual TDAQ farms
configuration
SV
ROSROSROS
PUPUPUXPUXPUPU
SFO
SFI
N. Garelli (CERN). NEC'2011 25
ATLAS Upgrade Draft Schedule – Phase1
Long Shut-Down
• TDAQ farm & network consolidation• L1 @ 100 kHz• IBL
2013 E = 6.5-7 TeVL = 1034cm-2s-1
9/13/2011
Upgrade Phases
after Shut-Down
ATLAS activities
TDAQ related
2017 PHASE 1 E = 7 TeVL = 2 1034 cm-2s-1
Level-1 Upgrade to cope with pile-up after phase-1• New muon detector
Small Wheel (SW)• Provide increased
calorimeter granularity• Level-1 topological trigger• Fast Track Processor (FTK)
CONSOLIDATION
N. Garelli (CERN). NEC'2011 26
New Muon Small Wheel (SW)• Muon precision chambers (CSC & MDT)
performance deteriorated − need to replace with a better detector
• Exploit new SW to provide also trigger information− today: 3 trigger stations in barrel (RPC) &
end-caps (TGC) New SW = 4th trigger station
− reduce fake − improve pT resolution− level-1 track segment with 1 mrad
resolution• Micromegas detector: new technology
which could be used
9/13/2011 Small Wheel
N. Garelli (CERN). NEC'2011 27
L1 Topological Trigger
• Proposal: additional electronics to have a Level-1 trigger based on topology criteria, to keep it efficient at high luminosities: Df, Dh, angular distance, back-to-back, not back-to-back, mass– di-electron low lepton pT in Z, ZZ/ZW,WW, H→WW/ZZ/tt and
multi-leptons SUSY modes– jet topology, muon isolation, …
• New topological trigger processor with input from calorimeter & muon detectors, connected to new Central Trigger Processor
• Consequence: longer latency, develop common tools for reconstructing topology both in muon & calorimeter detectors
9/13/2011
Under discussion
N. Garelli (CERN). NEC'2011 28
Fast Track Processor (FTK)
• Introduce highly parallel processor:– for full Si-Tracker– provides tracking for all L1-accepted events
within O(25μs) Reconstruct tracks >1 GeV
– 90% efficiency compared to offline– track isolation for lepton selection– fast identification of b & τ jets– primary vertex identification
• Tracks reconstruction has 2 time-consuming stages:– pattern recognition Associative memory– track fitting FPGA
• After L1, before L2– HLT selection software interface to FTK output (tracks available earlier)
9/13/2011
Pattern fromreconstruction
Good match betweenPre-stored & Recorded
patterns
Discarded patterns
Pre-stored patterns
N. Garelli (CERN). NEC'2011 29
ATLAS Upgrade Draft Schedule – Phase2
Long Shut-Down
• Reduce heterogeneity in TDAQ farms & networks
2013 PHASE 0 E = 6.5-7 TeVL = 1034cm-2s-1
9/13/2011
Upgrade Phases
after Shut-Down
ATLAS activities
TDAQ related
2017 PHASE 1 E = 7 TeVL = 2 1034 cm-2s-1
• FTK• L1 Topological trigger
2021 PHASE 2E = 7 TeVL = 5 1034 cm-2s-1
2. Precision muon chambers used in trigger logic dismount as less as possible3. L1 Track Trigger
1. Full digital read-out of calorimeter (data & trigger)• faster data transmission• trigger access to full calorimeter resolution (provides
finer cluster and better electron identification) proposed solution: fast rad-tolerant 10 Gb/s links
N. Garelli (CERN). NEC'2011 30
Improve L1 Muon Trigger – Phase2Current muon trigger: • trigger logic assumes tracks to come from interaction point (IP)• pT resolution limited by IP smearing (Phase2: 50mm ~150mm)• MDT resolution 100 times better than trigger chambers (RPC) Proposal: use precision chambers (MDT) in trigger logic
– reduce rates in barrel– no need for vertex assumption– improve selectivity for high-pT muons
9/13/2011
• Current limitation: MDT read-out serial & asynchronous Phase2: improve MDT electronics performance (solve latency problem)• Fast MDT readout options:
– seeded/tagged methoduse information from trigger chambers to define RoI & only consider small # of MDT tubes which falls into the RoI. Longer latency
