Performance test of new MPPC for a new neutrino detector WAGASCI - - PowerPoint PPT Presentation

Performance test of new MPPC for a new neutrino detector WAGASCI

Fuminao Hosomi The University of Tokyo, for the WAGASCI collaboration 9th July 2015, PhotoDet 2015, International Conference on New Photo-detectors 6th – 9th July 2015, Art School for Children, Moscow, Troitsk, Russia Детская школа искусств, Москва, Троицк, Россия

Contents

 Motivation for WAGASCI experiment  Performance test of new MPPCs  Preparation for mass test

2

Neutrino oscillation

• Mixture between flavor eigenstate and mass eigenstate
• Measured with neutrino-nucleus interaction
• Critical to understand this interaction

3

νe νμ ντ = UPMNS ν1 ν2 ν3

Flavor eigenstate Mass eigenstate

Motivation for WAGASCI experiment

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Systematic error sources νμ → νe νμ → νμ Cross section error due to nuclear difference 4.7% 5.0% Total 6.8% 7.7% Need to improve cross section measurement  WAGASCI experiment

J-PARC 30 GeV proton πμ+ν Super-Kamiokande H2O target 4π acceptance

νe,νμ,ντ νμ

ND280 CH target Forward scattering T2K experiment

//

Water Grid And Scintillator Goal: Measure cross section ratio between H2O/CH with 3% accuracy Site: J-PARC neutrino monitor hole Configuration:

• H2O and CH Target
• Sandwich structure with H2O and CH
• 3D grid-like scintillator
• Muon range detector (MRD)
• Iron and scintillator

WAGASCI experiment

5 H2O CH

MRD (Not to scale)

μ-

p

νμ

veto n

Target 3D grid-like scintillator

Target of WAGASCI detector

3D grid-like scintillator

• x + grid + y + grid + … layers
• 4π angular acceptance
• Readout by using WLS fibers and MPPCs
• Thin plastic scintillators (3 mm)
• To maximize the H2O fraction (79%)
• light yield is a concern

Need high photon detection efficiency and low noise rate  New MPPC will be used

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Development of MPPC

S10362 type: T2K INGRID and ND280

Around 56,000 MPPCs have been used since 2009

 Afterpulse and dark noise suppression S12825 type: released in summer 2013  Crosstalk suppression S13081 type: released in winter 2014

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S10362-11-050C 1 p.e. 2 p.e. 3 p.e. 20 ns 50 mV S12825-050C S13081-050CS

100x amplified Over voltage = 2.0 V p.e. = photon equivalent * All MPPCs in this page are 1.3 x 1.3 mm2 devices

S10362-11-050C S12825-050C

Micrographs

• f MPPC

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S13081-050CS Trench to prevent crosstalk

50x50 μm2 pixel

Performance evaluation

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For measuring For monitor LED: 470 nm

Pixel size: 50x50 μm2 * Same type as T2K INGRID and ND280 (S10362-13-050C) but different photosensitive area

Measured performance of three types of MPPC

• Using dark noise and self trigger
• Dark noise rate
• Crosstalk rate
• Using LED light source
• Gain
• Relative PDE

(photon detection efficiency)

Type number Features Photosensitive area S10362-11-050C Old MPPC * 1x1 mm2 S12825-050C Afterpulse suppression 1.3x1.3 mm2 S13081-050CS(X1) Crosstalk suppression 1.3x1.3 mm2

Dark Noise Rate

S12825 type and S13081 type have 1/10 dark noise rate as S10362 type We can operate the new MPPCs with higher over voltage

* Normalized to 1 mm2 active area ** Measured by using discriminator and scaler *** Dead time of scaler: 25 ns 10

Self trigger with 0.5 p.e. threshold Over voltage = (Bias voltage) – (Breakdown voltage)

Crosstalk Rate

Compare to S10362 type:

