M. Lefebvre, U. of Victoria ATLAS Physics Workshop, May 2003, Athens 1

Beam Test Results from FCal, HEC and HEC+EMEC

ATLAS Physics Workshop

Athens, Greece

21-25 May 2003

ATLAS CalorimetersForward (FCal)

1998 module 0 testHadronic Endcap (HEC)

1998-2001 production module testsHEC + Electromagnetic Endcap (EMEC)

2002 combined testFuture Endcap LAr Beam Tests

2003 FCal full system beam test2004 FCal+HEC+EMEC combined beam tests

Michel LefebvreUniversity of Victoria

Physics and Astronomy

M. Lefebvre, U. of Victoria ATLAS Physics Workshop, May 2003, Athens 2

ATLAS Calorimeters

Hadronic Tile Calorimeters feature Fe/scintillator tiled readout with ∆η x ∆φ = 0.1 x 0.1, 3 longitudinal samplings, coverage |η|<1.7;

Hadronic Liquid Argon EndCapCalorimeters have Cu absorbers in a parallel plate geometry, ∆η x ∆φ = 0.1 x 0.1 (1.5<|η|<2.5), ∆η x ∆φ = 0.2 x 0.2 (2.5<|η|<3.2), 4 samplings;

Forward Liquid Argon Calorimetersfeature Cu (FCal1) and W (FCal2/3) absorber with cylindrical ionization chambers parallel to the beam line. Each module weights 2.1/3.9/3.8 tons and are 28/91/89 Xo and 2.7/3.7/3.6 λ deep. Principal coverage is 3.1<|η|<4.9, with cells of ∆η x ∆φ ≈ 0.2 x 0.2 – but non-projective!

Eletromagnetic Liquid Argon Calorimeters feature accordion Pb absorbers, highly granular readout (190,000 channels, 0.003 ≤ ∆η ≤ 0.05, 0.025 ≤ ∆φ ≤ 0.1, 2-3 longitudinal samplings), ~24-26 X0 deep, covers |η|<3.2, presampler up to |η|<1.8;

Tile CalorimetersTile Calorimeters

Electromagnetic Liquid Argon Calorimeters

Electromagnetic Liquid Argon Calorimeters

Forward Liquid Argon CalorimetersForward Liquid Argon Calorimeters

η=1.475η=1.8

η=3.2

Hadronic Liquid ArgonEndCap CalorimetersHadronic Liquid ArgonEndCap Calorimeters

See F. Djama’s talk

M. Lefebvre, U. of Victoria ATLAS Physics Workshop, May 2003, Athens 3

Endcap Region

FCal1FCal1 FCal2FCal2 FCal3FCal3

Cryostat walls(warm/cold)

Cryostat walls(warm/cold)

to interactionvertex

Hadronic EndCap

(2 wheels)

Hadronic EndCap

(2 wheels)

ElectromagneticEndCap

ElectromagneticEndCap

Cu ShieldingCu Shielding

p from LHC

P. L

och,

Uni

vers

ity

o f A

r izo

n aFCal1 FCal2

FCal3

HEC2

HEC1 EMEC

M. Lefebvre, U. of Victoria ATLAS Physics Workshop, May 2003, Athens 4

P. Loch, University of Arizona

pre-production prototypes of the electromagnetic (FCal1) and first hadronic(FCal2) modules, built to confirm simulated performance estimates and establish production techniques for the final modules;

¼ azimuthal segments at full depth, sufficient for lateral electromagnetic andhadronic shower containment

H6 tests, modules tilted to η = 3.7 in ATLAS

FCal “module 0” beam tests (1998)

M. Lefebvre, U. of Victoria ATLAS Physics Workshop, May 2003, Athens 5

M. Lefebvre, U. of Victoria ATLAS Physics Workshop, May 2003, Athens 6

FCal: electron energy

Exp.

GEANT3

GEANT4

a [%

GeV1/

2 ]b

[GeV

]c

[%]

Noise Cut Level in Multiples of σnoise

Ave

rage

Sig

nal M

C/Ex

p [%

]

GEANT3.21

GEANT4.2.0

Comparison of Signal Linearity and Energy Resolution (Testbeam Data/Simulations) Comparison of Signal Linearity and Energy Resolution (Testbeam Data/Simulations)

P. Loch, University of Arizona

GEANT4 reproduces average signal within ±1% for all considered noise cuts;

GEANT3 shows larger deviations for higher cuts, but reproduces fluctuations at higher energies better (shower dominant regime);

