Reliability-based Calibration of Partial Safety Factors for Wind Turbine Blades
Maximize your calibration event rate with partial events
description
Transcript of Maximize your calibration event rate with partial events
Maximize your calibration event rate with partial events
Ignacio Aracena (SLAC)
SLAC ATLAS forum
March 18th 2009
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Outline
• Introduction– Motivation
– The ATLAS detector
– Calibration requirements
– The ATLAS TDAQ system
• Partial events for calibration
• Calibration with partial events– Inner detector alignment
– LAr calibration
– Tile calibration
– Test results
• Rate studies with partial events
• Open issues
• Summary
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Motivation
Physics at the LHC:
New physics with (relatively) high pt at few Hz
vs SM physics at ~kHz
ATLAS trigger strategy for new physics:• Improve physics object selection at three trigger levels• Region of Interest (RoI) minimizes data
requests/shipping through network
Level 1 : Identifies RoI to seed L2 @ 100kHz
Level 2 : Improves RoI eta, phi, pT by using
high detector granularity, accept event rate ~3kHz
Event Filter : full event data available for further
improvement, output rate ~200Hz, i.e. 300MB/s to
permanent storage for offline analyses.
Trigger architecture driven by physics programme
How much trigger rate can we afford for calibration events during physics run?
L1 out 100kHz
L2 out 3kHz5GB/s
EF out 200Hz300MB/s
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The ATLAS detector
EM calorimeter:
LAr calorimeter
Tracking :
Pixel, SCT, TRT
Muon spectrometer
TGC/RPC (trigger chambers)
CSC/MDT (precision chambers)
Hadronic calorimeter:
Tile calorimeter (barrel)
LAr calorimeter (endcaps)
ATLAS subdetectors
Precise and fast calibration of different subdetectors is crucial for achieving performance goals
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Event data volume composition
• Event data in terms of Readout buffers (ROBs) requested by
TDAQ:
– LAr 762 ROBs
– Tile 64 ROBs
– Pixel 132 ROBs
– SCT 86 ROBs
– TRT 192 ROBs
– Muons ~400 ROBs
– Total ~1600ROBs
• 1ROB ~ 1kB
• Full event with data of all the ROBs is ~1.5MB (about 50%
from LAr...)How much data is needed for calibration of subdetectors?
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Calibration requirements
• Inner detector alignment– Need 6-8 M isolated tracks in 6 hours for pixel/SCT and in 24 hours
for TRT
– Requires ~50Hz of isolated tracks
• LAr calibration– Study pulse shape of individual cells
– Requires ~5 Hz to achieve precision of <1%
• Muon spectrometer– Need to collect ~106 muons/day for MDT t0 calibration
– ~1kHz of muon tracks
• Tile calorimeter– Illuminate full calorimeter with dedicated tile calibration system, run
during empty bunch crossings
• New calibration types?
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Calibration vs Physics
L1 out 100kHz
L2 out 3kHz5GB/s
EF out 200Hz300MB/s
Muon spectromter calibration ~1kHz ≈ L2 accept rate
Inner detector alignment ~50Hz25% of EF output rate
LAr calibration ~5Hz3% of EF output rate
Calibration rate appear to be not matching the
rate limits of TDAQ design scheme at first glance!
Can we take calibration data during physics runs?
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The ATLAS TDAQ system
L1
L2
EF
ReadOut Systems (ROS)Readout buffers (ROBs)
Event builder (SFI)
Data logger (SFO)
3 kHz
200 Hz
3 kHzRoI
100 kHz
Tier0
200 Hz
hard
war
eso
ftw
are
Level1 : If RoI found, all detector data is kept in the
Readout buffers (ROBs) of the Readout system (ROS).
Level2 : Requests data from RoI, with full detector
granularity. If event is accepted, the event is fully built
Event builder : For L2 accepted events the full event
data from the ROS is pulled to build the full event.
Event Filter : Receives full event, which can be used for
further improvements. Sends accepted events to the data
logger (SFO)
SFO : Writes events into different data streams, sends
data to offline mass storage
Event dataflow
ATLAS TDAQ system is based on:
L1 100kHz → L2 3kHz → EF 200Hz
full event size ≈ 1.5MB, RoI size ≈ 3% of full event
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The TDAQ system
L1
L2
EF
Event builder (SFI)
Data logger (SFO)
3 kHz
200 Hz
3 kHzRoI
100 kHz
Tier0
200 Hz
hard
war
eso
ftw
are
ATLAS TDAQ system is based on:
L1 100kHz → L2 3kHz → EF 200Hz
full event size ≈ 1.5MB, RoI size ≈ 3% of full event
Network requirements:
bandwidth = event rate * event size
Max. bandwidth is fixed by the system installed at P1
(300MB/s)
(5600MB/s)Calibration events
should use small fraction of total bandwidth
need high trigger rate
don’t need the full event!
Can increase calibration event rates for same bandwidth budget by using partial events!
