The 3rd KMI International Symposium
2017/Jan/5-7

GRAINE project:
Cosmic Gamma-ray Observation
by Balloon-Borne Telescope with Nuclear Emulsion
GRAINE = Gamma-Ray Astro-Imager with Nuclear Emulsion

Shigeki Aoki (Kobe University)for GRAINE collaboration
Kobe University,
Nagoya University,
ISAS/JAXA,
Aichi University of Education,
Okayama University of Sciencephoto:GRAINE 2015
2015/May/12
Alice Springs,
Austraria©JAXA

Gamma-ray Telescopee-pairγγγ> 0.1 TeV

> 10 TeV

FERMI
0.02-100 GeV
Atmosphere
Air ShowerCTA© http://astronomy.nmsu.edu/tharriso/ast536/ast536lecture3.html

Gamma-ray Telescopee-pairγγγγ> 0.1 TeV

> 10 TeV

FERMI
0.02-100 GeV

Atmosphere
Air Showere-pair

GRAINE
CTA© http://astronomy.nmsu.edu/tharriso/ast536/ast536lecture3.html

Fermi's Five-year View of the Gamma-ray Sky(E > 1GeV)

Image credit: NASA/DOE/Fermi LAT Collaboration>3000 sources (3FGL)

Fermi's Five-year View of the Gamma-ray Sky(E > 1GeV)SNR W44
Abdo et al., Science, 2010
Color : 2-10GeV gamma-ray (Fermi LAT)
Contour : IR(Spitzer)

CrabA. J. Dean, et al., Science, 2008
INTEGRAL

Unknown
31%
Un-Identified

Polarization

Morphology

Image credit: NASA/DOE/Fermi LAT Collaboration>3000 sources (3FGL)

Nuclear emulsion

Microscopic view
10microne+/-Gamma-raye-/+Cross sectional view of an emulsion film
Powerful tracking device>High spatial resolution : ~1micron>Small radiation length : 0.002Xo

Gamma-rayEmulsion
PlasticbaseEmulsion

e-e+

0.3mm
(0.002Xo)High angular resolution for gamma-ray
Sensitive to gamma-ray polarization

Angular resolution
SPring-8 LEPSUVSORNew SUBARUUVSOR
New SUBARU

EGRET (1991-2000)

GRAINE 2011

GRAINE2011
Zenith : 0-47deg(Preliminary)Fermi-LAT (2008- )(P7SOURCE_V6)

SPring-8

1mrad

BackTotal
Front

GRAINE (MC)emulsion film(70,180,70)

1arcmin

1film
2films3films100MeV

1GeV

10GeV

100GeVGamma-Ray Astro-Imager with Nuclear Emulsion
W foil100µm(.030X0)
Emulsion
Film

290µm
(.002X0)

Si 400µm(.004X0)

Emulsion Film

228µm
pitchγbefore and afterof developmentc.f. Fermi-LAT

30mm10μm

Polarization
measurementγ

Microscope image

Cross-sectional view of Emulsion Filmγemulsion

1micron293μm
0.002XoTAC
base

emulsione-e+Polarization
measurementγ

Microscope image
Azimuthal Angle ωCross-sectional view of Emulsion Filmγemulsion

1micronK. Ozaki et al. NIM A833 (2016) 165-168

293μm
0.002Xo

Azimuthal Angle
TAC
base
SPring-8
Linearly Polarized Beamemulsione-N(ω) = p0⋅ ( 1+ p1⋅ cos(2(ω − p2) ) )Consistent with expectede+GRAINE

Gamma-Ray Astro-Imager with Nuclear Emulsion
γConverter

e- e+Emulsion + Copper foilTimestamper
Multi-stage shifter

CalorimeterEmulsion + metal plate

Attitude monitor* 10m2*εtrans*εconv*εdetStar camera

Fermi LAT
Angular resolution @100MeV@1GeV

6.0deg (105mrad)

x1/6GRAINE
1.0deg (17mrad)

0.90deg (16mrad) x1/9 0.1deg (1.7mrad)

Energy range

20MeV - 300GeV

10MeV - 100GeV

Polarization sensitivity

NoYes

Effective area @ 100MeV

0.25m2@ 1GeV
Dead time

0.88m226.5μsec(readout time)

x8x3

2.1m2 *
2.8m2 *
Dead time freeEmulsion gamma-ray Telescope
Converter
Emulsion stackγ

Timestamper

Multi-stage shifter

Calorimetere-

Balloon-borne,Large Area
Telescopee+

10m2, ~2t

Emulsion +metal plate

Attitude monitor
Star camera* 10m2*εtrans*εconv*εdet

Flow of experiment
Detector preparation

AnalysisScanning(2nd data taking)Observation(balloon flight)
several days - 1 week

Recovery of detector

Multi-stage shifter( time stamper )S. Takahashi et al.
NIM A620(2010) pp.192-195
dx
Shifter (1)Converter

timedxShifter (1)Shifter (2)))

dx

Shifter (2)))))
timeShifter (3)SimpleCompactLight
HV freeLow power consumption
Dead time free))))))dxShifter (3)time2nd multi stage shifterfor GRAINE2015

Aperture area: 3600cm2
W66cm×D145cm×H10cm
Weight： 65kg
Power consumption: 17W(typ.)Aiming ~10msec for Vela obs.

