The Calorimeter of the T2K-ND280 Detector System

11

The Calorimeter of the The Calorimeter of the T2K-ND280 T2K-ND280

Detector SystemDetector System Athans HatzikoutelisAthans Hatzikoutelis

Lancaster University Lancaster University UKUK

June 24, 2009June 24, 2009

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The T2K (Tokai to Kamioka) experiment.The T2K (Tokai to Kamioka) experiment.

The ND280 (Near Detector) Project.The ND280 (Near Detector) Project.

The Electro-magnetic tracking calorimeter.The Electro-magnetic tracking calorimeter.

The current sub-systemsThe current sub-systems

The future.The future.

Outline Outline

A. Hatzikoutelis , T2K CollaborationA. Hatzikoutelis , T2K Collaboration 22

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The T2K experimentThe T2K experiment

Tokai-to-Kamioka neutrino oscillation experiment Tokai-to-Kamioka neutrino oscillation experiment appearance of electron appearance of electron neutrinos in a muon neutrino beamneutrinos in a muon neutrino beam

30 GeV protons of 750 kW30 GeV protons of 750 kW produced at the new JPARC complexproduced at the new JPARC complex

integrated exposure of integrated exposure of 100 kW*1e7 s 100 kW*1e7 s starting in starting in April 2009.April 2009.


44

Key measurement in ν physicsKey measurement in ν physics

A A positive positive measurement of measurement of sinsin22(2(2θθ1313) > 0.01 ) > 0.01 – possibility to study CP possibility to study CP

violation in the lepton violation in the lepton sector sector

– the determination of the determination of the neutrino massthe neutrino mass

– hierarchy with hierarchy with upgraded conventional upgraded conventional super-beamssuper-beams

No evidence for No evidence for sinsin22(2(2θθ13) 13) – trigger intense trigger intense

discussions on how to discussions on how to best proceed below best proceed below sinsin22(2(2θθ1313) ) ≈ ≈ 0.010.01

27/05/0927/05/09 A. Hatzikoutelis , T2K CollaborationA. Hatzikoutelis , T2K Collaboration 44

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The Near detector The Near detector

Understand the Understand the neutrino beam.neutrino beam.On – Axis DetectorOn – Axis Detector Beam monitoringBeam monitoring Beam directionBeam direction

Off – Axis DetectorOff – Axis Detector Understand the neutrino Understand the neutrino

beam to SK.beam to SK. Beam FluxBeam Flux Beam Beam ee Contamination Contamination Background ProcessesBackground Processes Cross SectionsCross Sections

On-axis DetectorINGRID

neutrino beam


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Intense & narrow-band beamIntense & narrow-band beam

2.5º off-axis2.5º off-axis

Energy peak ~ 0.7 GeVEnergy peak ~ 0.7 GeV

Statistics at Far DetectorStatistics at Far Detector

– ~1600 ~1600 CC int./22.5kt/year CC int./22.5kt/year

(0.75 MW beam, no oscillation )(0.75 MW beam, no oscillation )

Purity of Purity of beam beam

– Beam Beam ee contamination ~0.4% contamination ~0.4%

at at peak energy peak energy

Running time: 5 years @ 750 kW Running time: 5 years @ 750 kW proton beam intensityproton beam intensity

0 m 280 m 295 km

p2.5ºTarget

Near Detector

Far Detector(SK)

120 m

Muon monitorDecay pipe&Horns On-axis detector

Off-axis Near Detector

J-PARC

Off-axis techniqueOff-axis technique


OA3

OA0OA2

OA2.5

Oscillation Prob.@ m2 = 3.010-3

energy spectrum(Flux X-section)

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Off-axis detectorOff-axis detector

operators

280 m downstream of the target

Arrays housed in UA1 magnet with 0.2 T.


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Pi-zero Detector (PØD)Pi-zero Detector (PØD)– measures NC measures NC interactions. interactions.

