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

PLANETOCOSMICS

L. Desorgher, M. Gurtner, E.O. Flückiger, and P. Nieminen

Physikalisches Institut, University of BernESA/ESTEC

PLANETOCOSMICS SPENVIS/GEANT4 workshop

Overview

Description of the code Earth simulationsMars simulationsMercury simulations Requirements

PLANETOCOSMICS SPENVIS/GEANT4 workshop

PLANETOCOSMICS Geant4 ApplicationInteraction of cosmic rays with Planet Atmosphere and Soil.

PLANETOCOSMICS SPENVIS/GEANT4 workshop

PLANETOCOSMICS Geant4 ApplicationPropagation of cosmics rays in the Planet Magnetosphere

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

Physics

DefaultQGSP_BIC_HP + StandardEM

•User selectedNearly all other available G4 pre-built physics list

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

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

PLANETOCOSMICS SPENVIS/GEANT4 workshop

Soil model

Different layers For each layer definition of

DensityComposition (50% SiO2, 25%...., )

Thickness (km, g/cm2)

PLANETOCOSMICS SPENVIS/GEANT4 workshop

Source model

Use of /gpsDefinition of position in different Space coordinate sytems GCR proton and alpha models

Gleeson and Axford (1968)

PLANETOCOSMICS SPENVIS/GEANT4 workshop

Space coordinate convertor

•Extension of Earth space coordinate to other planetsGeographic (GEO) -> Planetocentric (PLA) GEODETIC->Planetographic (PLAG) GSE->PSO, PSE, PSEQIf global magnetic field

MAG->PMAG, GSM->PSM, SM->PSMAG

Analysis

•Two versions of the code for histogramming:Output in ROOT +ASCII formatOutput in AIDA + ASCII format

•Use of 1D and 2D histogramsPrimary source informationPseudo trapped populationEdep vs atmospheric depthParticle fluxes at given altitude/depth•Spectrum•Angular distribution•Position distribution

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

PLANETOCOSMICS SPENVIS/GEANT4 workshop

Cutoff Rigidities vs position

Rc [G

V]

Magnetic shielding on Earth

PLANETOCOSMICS SPENVIS/GEANT4 workshop

Altitude [km]Ion

s p

air

pro

du

cti

on

rate

#/c

m-3/s

Secondary flux in Earth's atmosphere at Moscow for SolMax vs Balloon measurements

Om

nid

irecti

on

al fl

ux [

cm

-2s

-1]

Depth [g/cm2]

PLANETOCOSMICS SPENVIS/GEANT4 workshop

Muon Spectrum on Ground

Om

nid

irecti

on

al fl

ux [

cm

-2s

-1]

Depth [g/cm2]

PLANETOCOSMICS SPENVIS/GEANT4 workshop

Muon Spectrum on Ground

Om

nid

irecti

on

al fl

ux [

cm

-2s

-1]

Depth [g/cm2]

PLANETOCOSMICS SPENVIS/GEANT4 workshop

10MeV electrons in the region of Mars with the strongest crustal field

PLANETOCOSMICS SPENVIS/GEANT4 workshop

Magnetic shielding on Mars at -47.8 N and 174 E

10 MeV e- 1 MeV e-

Tracking of 107 downward monoenergetic particles starting at 300 km altitude and distributed uniformly over a 1200 km *1200 km wide areaDetection of nb of particles that hits the ground in function of position

PLANETOCOSMICS SPENVIS/GEANT4 workshop

Magnetic shielding on Mars at -47.8 N and 174 E

10 MeV proton 100 keV proton

PLANETOCOSMICS SPENVIS/GEANT4 workshop

Flux of e- and protons on Mars surface induced by galactic cosmic

ray protons

PLANETOCOSMICS SPENVIS/GEANT4 workshop

Flux of gamma induced by galactic cosmic ray protons during solar

minimum

PLANETOCOSMICS SPENVIS/GEANT4 workshop

Flux of neutrons on Mars induced by galactic cosmic ray protons at solar

minimum

Mercury Soil + Dipole B0= 300 nT

10 GeV protons from daysidee- >1 MeVe+ > 1 MeVproton > 10 MeV

Quasi trapped e- in Mercury dipole field

10 GeV protons neutronsgammas

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

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???.....

For more informations

For more information