1. PLANETOCOSMICS L. Desorgher, M. Gurtner, E.O. Flückiger, and P. Nieminen Physikalisches Institut, University of Bern ESA/ESTEC

2. PLANETOCOSMICS SPENVIS/GEANT4 workshop Overview Description of the code Earth simulations Mars simulations Mercury simulations Requirements

3. PLANETOCOSMICS SPENVIS/GEANT4 workshop PLANETOCOSMICS Geant4 Application Interaction of cosmic rays with Planet Atmosphere and Soil.

4. PLANETOCOSMICS SPENVIS/GEANT4 workshop PLANETOCOSMICS Geant4 Application Propagation of cosmics rays in the Planet Magnetosphere

5. PLANETOCOSMICS SPENVIS/GEANT4 workshop PLANETOCOSMICS Simulate the interaction of cosmic rays with planets Earth, Mars,Mercury, Jupiter (in development) ✔ Flux of secondaries at user defined altitude, atmospheric depth, on ground ✔ Atmospheric ionisation ✔ Cosmogenic nuclides ✔ Albedo flux Compute the propagation of charged particles in planetary magnetic field ✔ Cutoff rigidity ✔ Asymptotic direction of incidence

6. Physics Default QGSP_BIC_HP + StandardEM User selected Nearly all other available G4 pre-built physics list

7. Magnetic Field Models Common to all planets Dipole, Spherical Harmonic Constant field Orientation for flat geometry Flat grid model Specific to planets Earth=> IGRF, Tsyganenko89,96,01 Mars=> Crustal models: Purucker, Cain Mercury=> Dipole 300 nT

8. PlanetAtmosphere Common to all planets Definition of atmosphere structure by an ASCII table Specific to a planet Earth Model : NRMLSISE00, MSISE90 MarsModel : Python Interface to MarsGRAM2001

9. PLANETOCOSMICS SPENVIS/GEANT4 workshop Soil model Different layers For each layer definition of Density Composition (50% SiO 2, 25%...., ) Thickness (km, g/cm2)

10. PLANETOCOSMICS SPENVIS/GEANT4 workshop Source model Use of /gps Definition of position in different Space coordinate sytems GCR proton and alpha models Gleeson and Axford (1968)

11. PLANETOCOSMICS SPENVIS/GEANT4 workshop Space coordinate convertor Extension of Earth space coordinate to other planets Geographic (GEO) -> Planetocentric (PLA) GEODETIC->Planetographic (PLAG) GSE->PSO, PSE, PSEQ If global magnetic field MAG->PMAG, GSM->PSM, SM->PSMAG

12. Analysis Two versions of the code for histogramming: Output in ROOT +ASCII format Output in AIDA + ASCII format Use of 1D and 2D histograms Primary source information Pseudo trapped population Edep vs atmospheric depth Particle fluxes at given altitude/depth Spectrum Angular distribution Position distribution

13. PLANETOCOSMICS SPENVIS/GEANT4 workshop Visualisation Visualisation of primary and secondary particle trajectories in user selected colors Visualisation of backward and forward trajectories in magnetic field Visualisation of magnetic field lines

14. PLANETOCOSMICS SPENVIS/GEANT4 workshop Cutoff Rigidities vs position R c [GV] Magnetic shielding on Earth

15. PLANETOCOSMICS SPENVIS/GEANT4 workshop Altitude [km] Ions pair production rate #/cm -3 /s Secondary flux in Earth's atmosphere at Moscow for SolMax vs Balloon measurements Omnidirectional flux [cm -2 s -1 ] Depth [g/cm 2 ]

16. PLANETOCOSMICS SPENVIS/GEANT4 workshop Muon Spectrum on Ground Omnidirectional flux [cm -2 s -1 ] Depth [g/cm 2 ]

17. PLANETOCOSMICS SPENVIS/GEANT4 workshop Muon Spectrum on Ground Omnidirectional flux [cm -2 s -1 ] Depth [g/cm 2 ]

18. PLANETOCOSMICS SPENVIS/GEANT4 workshop 10MeV electrons in the region of Mars with the strongest crustal field

19. PLANETOCOSMICS SPENVIS/GEANT4 workshop Magnetic shielding on Mars at -47.8 N and 174 E 10 MeV e- 1 MeV e- Tracking of 10 7 downward monoenergetic particles starting at 300 km altitude and distributed uniformly over a 1200 km *1200 km wide area Detection of nb of particles that hits the ground in function of position

20. PLANETOCOSMICS SPENVIS/GEANT4 workshop Magnetic shielding on Mars at -47.8 N and 174 E 10 MeV proton 100 keV proton

21. PLANETOCOSMICS SPENVIS/GEANT4 workshop Flux of e- and protons on Mars surface induced by galactic cosmic ray protons

22. PLANETOCOSMICS SPENVIS/GEANT4 workshop Flux of gamma induced by galactic cosmic ray protons during solar minimum

23. PLANETOCOSMICS SPENVIS/GEANT4 workshop Flux of neutrons on Mars induced by galactic cosmic ray protons at solar minimum

24. Mercury Soil + Dipole B0= 300 nT 10 GeV protons from dayside e- >1 MeV e+ > 1 MeV proton > 10 MeV

25. Quasi trapped e- in Mercury dipole field

26. 10 GeV protons neutrons gammas

27. Possible future work Take into account the convection and induced electric field Implement a more accurate magnetosphere model for Mercury Add Jupiter case (study of magnetic shielding and CRAND) In study Modelise atomic sputtering process Take into account the gravitation field... All ideas of extension or input of new models are more than welcome

28. Requirements Extension of Ion nuclear interaction: Increase energy range to at least 100 GeV/nuc Modify physics list to better simulate elastic scattering on hydrogen, for Giant planet atmosphere Atomic sputtering ???.....

29. For more informations For more information