Balloon-borne Emulsion Gamma-ray Telescope …...Emulsion Telescope Detected gamma-rays Launching...
Transcript of Balloon-borne Emulsion Gamma-ray Telescope …...Emulsion Telescope Detected gamma-rays Launching...
Hiroki ROKUJO (Nagoya Univ.) for GRAINE collaboration
Balloon-borne Emulsion Gamma-ray Telescope
Gamma-Ray Astro-Imager with Nuclear Emulsion
GRAINE project
Galactic plane Galactic center
Gamma-ray souce
60MeV-2GeV
Gamma-ray Observation (GeV/sub-GeV region)
Telescope Detected sources
1990- 2001
EGRET spark chamber 271
2008- Fermi-LAT SSD tracker >3000
All-Sky Map via gamma-ray above 1 GeV
Galactic planeGalactic center
Gamma-ray souce
Gamma-ray Observation (GeV/sub-GeV region)
Nearby Galactic Center
Many sources & Extended diffuse gamma-ray
High-statistic → NEXT: Precise Observation
60MeV-2GeV
チャンドラ望遠鏡 0.5 秒角
Rotating Neutron Star(Crab pulsar)
Angular Resolutionx 1/4
■1999 Chandra(Δθ~0.5 arcsec)■1990 ROSAT (Δθ~2 arcsec)
Impact of High-Resolution Observation (An Example in X-ray Astronomy)
Impact of High-Resolution Observation (An Example in X-ray Astronomy)
チャンドラ望遠鏡 0.5 秒角
Improvement of Imaging Performance →New discoveries are expected!!
Rotating Neutron Star(Crab pulsar)
Ring Structure
Clear Evidence!!Jet Structure
Angular Resolutionx 1/4
CentralObject
■1999 Chandra(Δθ~0.5 arcsec)■1990 ROSAT (Δθ~2 arcsec)
Gamma-ray
e+e-
Emulsion
Emulsion
Plastic base
0.3mm (0.002Xo)
GTRUU=UJIVNRQHO=WNJX=RK=H=SOHVJ
Nuclear Emulsion
Gamma-ray e+/-
e-/+
10micronMicroscopic view
Angular resolution
1film
2films3films
TotalFront
Back
SPring-8 LEPSUVSOR
Fermi-LAT (2008- )(P7SOURCE_V6)
GRAINE (MC)emulsion film(70,180,70)
GRAINE2011(Zenith : 0-47deg)
100MeV 1GeV 10GeV 100GeV
1mrad
1arcmin
New SUBARU
SPring-8
GRAINE 2011
UVSORNew SUBARU
EGRET (1991-2000)
OUR ENERGY REGION
Angular Resolution for Gamma Ray
New technique for GRAINEMulti-stage Shifter (Time stamper)
time
time
1UV?UVHLJ=UMNKVJT=
time
3rd-stage shifter
dxdx
dx
Emulsion Chamber
S. Takahashi et al. NIM A620(2010) pp.192-195
Consisting of emulsion film.Low momentum threshold~10MeV/cHigh reliability & efficiencyEnlargeableSimple, compact, light weight, high-vol. free, low consumption, dead-time free
2nd?UVHLJ=UMNKVJT=
Emulsion Gamma-ray Telescope
Timestamper Multi-stage shifter
Attitude monitor Star camera
e+e-
γ
Calorimeter Emulsion + metal plate
Converter Emulsion stack
>=CBPD*εtrans*εconv*εdet
◉Higher Angular Resol.◉Polarization Sensitive◉Large Aperture Area
10m2, ~2t
Detector development /preparation
Observation(balloon flight) several days - 1 week Recovery of detector
Scanning (2nd data taking)
AnalysisFlow of experiment
GRAINE project
GRAINE 2015 Aperture:0.38m2 11.5 h@36-37km
GRAINE 2011 Aperture:0.013m2 1.6 h@35km
2004- Development on ground S.Takahashi et al. NIMA 620, 192 (2010) K.Ozaki et al. NIMA 833, 165 (2016)
2011(Jun.) 1st Balloon-Exp. • Checking Feasibility H.Rokujo et al. NIMA 701, 127 (2013). S.Takahashi et al. PTEP 2015 043H01
2015(May.) 2nd Balloon-Exp. • establishment of experimental flow • demonstration of detector K.Ozaki et al., JINST 10, P12018 (2015) S.Takahashi et al. PTEP 2016, 073F01 + in prep. (technical paper)
2018(Apr.) 3rd Balloon-Exp. • Celestial source detection
2021- Start scientific observation w/10m2
Prepare12. May. 2015 @ABLS, Australia
8.Jun. 2011 @TARF, Japan
2nd-Data taking by Scanning System
GRAINE 2015scanned
41m2 in total
Latest System “HTS” developed in Nagoya
current speed 4000 cm2/h→25000cm2/h by next generation system
Flight data
2 mm x 2 mm of single film
emulsion film records all charged particles. density ~400 tracks/mm2
Flight data
track connection plate by plate (colors indicate different plates)
Flight data
Flight data
select track starting intermediate with another partner track.
Flight data
select track starting intermediate with another partner track.
γe+e-
Flight data
reconstruct downstream tracks (Follow down for 95 plates in this event)
Flight data
Gamma-ray Energy:176 MeV (Recon.)
Track 1 Momentum: 46 MeV/c (Recon.)
Track 2 Momentum: 129 MeV/c (Recon.)
[MeV]trueE100 200 300
[MeV
]re
con.
E0
200
400
600
E/E
δEn
ergy
Res
olut
ion
0
0.2
0.4
0.6
Energy Resolution by converter(Simulation, max 20 plates)
EMC [MeV]
δE/E~20 %
E rec
on. [M
eV]
H.Rokujo, et al. in prep.
