NINJA Experiment :Neutrino Interaction research with
Nuclear emulsion and J-PARC Accelerator
Tsutomu Fukuda （Nagoya Univ.）
on behalf of the NINJA collaboration

10μｍ
J-PARC素粒子原子核セミナー, 23th Feb. 2017＠Tokai

2Contents• Introduction• Nuclear Emulsion Technology• NINJA Experiment

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Profile：福田 努（ふくだ つとむ）

2000年

OPERA実験が正式に承認。

参加

検出器準備

2003.12

2003年～ OPERAフィルムの大量生産開始。
東濃鉱山地下にてRefresh処理。
解析体制準備2005年～ KEK，Fermi Labでテスト実験開始。
→ OPERAの解析リハーサルを実施。

me

CSに記録された飛跡

ニュートリノビーム照射

2006年

CERNからニュートリノビームのテスト照射。OPERAで初めて原子核乾板上にニュートリノ反応からの飛跡を検出。

80mme
飛跡が見つかった瞬間

2006 9/7

2008年～ 検出器完成。ニュートリノビーム本格照射。

1st νOPERA実験本番開始。
2010年 1st タウニュートリノ反応候補検出。
2012年 2nd タウニュートリノ反応候補検出。
･･･

2nd ν

1998

42015
５thdone“発見”から“精密測定”へ

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原子核乾板Nuclear Emulsion

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What is Nuclear Emulsion ?

~100μm

3D tracking detector with submicron position accuracy

Photographic Film technology

7• Nuclear Emulsion is a special photographic film.
• Signal is amplified by chemical process.
Resolution of 0.3 μm

Recorded as silver grains
along the particle passing through lineFilm camera

MeritImage detectionHighresolution

ハロゲン化銀（Sliver halide）
光のエネルギーが起こす化学変化を利用した光化学反応。

Digital camera Real time 電荷結合素子（Charged-Coupled Device）

光のエネルギーを電気エネルギーに変換する光電変換。

78Largest Digital Camera
ATLAS detector(~1.6 x 108 image sensors)

human

Largest Film Camera
OPERA detector(~1020 AgBr crystals)
9000,000 emulsion films
human8Contribution for fundamental physics…
1896 (A. H. Becquerel )Discovery of Radioactivity

91947

μ1947 (C. F. Powell et al.)Discovery of 1971 (K.Niu et al.)Discovery of charm particle
in cosmic-ray
2001 (K.Niwa et al.)Direct observation of ν

1896
μππ1971Flight Length：280um

decaydecay

2001

1mmIron

DONUT  event

9Nuclear Emulsion Detector

3D reconstruction

Reconstruction of track dataScalability

OPERA検出器（1.25kton）
Analysis on an event by event basis

4π detection
Momentum, dE/dx measurement
150 μmUltra precise measurement

Low BG from  NC 0 production10

Nuclear Emulsion DetectorAg + e → Ag ・・・Ag+Polymer (C, (N,O))

Charged Particle-1

Silver halide crystal(AgBr)
e-eeeeeee-Development treatment

Silver grains(size : several
10 nm ~ 1 µm)

Ionized electrons concentrated on
the electron trap to form the latentimage specks in a crystal

11nNuclear Emulsion Detector
Polymer (C, (N,O))
Charged Particle

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Nuclear spallation reaction by heavy ion

Silver halide crystal(AgBr)Development treatment

Silver grains(size : several
10 nm ~ 1 µm)

100 µmSpatial resolution- silver halide crystal size
- number density of silver halide crystal
Sensitivity- Chemical treatment- Crystal defect and doping etc.

Readout of tracks in Emulsion
Microscope view
MicroscopeZ-axisImagesensorImagesensor

Resolution
512x512 pixels
Field of View
230x230m2

Nuclear emulsion film/plate

Objective 35x~3m Depth of Field

Emulsion(front side)
45~100 m

Film base200~800 m
Emulsion(back side)
45~100 m

Sensitivity
35 silver grains /100m

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Long history in Neutrino Research15• 1978-1983 Fermilab E531
charm physics,    oscillation~ 100kg<20GeV>• 1994-2000 CERN WA95 CHORUS   oscillation, charm physics~ 1 ton<27GeV>• 1997-2001 Fermilab E872 DONuT
first  direct observation~ 1 ton<80GeV>• 2008-1250 ton

CERN CNGS01 OPERA   oscillation<17GeV>Recent technical improvements
Readout techniqueHigh Speed Scanning

16Detector techniqueHigh Sensitive film

Time resolution
HTS 9,000cm2/h, x100 faster

RMS=1.5sec

Large angle tracking technique
Charge sign ID
νe/νe identification

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Gel Production Machine at Nagoya Univ.