Tracking System:Tracking System:– fine-grained detector (FGD) fine-grained detector (FGD) – time projection chambers (TPC)time projection chambers (TPC)– Targets of Targets of 1616O and O and 1212C for the C for the vv..– Measure CC interactions.Measure CC interactions.

Electromagnetic calorimeter Electromagnetic calorimeter (ECAL).(ECAL).– Total energy and particle id.Total energy and particle id.

Side muon-range detector Side muon-range detector (SMRD).(SMRD).– Cosmics veto.Cosmics veto.– Side-going muon id.Side-going muon id.

Five detector arraysFive detector arrays


99

P0DP0D


Simulated 440 MeV/c π˚

Active Scintillator Neutrino TargetActive Scintillator Neutrino Target– water + scintillatorwater + scintillator

NC π° NC π° – reconstruction efficiency ~30%reconstruction efficiency ~30%– signal to noise ~2.3signal to noise ~2.3

E&M resolution ~15%/√E (GeV)E&M resolution ~15%/√E (GeV)

Is build and being installedIs build and being installed Primary Measure GoalsNC and CC π° production

νν

Distance in P0D

1010

TPC FGD tracker detectorsTPC FGD tracker detectors

3D tracking for pattern 3D tracking for pattern recognition. recognition.

Measure momenta and Measure momenta and charge of charged particlescharge of charged particles

Distinguish electrons and Distinguish electrons and muons/pions and protons.muons/pions and protons.

B=0.2 T .B=0.2 T .

Micromegas technology was Micromegas technology was selected to provide the gas selected to provide the gas amplification for readoutamplification for readout


:_simulated_ pn

2.5 m

2.5

m

ννμμ

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After the tracker After the tracker detectors.detectors.

Perpendicular to the Perpendicular to the vv beam.beam.

DsEcal

Down-stream Calorimeter Down-stream Calorimeter

v beam


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Energy resolution from Energy resolution from simulations.simulations.– Dominated by sampling Dominated by sampling

fluctuations.fluctuations.

– Est: 7.5% √E(GeV).Est: 7.5% √E(GeV).

– up to 5 GeV.up to 5 GeV.

Good electron pion Good electron pion separation.separation.– 90% elec efficiency 90% elec efficiency

withwith

– 95% pion rejection.95% pion rejection.

v beam

P0D Ecal Barrel EcaL

P0D EcalBarrel Ecal

DsEcal

4x2 m2 x 0.5 m

2x2m2 x 0.5 m

P0DFGD & TPC trackers

Calorimeter Calorimeter


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Plastic scintillator Bar: 4cmx1cmx200cmCentre hole :1mmx2mm elliptical

Multiple layers of Multiple layers of scintillator lead.scintillator lead.– Extruded plastic from Fermi Extruded plastic from Fermi

National Labs.National Labs.– Similar to K2K-Scibar and Similar to K2K-Scibar and

Minos.Minos.

X-Y orientation change X-Y orientation change between even and odd between even and odd numbered layers.numbered layers.– One Y11 Kuraray fibre One Y11 Kuraray fibre

(WLS) per bar.(WLS) per bar.– Double- and single-ended Double- and single-ended

photo-sensor readout per photo-sensor readout per fibre.fibre.

MPPC from Hamamatsu.MPPC from Hamamatsu.– 11stst large deployment. large deployment.

Calorimeter : General DesignCalorimeter : General Design


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Dominated by the properties of Dominated by the properties of the fibers.the fibers.Tested with cosmics and Tested with cosmics and 137137Cs as Cs as function of distance from the end.function of distance from the end.– Light yield ~ Light yield ~ 12.5pe/mip12.5pe/mip (with PMT) (with PMT)

The solid curves are double The solid curves are double exponentials of attenuation exponentials of attenuation lengths.lengths.– Short=0.52m, Short=0.52m, – Long= 4.2mLong= 4.2m

Each channel of the calorimeter – Individual check (qual. assur.).– Labeled and logged.