25cm

emulsion film
37.75cm

1st multi stage shifter for GRAINE2011
Aperture area : 125cm2Time resolution : 0.15s

Co-developed with
Mitaka Kohki.Co.,Ltd

GRAINE roadmap (R&D has started in 2004)• Prototype Phase2011(done), TARF, JAXA Scientific Ballooning
125cm2 aperture area, 4.3hours (1.6hours@34.7km) flight– Working test for each element– Connection test between elements– Measurement of atmospheric gamma-rays• Demonstration Phase
2015(analyzing), Alice Springs, JAXA International Scientific Ballooning
3850cm2 aperture area, 14h22min (11h32min@36.0-37.4km) flight– Overall test by detecting known gamma-ray source (Vela pulser)• Working Phase
2018(planning)
2 to 10m2 aperture area, ~36 hours flight duration– Starting scientific observation

GRAINE roadmap (R&D has started in 2004)• Prototype Phase2011(done), TARF, JAXA Scientific Ballooning
125cm2 aperture area, 4.3hours (1.6hours@34.7km) flight– Working test for each element– Connection test between elements– Measurement of atmospheric gamma-rays• Demonstration Phase
2015(analyzing), Alice Springs, JAXA International Scientific Ballooning
3850cm2 aperture area, 14h22min (11h32min@36.0-37.4km) flight– Overall test by detecting known gamma-ray source (Vela pulser)• Working Phase
2018(planning)
2 to 10m2 aperture area, ~36 hours flight duration– Starting scientific observation

Time stamp to Gamma-ray event[counts/sec]

 Gamma-ray event rate

Stability check

30
150
14:00

15:00

16:00

17:00

18:00

 Angular distribution of Gamma-ray<on ground><in flight>

±45°

±45°

19:00

20:00

Cosmic-ray
Interaction Study
All charged par/cles are recordedin emulsion chamber with dead /me free.

multiplicity:44
b y M.MorishitaCosmic-ray
Interaction Study

multiplicity:44
b y M.Morishita

All charged par/cles are recordedin emulsion chamber with dead /me free.

Useful calibration source !
• Angular resolu/on of gamma rays.
• Detec/on eﬃciency.

b y H.Kawahara

Off-source region data
Differential Flux[cm-2 s-1 sr-1 MeV-1 (g/cm2)-1](atm. gamma-ray)
Kinzer et al.(1974), 4.5 GV
Staib et al.(1973), 4.5 GV

10-4Valdez et al.(1970), 4.5 GV
Kinzer et al.(1974), 12 GV
Staib et al.(1973), 12 GVThis work, 8 GV

10-510-6100
102200300

Energy[MeV]GRAINE roadmap (R&D has started in 2004)• Prototype Phase2011(done), TARF, JAXA Scientific Ballooning
125cm2 aperture area, 4.3hours (1.6hours@34.7km) flight– Working test for each element– Connection test between elements– Measurement of atmospheric gamma-rays• Demonstration Phase
2015(analyzing), Alice Springs, JAXA International Scientific Ballooning3850cm2 aperture area, 14h22min (11h32min@36.0-37.4km) flight– Overall test by detecting known gamma-ray source (Vela pulser)• Working Phase2018(planning)
2 to 10m2 aperture area, ~36 hours flight duration– Starting scientific observationbackup

Flow of the Analysis

Film Read-outp,α,e etc
0.37 g/ cm 2

0.47 g/ cm 2

Converter Analysis• Connection & Alignment• γ → e + e - Selection• Connection to Time Stamper

γTime Stamper
Analysise- e+Star Camera Analysis(Attitude monitor)
Pointing to celestial sphere• Off Source region (BG)
• Vela region (Signal)Film Read-out by HTS@Nagoya U.
400
350
Number of Scanned Plates

The First operation f o r realexperimental data taking

300
250
200
150
100
50
025x38cm 2
current speed 5 0 00 c m 2 / h(ﬁnal designed value 9 0 00 cm 2 /h)

