1. Electron Tracking Compton Camera
in MeVガンマ線天文学 (SMILE-project)
2. 最遠方ガンマ線バースト検出の可能性
3. 中間赤外線望遠鏡	
4. 極域での長時間気球観測	
5. まとめ	
１．京大大学院理学研究科 物理第2教室 宇宙線研究室
２．金沢大学 理工研究域 数物科学系	

2010 Sep.1７GRB-WS @ＣＲＣ将来計画シンポジウム	G.Weidenspointner, et.al. (A&A, 2001)

TOF of 2 detectors
ラインガンマ線	
元素合成 26Al・ 511 keV

backward

forward-20-10010 [nsec]○連続ガンマ線放射	
" ブラックホール等	
" 宇宙線加速 AGN, Pulsar, SNR,
" 宇宙の始まり	
ガンマ線バースト（GRB)+ 極地方での最小バースト 	24.25y24.2RMSx0.09613RMS

y0.105Mean

x162500Mean

24.25prox-yEntries

y24.2RMSx

0.09613RMS

y100.105Mean

518.21y22.04RMS

x0.03503RMS

y2.62Mean

x

149000Mean

18.21prox-yEntries

y22.04RMS

x

0.03503RMS

y2.62Mean

x

149000Mean-50-40-30-20-1001020304050-50-40-30-20-1001020304050prox-yEntries2x2	  events	  １	162500Mean

α-50-40-30-20-1001020304050-50-40-30-20-1001020304050prox-yEntries

Electron Tracking Compton Camera(ETCC)
1. Determination of the direction of eachgamma ray
2. Noise Reduction by Kinematics(α)
3. Large FoV. ~3str
4. For All Sky MeV-γ Survey with >10
better than COMPTEL
In use of electron
track
150
events	no use of electron track100

αmeasure-αkin

3-45°
ARM-180°0°1625
events

0°

45°

cut

180°

GSO
Pixel

Timing Projection Chamber (TPC)

E（電場）	e	TPC
3x3 array

連続ガンマ線イメージング	
µ-PIC
Micro Pixel Chamber

400µm
Imaging of 3D tracks
Cal. source
Ba. 335keV

Thyroidtumor
60cm	  6cm

Liverelectron

Middle animal imaging(I-131-MIBG)

Zn-65-Porphyrin (1.1MeV)ARM (FWHM) [degree]	

50	
SMILE-I 2006
(Xe + GSO)	
Ar TPC+ GSO(2008)	

10	5	

1	

Ar TPC+ LaBr3(2008)	

4.2o@662keV(FWHM)

ΔE/E

ΔX/X

Doppler

角度分
解能
実測値	

角度分
解能	

GSO	 5.0 ± 0.2

5.2		

4.3

2.80.9LaBr3	

4.32.7

3.20.94.2 ± 0.3

（計算値）	

ΔX/X -> Depth-of-interaction (DOI)	

ガンマ線	

TPC	

ΔX	
シンチレータ	

2段DOIー＞3度＠662keV、	さらにシンチレータ-5.8%->4%で	2度以下も可能	
1MeV->1.3度（COMPTEL；4.7度）	

Event Selection

All Trigger enent 2.3x105 events
Signal⇒ ~420 events

Simulation ⇒ ~400events (GEANT4 base)Diffuse Cosmic γ	

Takada et al., ApJ 2011	

Atmospheric γ	prototype• Absorber: 36 GSO-PSAs• Tracker gas: Ar 1atm

30cm30cm

TPC	

Scintillator
Effective area

TPC	

Scintillator

Flight Model• Absorber: 216 GSO-PSAs• Tracker gas: CF4+Ar 1.5atm• Azimuthal Tracking of target• New Reconstruction method
SMILE-I
SMILE-II×50

sensitivity20092008

Z measured (z>3)

Fluence (10-7cm-2 )Fluence (10-7cm-2 )Swift GRB	

3.0
4.1
3.4 3.0
3.4
3.5 3.9 3.8
3.2

T90(S)

86 4.5
4.8.
4.7
4T90(S)	

Sensitivity of X-ray Burst Trigger	

consistent to Salvaterra et al. 2008

Imaging GRB Trigger in Sub-MeV"

ETCC measure the each photon direction >100keV"

Cosmic BG >100keV; ~8ph./102s >100keV in 4ox4o @100cm2"

BG; several 10 x of Diffuse γ but rejected by Kinematical cut 	

BG Rejection (SMILE-I off-line)

2.23×105
eventsObtained Gamma-ray Spectrum

"""

420 γ

Several γ Mapping in Lab.

