Cosmic Rays for ATLAS Cosmic Rays for ATLAS Commissioning Commissioning Commissioning MeetingCommissioning Meeting

ATLAS Physics WorkshopATLAS Physics Workshop

Athens May 2003Athens May 2003

Halo+Cosmics group:Halo+Cosmics group: M.Boonekamp, F.Gianotti, M.Boonekamp, F.Gianotti, R.McPherson, P.Nevski, J.Pinfold, R.SolukR.McPherson, P.Nevski, J.Pinfold, R.Soluk

Cosmics Info:Cosmics Info: http://cern.ch/rmcphers/atlas/cosmics/ http://cern.ch/rmcphers/atlas/cosmics/

Athens May 2003 ATLAS Physics Workshop 2

OverviewOverview

Scheduled ~ 40 days of cosmic running end 2006Scheduled ~ 40 days of cosmic running end 2006 Could also imagine cosmic running with only Could also imagine cosmic running with only

calorimeters earlier, and further running in calorimeters earlier, and further running in January—March 2007 (machine cool down)January—March 2007 (machine cool down)

IS IT USEFUL? Study:Study:

Cosmic rates entering ATLAS cavern Hit or Geant “Digit” rate in different detector elements Calorimeter energy deposition (Triggers) (Offline Reconstruction)

Athens May 2003 ATLAS Physics Workshop 3

ATLAS GeometryATLAS Geometry

SX1

PX14PX16

PX15

UX15

USA15

Shafts (PX14 Shafts (PX14 and PX16) and PX16) Large windowsLarge windows

Critical to include in simulation

G3 GeometryG3 Geometry Surface buildings PX14, PX16 Shielding Concrete …

Athens May 2003 ATLAS Physics Workshop 4

Current Geant 3 simulationCurrent Geant 3 simulation

Rock ~ Silicon

600m x 600m x 200m deep

(2.33 g/cm3)

AirConcrete

Density = 2.5 g/cm3

Surface building

PX14/16 shielding

PX14

(14 m Inner Dia.)

PX16

(10 m Inner Dia.)

Full ATLAS Geant 3 Simulation (atlsim)

- Release 6.0.3

- Initial detector

- Full B fields

Athens May 2003 ATLAS Physics Workshop 5

In progress: refined descriptionIn progress: refined description

Ground density Ground density variation with depthvariation with depth

Suspension hallsSuspension halls Other caverns Other caverns

(USA15, US15)(USA15, US15) Being implemented by

R.Soluk and J.Pinfold in consultation with CERN civil engineers

Can be used for later simulations

Athens May 2003 ATLAS Physics Workshop 6

Cosmic Cosmic Flux Flux Two generators used so farTwo generators used so far

PDG approximation formula Single muon flux (Energy, cos ) Neglects muon decay-in-flight

Fit to measured fluxes Code from Alois Putzer (ALEPH simulation) Agrees at few % level with measured fluxes

Allkofer et al, Phys. Lett. 36B (1971), 425; A. Dar, Phys. Rev. Lett. 51 (1983), 227

For E > 50 GeV Agreement < 20% level between 2 generators

Third generator also under study (Soluk)Third generator also under study (Soluk) “CORSIKA” full cosmic ray shower program Useful for cosmic ray physics studies with ATLAS Includes “multi-muon” events, not present in other

generators

Athens May 2003 ATLAS Physics Workshop 7

Sample studiedSample studied

PDG single PDG single flux with cuts: flux with cuts: SURFACE :

0.35 < cos < 1 (above 70o hit earth’s

curvature)50 GeV < E < 5000 GeV -300 m < X0 < +300m -300 m < Z0 < +300m

(allow at 70o to enter ATLAS cavern)

ATLAS Y=0: use speed-up cuts (track extrapolation)

-30 m < X(Y=0) < +30 m -30 m < Z(Y=0) < +30 m

SURFACE RATES (before Y=0 cuts):

3 x 10-4 / (cm2 s)

1 x 106 / s

CURRENT SAMPLE:

1.2 x 109 18 min)

Athens May 2003 ATLAS Physics Workshop 8

Cosmics Cosmics in 0.01 sec in 0.01 sec

Athens May 2003 ATLAS Physics Workshop 9

Kine Distributions … Kine Distributions …

““Cavern”:Cavern”: ATLAS G3

volume

E, cos E, cos of of entering entering caverncavern

Athens May 2003 ATLAS Physics Workshop 10

Kine Distributions … Kine Distributions …

““Digit”:Digit”: Any G3 digit

(mostly MDT)