Crystal size
Crystal shapeSensitivity
Stability

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NINJA Experiment20

Current situation on neutrino physics
Neutrino oscillation δCP, mass hierarchy
OPERA

T2KSterile Neutrinos
 4th generation ? Dark matter ?
MiniBooNE

DayaBay

DUNE
JUNO

LSND

MicroBooNE
JSNS2T2HK
ICARUS0νdouble beta decay majorana / dirac ? νmass meas.

Cosmic neutrinos
 Ultra-high energy, Supernova,…
SN1987A

PeVν
SuperNEMO
KamLAND-ZEN

GERDA2CANDLESSKGd
KM4NeT

この他にも多くの実験が計画・実施・遂行されている。

IceCube-Gen2

21Motivation• Precise neutrino-nucleus interaction measurement is importantto reduce the systematic uncertainty in future neutrino oscillation
experiments.
• We started a new experiment at J-PARC to study low energy
neutrino interactions by introducing nuclear emulsion technique.

• The emulsion technique can measure all the final state particles
with low energy threshold for a variety of targets (H2O, Fe, C,…).
• Furthermore its ultimate position resolution allow to measureνe cross section and to explore of a sterile neutrino.

MiniBooNE
Water Target Emulsion Chamber

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Precise measurement of
neutrino-nucleus interactions• CCQE interaction events are used as signal to reconstruct energy in
μT2K/SK.
ν• Other interaction modes contaminate due to final state interaction in
nucleon and detector inefficiency.
• Energy can’t be reconstructed correctly with these interaction modes.
 Need precise understanding about neutrino interaction.

ｐ2p-2h interaction in CCQE samples(Meson Exchange Current: MEC)NINJA 実験

23
Neutrino Interaction research with
Nuclear emulsion and J-PARC Accelerator

OPERA

T2K

MEC
MEC

NINJA
T2K

原子核乾板は、MEC反応を測定する極めて有効な手段

ニュートリノ反応の精密測定ν exposure status of NINJAPAC July/15/2015

Detector Run

Physics Run

60kg Iron
A few kg Water
A few kg Iron・ Data-MC comparison withhigh statistics
・ νe CC interaction detection
・ Emulsion handling @J-PARC・ Demonstration of ν event detection
・ Hybrid analysis with T2K near detector・ ν– Water interaction detection
with Emulsion Detector• We have demonstrated the basic experimental concept at J-PARC site.
• “Detector performance run” was started from last Jan.

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NINJA Roadmap
Preliminary measurements RUN Feasibility study at J-PARC

J-PARC T60/T66 experiment

Detector RUNDetector performance check

Future plan

Target mass: 30- 60kg

Physics RUN Ⅰ

Neutrino-nucleus interaction study
Target mass: 100- 300kg

Physics RUN ⅡSearch for sterile neutrino
Target mass: 1- 3ton
Target mass: 6-10ton• The aim of T60/T66 is a feasibility study and detector performancecheck to make a future plan.
• We will expand the scale of detector gradually, step by step.

Status review of NINJA

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Status review of NINJA

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Conceptual detector design
2kg iron target ECC

SS floor @J-PARC(Jan. 2015)••••

Emulsion Cloud Chamber is a sandwich structure ofemulsion films and iron plates.
Emulsion detector is placed in front of T2K near detector,
INGRID.
Emulsion Shifter is re-used from GRAINE project to givea timing info. to emulsion tracks.
Muon ID is possible by combined analysis with INGRID.

Status review of NINJA

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Reconstructed track data
Track Quality Selection

All emulsion films were scanned by HTS.
First of all, noise tracks were rejected byevaluating the quality of each tracks.
Then tracks were reconstructed.
all tracks

ν（|tanθ| ＜ 0.1 ）（1.4＜ |tanθ| ）

PL41

PL01
Penetrated tracks

Iron
2.0cm

Plate by plate, angle by angle
track efficiency

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Track reconstruction••

Two base track segments are tried to be connected assuming cut offmomentum.
They are connected if the position and angular difference within the allowance.
- Position difference between two segments extrapolating at middle place.
- Angular differenceContinue to all possible combination of two tracks  all tracks are reconstructed.

Status review of NINJA

Event analysis sample

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Automatic procedure

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Opening angle of 2MIP

e+e- pair from Gamma-rays

Status review of NINJA

32Interacted in emulsion region

Systematic emulsion analysisMomentum measurement

dE/dX

Proton Identification

Multiple Coulomb Scattering momentum measurement

Status review of NINJA

33Time stamp for ν event with Emulsion ShifterEmulsion films are set on moving stages controlled by stepping
motor.
Time stamp is given by coincidence of tracks on each stage.
 Position difference from reference point= Timing information
Spot 13Mar.12 2:23:35~ Mar.14 14:23:57

Spot 7Mar.21 2:25:49~ Mar.23 14:26:12

Information fromTop stage

All tracks

Neutrino event tracks

Status review of NINJA

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Emulsion-INGRID Hybrid analysis<Event time>
2015/Mar./13 1:42:23.9

Event topology is clearly matched.
Expected range for each tracks is consistent with INGRID hits.

