1. Geant4 in Space selected recent investigations
Giovanni Santin, Petteri Nieminen
European Space Agency
Geant4 ‘07
Hebden Bridge, Sep 2007

2. Outline Planetary exploration Looking outside the solar system
Geant4 usability: Tools and Engineering aspects
Space Users’ community
Giovanni Santin - Geant4 in Space - Geant4 '07, Hebden Bridge, Sep 2007

3. 2. Planetary exploration
Physics models
Scientific Exploration:
Low En EM
Manned space flight:
Even Lower En EM and physics for hadrons
Interfaces
(Engineering) Tools
Giovanni Santin - Geant4 in Space - Geant4 '07, Hebden Bridge, Sep 2007

4. Solar event gamma-rays
Electron Bremsstrahlung – induced gammas
in solar flares
Compton back-scattering
 observable gamma-ray spectrum
much softer than predicted by simple
analytic calculations
Giovanni Santin - Geant4 in Space - Geant4 '07, Hebden Bridge, Sep 2007

5. Mercury surface ? Bepi Colombo: X-Ray Mineralogical Survey of Mercury
Fluorescence development in Geant4
Giovanni Santin - Geant4 in Space - Geant4 '07, Hebden Bridge, Sep 2007

6. PlanetoCosmics Mercury soil and magnetic field
+ Dipole B0 = 300 nT
Giovanni Santin - Geant4 in Space - Geant4 '07, Hebden Bridge, Sep 2007

7. Detectors for Mercury (and Mars)
High-Purity Germanium detectors (HPGe) used in astrophysics / planetary exploration gamma-ray spectrometers
GCR and secondary fast neutrons  degradation of energy resolution, normally recovered by annealing (e.g. Mars Odyssey, INTEGRAL)
For missions to inner solar system (Mars Observer, Messenger, BepiColombo) solar protons becoming major source of degradation (NIEL)
Giovanni Santin - Geant4 in Space - Geant4 '07, Hebden Bridge, Sep 2007

8. PlanetoCosmics Geant4 simulation of Cosmic Rays in planetary Atmo- / Magneto- spheres
Laurent Desorgher, University of Bern
Giovanni Santin - Geant4 in Space - Geant4 '07, Hebden Bridge, Sep 2007

9. DESIRE Dose Estimation by Simulation of the ISS Radiation Environment
T. Ersmark1, P. Carlson1, E. Daly2, C. Fuglesang3, I. Gudowska4, B. Lund-Jensen1, R. Nartallo2, P. Nieminen2, M. Pearce1, G. Santin2, N. Sobolevsky5
1Royal Institute of Technology (KTH) (Stockholm), 2ESA-ESTEC (Noordwijk), 3EAC/JSC (Cologne/Houston), 4Karolinska Institutet (Stockholm), 5Institute for Nuclear Research (Moscow)
DESIRE Dose Estimation by Simulation of the ISS Radiation Environment
GOAL
Accurate Monte Carlo calculations (Geant4) of the radiation fields and doses to astronauts inside the European Columbus module of the International Space Station.
ISS AND COLUMBUS
INCIDENT RADIATION
Trapped protons
Galactic cosmic rays
Solar particle events
Earth albedo neutrons
SPELLCHECK!
Circular orbit
400 km altitude
51.6º inclination
370 tons (14A)
110 by 75 m
Giovanni Santin - Geant4 in Space - Geant4 '07, Hebden Bridge, Sep 2007
Courtesy NASA

