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Space Application of Geant4 Space Application of Geant4 for the Japanese Xfor the Japanese X--ray and ray and
GammaGamma--ray Missionray Mission
Yukikatsu Terada(RIKEN, Japan),
Shin Watanabe, Masanobu Ozaki, Tadayuki Takahashi (ISAS/JAXA),
and Motohide Kokubun (Univ. of Tokyo)
XX--ray to Gammaray to Gamma--ray detectors in Spaceray detectors in Space
Many detectors, designed for astrophysical observations
• Photo-absorption + Collimator
• Coded mask + Position Sensitive Detector
• Compton telescope
BeppoSAX PDS, CGRO OSSE,Suzaku HXD etc..
INTEGRAL SPI&ISGRI,Swift BAT, Yohko,RHESSI (rotation mask),
CGRO COMPTEL
To success the XTo success the X--ray to Gammaray to Gamma--ray missionray mission• Energy Response is the key • Low Background is the key
Absolute energy/flux calibrationAccurate pulse height distribution
Reduce the systematic errorin the background estimation
Need Monte Carlo simulation with Geant4Need Monte Carlo simulation with Geant4
Cyclotron absorption featureby magnetic field of a neutron star
Signal: 1/1000 of Crab
Large area High BGD
Small areaLow BGD
5e-4ph/s/cm2/keV
3300cm2
5e-7ph/s/cm2/keV
100cm2
Preliminary
Design phase
In Orbit phase
Soft GammaSoft Gamma--ray detectors onray detectors on--board board Japanese XJapanese X--ray Satellitesray Satellites
Current Mission:Suzaku (2005~)
Future Mission:NeXT (2011~)
Hard X-ray detector (HXD) Super X-ray Telescopewith
Hard X-ray Imager (HXI)
Soft Gamma-rayDetector (SGD)
1010––600 600 keVkeV, 10, 10--55cnt/s/cmcnt/s/cm22/keV/keV1010––70 70 keVkeV, , 1010--88cnt/s/cmcnt/s/cm22/keV/keV
5050––400 400 keVkeV, , 1010--77cnt/s/cmcnt/s/cm22/keV/keV
Successful launch of AstroSuccessful launch of Astro--E2, Suzaku E2, Suzaku The fifth Japanese X-ray satellite, Astro-E2Launched on 10th July 2005, 03:30UTNamed as “Suzaku”
Copyright ISAS/JAXA Copyright ISAS/JAXA
Copyright ISAS/JAXA
Hard X-ray Detector (HXD)
10–600 keV105cnt/s/cm2/keV
RIKEN, RIKEN, Univ. of Tokyo,Univ. of Tokyo,ISAS/JAXA,ISAS/JAXA,AoyamaAoyama--Gakuin, Gakuin, Saitama Univ.,Saitama Univ.,Hiroshima Univ.,Hiroshima Univ.,Kanazawa Univ.,Kanazawa Univ.,Osaka Univ.,Osaka Univ.,Stanford Univ.Stanford Univ.
HXD-II team, with HXD Sensor before integration (June, 2004)
Orbit: altitude 568kmeccentricity less than 0.0002% (Circle)inclination 31.4 degrees
Hard XHard X--ray Detector, HXDray Detector, HXDCross Section Top View
Photo-absorber:PIN PIN SiSi diodediodeGSO GSO scintillatorscintillator
Passive Collimator
Anti coincidence shieldBGO BGO scintillatorscintillator
16 Well-type Units and 20 Anti BGO Units
Optical Axis
M. Kokubun et.al., IEEE T.N.S,51,1991,2004M. Tashiro et.al., IEEE T.N.S.,49,1893,2002and references therein.Original concept in
T. Kamae et.al. Proc.SPIE,2806,314,1996
Suzaku Geant4 simulatorSuzaku Geant4 simulatorReal World Geant4
• Two main purposeconstruct the energy responseestimate background in orbit
•Suzaku original framework, ANLto share standard analysis tools anddata base for the actual dataM.Ozaki et.al., IEEE T.N.S. submitted
• Original Detector-Constructionclass and Material-Factory classcollaborate with other instrumentsonboard Suzaku
• Pre-flight studies for the HXDvalidate the simulation with actual data in the calibration experimentsY.Terada et.al., IEEE T.N.S.,54,902,2005M.Ohno et.al., IEEE T.N.S. sumitted
Overview
Comparison with the PreComparison with the Pre--flight data Iflight data I
PIN PI (channel energy)
Coun
ts
PIN Spectrum
GSO Spectrum
Calculate an Energy deposit
Digitization RI irradiation test
PH o
f Sl
ow S
hape
r
PH of Fast Shaper
PH o
f Sl
ow S
hape
r
PH of Fast Shaper
Real WorldGeant4
include the Sensor response
Comparison with the PreComparison with the Pre--flight data IIflight data IIReal WorldGeant4
RI scanning test around HXD,before and after integration
HXD BGO Units
RI
Absorption map
Geant4 Geometry of Suzaku
Comparison with the inComparison with the in--orbit dataorbit datafor the calibration purposeReal WorldGeant4
Incident Energy spectraof
Known astrophysical objects
×Energy Response by Geant4:Matrix of (incident energy
v.s. Pulse height)
Expected pulse height distribution
Crab Nebula
Preliminary
Preliminary
Currently: 5-10%Goal: 1-2%
Background study and estimationBackground study and estimationReal WorldGeant4 (plan)
Under developing!!Under developing!!Under developing!!
H2+,135MeV/nuc
Total 1.1x109cntsExposure: 15min
Beam Experiment (RIKEN)
Irradiated particle flux,counted by HXD-PIN.
HXD WAM count rate (1 day)
Particle in orbit
Geant4 Mass Model
Hadron/Nucleonproduce secondary particleradio-activate process
Nuclear/Atomicde-excitation
EM transport
Detector response
In orbit
Simulation (MGGPOD)
Concept study for NeXT MissionConcept study for NeXT Mission
Scientific simulation
Performance estimation with Geant4NeXT SGDNarrow Field Compton Telescope50–400 keV, 107cnt/s/cm2/keV
Compton ImageTwo source, 122keV
Laboratory:40 layer CdTe stack
S.Watanebe et.al. IEEETNS 49,p1292,2002 T.Tanaka et.al. SPIE,2004
H.Tajima et.al. IEEE NSS-CR, vol.1,p314,2004