<Event time>
2015/Mar./22 15:06:35.0

Time resolution for emulsion tracks

Status review of NINJA

ν exposure in May 2015.

Water target emulsion detector
水標的・原子核乾板検出器

Frame typeplastic spacer( 2mm thickness)

Emulsion films (vacuum packed)
Interacted in Water region

陽子
Range~2cm
Sandwich structure of Emulsion
films and Frame type spacers

Pouring waterFirst detection of ν - Water interaction with Emulsion Detector

35Status review of NINJA

Detector Run
We are starting Detector Run to compare MC with high statistics.

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Detector construction

Detector preparation

ν beam exposure Hardware treatment and Scan

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Detector construction

ν beam exposure Hardware treatment and Scan

Detector installation

INGRID2016．Ｊan. 14

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Detector construction

ν beam exposure Hardware treatment and Scan

Condition of the emulsion film

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Detector construction
Dark room(Nihon Univ.)

ν beam exposure Hardware treatment and ScanDeveloping

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Detector construction

ν beam exposure Hardware treatment and Scan

2. Surface silver cleaning

Emulsion swelling
Recovering of emulsion thickness

Beam exposure

developmentemulsion

After swelling

60μm
Before wiping

70.0±3.0μm

After wiping

More than 300 films were completed.

Glycerol water

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Detector construction

ν beam exposure Hardware treatment and Scan

Tracking efficiency of one area
(plate by plate, angle by angle)● ：0.0＜|tanθ|＜0.3△ ：0.4＜|tanθ|＜0.6○ ：0.9＜|tanθ|＜1.1△ ：1.4＜|tanθ|＜1.6

Data quality check and track reconstruction is under progress.

Status review of NINJA

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Event analysis is now in progress !
Neutrino event candidates

Very preliminary

Multiplicity>3

Track multiplicity (218 events)

First result will be reported at JPS meeting (March)・ ~80% of event have proton
・ 0 MIP events are detected.
 neutron interaction ?

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Examples of neutrino event
one by oneν beam exposure：Dec. 2016- Apr.2017
Detector Run(T66)- R&D for Water target Emulsion detector

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Detector structure~100 ν- Water int. expected

大型水標的検出器によるニュートリノ－水反応の精密測定に向けて検出器R&Dを継続中
2018年後半に100kg 級の検出器を設置予定。

46Summary• We are performing a neutrino experiments at J-PARC
to study low energy neutrino - nucleus interactions withnuclear emulsion （NINJA！）.

• We are carrying out a test experiment at J-PARC tocheck the feasibility and detector performance.
• Beam exposure and film development for the 60kg
iron target ECC was successfully done and the event
analysis is now in progress.
• R&D for Water target ECC is performing.

• Now we are discussing about next Physics Run witha large scale water target emulsion detector.

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Back upFeasibility study: 1.5kg Water target ECC

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Water target emulsion chamberCool box (wine cellar)
to keep a good environment foremulsion tracks

Removal of air bubbles

SS ｆloor
down stream of T2K near det.
Interacted in Water region

protonRange~2cm① （tanθx, tanθy）=（-0.040, 0.845）

M.I.P② （tanθx, tanθy）=（-0.589, -0.074）

protonMinimum distance(①‐②)=2.4um,depth=620um

First detection of ν - Water interaction with Emulsion Detector

Detector Run: 60kg Iron target ECC

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Detector preparation
We carried out “Refresh” process to delete noise tracks like OPERA experiment.
Emulsion film Refresh 2015. Dec @Toho Univ.
－Temperature－Humiditydrying
24hours

Refresh24hours

Humidity (%ＲＨ)

Film storing for refreshin dark room

time

Compton electrondensity(/6000um3)
beforeRefreshed

5 refresh process were carried out# of refreshed films

Temperature (deg C)

1 cycleAll 346 films were refreshed.
(date)

Detector Run: 60kg Iron target ECC

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Installation @J-PARC (Jan. 11-20)

Detector was constructed @SS floor.
T60 emulsion detector is mounted in cooling box to keep good quality (no refresh).
compressor
EmulsionshifterPMν

Iron target
ECC

INGRID
Fall prevention frame

Drain hose

Laptop PCfor operationmonitoringν51

Large angle scanning on HTS

FTS@Toho Univ.
Very preliminary
1st trial (Y. Suzuki)
xzx|tan θ|z =We will optimize HTS for LA ScanningRelated activitypνμπ＋μ＋
ニュートリノフラックスの推定↓
ハドロン生成の詳細研究

ニュートリノフラックスの系統誤差の低減

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