10. Solar event of 13 December 2006
Giovanni Santin - Geant4 in Space - Geant4 '07, Hebden Bridge, Sep 2007

11. STS-116 mission to ISS
Giovanni Santin - Geant4 in Space - Geant4 '07, Hebden Bridge, Sep 2007

12. Life on Mars?
Giovanni Santin - Geant4 in Space - Geant4 '07, Hebden Bridge, Sep 2007

13. PlanetoCosmics Mars field and atmosphere
MGS observation 400 km
Connerney et al., Geophys.Res.Let. 28, 21, , 2001
Cain 50-degree spherical harmonic model (2003)
Geant4 implementation courtesy L. Desorgher, University of Bern
NASA Mars-GRAM2001 model
p,n, T in function of :
Lat., long. (topography from MOLA)
Altitude, season, local time, F10.7
Dust models
Based on :
Nasa MGCM 0-80 km
Univ. of Arizona MTGCM km
Mars Global Surveyor (MGS):
●Aerobraking orbits (alt >101.6km)
●Science phasing orbits (alt >170. km)
●Mapping orbit (alt ~400 km)
MGS Magnetic field measurement :
●No global field (dipole at equator <0.5 nT)
●Strong crustal field in the southern high lands :
1600 nT at 100 km over some regions
10x higher than on Earth
Signature of an old global magnetic field
●Interaction of the solar wind with Mars
ionosphere and crustal field
Crustal magnetization seems to follow the topographical
dichotomy of Mars:
– low lands B weak, high lands B strong
– north lands were probably formed after the cessation of
the Mars dynamo
•East-west band of inverse polarity in high lands at ~180 lon:
– possible signature of early sea floor spreading
–change of the polarity of Mars global field in the past
•No magnetization over large impact basins of Hellas and
Argyre:
–Large impact did remove the crustal field in these regions
MGS observation Interpretation
Mars Crustal field models
Cain et al., J. Geophys. Res. 108, E2, 5008, 2003:
90 and 50- degree spherical harmonic model
90 degree model developed to best-fit all MGS data
50 degree model developed to best fit the MGS mapping
orbit data (~400 km)
The 90 degree model is needed to match the smaller scale
structure
Probably the best one
Available and implemented in PLANETOCOSMICS
Giovanni Santin - Geant4 in Space - Geant4 '07, Hebden Bridge, Sep 2007

14. MarsREM See dedicated talk on Friday afternoon
Models for Mars, Phobos and Deimos
Surface topology and composition, subsurface, atmospheric composition and density (including diurnal and annual variations), local magnetic fields
Active magnetic shielding: review and development of a G4 tool
User-friendly engineering tool (QARM)
New ion physics
Consortium led by QinetiQ. ESA funding
See dedicated talk on Friday afternoon
Parallel Session 2- Aero/Space Applications
Giovanni Santin - Geant4 in Space - Geant4 '07, Hebden Bridge, Sep 2007

15. No humans on Jupiter Laurent Desorgher et al, Planetocosmics tool
Environments and doses on Jupiter Europa
ESA / ESTEC, GRAS tool
JURA Jupiter mission feasibility study
focusing on radiation
Giovanni Santin - Geant4 in Space - Geant4 '07, Hebden Bridge, Sep 2007

16. Looking outside GRB X-ray sources GLAST-LAT / GBM SWIFT
XMM from ICATPP
Japanese missions
These images, taken by the Optical Monitor on board ESA's XMM-Newton observatory on 3 and 4 July 2005, show a comparison between the states of the comet before and just after impact.
The images were taken in the blue (top) and ultraviolet channels (bottom) of the instrument. The ultraviolet images show the emissions of hydroxyl ions, the direct decay product of water.
About 1.5 hours after the impact, the brightness of hydroxyl groups is increased by a factor of about five. Later, about 4.5 hours after the impact the ultraviolet emission is decreased again which indicates that the peak has passed.
The presence of water in Tempel 1 is consistent with preliminary measurements of the composition of the comet made last week by the ALICE instrument on ESA's Rosetta spacecraft.
For more information on this story please visit the ESA website.
XMM-Newton probes formation of galaxy clusters Wednesday, August ESA's X-ray observatory, XMM-Newton, has for the first time allowed scientists to study in detail the formation history of galaxy clusters, not only with single arbitrarily selected objects, but with a complete representative sample of clusters.
Knowing how these massive objects formed is a key to understanding the past and future of the Universe. Scientists currently base their well-founded picture of cosmic evolution on a model of structure formation where small structures form first and these then make up larger astronomical objects.
Galaxy clusters are the largest and most recently formed objects in the known Universe, and they have many properties that make them great astrophysical 'laboratories'. For example, they are important witnesses of the structure formation process and important 'probes' to test cosmological models.
To successfully test such cosmological models, we must have a good observational understanding of the dynamical structure of the individual galaxy clusters from representative cluster samples.
For example, we need to know how many clusters are well evolved. We also need to know which clusters have experienced a recent substantial gravitational accretion of mass, and which clusters are in a stage of collision and merging. In addition, a precise cluster mass measurement, performed with the same XMM-Newton data, is also a necessary prerequisite for quantitative cosmological studies.
The most easily visible part of galaxy clusters, i.e. the stars in all the galaxies, make up only a small fraction of the total of what makes up the cluster. Most of the observable matter of the cluster is composed of a hot gas ( million degrees) trapped by the gravitational potential force of the cluster. This gas is completely invisible to human eyes, but because of its temperature, it is visible by its X-ray emission.
This is where XMM-Newton comes in. With its unprecedented photon-collecting power and capability of spatially resolved spectroscopy, XMM-Newton has enabled scientists to perform these studies so effectively that not only single objects, but also whole representative samples can be studied routinely.
Giovanni Santin - Geant4 in Space - Geant4 '07, Hebden Bridge, Sep 2007