• Same rate for S12825 type
• 1/10 reduction for S13081 type

It become possible to lower signal threshold level

* Measured by using discriminator and scaler 11

Crosstalk rate = 1.5 p.e. threshold dark noise 0.5 p.e. threshold dark noise

Gain

• Same gain but wider operation

voltage for newer MPPCs

• With higher over voltage:
• Higher gain
• Relatively unaffected

by temperature changes

* Measured by using charge integrated ADC ** ADC gate width: 120 ns *** LED gate width: 20 ns

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MPPC Gain = [(1 p.e. ADC ch)−(pedestal ADC ch)]×(ADC charge per ch) elementary charge

Relative PDE

• # of photons = -ln(P0)
• P0 = fraction of pedestal events
• To avoid the effect of afterpulse

and crosstalk

• With higher over voltage, higher PDE

achieved for new MPPCs

* Measured by using charge integrated ADC ** Effect of dark noise subtracted *** ΔV = over voltage **** Normalized to 1 mm2 active area

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Relative PDE = # of photons detected by each MPPC # of photons detected by S10362 MPPC with ΔV=1.0 V

Comparison of performance

Noise rate (kcps) Crosstalk rate (%) Gain (x106) Relative PDE S10362-11-050C Over voltage=1.1 V * 179 1 4.18 1 0.666 1 1.12 1 S13081-050CS(X1) Over voltage=1.1 V 13.7 0.077 N/A N/A 0.709 1.1 0.969 0.87 S13081-050CS(X1) Over voltage=4.0 V 44.4 0.25 0.896 0.21 2.46 3.6 2.09 1.9

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Summary of new MPPCs’ performance Red text shows ratio of value to that of S10362 type

* Over voltage=1.1 V is used in T2K INGRID and ND280 for operating MPPCs

Checking light yield

• 3 mm thin scintillator + crosstalk suppression type MPPC
• Injecting 600 MeV positron beam

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• 10 p.e. light yield

event in the edge of scintillator

• 99% detection efficiency

> 10 p.e.

MPPCs used in WAGASCI detector

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Target: array type MPPC

1.5 mm φ

• Ceramic type MPPC (2,750 ch)
• Same method as T2K INGRID and ND280
• Array type MPPC (168 x 32 ch)
• Newly developed for WAGASCI
• Consists of 32 ch MPPCs
• 50 x 50 μm2 pixel size
• 1.5 mm diameter active area

to fit WLS fibers

• Crosstalk suppression type
• Compact readout for large amount
• f channels

MRD: ceramic type MPPC

Mass test of WAGASCI MPPCs

• In total 8,126 ch will be used
• Mass test under preparation
• Items of measurement
• Gain
• Relative PDE
• Dark noise rate
• Crosstalk + Afterpulse rate
• Goal: 128 ch at once
• Using NIM-EASIROC (General purpose MPPC readout module)

17 LED MPPCs EASIROC module PC Incubator

Mass test

• Array type MPPC
• Ceramic type MPPC

(for comparison)

• Measured 16 ch

at once

• Array type MPPC has

same performance as ceramic type MPPC

18 Gain PDE Dark noise rate Crosstalk rate

Summary

• Propose a new neutrino detector WAGASCI
• Measure the performance of

crosstalk suppression type MPPCs

• Low noise rate and crosstalk rate
• Higher PDE

 Achieve high detection efficiency with even thin scintillator

• Develop array type MPPC

for WAGASCI target

• Prepare mass test of 8,126 ch MPPCs

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S13018-050CS

Thank you!

