instrumental development in japan for future missions 1.si strip detectors(glast) 2.supermirror...
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Instrumental Developmentin Japan for Future Missions
1. Si strip detectors(GLAST)
2. Supermirror technology
3. New hard-X/ detectors
4. TES calorimeters
5. Science from NeXT
Takaya Ohashi (Tokyo Metropolitan U.)
Development of Silicon Strip Detector ( SSD )
0.01-1mm Position Reso. Good Time Reso. ( a few s )Stability/Radiation Hardness confirmed with accelerators.
Small number of readout channels compared with pixel detectosModerate Energy Resolution ~ 1keV ( at 0℃)
Thickness: 0.3-0.5mmTeam in Hiroshima Univ. has developed SSDs for Astrophysics.
15 cm
GLAST-SSD(0.4mmt)Single-Side Strip0.23mm pitch, 384ch
For GLAST,
SSD as Tracker of pair produced particles
Achieved Large area (6 inch wafer)SSD technology will open a new era of GeV gammay-ray astronomy.
Y. Fukazawa, T. Ohsugi et al. (Hiroshima U.)
full depletion voltage
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Leakage Current @150V
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70nA
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Mass Production is now running (10k SSDs for GLAST).Stable Performance and Low dead channels ( <0.01%)
Depletion Voltage Leak Current
Double-Side SSD is now under development for Compton Gamma-ray Camera.
Good scattering material with good position resolutionFast time resolution (for BGD rejection)
Combination with CdTe is a good solution.
By Hiroshima U., SLAC, ISAS( Candidate for NeXT )
100V200nA
Focal length : 8 m Dia. 40 cm Energy band 20 - 40 keVFOV (fwhm) 9’ Ang. Resol. (HPD) 2’
Development of Hard X-ray Telescope --- Multilayer Supermirror ---
Replica foil mirrors and telescope [ InFOCuS-1 ]
Eff. Area 50 cm2
PSF : HPD = 2.1 arcminBalloon Experiment : InFOCuS, NUSMIT
Satellite Mission : NeXT, XEUS
K.Yamashita, Y.Tawara, H. Kunieda et al. (Nagoya U., ISAS)
NeXT• launch 〜 2010• D= 60 cm, f=12 m• 6 modules• Seff= 1200 cm2@40 keV• HPD = 15 arcsec(goal)
Refle
ctiv
ity
Energy (keV)
NeXTSensitivity100 ks/5 detection
X-ray ReflectivityPt/C MLSupermirrord=2.4-13 nm
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10040 keV 100 keVCdTe
Ge
Si
Thickness (mm) Thickness (mm)
CdTe
Ge
SiA
bsor
ptio
n E
ffici
ency
(%
)
Abs
orpt
ion
Effi
cien
cy (
%)
0.1 0.2 0.5 1.0 2.0 5.0 10.00.1 0.2 0.5 1.0 2.0 5.0 10.00
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ISAS
• High Z semiconductor (ZCd = 48, ZTe = 52) • High density(5.8 g/cm3) • Room Temperature Operation (Eg ~ 1.5 eV) • High Resolution CdTe Diode by ISAS
VA2TA(IDE)
CdTe
1cm
Applications1. Focal plane detector of the Hard X-ray Mirror2. Next Generation Compton Telescope
First Prototype (pixel size 625μmx625μm) 400 pixels
Cadmium Telluride (CdTe) Diode Detector for Hard X-ray/Gamma-ray Observations
T. Takahashi et al. (ISAS)
New Gamma-ray Detector for the NeXT
E1
E2
Ein
θ
Incident angle of rays is defined by an active collimater
- Compton Kinematics -
Background events (activation / intrinsic, shield leakage) can be reduced significantly by requiring this relation for E1 and E2.
E2 Ein
1 Einmoc
2(1 cos )
;Ein E1 E2
CdTe/SiStrip or Pixel
ISAS
T.Takahashi et al (ISAS, SLAC, Hiroshima U., U. Tokyo. Osaka U.)
Astro-E2 XRS (2005 ~ )
X-ray Spectrometer 1m
Large format array of ( ~ 32x32 pixel)
TES calorimeter (ΔE ~ 3 eV)
32 pixel semiconductor- calorimeter array
2.5 mm×5.3 mm (1.9’ ×4.1’ )
ΔE ~ 10 – 12 eV
3 year life time of coolant
TES (Transition Edge Sensor)
(Irwin et al. 2000, NIMA 444, 184)
Using sharp edge at normal to superconductor transition
Higher sensitivity of thermometer
Faster response by electro-thermal feedback
Development of High ResolutionDevelopment of High Resolution
NeXT
K. Mitsuda et al. (ISAS, Tokyo Metr. U., )
TES calorimeter fabricated by Seiko Instruments In
c.
TES CalorimeterPresent Performance of
1m
0.5 mm
1.7 mm
0.5 mmTES
Si
TTcc == 105 mK105 mKα≡ dlnα≡ dlnRR/dln/dlnTT ~ ~ 100100
Mn - KMn - K2 2 (5.888 ke(5.888 ke
V)V)
KK1 1 (5.899 ke(5.899 ke
V)V)
0.5 x 0.5 mm Ti / Au bilayer TES0.3 x 0.3 mm Au absorber, Ti/Au/Au=40/110/300 nm thick
9.2±0.4 eVYesterday!
Making of Large Format ArrayExperimental production ofmushroom-shaped Sn absorber
500m
1 mm size
16 x 16 calorimeter array structure
Through hole wiringelectrodeposit Sn & polish i
t to 8 μm thick
NeXT: Dynamics and Acceleration in the Universe
Chandra, XMM .... 1999
Astro-E2 .............. 2005
NeXT ................. ~2010