17. XMM Firsov + multiple scattering
H. Winter et al., NIM(B) vol 125, p , 1997
DD induced CCD CTE loss observed on ACIS instrument on board Chandra
Radiation belt low-energy protons scattering off X-ray mirrors
Surface scattering: new physics in Geant4: proton scattering at very small angles
Proton efficiency to reach the detector
Experimental data show :
Scattered protons suffer little energy loss: ~3 keV for protons in energy range 30 – 710 keV
Energy loss independent of incidence angle (for angles <1 degree)
Largely independent of surface material
Multiple scattering alone cannot account for the behaviour of protons scattering at grazing incidence angles
Song & Wang [NIM B153 (1999)] proved that low-angle incident protons only interact with the electron plasma cloud without entering the surface
Giovanni Santin - Geant4 in Space - Geant4 '07, Hebden Bridge, Sep 2007

18. X- and Gamma-ray “Suzaku” Observatory
JAXA / NASA-GSFC, launched July 2005
High-precision and Low-noise detector systems
XIS: X-ray [0.3—12 keV]
imaging spectrometer, 4 CCD
HXD: Hard X-ray [10—600 keV]
GSO-BGO phoswich, embedded CCD
Geant4 simulation:
Energy deposition
+ Charge-diffusion in CCD
Courtesy of Masanobu Ozaki (ISAS/JAXA and JST/CREST)
XIS
HXD
Succeeded in representing the BGD spectrum and resolving the BGD generation mechanism
Giovanni Santin - Geant4 in Space - Geant4 '07, Hebden Bridge, Sep 2007

19. Gamma-rays from neutron stars
December 27, 2004
One of the biggest explosions ever observed by humans
Saturation in Konus-Wind direct observation
Compton gammas from Moon surface detected by Helicon-Corona-F
response matrix computed with Geant4
Direct Conus-Wind gamma ray spectrometer
Giovanni Santin - Geant4 in Space - Geant4 '07, Hebden Bridge, Sep 2007

20. LISA
JWST
INTEGRAL
ACE
LISA Pathfinder
RHESSI
Herschel
Cassini
GLAST
Messenger
Bepi Colombo
GAIA
SWIFT
SOHO
SELENE
Astro-E2
XMM-Newton
ConeXpress
EUSO
AMS
MAXI
ISS Columbus

21. Geant4 usability Developments oriented to both science and engineering
Interfaces / Geometry
Formats, interfaces: Geometry: GDML, STEP-SPE
CAD Geometry modelling: FASTRAD, ESABASE2
Geometry model database
Tools
Detector / Shielding :SSAT, MULASSIS, GRAS
Planetary environments: PLANETOCOSMICS
Microdosimetry: GEMAT (QinetiQ), RADSAFE (Vanderbilt)
Reverse MC
Prototype successful implementation - ongoing
Laurent Desorgher, ESA REAT-MS project
See talks by
Fan Lei - Friday Plenary session
TRAD – Aerospace Parallel session
Giovanni Santin - Geant4 in Space - Geant4 '07, Hebden Bridge, Sep 2007

22. CAD geometry interface (and 3D modelling GUI)
ESA REAT-MS contract
CAD
Using G4TessellatedSolid by P.Truscott (ESA REAT_MS1)
Prototype used to require ST-Viewer commercial S/W (~300 USD)
GDML module reads ST-Viewer files
New: Direct GDML output from 3D modelling tools tools (ESA REAT_MS2)
CAD STEP interface (and normal 3D models)
FASTRAD and ESABASE2
GDML (Witek Pokorski)
Tessellated shape, modular (multi-file) models, loops
FASTRAD, ESABASE2
GUI for 3D modelling
GDML output
See FASTRAD talk in Aerospace parallel session
Giovanni Santin - Geant4 in Space - Geant4 '07, Hebden Bridge, Sep 2007

23. Geant4 Reverse MC Full implementation (REAT_MS 2)
“Adjoint” technique [see e.g. Kalos, 1968]
Transport analogous to the forward one, but backward
successive points are higher in energy, earlier in time
Feasibility study (REAT_MS 1)
Only continuous energy loss and simple multiple scattering
Laurent Desorgher
Space IT and Uni. Bern
Full implementation (REAT_MS 2)
RMC in G4 for fast e- dose computation
Backward simulation of :
e- ionisation with delta production, continuous energy loss and multiple scattering
Bremstrahlung, compton scattering, photo-electric effect
Ongoing development
Proposed to be included in Geant4 release
Giovanni Santin - Geant4 in Space - Geant4 '07, Hebden Bridge, Sep 2007

24. Space community Geant4 Space Users’ web page Space Users’ Workshop
Users, publications, news
Feedback appreciated
Space Users’ Workshop
Tokyo University, Japan, Feb 2008
Giovanni Santin - Geant4 in Space - Geant4 '07, Hebden Bridge, Sep 2007