the atlas tile calorimeter: commissioning and preparation for collisions presented by oleg...
TRANSCRIPT
The ATLAS Tile Calorimeter:Commissioning and Preparation for Collisions
Presented by Oleg Solovyanov On behalf of the Tile Calorimeter Collaboration of ATLAS experiment
Other talks about Tile Calorimeter:ATLAS Tile Calorimeter performance for single particles in beam tests, T.DavidekThe response of ATLAS Tile Calorimeter to pions and protons, M.SimonyanMC Comparison in the ATLAS Combined test-beam, P.Speckmayer
CommissioningCalibration systemsCosmicsPreparation for collisions
XIII International Conferenceon Calorimetry
in High Energy Physics
CALOR 2006Pavia, Italy
Tile Calorimeter
Barrel part (<1.7) of the ATLAS Hadron CalorimeterSampling calorimeter: iron/scintillating tiles (perpendicular to beam axis)Double PMT readout via WLS fibersTile readout is grouped into projective geometry cells10K readout channels in 256 electronics “drawers”, data sent over fiber linksAnalog trigger sums from projective towers to L1 trigger system
CALOR 2006, 26-30 May, Pavia O.Solovyanov IHEP 2
CALOR 2006, 26-30 May, Pavia O.Solovyanov IHEP 3
Status at CALOR 2006:
Barrel at final position Z=0Ext.Barrels completeServices being connectedFinal power supplies are comingStandalone FE commissioning
Still to do in 2006-2008:Finish servicesInstall power suppliesFinish FE commissioningCalibration systemsIntegration within ATLASCosmic runsMore...
Today’s status. Services
All the services have been connected&testedCoolingPowerTriggerReadout
Auxiliary fibers connection
Connection aux.fiber-Patch Panel
Drawer Connection
Interface board connection inside drawer (End of Fiber)
USA15-UX15 fiber
Special tests for optical fibers: Attenuation test:
LED source & meter at 2 frequencies 1300, 850 nm with maximum acceptable loss of 3dB
OTDR: Optical Time Domain Reflectometer Analyses the loss in an optical fiber by: Injecting short laser pulses into it Counting the backscattering and reflection
photons as a function of time. The idea is to locate with a precision of few
centimeters any break or splice loss Length of fibers can be measured (used for
trigger delays) 12 fibers of barrel (out of 512) had to be
respliced (~2%) Tests done for trigger, readout, and laser fibers
CALOR 2006, 26-30 May, Pavia O.Solovyanov IHEP 4
In-situ certification with mobile readout unit
Online commissioning - final backend - real-time: fast response - low statistics
Offline commissioning - final TDAQ system - athena reconstruction - high precision - data integrity studies - calibration constants
FE electronics commissioning
Comissioning steps:Comissioning steps:
Pedestals: noise
Charge injection: electronics calibration digitizers
LED(Laser): PMTs, HV system
Cosmics: Tiles+PMT+readout
Data types:Data types:
I.Korolkov CALOR2006 – FE commissioning details
Tools
5
FE electronics long-term stability
Pedestals: high-frequency noise (pedestals, cosmic runs) - stablity of noise: variation in 4 months: < 0.1 ADC counts - stability in b-field: variation ON-OFF: < 0.1 ADC counts
Calibration constants (CIS data): - digitizer readout chain: RMS in 3 months: < 0.1% - integrator readout chain: RMS in 15 months: <0.1%
PMT gains (LED data) - stability in variying B-field: variation ON-OFF < 0.1%
Stability of PMT gain in B-field: variation ON-OFF < 0.1%
Stability of electronics calibration constant (3 months): Relative variation of calibration constant: < 0.1 %
Integrator gain stability (15 months) Relative variation for 20 modules < 0.1%
Module number Module number
low gain
high gain
RM
S/M
ean
LBA52
Vari
ati
on/M
ean
Summary: long-term stability < 0.1%
CALOR 2006, 26-30 May, Pavia O.Solovyanov IHEP 6
April 2007 – Extended barrel ready to move inside7
February 2008 – Extended Barrels moved in8
May 2008 – calorimeters closed and ready in final position 9
Detector control system (DCS)
DCS system is fully operational All FE modules are powered HV is on Monitoring tools are provided Operating parameters are stableCALOR 2006, 26-30 May, Pavia O.Solovyanov IHEP
10
Data Acquisition System (DAQ)
106 hours of continous cosmic running!