Construction and calibration database.

light attenuation from cosmic muons 10-12hour runs each

0

10

20

30

40

50

60

70

0 50 100 150 200 250

distance from the pmt

de

tec

ted

pe

(s

am

plin

g w

ith

3

-fib

ers

)

cosm2 (pe)

total light

total light

cosm1 (pe)

MPPC readout : integral of current

output

Radiation source activating a scintillator

Light AttenuationLight Attenuation

The errors in distance-axis come from the size of the trigger-scintillator pads.


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Surrounds the P0D array.Surrounds the P0D array.

Detects escaping photons, muons.Detects escaping photons, muons.

– 6 scintillator bar layers.6 scintillator bar layers.

– 4 lead sheets 5mm.4 lead sheets 5mm.

– 4 X4 X00 radiation lengths. radiation lengths.

Single-ended readout.Single-ended readout.

Low requirement for energy and Low requirement for energy and

spatial resolution. spatial resolution.

Effective depth. Effective depth.

Surrounds the tracking detectors.Surrounds the tracking detectors.

Measures particles that leave the Measures particles that leave the volume.volume.

Separated in 6 parts to move with Separated in 6 parts to move with the opening of the magnet.the opening of the magnet.– 32 scintillator bar layers thick.32 scintillator bar layers thick.– 31 lead sheets x 1.75mm 31 lead sheets x 1.75mm

– 10.5 X10.5 X0 0 radiation lengths.radiation lengths.

18,000 double- and single-ended 18,000 double- and single-ended readout.readout.

Good reconstruction efficiency for Good reconstruction efficiency for pions.pions.

Good spatial resolution for Good spatial resolution for photons.photons.

The P0D EcalThe P0D Ecal The Barrel EcalThe Barrel Ecal


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ECAL constructionECAL construction(DsEcal example)(DsEcal example)

The first part of the Ecal to be The first part of the Ecal to be constructed.constructed.– Area 2 x 2 m Area 2 x 2 m 2 2

– 34 scint-lead layers, 1.75mm 34 scint-lead layers, 1.75mm lead sheets. lead sheets.

– 11 X11 X00 radiation lengths. radiation lengths.

– 3400 double-ended readout.3400 double-ended readout.– Kuraray Y11, straight canesKuraray Y11, straight canes


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50 micron 2

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MultiPixel-PhotoCounters.MultiPixel-PhotoCounters.

100~1600 small avalanche 100~1600 small avalanche photo diodes( APD ) photo diodes( APD )

1.3mm1.3mm22 sensitive region. sensitive region.

Magnetically unaffected. Magnetically unaffected.

New device, first large scale New device, first large scale deployment.deployment.– 50,000 in ND280.50,000 in ND280.– 23,000 for the Ecal.23,000 for the Ecal.– Each individually checked and Each individually checked and

labelled.labelled.

Photo sensors Photo sensors


Sensitive region of MPPC400pixel type

50 micron 2

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Basic performance of MPPCBasic performance of MPPCTwice the PDE Twice the PDE (efficiency) than (efficiency) than PMT’s.PMT’s.

We can observe We can observe 1p.e, 2p.e, etc, 1p.e, 2p.e, etc, signal peaks.signal peaks.

High noise rate , High noise rate , ~80kHz.~80kHz.

prototyped and characterized at Kyoto prototyped and characterized at Kyoto

univ.univ.


Pedestal

2pe

3pe

1pe

2pe

1pe

3pe

4pe?

MPPC raw signalMPPC raw signal

Digitized MPPC signal

Digitized MPPC signal

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Monitoring MPPC Monitoring MPPC gain and fibre gain and fibre integrity.integrity.Positioned in the Positioned in the cavity between the cavity between the detector frames and detector frames and the bulkhead.the bulkhead.Specifically tuned Specifically tuned driver boards.driver boards.Illuminate uniformly Illuminate uniformly the exposed fibres.the exposed fibres.