Plim ~30 ph. >100keV in 4ox4o @~100cm2 in 102 sec (8σ)
Point Accuracy for GRBs <0.2o for 300γ, 0.5o for 30γ	With a wide field of view infra red or X-ray telescope (~0o.5)

Expected Flux >100keV for GRB@z~20
Expected Photon #(>100keV) for GRB @z=20 & Eiso=1052 erg ->1000 ph.
Detection limit ~100ph. ->1051erg @z=20 and 3str ->1 GRB@day（Almost all GRBs in the universe would be detected !）	
Eiso(1052erg)

Expected γ(>100keV)

89

2.6x103

72 x103	

38

1.7x104	
3x103

Requirements

Detection Area 30~100cm2
from 0.1-100MeV
Angular Res. 4o~0.3o <0.1-100MeV-> Position Res. 0.2o for 100 photons

201.2x104

31.7x103	

52 x103	

GUNDAM（仮称）	  Gamma-­‐ray	  burst	  	  for	  UNravelling	  Dark	  Ages	  Mission	  PATHFINDER	  米徳大輔,	  	  村上敏夫 (金沢大学),	  	  	  谷森達,	  	  黒澤俊介 (京都大学),	  沖田博文 (東北大学),	  	  	  郡司修一 (山形大学),	  筒井亮,	  	  中村卓史,	  	  井上進 (京都大学),	  	  	  戸谷友則 (京都大学)	  高橋慶太郎 (名古屋大学),	  井岡邦仁,	  	  水田晃,	  	  川中宣太 (KEK)	  中島正裕 (東京大学),	  松浦周二,	  	  坂井真一郎 (ISAS/JAXA)	  e+e-	e-	Compton	

~40cm~80x40cm
45cm鏡	NIR	  /	  OpDcal	  Detector	  Module	with 1m class NIR telescope	ERGSatellite(Energization and Radiation in Geospace)	

MeV-eThunder

100keV-e	DθLdirect-e	Northern Polar Long Flight	Χιρχυµπολαρ φλιγητσ, συµµερ	Crab	PreliminaryCrab	  	  orbit	  8.7MeV	

18.0MeV	8.4°(68%containment)	

1m3 TPC(Xe7.0°(68%containment)	

2atm)	

Fermi	

MEGA	

thiswork	

EGRET

Simulation for experiment	
Due to loss by hole

EGRET	
1m3 TPC(CF4 2atm)	
this work	
Effective Area	

Full cover detector without
energy info
(Ar:C2H6=90:10)
with energy info.
(Ar:C2H6=90:10)	

"""

Except usual Compton Camera objects
Good & High Statistical Images for 50-100MeVΔθ <<0.5oCosmic-ray origin (Proton identification fromSpectrum; 10-100MeV) 	

πο	

MeV

まとめ（今後）	
" ＥＴＣＣは連続ガンマ線探査に強い	
" 中型ＥＴＣＣ，SMILE-II

201@Taiki 試験飛行

2013〜 Kiruna から北極周回観測へ	
" 毎年200-300時間程度の観測

地球（REP-γ、太陽中性子＋γ） ー＞精密粒子加速機構研究、宇宙（コンパクト天体、ＡＧＮ、ＧＲＢ検出の試験）。	

" 定点観測（気球の必要性）による新しい地球・宇宙観測基地へ

30cm角ＥＴＣＣから数年後50ｃｍ角ＥＴＣＣレベル以上へ！
" 中間赤外望遠鏡＋ガンマ線（又はＸ線）イメージング装

置の小型、中型遠方ＧＲＢ探査衛星計画始動！	

Ei = 10MeV	

0	4	8	 12	16	 20	

Ei = 40MeV	

0	4	8	 12	θ =difference between incident andreconstructed direction (deg.)	

Opening Ang. of e (degree)

Ei = 20MeV	806016	 20	Opening Ang. of e-(deg.) 	

Simulation Study
40	30	20	10	00Ei = 20MeV	

10	 20	 30	 40	Opening Ang. of e+(deg.)	

Angular resolution determined bymultiple scatterings of e+e- andtheir opening angle.

40
2000	20	40	60	80	

Opening angle (deg.)	

Low density material and fine
Tracking are necessary for <100MeV
gamma rays.

10cm cube camera @ Japan (Sep. 1st 2006)• Observation of diffuse cosmic/atmospheric γ	

~400 photons during 3 hours (100 keV~1MeV)

30cm cube camera with Domestic balloon @Japan@Kiruna" Observation of Crab/Crg X-1 + REP-γ	

40cm cube camra with long duration observation" Galactic survy" Test of Gamma-Ray Burst Detection

50cm or 1m cube camera with satellite" All sky survey, detection of highest-z GRB