ReadOut Systems (ROS)Readout buffers (ROBs)
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Partial events for calibration
L1
L2
EF
Event builder (SFI)
Data logger (SFO)
3 kHz
200 Hz
3 kHzRoI
100 kHz
Tier0
200 Hz
hard
war
eso
ftw
are
(300MB/s)
(5GB/s)
Select calibration event at Level 2: • Fill list of detector (ROB) identifiers needed for a
specific calibration purpose.• In the event builder (SFI) use this list to pull out data
only from identifiers in this list and build partial event• Send partial event to SFO, no need to go through EF.
partial event building
Select calibration event at the Event Filer:• All events that are processed in the EF are fully built• Fill list of detector (ROB) identifiers needed for a
specific calibration purpose.• In the SFO use this list to extract only data fragments
from listed ROB identfiers• Create a partial event from the full event : event
stripping, ship and store only partial event
event stripping
For an allocated bandwidth partial events allow higher trigger rates of calibration events, i.e.partial events save bandwidth at the SFI and SFO
ReadOut Systems (ROS)Readout buffers (ROBs)
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Calibration + physics events
Logic to recover the partial event for calibration implemented • If only overlap at L2, apply event stripping in the EFD
•Allows further save of bandwidth in the EFD• If overlap at EF, apply event stripping at the SFO
Overlapping events: events that are selected by calibration triggers and physics triggers
PT = EF processing task
EFD = Event Filter data flow program
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Calibration requirements and partial events
• Inner detector alignment– Need 6-8 M isolated tracks in 6 hours for pixel/SCT and in 24 hours for TRT– Requires ~50Hz of isolated tracks– partial event build
• LAr calibration– Study pulse shape of individual cells– Requires ~5 Hz to achieve precision of <1%– event stripping
• Muon spectrometer– Need to collect ~106 muons/day for MDT t0 calibration– ~1kHz of muon tracks– partial event building? Muon group has developed a standalone “TDAQ”
system to extract muon tracks. Less flexible than using partial event from TDAQ
• Tile calorimeter– Illuminate full calorimeter with dedicated tile calibration system, run during
empty bunch crossings– partial event building
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Inner Detector alignment
Requirements• Get high rate O(50Hz) over wide pT range
Chains in current Lumi1E31 menu (athena 15.0.0):• trk9i_id, prescale 40• trk16i_id, no prescale • Route to “calibration_IDTracks” stream
Fill list of ROBs at L2 use case for partial event building
(Anna Sfyrla, Carlos Escobar)
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LAr calibration
Requirements• Sufficient rate (5Hz) given by photon triggers
into EF, no need for additional rate using
partial EB• Minimize bandwidth at the EFD/SFOChains in current Lumi1E31 menu (athena 15.0.0):
• g3_larcalib (PS 10^6)• g10_larcalib (PS 100)• g20_larcalib (PS 1)• g20i_larcalib • j10_larcalib (PS 10^6)• j80_larcalib (PS 10^6)
Fill list of ROBs only at EF selectionuse case for event stripping
(Nicolas Berger, Guillame Unal, Isabelle Wingerter-Seez)
LVL1EM RoI
LVL2photon selection
EFphoton selction
event stripping use only ROBs
inside RoI
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Tile calibration
Tile calorimeter has dedicated calibration system:• Laser injection (timing studies)• Charge injection (pulse shape)
which illuminates the full tile calorimeter
Used during emtpy bunch crossing
Chains used in cosmic trigger menu• TileCalib_laser• TileCalib_cis
Trivial use case of partial event with a complete subdetector (Andrea Dotti, Oleg Solovyanov)
LVL1CALREQ
LVL2fill list with all
tile ROBs
partial event build
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Tests with AtlasHLT-14.5.0
• Setup multihost partition on lxplus with AtlasHTL-14.5.0 (tdaq-02-00-00)– 2 L2 segments (L2SV, L2PUs), – 1 EBEF segments (2 SFIs, 1 SFO, 1 EF segment, 4PTs)– 1 ROS segment (8 ROSs)
• Data sample : /pcatr-srv1/data/files/aagaard/14.5.0/enhancedBias10TeV/BS/ (1200 events)– “enhanced bias” = L1 preselection EM3, MU4, TAU5, J18, FJ18,
XE25, TE250 – preload the data on ROS (ROS application running on lxplus node)
• Lumi1E31 menu– testing the ID and LAr calibration streams
• Recorded monitoring histograms after ~1hour run• Monitoring plots from this test on the following slides
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Partial event building performance – event size
Size of built events in the SFI Event size vs streams in the SFI
Full event size ~2MB (MC data)Partial event ~50kB (~3% of full event)
overlapping events (calib + phys)need to be stripped
partial events for ID alignment
About 30% of ID alignment events overlap with physics eventsOverlap fraction can be tuned with the menu
Impact on resources? See next slide
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Partial event building performance – rates
Contribution to event rate at the SFI Bandwidth contribution at the SFI
ID alignment event rate comparable to physics event rates
stream X event rate / total event rate stream X event build rate / total event building rate
Pure ID alignment events use very small fraction of total bandwitdh
overlapping events (calib + phys)need to be stripped