LED strips

Drive boards

Laye

r 00

1

Layer 001

Side view Top view

WLS fiber

Lay

er 0

01

Light Injection SystemLight Injection System


2020

Module ScannerModule ScannerProgrammable motor control. Programmable motor control. Sliders give the arm motion in two Sliders give the arm motion in two

dimensions.dimensions. Arm places the source 14mm from Arm places the source 14mm from

top of lead sheet of layer. top of lead sheet of layer. 3mCu 3mCu 137137Cs source.Cs source. Run along each bar.Run along each bar.

Define the detector limits.Define the detector limits.

27/05/0927/05/09 2020A. Hatzikoutelis , T2K CollaborationA. Hatzikoutelis , T2K Collaboration

Scan directionQuick return

137Cs

x

Y

http://www.hep.lancs.ac.uk/~scanner/T2KPIX/pix070708/SS850481.AVIhttp://www.hep.lancs.ac.uk/~scanner/T2KPIX/pix070708/SS850482.AVI

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Front –End ReadoutFront –End Readout


4 Trip-t chips.4 Trip-t chips.

Ethernet 1MB comm.Ethernet 1MB comm.

64 channels per front-64 channels per front-end board.end board.

2 ADC and 1 TDC output 2 ADC and 1 TDC output per channelper channel..

All power and cooling All power and cooling on board.on board.

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Commissioning Commissioning Hardware CommissioningHardware Commissioning

Commissioning of the data acquisition and Commissioning of the data acquisition and light injection systems.light injection systems.

Tuning the cosmic trigger.Tuning the cosmic trigger.

Software CommissioningSoftware Commissioning


Low energy noise from the MPPC

m.i.p. signal distribution. Mean 25 p.e.

ADC chn (arb units)

Indicative spectrum of cosmicsBar (arb coice) at the center of the calorimeter over 16 hours at 55Hz

cosmics RALISIS Hall


40000 cosmic triggers sample

Hit density distribution (Hit-map)Hit density distribution (Hit-map)Top view

Front,

xcosmic

cosmic

Side view

Front

cosmic

Front

Tuning the cosmic triggerTuning the cosmic trigger..

Calibration of all channels and pixels Calibration of all channels and pixels with cosmic muons.with cosmic muons.– Self-triggered on the front half.Self-triggered on the front half.

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Calibration with cosmicsCalibration with cosmics


Tuning Tuning ReconstructionReconstruction& PID.& PID.

First physics First physics analysis using analysis using observed dataobserved data

Event dispaly of cosmic muon (2-4MeV)

TOP

Left

Iso-view

The bars that are hit are clearly lighted up with Signal clearly above the MPPC noise.

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Calibration with test-beam.Calibration with test-beam.

– CERN T9 beam-line at East CERN T9 beam-line at East

area Hall.area Hall.

– Library of clean data profiles Library of clean data profiles

at energies 0.4 to 4GeV.at energies 0.4 to 4GeV.

– hadronic and hadronic and

– electromagnetic showerelectromagnetic shower


CERN , PS, T9, pions,muons,electrons

electronspions

Test-beam @ CERNTest-beam @ CERN

prelim.

Beam composition (%)

Beam energy (GeV)

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ECAL PIDECAL PID

Particle Identification Particle Identification algorithmalgorithm– uses an artificial uses an artificial

neural network.neural network.– discriminate between discriminate between

electromagnetic electromagnetic showers, hadronic showers, hadronic showers and tracks.showers and tracks.


muon

shower3d event view

collected on test-beam run of

May 7 ‘09

+ pion, 3.2GeV

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particle id with ECALparticle id with ECAL(preliminary)(preliminary)

Simulated medium energy electron Simulated medium energy electron shower.shower.

Event display of beam electrons Event display of beam electrons


600MeV e

600MeV e

side view

Top view

Medium energy Beam e

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Tracks PID Tracks PID (preliminary)(preliminary)

Tracks come from mips.Tracks come from mips.