CALOR 2006, 26-30 May, Pavia O.Solovyanov IHEP 11
Data Quality Monitoring
Channel based monitoring, pedestals and samples
Physics quality, timing, occupancy
Automated histogram/plots checks
Monitoring at all levels of with appropriate focus
CALOR 2006, 26-30 May, Pavia O.Solovyanov IHEP 12
Mixer
Tile
Fibre
PMT
Divider
3-in-1
Analog
Digital
Optical Interface
IntegratorADC-I Adder
Digitizer
Physics events
Minimum Bias
Cesium
Laser
Charge Injection
ROD
HVOpto
HVMicro
Canbus
Canbus
HV
Energyµ
TriggerHad
Trigger
DC Calibrations,Luminosity Monitoring
Mother Board
PMT Block
TileCal cell
L H
Drawer
TTC
Calibration Systems
Laser calibration system
Laser calibration system is fully installedCommissioning is well under wayLaser runs are taken routinelyAllows timing equalisation
An adjustment of fibers has been doneMore narrow amplitude spread achieved
CALOR 2006, 26-30 May, Pavia O.Solovyanov IHEP 14
First Cesium scans of installed modules in the pit
Cesium calibration system is working3 Cs137 sources installed to calibrate all systemsFirst runs performed in all modules, 8 hours per runNo serious problems have been foundHV setup and tuning is under wayTests with full magnetic field until JulyAim to calibrate all 10K channels at em scale ~2%
PMT response to passing source
L1 Calo tests
CosmicsD.Prieur
L1 calorimetry trigger is taking shape:
Mapping tests using CIS pulses
Timing tests using Laser
Energy calibration using CIS
Energy calibration using cosmics
Calibration with cosmic muonsTime distribution of cosmic signals
CALOR 2006, 26-30 May, Pavia O.Solovyanov IHEP 16
Integration milestone weeks
Starting from the end of 2006 a number of integration weeks was organized Move from standalone detector commissioning to the combined one Collect cosmic data, with different trigger sources Perform calibrations, timing and trigger setup Train shifters, multiply experts, enhance monitoring tools and documentation Prepare for beam!
CALOR 2006, 26-30 May, Pavia O.Solovyanov IHEP 17
M1 – 2006-12
M2 – 2007-02
M3 – 2007-06
M4 – 2007-08
M5 – 2007-10
M6 – 2008-02
M7 – 2008-05
Beam!
Cosmic muon event in extended barrel triggered by L1Calo
CALOR 2006, 26-30 May, Pavia O.Solovyanov IHEP 18
Cosmic muon event in the TileCal barrel
CALOR 2006, 26-30 May, Pavia O.Solovyanov IHEP 19
3D display of cosmic muon event in TileCal
CALOR 2006, 26-30 May, Pavia O.Solovyanov IHEP 20
Another 3D event in Tile
CALOR 2006, 26-30 May, Pavia O.Solovyanov IHEP 21
Fake Missing ET From Cosmic Rays
Events with 4 TeV MET?
Events with > 200 GeV MET, rate: ~ few/day
2007 data runs 15923 to 17020, bad channels removed, Ecell>400MeV, MET@cell level, em scale
04/21/23 LAr Commissioning 23
Air shower, good pulse shapesET miss (TileCal) = 130 GeV
Δt = -16 ns
04/21/23 LAr Commissioning 24
Hard bremsstrahlungET miss (TileCal) = 1.2 TeV
Good signal pulse shapesIn TileCal (& LAr)
Δt = -16 ns
04/21/23 LAr Commissioning 25
Hard bremsstrahlungETmiss = 4 TeVTileCal 10-bit ADC saturated (1023)
Signal reconstruction assigns large error to saturated samples, fits remaining samples(tested in high/low gain)
Also neighbouring cells with normal pulse shapes, including 1 cell with 200 GeV. Energy loss in just 1 scintillator tile less likely.Highest energy event recorded in ATLAS? Δt = -30 ns
Background Rejection via
Calorimeter Timing
04/21/23 26
Transit time from top to bottom of
Calorimeter (~ 6m)
~ 18 -19 ns
Jets MC
Cosmics MC
ATLASCosmicData2007
Muons on top: t<0
Muons on bottom: t>0
IP
Jet: t=0
Jet: t=0
Timing resolution order 1 ns
Rejection via Electromagnetic Fraction in Data
04/21/23Note: not quite a fair data/MC comparison as clustering not applied to data.Rather meant to indicate a cut which can be applied to reject background.
LAr Commissioning
Saturated PMT and surrounding cells
1.13 GeV
2496.36 GeV
0.58 GeV0.43 GeV
2.87 GeV
0.79 GeV
Conclusions
ATLAS Tile Calorimeter is fully installed and powered with all the necessary servicesAll FE and BE electronics have been thoroughly commissioned to arrive to the first collisions with minimal number of bad channels (<1%)DCS and DAQ systems are running in full swingA massive number of sofware and hardware tools have been developed during commissioning and used to ensure good performanceA good set of monitoring tools are ready to monitor the performance of the detectorAll calibrations systems are installed and working to provide well-calibrated detector for the first beamsTile Calorimeter is fully integrated with other ATLAS subsystems, including L1 triggerLarge data sets of cosmics data have been acquired and being studiedAn impressive number of experts and shifters are prepared for ATLAS running
Waiting for collisions!
Backup slides
M5 cosmics, triggered by muon chambers
Bottom
Top
M3 cosmics, energy deposited in TileCal, triggered by Tile
IPP Canada April 2005 Richard Teuscher 33
Examples of beam-halo muons in ATLAS
A typical snake …
Total rate 105 kHz E > 10 GeV 16 kHzE > 100 GeV 1 kHzE > 1 TeV 10 Hz
L=1034
Muons at cavern entrance