Film# of converter0 20 40 60 80 100
)29
cm×
Num
ber
of tr
acks
/eve
nts p
er p
roce
ss u
nit(1
3
1
10
210
310
410
510
610
Bottom← →Top
|<1.3)θAll B-tracks (|tanAfter elimination of penetrating tracksTracks starting from target filmGamma-ray candidates (with partner track)Events connected to bottom film
■Automatic γ→e+e− Selection for the whole of the chamber
Detected event numberGRAINE2011157 eventsreliability 98%, partial analysis
GRAINE2015~10^6 eventsreliability 95%, almost full analysis (~75%)
x10000
All tracks
e-paircandidatesin each film
Recent Progress of GRAINE
Energy [MeV]0 50 100 150 200 250 300
- e+ e
→γ
Det
ecti
on E
ffic
ien
cy f
or
0
0.2
0.4
0.6
0.8
1
Events converting at plate#10
Events converting at plate#95
GRAINE 2011
Sele
ctio
n Ef
ficie
ncy
GRAINE2011
GRAINE2015 with Nagoya-gel film
■Selection Performance(MC)
Recent Progress of GRAINEH.Rokujo, et al. in prep.
Energy[MeV]210
]-1 )2
(g/
cm-1
MeV
-1 s
r-1
s-2
Dif
fere
nti
al F
lux[
cm
6−10
5−10
4−10Kinzer et al.(1974), 4.5 GVStaib et al.(1973), 4.5 GVValdez et al.(1970), 4.5 GVKinzer et al.(1974), 12 GVStaib et al.(1973), 12 GV
GRAINE 2011(50-300 MeV), 8 GV
This work, 8 GV
GRAINE2011
GRAINE2015
■BG measurement(atmospheric gamma rays)
Phase-resolved analysis for pulsars is capable.
Altitude & Track rate
s=4.9mm w/ 500mm/sec operationÆTime resolution 9.8msec
Hadron event on spike structure
GRAINE 2015, Flight data analysis, Timestamper
10cm
e.g. 89msec period of Vela pulsar
Simultaneity of hadron event tracks
15 min.Altitude
Posit
ion
Y
Position X
Anglescale
Analyzed by F.Mizutani
~~~~ ~~
CR (protons, etc.)
4.4 m
Extrapolated positions at the height of the launching plate
~~~~
25 cm
38 cmEmulsion Telescope
Detected gamma-rays
Launching Plate
17 cm
Demonstration of Gamma-ray Imaging during Balloon Observation
Aluminum 4.6 kg
17 cm
emulsion telescope
~~~~ ~~
CR (protons, etc.)
4.4 m
Extrapolated positions at the height of the launching plate
~~~~
25 cm
38 cmEmulsion Telescope
Detected gamma-rays
Launching Plate
17 cm
Extrapolated Position X [cm]40− 30− 20− 10− 0 10 20 30 40
Extra
polate
d Posi
tion Y
[cm]
40−
30−
20−
10−
0
10
20
30
40
Event
s in 5-
cm ra
dius
60
80
100
120
140
160
180
200
220Preliminary
]2) [cm2+Y2 (=X2R0 100 200 300 400 500 600
20−
0
20
40
60
80
100
120 Preliminary
Gamma-ray Image of the launching plate
Extrapolated Position X [cm]40− 30− 20− 10− 0 10 20 30 40
Extr
apol
ated
Pos
ition
Y [c
m]
40−
30−
20−
10−
0
10
20
30
40
Even
ts in
5-c
m r
adiu
s
60
80
100
120
140
160
180
200
220Preliminary
]2) [cm2+Y2 (=X2R0 100 200 300 400 500 600
20−
0
20
40
60
80
100
120 Preliminary
This result is the first demonstration with the whole of enlarged area.(So far, with a small area using accel. beam)
100-300 MeV
R2 distributionclear excess
H.Rokujo, et al. in prep.
]2 [cm2R0 100 200 300 400 500 600
0
50
100
150
200This work
0.0)×MC (angular res.
1.0)×MC (angular res.
1.5)×MC (angular res.
2.0)×MC (angular res.
100-300 MeV
Energy [MeV]100 150 200 250 300
]-1
MeV
-1 s-1
[cm
plat
eG
amm
a-ra
y flu
x F
8−10
7−10
6−10
This work
Simulation
Preliminary
H.Rokujo, et al. in prep.
R2 distribution
Gamma-ray fluxfrom the plate
~~~~ ~~
CR (protons, etc.)
4.4 m
Extrapolated positions at the height of the launching plate
~~~~
25 cm
38 cmEmulsion Telescope
Detected gamma-rays
Launching Plate
17 cm
Gamma-ray Image of the launching plate
Emulsion telescope has the good performance as expected.→Next: overall demonstration by detecting celestial gamma-ray sources
Summary & Prospects•GRAINE project - Precise observation by balloon-borne emulsion gamma-ray telescope - High angular resolution, Polarization sensitive, Large effective area - SNR, Galactic center/plane, un-ID sources, Polarimetry, Burst events •2015-Balloon experiment in AUS - Flight, Scanning, and Analysis were established. - Achieved 9.8 ms of time resolution by multi-stage shifter. - Demonstrated gamma-ray imaging performance @100-300 MeV as expected •Next balloon experiment - The goal is confirming the overall performance by detecting a celestial gamma-ray source(Vela pulsar). - Please go to the following Poster Sessions!! • Y. Nakamura: Preparation of emulsion films • K. Kuretsubo: Preparation of Multi-stage shifter