M. Lefebvre, U. of Victoria ATLAS Physics Workshop, May 2003, Athens 7

FCal: pion energy calibrationnew hadronic calibration scheme with cell signal weights depending on the radial distance

of the cell to the shower axis;

weights determined by resolution optimization fit to 200 GeV testbeam pions;

requires reconstruction of impact point and shower axis;

weights applied to pions and electrons (!) of all other energies to measure signal linearity, energy resolution and the e/pi signal ratio;

electroncalibrationelectron

calibrationelectron

calibrationelectron

calibration

hadronic halo boosthadronic halo boost

hadronic FCal2hadronic FCal2electromagneticFCal1

electromagneticFCal1

electromagneticcore suppressionelectromagneticcore suppression

electromagneticcore suppressionelectromagneticcore suppression

thermal noisesuppression

thermal noisesuppression

thermal noisesuppression

thermal noisesuppression

coherent noise suppressioncoherent noise suppression

10 cm 15 cm 10 cm 15 cm

Calibration Weights from 200 GeV Pions (Testbeam Data)Calibration Weights from 200 GeV Pions (Testbeam Data)Re

lat i

ve S

i gna

l Wei

g ht

Distance to Shower Axis D [mm] D [mm]

max ~ 3max ~ 3max ~ 2.5max ~ 2.5

A. Savine and P. Loch, University of Arizona

GEANT4 reproduces average signal within ±1% for all considered noise cuts; GEANT3 shows larger deviations for higher cuts, but reproduces fluctuations at higher energies better (shower dominant regime);

M. Lefebvre, U. of Victoria ATLAS Physics Workshop, May 2003, Athens 8

FCal: pion energy resolution

fixed calibration

radial weightsradial weights

fixed calibration

( )a = 89.7 ±1.09 % GeV( )c = 7.20 ± 0.10 %

( )a = 80.7 ± 0.73 % GeV( )c = 2.74 ± 0.16 %

Pion Energy Resolution (Testbeam Data)Pion Energy Resolution (Testbeam Data)

A. Savine and P. Loch, University of Arizona

pion signal linearity measured with “standard” fixed calibration (1 energy-independent constant/module, determined with 200 GeV pions) and “new” weighting scheme;

significant reduction of non-linearitiesby a factor 1.5-2 for Ebeam < 200 GeV by new calibration scheme;

remaining ~4% non-linearity probably not too important for ATLAS, as typical energies are significantly higher -> expect response to higher energy jets (!!) to be more linear;

method can work in jets in the forward direction as well, as jet shape in the FCal is more determined byhadronic shower spread than (transverse) energy flow in cone;

ATLAS requirement of energy reconstructionexceeded

( )( )100% 10%

GeVEE E

σ= ⊕

M. Lefebvre, U. of Victoria ATLAS Physics Workshop, May 2003, Athens 9

HEC beam tests

depth 1

depth 2

depth 3

depth 4

First HEC module 0 tests in 1998;

Results (2000 beam tests) published in NIM A482 (2002) 94-124;

3 modules (in phi) for HEC1 and 3 modules for HEC2 (3/32 of a complete endcap);

2 depth readout in each wheel;

H6 tests; due to cryostat size, non-pointing setup!

M. Lefebvre, U. of Victoria ATLAS Physics Workshop, May 2003, Athens 10

HEC beam tests

beam setup is non-pointing…

total leakage about 3.2%

front wheel: HEC1back wheel: HEC2

3 modules in azimuth cryostat beam window

accessible beam positions

NIM A482 (2002) 94-124

beam

M. Lefebvre, U. of Victoria ATLAS Physics Workshop, May 2003, Athens 11

HEC: electron energy

NIM

A48

2 (2

002)

94-

124

NIM

A48

2 (2

002)

94-

124

( )E a bE Eσ

= ⊕

energy resolution for 3 different impact points

response linearity for 4 different impact points is well within ±1%. Low energy decrease mainly due to 0.6Xo material in front of calo2.93±0.03 MeV/nA

M. Lefebvre, U. of Victoria ATLAS Physics Workshop, May 2003, Athens 12

HEC: muon response

NIM

A48

2 (2

002)

94-

124

NIM

A48

2 (2

002)

94-

124

180 GeV muon response: HEC can see muons

120 GeV muon response compared with simulation

M. Lefebvre, U. of Victoria ATLAS Physics Workshop, May 2003, Athens 13

HEC: pion energy response

NIM

A48

2 (2

002)

94-

124

NIM

A48

2 (2

002)

94-

124

energy dependence of the e/π ratio

for uncorrected data;

after correcting for energy leakage;

( )1.5

1 1 e he e h

e h fππ = ⇒

+ −∼

energy dependence of the mean energy fraction deposited in the longitudinal depth segments; open points are GCALOR; agreement is also good for lateral shower shape

depth 1 depth 2

depth 3 depth 4

M. Lefebvre, U. of Victoria ATLAS Physics Workshop, May 2003, Athens 14

HEC: pion energy resolutionenergy resolution for 3 different impact points

after electronic noise subtracted in quadrature

NIM

A48

2 (2

002)

94-

124

NIM

A48

2 (2

002)