Relatively small spread Relatively small spread in charge deposits.in charge deposits.– narrow, narrow,

– long shapelong shape

– uniform charge uniform charge deposition. deposition.


Simulated muon 940 MeV

Beam muon 800MeV

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Pions ID in ECAL Pions ID in ECAL (prelim)(prelim)

Simulated hadronic showersSimulated hadronic showers Charged beam pionsCharged beam pions


1GeVTop view

3GeVSide view

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Time cuts Time cuts (prelim) (prelim)

Charged beam 2.2GeV Charged beam 2.2GeV particles coincident in particles coincident in the detector.the detector.


Top viewClearly a pion

Side viewClearly a stopped muonSide view


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The T2K experiment will measure The T2K experiment will measure – How small is How small is θθ13 13 ??

– Does Does θθ2323 represent maximal mixing? represent maximal mixing?

– Can we search for CP violation in the lepton sector?Can we search for CP violation in the lepton sector?

ND280 off-axis detector will aim to addressND280 off-axis detector will aim to address– energy spectrum, backgrounds, neutrino interactionsenergy spectrum, backgrounds, neutrino interactions

The Electromagnetic calorimeter will assist the The Electromagnetic calorimeter will assist the measurements by helping id the beam profile.measurements by helping id the beam profile.

The first part of the Ecal is ready for calibration. The first part of the Ecal is ready for calibration.

The rest of the Ecal is on target for construction.The rest of the Ecal is on target for construction.

Conclusions Conclusions


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February 2006

Neutrino beam lineNeutrino beam line

Neutrino beamNeutrino beam(to Super-K)(to Super-K)

LINACLINAC3 GeV Synchrotron (RCS)3 GeV Synchrotron (RCS)

50 GeV Synchrotron (MR)50 GeV Synchrotron (MR)

J-PARC acceleratorJ-PARC accelerator


3434

Expecetd sensitivity Expecetd sensitivity – sin2(2sin2(2θθ13) < 0.01 13) < 0.01

(90%C.L.) (90%C.L.) – after 5 years at nominal after 5 years at nominal

intensity.intensity.

• • T2K uses high intensity T2K uses high intensity 30 GeV protons 30 GeV protons produced at the new produced at the new JPARC complex.JPARC complex.

Sensitivity Sensitivity sin2(2sin2(2θθ13) 13) < 0.01 < 0.01 (90%C.L.) (90%C.L.) – after 5 years at after 5 years at

nominal intensity.nominal intensity.

A plan to upgrade A plan to upgrade the power to the power to 1.6 MW 1.6 MW has been presented has been presented in the in the KEK roadmap, KEK roadmap, opening the path opening the path towards an upgraded towards an upgraded Asian long-baseline Asian long-baseline neutrinoneutrino

The T2K beamline The T2K beamline is is designed for MW designed for MW power power and has and has successfully started successfully started commissioning in commissioning in April April 2009 2009 and the firstand the first


measure measure →→ννττ disappearance, disappearance, – Atmospheric parameter Atmospheric parameter

2323 and and mm222323 (~(~mm22

1313))

search for search for ee appearance, i.e. non-zero appearance, i.e. non-zero 1313

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Neutrino beam will start in Apr. 2009Neutrino beam will start in Apr. 2009

ND280 on-axis detector will be ready for data ND280 on-axis detector will be ready for data taking when taking when beam starts beam starts

ND280 off-axis detector will be installed by fall ND280 off-axis detector will be installed by fall 2009 to be ready for data taking2009 to be ready for data taking

A plan to upgrade the Main Ring to 1.6 MW has A plan to upgrade the Main Ring to 1.6 MW has been presented in the KEK roadmapbeen presented in the KEK roadmap

These experiments are the « Phase II »These experiments are the « Phase II »

T2K start-up ScheduleT2K start-up Schedule


3636

T2K ND280 purpose T2K ND280 purpose

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The Calorimeter of the T2K-ND280 Detector System

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