The PLANETOCOSMICS Geant4 application

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The PLANETOCOSMICS Geant4 application
L. Desorgher Physikalisches Institut,
University of Bern
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Outline

• Motivation
• Description of the code
• Simulation results for the Earth validation
• Simulation results for Mars
• Simulation results for Mercury
• Results for Jupiter and Europa

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Energetic particles in space

• Galactic cosmic rays 10 MeV-gt1026 eV
• Solar energetic particles keV-gt GeV
• Radiation belts in magnetosphere keV-gt102 MeV

Permises
Interdites
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Motivation model the interactions of energetic
particles with planets

• Atmosphere ionisation
• Sputtering of atmosphere and surface
• Production of cosmogenic nuclides
• Measurements of the soil composition
• Quantify the radiation environment of planets
• Albedo, CRAND process
• Dose for aircrew and space mission
• Dose vs depth in soil

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Interdites
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PLANETOCOSMICS

• Interaction of energetic particles with Earth,
  Mars, Mercury
• Fluxes of secondary particles at user defined
  altitudes
• atmospheric depths, and soil depths
• Energy deposited vs atmospheric depth and vs soil
  depth
• Propagation in magnetic field
• Different coordinate system relative to planets
• Visualisation of particle trajectories and field
  lines
• Analysis based on Root or AIDA

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Interdites
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Flux of ionising particles overMoscow in 2000

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Atmosphere ionisation induced by GCR
New Hampshire Durham 1969

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Neutron flux at 56 g cm-2 Rc 0.8 GV in June
1997

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The 20th January 2005 Ground Level
Enhancement
Neutron Monitor Observations
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January 20, 2005 GLE The Method

• From NM data we deduce the characteristic of the
• solar proton population outside the
  magnetosphere
• apparent source
• pitch angle distribution
• rigidity spectrum

• Propagation in the magnetosphere with
• PLANETOCOSMICS
• Flux at the top of the atmosphere

• Air shower computed with
• PLANETOCOSMICS
• Ionisation
• secondary flux
• Effective dose

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Atmospheric ionisation at 300 g cm-2 at 0657 on
January 20th , 2005
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Flux of neutrons on Mars (-47.8 N and 174 E)
induced by galactic cosmic ray protons at solar
minimum

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ENDF
This work

Interdites
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Contribution of different particle types to
Ambient equivalent dose on Mars

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This work
Interdites

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10 MeV e- in the most magnetized region of Mars

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This work
Interdites

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Magnetic shielding on Mars at -47.8 N and 174 E
Tracking of 107 downward mono-energetic particles
starting at 300 km altitude Detection of number
of particles that hits the ground in function of
position

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ENDF
This work
1 10 MeV e-
10 MeV protons

Interdites
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10 GeV protons from dayside
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Quasi trapped e- in Mercury dipole

Gurtner et al, 2006
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Effective Vertical Cut-off Rigidity at Jupiter
Effective Vertical Cut-off Rigidity at Jupiter

Gurtner et al, 2006
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Radiations at Europa (9.4 Rj)

Gurtner et al, 2006
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Dose in Europa soil (ice)

Gurtner et al, 2006
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More informations on

cosray.unibe.ch/laurent/planetocosmics
Gurtner et al, 2005