– unseeded/untagged methodstand-alone track finding in MDT chambers. Larger bandwidth required to transfer MDT hit pattern
N. Garelli (CERN). NEC'2011 31
Track Trigger – Phase2
• Possible to introduce L1 track trigger keep L1 rate @ 100 kHz– combine with calorimeter to improve electron selection– correlate muon with track in ID & reduce fake tracks– possible L1 b-tagging
• L1 track trigger Self Seeded– use high pT tracks as seed– need fast communication to form coincidences between layers– latency of ~3m s
• L1 track trigger ROI Seeded– need to introduce a L0 trigger to select RoI at L1– long ~10m s L1 latency
9/13/2011
New Inner Detector • only with silicon sensors• better resolution, reduced occupancy• more pixel layers for b-tagging
N. Garelli (CERN). NEC'2011 32
multi-jet event at 7 TeV
CMSThe Compact Muon Solenoid
9/13/2011
N. Garelli (CERN). NEC'2011 33
CMS Consolidation Phase
Long Shut-Down
Trigger & DAQ consolidation• x3 increase HLT farm
processing power• replace HW for Online DB
2013
9/13/2011
Upgrade Phases
after Shut-Down
CMS activities
TDAQ related
CONSOLIDATION
MuonsCMS design: space for a 4th layer of forward muon chambers (CSC & RPCs)• better trigger robustness in
1.2<|h|<1.8 • preserve low pT threshold
E = 6.5-7 TeVL = 1034 cm-2s-1
N. Garelli (CERN). NEC'2011 34
CMS Upgrade Draft Schedule – Phase1
Long Shut-Down
2013 E = 6.5-7 TeVL = 1034 cm-2s-1
9/13/2011
Upgrade Phases
after Shut-Down
CMS activities
TDAQ related
2017 PHASE 1 E = 7 TeVL = 2 1034 cm-2s-1
• New pixel detector• Upgrade hadron
calorimeter (HCAL) silicon photomultipliers. Finer segmentation of readout in depth
• New trigger system• Event Builder & HLT
farm upgrade
CONSOLIDATION • Trigger & DAQ consolidation• 4th layer muon detectors
Phase-1 requirements&plans as ATLAS• radiation damage change silicon
innermost tracker• maintain Level-1 < 100 kHz, low
latency, good selection tracking info @ L1+ more granularity in calorimeters DAQ evolution to cope with new
design
N. Garelli (CERN). NEC'2011 35
CMS New Pixel Detector – Phase1
• New pixel detector (4 barrel layers, 3 end-caps)• Need for replacement
– radiation damage(innermost layer might be replaced before)
– read-out chips just adequate for L=1034 cm-2s-1 with 4% dynamic data loss due to read-out latency & buffer to improve
• Goal– gives better tracking performance– improved b-tagging capabilities– reduce material using a new cooling system CO2 instead of C6F14
9/13/2011
N. Garelli (CERN). NEC'2011 36
CMS New Trigger System – Phase1• Introduce regional calorimeter trigger
– to use full granularity for internal processing– more sophisticated clustering & isolation algorithms to handle higher
rates and complex events • New infrastructure based on μTCA for increased bandwidth,
maintenance, flexibility• Muon trigger upgrade to handle additional channels & faster FPGA
9/13/2011
moving from custom ASICs to powerful modern FPGAs with huge processing & I/O capability to implement more sophisticated algorithms
Advanced TelecommunicationsComputing Architecture (ATCA). Dramatic increase in computing power & I/O
N. Garelli (CERN). NEC'2011 37
CMS Upgrade Draft Schedule – Phase2
Long Shut-Down
2013
9/13/2011
Upgrade Phases
after Shut-Down
CMS activities
TDAQ related
2017 PHASE 1 E = 7 TeVL = 2 1034 cm-2s-1
2021 PHASE 2 E = 7 TeVL = 5 1034cm-2s-1
CONSOLIDATION • Trigger & DAQ consolidation• 4th layer muon detectors
• New pixel detector• Upgrade HCAL silicon
photomultipliers• New trigger system• EventBuilder&HLT farm upgrade
• Install new tracking system track trigger
• Major consolidation of electronics systems
• Calorimeter end-caps • DAQ system upgrade
E = 6.5-7 TeVL = 1034 cm-2s-1
N. Garelli (CERN). NEC'2011 38
New Tracker• R/D projects for new sensors, new front-end, high speed link (customized
version of GBT), tracker geometry arrangement– >200M pixels, >100M strips