94-

124

( )E a bE Eσ

= ⊕

intrinsic energy resolution is obtained after correcting for energy leakage; the result isa = (62.2 ±1.8)% GeV½ and b = (5.2 ± 0.2)%

Monte Carlo extrapolation to jets in ATLAS:pions: a = (54 ± 2)% GeV½

b = (2.6 ± 0.1)%jets: a = (56 ±3)% GeV½

b = (2.0 ± 0.2)%meets ATLAS requirements

M. Lefebvre, U. of Victoria ATLAS Physics Workshop, May 2003, Athens 15

HEC+EMEC combined beam test

2 x ½ HEC2 or 1/16 of a wheel

1/8 of an EMEC wheeldepth 1

depth 2depth 3

3 x HEC1 or 3/32 of a wheel

summer 2002; first combined test in the endcap region;

EMEC included the presampler for a total of 4 readout depths;

all results very preliminary!!!

L. Betev, Frankfurt University, Germany

M. Lefebvre, U. of Victoria ATLAS Physics Workshop, May 2003, Athens 16

HEC+EMEC combined beam testbeam setup is non-pointing…

beam

M. Lefebvre, U. of Victoria ATLAS Physics Workshop, May 2003, Athens 17

HEC+EMEC: typical signal for electrons and pions

electrons pions

H. Bartko and S. Menke, MPI

M. Lefebvre, U. of Victoria ATLAS Physics Workshop, May 2003, Athens 18

HEC+EMEC: electron response linearity of response effect of accordion geometry

H. B

artk

o an

d S.

Men

ke, M

PI

H. B

artk

o an

d S.

Men

ke, M

PI

0.414 MeV/nA;

decrease at low energy under investigation

shower shape under way

M. Lefebvre, U. of Victoria ATLAS Physics Workshop, May 2003, Athens 19

HEC+EMEC: pion energy reconstruction

H. Bartko and S. Menke, MPI

combine EMEC and HEC response (EM scale) with one weight for the HEC0.414 MeV/nA;

2.93±0.03 MeV/nA

EM EMEMEC HECE E x E= + ⋅

at 180 GeV, the optimum energy resolution obtained is 8.6% for x ≈ 1.12

M. Lefebvre, U. of Victoria ATLAS Physics Workshop, May 2003, Athens 20

HEC+EMEC: pion energy resolution

H. B

artk

o an

d S.

Men

ke, M

PI

x depends on energycombined resolution

compared with HEC stand-alone resuls

(%)

M. Lefebvre, U. of Victoria ATLAS Physics Workshop, May 2003, Athens 21

HEC+EMEC: Athena softwareHEC-EMEC raw test beamEPIO data

ntuple

Root user analysis

ConverterLArHECTBCnv

Athena packages

Athena data classes

PedestalsLArHECTBPed

ATLAS Transient Data StoreAthena TB Event

LArTBEvent

LArTBBeamChambersContLArTBCalibContainerLArTBEventLArTBHVDataContainerLArTBInstrumentLArTBRunLArTBSlowConrol

Athena EventLArRawEvent

LArDigitContainerLArFEB_DataContainer

TB ReconstructionLArHECTBAna

LArTBTimingObjectLArTBSignalContainer

At la

s LA

r Te

stbe

amA

t las

LAr

HE C

-EM

ECTe

stbe

am

MonitoringLArHECTBMon

TB ReconstructionLArHECTBAna

LArTBTimingLArPedestalSubtractLArSimplePolynomialLArTimeSubtract

LArTBSignalBuilderLArPedestalSubtractLArSimplePolynomialLArTDCCorrectionLArDigitalFilteringLArCalibrationLArSignalCorrectionLArReadGeometry

LArTBStandardNtupLArTBCombinedNtupLArHECUserHist

(User Analysis)

not in Athena

Athena (sub)Algorithms

M. Lefebvre, U. of Victoria ATLAS Physics Workshop, May 2003, Athens 22

FCal and FCal+HEC+EMEC

Pete

r Loc

h, L

eif S

have

r, Jo

hnR

uthe

rfoor

d

cold tail catcher

warm tail catcher

FCal2 Module 0

FCal1 Module 0

EMEC small wheel

4 x HEC mini modules

FCal+HEC+EMEC beam tests: spring-summer 2004;

requires purpose built HEC mini modules;

production of a cold tail catcher; brass/LAr 16 Xoand 1.6 λ;

production of a warm tail catcher; Fe/Scintillator

FCal full system test:summer 2003;

M. Lefebvre, U. of Victoria ATLAS Physics Workshop, May 2003, Athens 23

Summary

FCal1998 module 0 beam test: FCal meets ATLAS requirements2003 full calibration beam test starting next month

HEC1998-2001 production module tests: HEC meets ATLAS requirements

HEC+EMEC2002 combined test done: data analysis progressingFirst use of Athena during tests (monitoring) and for analysis

FCal+HEC+EMEC2004 combined beam test under preparation