8/18/2004 E. Monnier - CPPM - ICHEP04 - Beijing 1
Atlas liquid argon calorimeter status
E. Monnieron behalf of the Atlas liquid argon calorimeter group
Introduction Construction and integration status Performances Conclusion
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Design performances
Benchmark channels: H→, H→4e, W’, Z’…
+ running conditions Design requirements: energy resolution and uniformity
σ/E = 10%/√E ⊕ 0.7% for e, σ/E = 50(100)%/√E ⊕ 3(10)% for jet |η|<3 (3<|η|<5)
Angular resolution: 50 mrad/√E for e, Linearity of 0.1% for e, and <2% for hadronic Particle id and separation: e, jets, , π0
Dynamic range 20 MeV to a few TeV Time measurements, Hermiticity, Radiation….
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EM Endcap Ps |η|<1.8
EM Barrel+Ps
Hadronic Endcap
Forward
The Atlas larg calorimeters
Em barrel |η|<1.475 (Pb/Lar) Em endcap 1.375<|η|<3.2 (Pb/Lar) Hadronic endcap 1.5<|η|<3.2 (Cu/Lar) Forward 3.2<|η|<4.9 (Cu, W/Lar)
> 200000 channels
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32 Modules coldtested and integrated
EM Barrel
Barrel Closed
cooled down
MC
e
<0.014% dead channels ! 0.1% HV ½ gap isolated Barrel at LArg temperature Under extensive test In the pit early October
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Endcap: EM 1/4
8 Modules coldtested and integratedPer wheel !
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Endcap: HEC 2/4
32 Modules cold tested and integrated
Per wheel (2x2)
Space to insert Fcal
Hec2, Hec1, Emec
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Endcap: FCAL 3/4
3 Modules cold tested and integrated per wheel
Cu (em)W (had)
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Endcap 4/4
EC C, Em+Had+Fcal integrated Closed and ready for cold test
EC A, Em integrated, Had under integration, Fcal ready for integration
Em: <0.005% dead channels and 0.1% HV ½ gap isolated Hec: 0.03 % dead channels and 0.14% HV gap isolated Fcal: 0.03, 0.17 and 0.55 % of HVRod isolated Calorimeter system moving toward commissioning phase !!
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Beam test Performances
4 barrel and 3 endcap EM production modules tested 24 HEC prod modules tested (3 frt+3 rear/test) Fcal-C tested HEC/EMEC combined testEM End-capEM Barrel EMEC/HEC
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EM linearity and energy
resolution
Linearity within ±0.25 (0.1)% for E>10 (40) GeV Energy resolution within spec and MC agreement
Normalized to 100 GeV η=0.7
Beam energy (GeV)
Lin
eari
ty (
Er e
c/ E
beam
)
Beam energy (GeV)En
erg
y r
esolu
tion
9.4% /E0.1%
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EM Uniformity
Global constant term within spec (0.7%)
Barrel P13 P15<E> 233.3 GeV 236.6 GeVRMS 0.57% 0.64%
EndCap ECC0 ECC1 ECC5<E> 119.7 GeV 120.0 GeV 120.2 GeVRMS 0.58% 0.53% 0.55%
EndCapBarrel
Energy (GeV)η (middle)
En
erg
y (
GeV
)
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Position and angular resolution
within spec
55 mrad/√E
Z~20mm
Z~5mm
245 GeV e
Endcap ~1.7
Energy (GeV)20 100 150
θ (
mra
d)
x √E
~550 mmat =0
~250 mmat =0
Barrel
Barrel
re
solu
tion
(
un
its x
1000)
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Time measurement
Cell energy (GeV)
Barrel
Tim
e r
esolu
tion
(p
s)
Fast signal in Argon accurate time measurement Zvertex measurement, long lived particle id,… Front end electronic very low constant term < 20ps
70ps constant term within spec (100ps)
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Muon measurements
Muon signal large enough in middle layer but also seen in strips: S/N = 7 Endcap S2 S/N = 7-10 in Barrel S2 Seen also in HEC
Endcap
Barrel
Powerful tool for commissioning:intercalibration (1ns), position (0.5mm EM, mms HEC),uniformity (<3‰ EM, 1% HEC) …
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(84.1 0.3)% /E
Emec/Hec combined test
Emec + Hec (3frt+2rear), non pointing geometry Study 1.6<||<1.8 calibration constants for atlas e/h compensation: weighting of em cluster energy MC validation: room for improvement
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Fcal calibration run
FCAL energy calibration Edge scan at high || + HV test
a=(3.760.06)%b=(24.50.84)GeV %c=(145.51.6) GeV%
P
c
P
ba
E (GeV)
σ/E
(%
)
Electron energy resolution
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Combined tests with “final” atlas setup and readout Barrel: Tracker, EM, hadronic calo, Muons system End-cap: EM, HEC, FCAL Tuning ATLAS hardware, online and offline software, calibration…
TRT LAr
Tilecal
MDT-RPC
EMEC
HEC front
HECrear
FCAL 1
FCAL 2Cold TC
WarmTC
2004 beam tests
(the last before LHC)
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Next
2005: Install electronicsOctober 2004
1 March 2004April 2004
2005: EC cryostats…
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Conclusions
Larg calorimeter system in its final integration stage before installation in the pit: October for barrel Beam tests have exhibited required performances Combined 2004 beam test with final ATLAS readout system ongoing successfully Readout electronic under production Commissioning phase will start next year
But still a lot of work and understanding of the system to be ready for first data in 2007