… and Backup

WAGASCI Collaborators

— The University of Tokyo —

• F. Hosomi, N. Chikuma, A. Izmaylov, T. Koga, M. Yokoyama

— Institute for Nuclear Research of the Russian Academy of Sciences —

• I. Karpikov, M. Khabibullin, A. Khotjantsev, Y. Kudenko, A. Mefodiev, O. Mineev, T. Ovsjannikova,
• S. Suvorov, N. Yershov

— Laboratoire Leprince-Ringuet Ecole Polytechnique —

• A. Bonnemaison, R. Cornat, O. Drapier, O. Ferreira, F. Gastaldi, M.Gonin, Th. A. Mueller

— University of Geneva —

• A. Blondel, F. Cadoux, Y. Favre, E. Noah, M. Rayner

— Kyoto University —

• T. Hayashino, A. K. Ichikawa, A. Minamino, K. Nakamura, T. Nakaya, B. Quilain

— Osaka City University —

• J. Harada, K. Kin, Y. Seiya, K. Yamamoto

— Institute for Cosmic Ray Research —

• Y. Hayato

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Schedule

• Aug. 2015: Construction of prototype
• Dec. 2015: Installation of prototype
• Apr. 2016: Date taking with prototype
• Summer 2016: Construction of full WAGASCI
• Early 2017: Data taking with full WAGASCI

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WAter Grid And SCIntillator WAGASCI

23

Box for Japanese sweets (Wagashi)

Candidate Site

• The B2 floor of the T2K near detector hall

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Multi-Pixel Photon Counter

Photon counting device using multiple APD developed by Hamamatsu Photonics

• Good linearity between gain and

Over voltage = (Bias voltage) – (Breakdown voltage)

• High gain / High photon detection efficiency (PDE)
• Dark noise: produced by thermally generated carriers
• Afterpulse: trapped carriers by lattice defects
• Crosstalk: secondary photons detected by other pixels

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Scintillator and WLS etc.

• Scintillator
• Processed by Fermilab
• Polystyrene
• PPO 1.0%
• POPOP 0.03%
• Wavelength: 420 nm
• Reflective paint
• EJ-510 – ELJEN Technology
• TiO2 based
• May be supplanted?
• Wavelength shifting fiber
• Y-11(200)MS – Kuraray
• 1 mm diameter
• Blue to Green
• Core: Polystyrene
• Inner cladding: PMMA
• Outer cladding: FP
• Optical cement
• EJ-500 – ELJEN Technology
• Optically bonding plastic scintillators and

acrylic (PMMA) light guides

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Typical Charge Distribution

Using ADC with 0.25 pC/ch Crosstalk suppression type:

• ver voltage = 3.0 V

Fitting with double Gaussian Evaluate gain and number of pedestal events

27 pedestal 1 p.e. 2 p.e.

Systematic Error Estimate

Estimate systematic error from attaching and detaching MPPC to measurement device Measured five times Deviation of relative PDE is about 5%

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Latching pulse with Vover=5.0 V

• Pre production
• June 2014
• Latching

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• S13081-050CS(X)
• Dec. 2014
• Improved
• S13081-050CS(X1)
• Feb. 2015
• Rarely

Relative PDE Derivation

Suppose Poisson distribution Probability that N photons are detected: P(N)=λN e-λ / N! λ is mean value of detected photon. P(0) = # of pedestal events / # of total entries λ = -ln P(0)

30

MPPC Specification by HPK

Measured MPPCs

31 Type number Serial number Operation voltage (V) Gain (x106) Dark noise rate (kcps) Breakdown voltage V max Notes S10362-11- 050C 2660 71.12 0.750 396 For monitor S10362-11- 050C 2664 71.16 0.748 409 69.9 * S12825- 050C 627 66.77 1.24 111 64.3 * Crosstalk suppression 105 54.96 1.50 55.1 51.96 55.96

* Measured value

Higher Over Voltage

• S12825 type

with over voltage = 4.4 V

• Charge distribution has a tail

with lower channel

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Setup for measuring PDE

Prepare two MPPCs;

• ne for measuring and one for monitor

Take a ratio of these PDE and reduce LED light yield deviation LED light source

OptoSupply OSB5SA5111A-1V λD = 465-475 nm

Attach a piece of white paper on LED to diffuse light

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For measuring

For monitor LED

Setup using self trigger

note

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Setup using LED

note

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