A. Takada, T. Tanimori, H. Kubo, K. Miuchi, S. Kabuki, J. D. Parker, Y. Kishimoto, T. Mizumoto, K. Ueno, S. Kurosawa, S. Iwaki, T. Sawano, K. Taniue, K. Nakamura, N. Higashi, Y. Matsuoka, S. Komura, Y. Sato (Kyoto Univ.), S. Arvelius (Lulea Univ.), E. Turunen (EISCAT Association) 1. MeV gamma ray Imaging & ETCC 2. Results of SMILE-I 3. Preparations of SMILE-II
Observation of MeV gamma-ray will provide us… Nucleosynthesis SNR : Radio-isotopes Galactic plane : 26 Al ・ 60 Fe Annihilation Bad erg / (cm 2 sec) Acceleration EGRET Sensitivity Jet (AGN) : Synchrotron Air Cherenkov Fermi + Inverse Compton Astro-H Strong Gravitational Potential Obs. Time : 10 6 sec Black Hole : accretion disk, π 0 Good Etc. ～１ ° Gamma-ray Pulsar, solar flare • The observation of continuum component is also important. • Where are MeV gamma-ray objects? • There are many background events which obstruct the observations. • Wide-band detection Requirements for • Large Field of View the next-generation detectors are … • Background rejection
Observation of MeV gamma-ray will provide us… Nucleosynthesis SNR : Radio-isotopes Galactic plane : 26 Al ・ 60 Fe Annihilation Bad erg / (cm 2 sec) Acceleration EGRET Sensitivity Jet (AGN) : Synchrotron Air Cherenkov Fermi + Inverse Compton Astro-H Strong Gravitational Potential Obs. Time : 10 6 sec Black Hole : accretion disk, π 0 Good Etc. ～１ ° Gamma-ray Pulsar, solar flare • The observation of continuum component is also important. • Where are MeV gamma-ray objects? • There are many background events which obstruct the observations. • Wide-band detection Requirements for • Large Field of View the next-generation detectors are … • Background rejection
Using Compton Scattering energies of scattered gamma E 0 and recoil electron Energy of incident gamma Scattering angle φ Liquid scinti. Compton scattering point E 1 & Absorption point NaI(Tl) Direction of scattered gamma E 2 ignore the direction of recoil electron Restrict the direction of incident gamma-ray to a circle The source position is determined fully by piling up circles require 3 γ at least
G.Weidenspointner, et.al. (A&A, 2001) A ： external γ Intrinsic B ： internal γ background C ： two γ D ： random coincidence E: proton-induced γ Other background neutron TOF of 2 detectors electron gamma from atmosphere backward COMPTEL has rejected such background by the measurement of the Time Of Flight forward between 2 detectors. Background rejection was not complete -20 -10 0 10 [nsec] Bad S/N
Gaseous TPC : Tracker track and energy of recoil electron Scintillator : Absorber position and energy of scattered gamma Reconstruct Compton scattering event by event 1 photon ⇒ direction + energy Large FOV (~3str) Kinematical background rejection E γ : Energy of scattered gamma-ray g : unit vector of scattering direction K e : Kinematic energy of recoil electron e : unit vector of recoil direction m e c 2 : Rest mass of electron
Electron-Tracking Compton Usual Compton Imaging (COMPTEL) (ETCC) Using the electron tracks Not using the electron tracks • complete direction within • only event circle within sector form error region ring form error region Simply overlay Simply overlay 2 sources were Hard to separate separated clearly 2 sources 15 15 150 events Y [cm] Y [cm] 600 events -15 -15 -15 X [cm] 15 -15 X [cm] 15 137 Cs(1MBq) × 2, usual Compton 137 Cs(1MBq) × 2, Advanced Compton
10cm cube camera @ Sanriku (Sep. 1 st 2006) Operation test @ balloon altitude Observation of diffuse cosmic/atmospheric gamma ~400 photons during 3 hours (100 keV~1MeV) 30cm cube camera Sub-MeV ~ MeV Observation of Crab/Cyg X-1 40cm cube camra Long duration observation with super pressure balloon Adding pair-creation mode 50cm cube camera All sky survey (load on a satellite)
Absorber Gas : Xe 80% + Ar 18% + C 2 H 6 2% Scintillator : GSO(Ce) 1atm, sealed Pixel size : 6x6x13 mm 3 Gain : ~35000 Photo readout : H8500 (HPK) Drift velocity (V d =400V/cm) : DC/HV : EMCO Q12N-5 measured 2.5cm/ µ sec A unit consists of 192 pixels, 3 simulation 2.48cm/ µ sec PMTs, 3 DC/HV and 4 preamplifier Volume : 10 × 10 × 14 cm 3 4 channels readout with resistive Energy resolution : chain (H. Sekiya et al., NIM, 2006) ~45% (22.2keV, FWHM) Bottom : 3 × 3 PMTs 2112 Position resolution : ~500 µ m Side : 3 × 2 PMTs × 4 pixels Energy resolution : Recoil electron ~11% (662keV, FWHM) 5cm 15cm Flat Panel PMT H8500