2015/09/01

2015/11/01
Date

201/01/01

Flightdata

2 mm x 2 mm o f single ﬁlm

Flightdata

density ~400 tracks/mm 2

Flight dataTracks per Unit Area (13x9cm2)γ→e+e- SelectionAll Tracks

tr 106acksof 105

Eliminate penetrating

1/2000Starting from middle

104
numb
er 103e-pair candidate(with partner track)102
101020Down Stream Plate

406080100
Up Stream plate
Plate|tanθ|<1.0Tracks per Unit Area (13x9cm2)γ→e+e- Selection

Track Follow Down

All Tracks

tr 106ac
ksof 105

Eliminate penetrating

1/2000Starting from middle

104
numb
er 103e-pair candidate

Track Follow Down
(with partner track)to the Bottom→ Connection to Time Stamper

102101020Down Stream Plate

406080100
Up Stream plate
Plate|tanθ|<1.0Detector Response
Emulsionfilm

Track Detection Efficiency with Single Plate
Nagoya gel ﬁlm

Exist?
or N o ?

previous ﬁlm ~80%

K. Ozaki et al., JINST(2016)10 P12018

EmulsionfilmδθRMS(ο8) [rad]Track Reconstruction Accuracy
0.03
0.025
0.02
0.015
0.01
0.005
00

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

I n c i d e n t A n g l e ( t a n 8 )13x9cm2
Detected Events[/10MeV]

Energy Reconstruction
5000

4000

3000

P e =13.6/RMS(δθ)*㲋(x/X 0 ) [MeV/c]
2000

preliminary

1000

00100

200

300

400

500
600
700800Pe+Pp = ReconstructEnergy[MeV]

74% of total events are analyzed

CheckingDATA⇔MC(w/ detector response)

Detected event

Flow of the Analysis

Film Read-out

p,α,e etc
0.37 g/ cm 2

0.47 g/ cm 2Converter Analysis• Connection & Alignment• γ → e + e - Selection• Connection to Time Stamper

γTime StamperAnalysise- e+Star Camera Analysis(Attitude monitor)
Pointing to celestial sphere• Off Source region (BG)
• Vela region (Signal)

Time Stamp by Shifter 1st Stage# of tracks

Bottom of Converter
Launch～ non Vela7.2 hourdx1
Shifter 1st stage(Vela in the field of view
18.8 min/spot, 310 μm-pitch

7:00

20:00 観測終了

mode change

6:33 launch

altitude [m]dx1 [μm]

9:00 11:00 13:00 15:00 17:00 19:00 21:00

現地時刻

# of Tracks

Shifter
2nd Stge
放球～
Vela観測前
7.2 hour

Bottom of Converter
dx1
Shifter 1st stageConverter↓
1st Stage(dx2

2nd stage ((dx1 [μm]6.7 min/spot, 160 μm-pitch

1st Stage↓
2nd Stage

X2=dx1+dx2 [μm]

# of Tracks

1st Stage↓
2nd Stage# of Tracks

X2=dx1+dx2 [μm]2nd Stage↓3rd Stage
4000μm continuously
back-and-forth

X3=dx1+dx2 +dx3 [μm]• Optics Filter
Schneider Optics B+W091

Day Time Star Camera
Optics filter
cut-on below 610nm• Camera Lens
Nikon AF Nikkor 85mm F1.4D– diameter：60.7mm– focal length：85mm• CCD Camera
HAMAMATSU C3077-79(near-IR camera)– pixels：640×480• CPU board
ADVANTECH PCM-3362- CPU：Intel Atom N450 1.66GHz：Daytime sky BG（Dietz et al.,2002）■：Star spectrum（M-type:3200K）◆Field of View：Sensory Frame Grabber Model 311 5.9deg(H)×4.5deg(V)- ADC ：8bit
Limiting magnitude：6- Frame rate：30FPS
Monitoring accuracy：0.16mrad• Video Capture board• SSD(128GB)TOSHIBA SSDN-ST128H

K.Ozaki, et al., Proc. of Balloon
Sympo., isas12-sbs-022 (in Japanese)

Attitude analysis

K. Ozaki et al.,Proc. of Balloon Sympo.,
isas12-sbs-022

8:11:00(JST) @35km

Working rate: 74 %Monitoring
accuracy: < mrad

Daytime star camera view

Star catalog data

pattern match

Elevation < 0.25mrad
Azimuth < 0.44mrad

Rotation speed of the balloon
95% time during level flightwas ω <0.15deg/sec.

It is important to decide telescope
attitude to celestial coordinate
better than emulsion angularresolution(0.08deg).

We confirmed attitude decisionaccuracy was <ω σt< 0.02deg.