Partial event building minimizes the bandwidth fraction used for calibration events
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Event stripping performance – event size
Event size vs streams in the SFO
(ignore calibration_LArCells, bug in menu)stripped events for LAr calibration
(full events from calibration_LArCells, bug in menu)
Full event size ~2MB (MC data)Partial event ~50kB (~3% of full event)
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Event stripping performance – event size
Event size vs streams in the SFO
(ignore calibration_LArCells, bug in menu)stripped events for LAr calibration
(full events from calibration_LArCells, bug in menu)
Full event size ~2MB (MC data)Partial event ~50kB (~3% of full event)
ID alignment events not strippedbug, fixed in 15.0.0
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Event stripping performance – rates
LAr calib event rate comparable to physics event rates
Contribution to event rate at the SFOstream X event rate / total event rate
Bandwidth contribution at the SFOstream X event build rate / total event building rate
LAr calib events use very small fraction of total bandwitdh
Event stripping minimizes the bandwidth fraction used for calibration events
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Examples from cosmic data taking runs
• Previous slides showed only tests with MC data
• Tile calibration and ID alignment stream exercised during
cosmic data taking runs in following slides
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Tile calibration – example from cosmic
Exercised during cosmic runs, example here from run 92082• Full event size ~5MB (LAr requesting 10 samples)• Tile calibration event size ~200kB, i.e. ~1% of full event• No rate monitoring plots for this run (Atlas release 14.2.23), but with given event
size uses only ~1% of bandwidth• Event successfully used for calibration
Num
ber
of
even
ts
Event Size (kB)
full event ~5MBpartial event ~200kB
LVL1CALREQ
LVL2fill list with
all tile ROBs
partial event build
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Inner detector alignment with cosmics
Run 90943
Use chains developed for cosmic data (e.g. CosmicsAllTeTRTxK*, CosmicsAllTeSiTrack*, CosmicsAllTeIDScan*) and apply PEB on those
✘ … CosmicsAllTe chains do not have ‘well defined’ RoIs
✘ … chains that do tracking at the TRT are not good for testing since TRT does not provide η measurement.
Modify the TrigROBListWriter.cxx to loop over the tracks and get η-φ range from the tracks
Apply modified TrigROBListWriter.cxx to two chains: o CosmicsAllTeIDSCAN_AllPhysics_TrkHypo ando CosmicsAllTeSiTrack_AllPhysics_TrkHypo
Generate new cosmic menu that contains these new chains, and run with this menu on cosmic data.
The generated raw data will contain information from the ID only and for the η-φ range that is defined by the modified TrigROBListWriter.cxx
Compared raw data generated with and without
the PEB applied in the chains
(Anna Sfyrla, Carlos Escobar)
Partial events gives same results as full event data
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HLT rate studies with partial events
• Use partial event to store only trigger decision bits from L1/L2/EF– Allows high statistics rate studies
– https://twiki.cern.ch/twiki/bin/view/Atlas/BeatenbergActions#General_Action_Items , see “T4”
• Could also be combined with monitoring information for TDAQ performance tests
• Basic TDAQ infrastructure ready. Need to configure menu “chain”, study the impact on the resources
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Open issues
• Only one list of ROBs (subdetectors) per event. List is union
of all partial events. Results in overlapping ROBs (e.g. LAr
ROBs showing up in ID alignment events)
• Tests on MC show no overlap between LAr calibration and ID
alignment. More studies needed
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Open issues
• Only one list of ROBs (subdetectors) per event. List is union
of all partial events. Results in overlapping ROBs (e.g. LAr
ROBs showing up in ID alignment events)
• Tests on MC show no overlap between LAr calibration and ID
alignment. More studies needed
• Bandwidth budget per sub-detector calibration?
– Need to establish rules/policy
– Needs to be discussed across sub-detector groups and TDAQ group
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Summary
• Calibration with partial events – Using partial events for calibration of sub-detectors allows to increase
the event rate for a given bandwidth budget
– Flexible system that allows calibration data taking with all subdetectors
• Being used by LAr, ID, Tile– Partial event already tested and used at P1 during technical runs, cosmic
data taking
– Muon MDT t0 calibration? Standalone system does not offer flexibility of partial events. Next customer on the list
• Potential new use case discussed in Beatenberg– Partial event build with only trigger decision bit information for trigger
rate studies
• New calibration types?– Advantage of partial event is flexibility, can accommodate all sub-
detectors
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Outlook
• Run test at P1– Uses real system
– Larger statistics available
– Can re-play cosmics and/or pre-load MC data
• Implement monitoring– Rate plots shown here not implemented yet in official SFI/SFO tags
– New monitoring plots?