Athens May 2003 ATLAS Physics Workshop 11

Kine Distributions … Kine Distributions …

Through-goingThrough-going RPC digit, Y>0 RPC digit, Y<0 ID Digits

Can(?) adjust Can(?) adjust LVL1 RPC LVL1 RPC trigger for thesetrigger for these

Athens May 2003 ATLAS Physics Workshop 12

Kine Distributions … Kine Distributions …

Through-goingThrough-going RPC digit, Y>0 RPC digit, Y<0 Pixel Digits

LVL1 RPC trigger LVL1 RPC trigger should work (with should work (with timing adjustments)timing adjustments)

Athens May 2003 ATLAS Physics Workshop 13

Digit Distributions … Digit Distributions …

Detector planesDetector planes From digit

counting Number of

“ihit=1” hits

Athens May 2003 ATLAS Physics Workshop 14

Digit Distributions … Digit Distributions …

Detector planesDetector planes From digit

counting Number of

“ihit=1” hits

Athens May 2003 ATLAS Physics Workshop 15

Digit Distributions … Digit Distributions …

Detector planesDetector planes From digit

counting Number of

“ihit=1” hits

Athens May 2003 ATLAS Physics Workshop 16

Digit Distributions … Digit Distributions …

Detector planesDetector planes From digit

counting Number of

“ihit=1” hits

Athens May 2003 ATLAS Physics Workshop 17

Digit closest to (0,0,0) Digit closest to (0,0,0)

Athens May 2003 ATLAS Physics Workshop 18

EM Cal Transverse EnergiesEM Cal Transverse Energies

EM endcaps EM endcaps and barreland barrel

ECALREC for ECALREC for reconstruction reconstruction and clusteringand clustering

EM ScaleEM Scale

Athens May 2003 ATLAS Physics Workshop 19

Tile EnergyTile Energy

Tile calorimeterTile calorimeter Used DIGI(4) for Used DIGI(4) for

energyenergy EM ScaleEM Scale

Athens May 2003 ATLAS Physics Workshop 20

HEC EnergyHEC Energy

Hadronic ECHadronic EC Used DIGI(4) for Used DIGI(4) for

energyenergy EM ScaleEM Scale

Athens May 2003 ATLAS Physics Workshop 21

FCAL EnergyFCAL Energy

Forward CalForward Cal Used DIGI(4) for Used DIGI(4) for

energyenergy EM ScaleEM Scale

Athens May 2003 ATLAS Physics Workshop 22

Rates SummaryRates SummarySystemSystem ConditionCondition Rate (Hz)Rate (Hz)

ATLAS CavernATLAS Cavern ---- 34003400

Any G3 DigitAny G3 Digit ---- 14501450

ThroughThrough RPCRPCY>0Y>0 x RPC x RPCY<0 Y<0 x IDx IDDIGIDIGI 13.713.7

GoingGoing RPCRPCY>0Y>0 x RPC x RPCY<0 Y<0 x PIXx PIXDIGIDIGI 0.340.34

PassedPassed |Z|ZDIGIDIGI| < 300, |R| < 300, |RDIGIDIGI| < 60 cm| < 60 cm 6.056.05

originorigin |Z|ZDIGIDIGI| < 100, |R| < 100, |RDIGIDIGI| < 30 cm| < 30 cm 1.121.12

|Z|ZDIGIDIGI| < 60, |R| < 60, |RDIGIDIGI| < 20cm| < 20cm 0.320.32

EETTCELL CELL > 5 GeV> 5 GeV 0.090.09

EM CalEM Cal EETTCLUSTER CLUSTER > 5 GeV> 5 GeV 0.210.21

EETOTAL TOTAL > 5 GeV> 5 GeV 0.360.36

Tile CalTile Cal EETOTAL TOTAL > 20 GeV> 20 GeV 1.371.37

HECHEC EETOTAL TOTAL > 20 GeV> 20 GeV 0.140.14

FCALFCAL EETOTAL TOTAL > 20 GeV> 20 GeV 0.0150.015Rate error (generator comparisons) 20%

Athens May 2003 ATLAS Physics Workshop 23

Summary, Plans Summary, Plans Working cosmic Working cosmic G3 (atlsim) MC for ATLASG3 (atlsim) MC for ATLAS

Different generators 4-vectors samples of muons entering cavern ZEBRA event files for offline studies

Rates seem to be large enough for initial Rates seem to be large enough for initial electronics shake-downelectronics shake-down

Dead channel maps, electronics+DAQ checks, etc.

To-do: triggers and offline reconstruction …To-do: triggers and offline reconstruction … Simplified trigger studies: have input already for LVL1 RPC

(Gianpaolo Carlino, Leandro Nisati, Stefano Veneziano) and Tiles (Alan Watson), and also from Nick Ellis

Full trigger studies: switch to full ATHENA trigger simulations, currently under development

Many issues for both triggers and reconstruction due to non-pointing, out of time tracks must be studied

Studies: reconstruction, alignment, calorimeter calibration …