• Level-1 @ high luminosity need for L1 tracking
9/13/2011
~ 1 mm
~ 100 μm
pass fail2
• Delivering information for Level-1– impossible to use all channels for individual
triggers– Idea: exploit strong 3.8 T magnetic field and
design modules able to reject signals from low-pT particles
• Different discrimination proposals to reject hits from low-pT tracks data transmission at 40 MHz feasible:1. within a single sensor, based on cluster width 2. correlating signals from stacked sensor pairs
pass fail1
N. Garelli (CERN). NEC'2011 39
LHCbThe Large Hadron Collider beauty experiment
B0s meson μ+ μ-
9/13/2011
N. Garelli (CERN). NEC'2011 40
LCHb Trigger & DAQ Today
9/13/2011
Single-arm forward spectrometer (~300 mrad acceptance) for precision measurements of CP violation & rare B-meson decays
L0e, g
L0had
L0m
HLT1. High pT tracks with IP != 0
Global reconstruction
HLT2. Inclusive & exclusive selection
40 MHz
< 1 MHz
30 kHz
3 kHz
• Designed to run with average # of collisions per BX ~ 0.5 & nb~2600 L ~ 2 1032 cm-2s-1 running with L = 3.3 1032 cm-2s-1
• Reads-out 10 times more often than ATLAS/CMS to reconstruct secondary decay vertices very high rate of small events (~55 kB today)
• L0 trigger: high efficiency on dimuon events, but removes half of the hadronic signals
• All trigger candidates stored in raw data & compared with offline candidates:
• HLT1: tight CPU constraint (12 ms), reconstruct particles in VELO, determine position of vertices
• HLT2: Global track reconstruction, searches for secondary vertices
Event size ~35 kB
HW
SW
N. Garelli (CERN). NEC'2011 41
LCHb Upgrade – Phase1Interesting physics with ~ 50 fb-1 (design: 5 fb-1):• precision measurements (charm CPV, …)• searches (~1 GeV Majorana neutrinos,…)
9/13/2011
LLTpT of had, m, e,/y
40 MHz
• 2011: L ~O(150%) of design, O(35%) of bunches
• after 2017: Higher rate higher ET threshold even less hadronic signals
Calo, Muon
1-40 MHzAll sub-detectors
HLTTracking, vertexing, inclusive/exclusive selections
20 kHz
CPU
farm
Cust
om
elec
tron
ics
UPGRADE NEEDED• increase read-out to 40 MHz & eliminate
trigger limitations• LLT will not simply reduce rate as L0, but will enrich
selected sample• new VELO detector• no major changes for muon & calo• upgrade electronics & DAQ
• data link from detector: components from GBTreadout-network made for ~ 24 Tb/s
• common back-end read-out board: TELL40. Parallel optical I/Os (12 x > 4.8 Gb/s), GBT compatible
42
Need for Bandwidth – Phase2
• New front-end GigaBit Transceiver (GBT) chipset – point-to-point high speed bi-directional link to send data from/to counting room at
~5Gb/s– simultaneous transmission of data for DAQ, Slow Control, Timing Trigger & Control (TTC)
systems– robust error correction scheme to correct errors caused by SEUs
• Advanced Telecommunications Computing Architecture (ATCA)– point-to-point connections between crate modules – higher bandwidth in output
• Which electronics in 20 y? Will VME be still ok? Do we need ATCA functionality?9/13/2011 N. Garelli (CERN). NEC'2011
Front-End~200 Mb/s BoardBoard
VME
PC
~40 Mb/s
S-link~200 Mb/s
Ethernet1 Gb/s
Read-Out System
Read-out from cavern to counting room
GBT ~5 Gb/s
ATCA
~40 Gb/s
Ethernet ~40 Gb/s
N. Garelli (CERN). NEC'2011 43
Conclusion• Trigger & DAQ systems worked extremely well until now• After the long LHC shutdown of 2017: beyond design
– increased luminosity – increased pile-up
• Experiments need to upgrade to work beyond design– New Inner Tracker: radiation damage & more pile-up– Level-1 trigger: more complex hardware selection & deal with longer
latency– New read-out links: higher bandwidth– Scale DAQ and Network
• Difficult to define upgrade strategy as of today– unstable schedule– maintaining current experiments
• One thing is sure: LHC experiments upgrade will be exciting
9/13/2011