FGT ND-ECAL Simulation

Soumya Ranjan Das

Department of PhysicsIndian Institute of Technology Guwahati

November 12, 2015

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Outline

DUNE FGT Near Detector

ND-ECAL Parameters

Simulation Update

Downstream ECAL Energy Resolution

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DUNE FGT Near Detector

The various components of the FGT near detector for DUNE are,

Active straw tube tracker (STT)

4π lead-plastic scintillator Electromagnetic Calorimeter surrounding theSTT, consisting of a forward, backward and barrel type electromagneticcalorimeter

0.4 T dipole magnet inside which the STT and ECAL modules will reside

4π muon-ID detector made of Resistive Plate Chambers (RPC) whichwill surrond the dipole magnet and will also be outside the magnet

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Figure : Layout of HIRESMNU with external muon detectors

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Figure : Layout of HIRESMNU with external muon detectors

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DUNE Near Detector ECAL Parameters

Forward ECAL: 60 layers of alternating horizontal/vertical plastic scintillatorbars per 1.75 mm of lead along the z-direction. Dimensions of each plasticscintillator bar is 3.2 m × 2.5 cm × 1 cm. 128 bars per scintillator plane and7680 scintillator bars in total. There will be two sided readout via extrudedWLS fiber and SiPM. 20 Xo .

Barrel ECAL: Will surround the sides of the STT. 16 layers of plasticscintillator bars (horizontal along the axis of the magnet) per 3.5 mm of leadalong the z-direction. Same dimensions of scintillator bars like forward ecal.128 bars per scintillator plane and 16,384 scintillator bars in total. 10 Xo .

Backward ECAL: 16 layers of alternating horizontal/vertical plasticscintillator bars per 3.5 mm of lead along the z-direction. Same dimensions ofscintillator bars like forward ecal. 128 bars per scintillator plane and 2048scintillator bars in total. 10 Xo .

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FGT ND-ECAL Simulation Progress

To simulate and optimize the ECAL in the HiSoft frameworkNow has a new repository called dunefgt created by Tyler.

GDML geometry of the forward, backward and the barrel ecal has beenprepared and initialized.

The preliminary simulation has been done by shooting 2 GeV photons,electrons, positrons, pizeros and muons for 500 art events into the forwardecal

To find the energy resolution of the forward, backward and the barrel ecal fordifferent values of incident energy of incoming electrons and photons and fordifferent angles of incidence

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2 GeV Electron- Energy deposited and step size for allsteps and for steps in scint. bars

Entries 5553578Mean 0.1041RMS 0.1093

Energy (MeV)0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5

Ste

ps

0

50

100

150

200

250

300

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400

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310×

Entries 5553578Mean 0.1041RMS 0.1093

Energy deposited per step

Energy deposited per step in scintillator bars

Entries 5553578Mean 0.0172RMS 0.03249

Step Size (cm)0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2

Ste

ps

0

100

200

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310×

Entries 5553578Mean 0.0172RMS 0.03249

Step sizeStep size in scintillator bars

Figure : plots of energy deposited per step and step size for all G4 steps and for all G4steps in the scintillator bars

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Peak around 88-88.5 KeV! Why?

Figure : Source: PDG Review. Peak at 88 KeV corresponds to atomic photoelectriceffect (electron ejection, photon absorption)

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PDG code of particles for .1 MeV G4 steps and for all steps

PDG code of EM Shower Daughters

Entries 74470Mean 21.69RMS 2.445

PDG Code40− 20− 0 20 40

0

10000

20000

30000

40000

50000

60000

70000

PDG code of EM Shower Daughters

Entries 74470Mean 21.69RMS 2.445

(a) PDG Code of particles for .1 MeV steps

PDG code of EM Shower Daughters

Entries 1114296Mean 8.35RMS 8.844

PDG Code40− 20− 0 20 40

0

100

200

300

400

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600

700

800

900310× PDG code of EM Shower Daughters

Entries 1114296Mean 8.35RMS 8.844

(b) PDG Code of particles for all steps

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Downstream ECAL Energy Resolution

Figure : Average measured energy from all the scintillator bars per event vs the incidentelectron energy for normal incidence

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Downstream ECAL Energy Resolution

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Downstream ECAL Energy Resolution

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Future Plan

Find the energy resolution of the backward and barrel ecal

Effect on energy resolution of ecal for varying angles of incidence of incomingbeam

Any Suggestions, please?

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Thank You

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