• Gondola size: 1.45 × 1.2 × 1.55m 3 • Gondola weight: 397kg • Bessel: φ 1 × 1.4m 3 • Power: ~350W in Bessel ： 220W TPC ASD In Bessel (1 atm) Flight Control Detector, DAQ system, Telemetry, Storage, Thermometer, Transponder, Buoy, Radiosonde, Pressure gauge, GSO GPS, Clinometer GPS, Thermometer, Pressure gauge, etc. Out of Bessel Balloon NIM encoder Battery & Regulator, B100 (100,000m 3 ) Thermometer, Weight 816kg Pressure gauge, VME Buoyancy 888.2kg GPS antenna, Geomagnetic aspectmeter
• Gondola size: 1.45 × 1.2 × 1.55m 3 • Gondola weight: 397kg • Bessel: φ 1 × 1.4m 3 • Power: ~350W in Bessel ： 220W TPC ASD In Bessel (1 atm) Flight Control φ ~1m Detector, DAQ system, Telemetry, Storage, Thermometer, Transponder, Buoy, Radiosonde, Pressure gauge, 1.4m GSO GPS, Clinometer GPS, Thermometer, Pressure gauge, etc. Out of Bessel Balloon NIM encoder Battery & Regulator, B100 (100,000m 3 ) Thermometer, Weight 816kg Pressure gauge, VME Buoyancy 888.2kg GPS antenna, Geomagnetic aspectmeter
• Gondola size: 1.45 × 1.2 × 1.55m 3 • Gondola weight: 397kg • Bessel: φ 1 × 1.4m 3 • Power: ~350W in Bessel ： 220W GA TPC Regulator ASD Bessel In Bessel (1 atm) Flight Control Battery φ ~1m Detector, DAQ system, Telemetry, Storage, Thermometer, Transponder, Buoy, Radiosonde, Pressure gauge, 1.4m GSO GPS, Clinometer GPS, Thermometer, Pressure gauge, etc. Ballast Out of Bessel Balloon NIM Battery encoder Battery & Regulator, B100 (100,000m 3 ) Thermometer, Weight 816kg Pressure gauge, VME Buoyancy 888.2kg GPS antenna, Geomagnetic aspectmeter
• Gondola size: 1.45 × 1.2 × 1.55m 3 • Gondola weight: 397kg • Bessel: φ 1 × 1.4m 3 • Power: ~350W in Bessel ： 220W GA TPC Regulator ASD Bessel In Bessel (1 atm) Flight Control Battery φ ~1m Detector, DAQ system, Telemetry, Storage, Thermometer, Transponder, Buoy, Radiosonde, Pressure gauge, 1.4m GSO GPS, Clinometer GPS, Thermometer, Pressure gauge, etc. Ballast Out of Bessel Balloon NIM Battery encoder Battery & Regulator, 1.55m B100 (100,000m 3 ) Thermometer, Weight 816kg Pressure gauge, VME Buoyancy 888.2kg GPS antenna, Geomagnetic aspectmeter 1.20m 1.45m
Atmospheric gamma-ray flux Cosmic gamma-ray flux (Scaled to R cut = 9.7GV) SMILE-I SMILE-I A. Takada et al., A. Takada et al., ApJ, 733, 13 (2011) ApJ, 733, 13 (2011) Our results were consistent with those of past observations!!!
SMILE-I Bad erg / (cm 2 sec) EGRET Sensitivity goal Air Fermi Cherenkov Astro-H Obs. Time : 10 6 sec Good ～１ °
10cm cube camera @ Sanriku (Sep. 1 st 2006) Operation test @ balloon altitude Observation of diffuse cosmic/atmospheric gamma ~400 photons during 3 hours (100 keV~1MeV) 30cm cube camera 2012- test flight @ Taiki Sub-MeV ~ MeV 2013- Observation @ Kiruna Observation of Crab nebula with circumpolar balloon 40cm cube camra Long duration observation with super pressure balloon Adding pair-creation mode 50cm cube camera All sky survey (load on a satellite)
SMILE-I : 1 st Sep. 2006 launched • Observation of diffuse cosmic/atmospheric gamma-rays -> detection by integration in a large FOV • Electron Tracker : 10x10x15 cm 3 , Xe+Ar 1atm • Absorber : 15x15x1.3 cm 3 @ Bottom 15x10x1.3 cm 3 x4 @ Side Effective area : ~2x10 -2 cm 2 SMILE-II • Observation of a Bright object (Crab nebula) Requirement : ~0.5 cm 2 • Electron Tracker : 30x30x30 cm 3 , Ar/CF 4 1.5atm • Absorber : 40x45x1.3 cm 3 @ Bottom 40x20x1.3 cm 3 x4 @ Side • Improvement of Angular resolution
SMILE-I Bad erg / (cm 2 sec) SMILE-II EGRET Sensitivity goal Air Fermi Cherenkov Astro-H Obs. Time : 10 6 sec Good ～１ °
30 30 × 30 30 × 30c 30cm 3 ETCC c curre urrent nt st status us We are developing a larger ETCC based on the 30cm × 30cm × 30cm TPC and 6 x 6 scintillation cameras. Gaseous TPC Scintillation Camera • number of pixels : 2304 pixels • volume : 30 × 30 × 30 cm 3 • Crystal : GSO(Ce) • gas : Ar 90% + C 2 H 6 10% (1atm) • pixel size : 6 × 6 × 13mm 3 • drift velocity : 4 cm/ μsec • energy resolution : 10.9% • gain : ～ 100000 (@662keV, FWHM) • energy resolution : 46%@32keV • position resolution : 6mm • position resolution: 400μm 30cm
40cm Gaseous TPC 40cm Encoder (FPGA board) 60cm ASD (PreAmp) Scintillation camera Setup source Z Gaseous TPC Y Center of μ ＰＩＣ : (0,0,0) X Center of Scinti. :(-3.3, 0.2, 5.7) Scintillation camera
137 Cs : 662keV, 1MBq (X,Y,Z) = (5, 5, -52) [cm] 54 Mn : 835keV, 1MBq (X,Y,Z) = (-5, -5, -52) [cm] All range 580-740keV 760-910keV 54 Mn:835keV 137 Cs 137 Cs:662keV 54 Mn [cm] [cm] [cm] Energy[keV] Energy[keV] Energy[keV]
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