250 lines
8.9 KiB
Plaintext
250 lines
8.9 KiB
Plaintext
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=========================================================
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Geant4 - Radioprotection example
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=========================================================
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README
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---------------------
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0. INTRODUCTION
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The Radioprotection example derives from a Geant4 application
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( look www.ge.infn.it/geant4/space/remsim for more details ) whose scope
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is to evaluate the dose in astronauts, in vehicle concepts and
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Moon surface habitat configurations, in a defined interplanetary space
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radiation environment.
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1. GEOMETRY
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The user can calculate the dose in the astronaut (phantom) in the
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following set-ups:
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- Vehicle configuration
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| ||sh| | | | |
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|S||ie| |SPE | | |
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----> |I||ld| |she | |phantom|
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beam |H||in| |lter| | |
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| ||g | | | | |
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--------------------------------------->
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Z axis
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- The SIH is the Simplified Inflatable Habitat.
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- The shielding is a layer of water, its scope it to protect the astronaut
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from Galactic Cosmic Rays (GCR). The user can add, delete this element
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in the geometrical configuration, change its thickness through UI comands.
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- The SPE shelter is a water layer (thickness = 75.cm along Z axis), its scope
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it to protect the astronaut from Solar Particle Events (SPE).
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The user can add, delete this element in the geometrical configuration
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through UI comands.
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- The phantom is the astronaut model; the energy deposit is collected in this
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geometrical component. The phantom is a box of water,
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it is 30. cm wide along Z axis, it is voxelised in 30 slices along Z axis.
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The energy deposit of primary and secondary particles is collected in
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each voxel.
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- Moon Habitat configuration
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_______________________________
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/ |Moon Surface |
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/ | |
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| x | _________ |
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|<->|| _____ | |
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---->| || |Phan | | <---shelter |
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beam | || |thom | | |
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| || |_____| | |
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\ ||_________| |
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\ | |
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pyramid |
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log| |
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|______________________________|
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------------------------------------------->
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Z axis
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- The astronaut/phantom is set in the astronaut habitat (shelter).
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- The pyramid log is made of moon soil and protects the astronaut from
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GCR and SPE. The user can add, delete this element in the geometrical
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configuration, change its thickness (x) through UI comands.
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- The phantom is the astronaut model; the energy deposit is collected in this
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geometrical component. The phantom is a box of water,
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it is 30. cm wide along Z axis, it is voxelised in 30 slices along Z axis.
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The energy deposit of primary and secondary particles is collected in
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each voxel.
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1.1 UI
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- The user can change the geometry set-up with the following UI commands:
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/configuration/choose vehicle -> choose the Vehicle configuration
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/configuration/choose moon -> choose the Moon Habitat configuration
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The user can not switch between these two configurations interactively.
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- The user can select in the vehicle configuration:
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/configuration/AddShielding On -> set the shielding water layer
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/configuration/AddShielding Off -> destroy the shielding water layer
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/shielding/thickness 30.cm -> set the thickness of the shielding layer
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/configuration/AddSPE On -> set the SPE shelter
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/configuration/AddSPE Off -> destroy the SPE shelter
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- The user can select in the Moon surface habitat configuration:
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/configuration/AddRoof On -> set the pyramid log
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/configuration/AddRoof Off -> destroy the pyramid log
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/roof/thickness 1. m -> set the height (x) of the pyramid log
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2. PHYSICS LIST
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The user can select the physics processes to activate interactively as
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shown in the macro vis.mac.
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The example is provided of:
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- Low Energy electromagnetic processes for photons, e-
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- Standard electromagnetic processes for e+
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- Low Energy or Standard electromagnetic processes with ICRU parameterisation
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for p, alpha and ions
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- Muon electromagnetic processes
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- Decay
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- Hadronic processes for p and alpha particles as primary particles.
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3. PRIMARY PARTICLES
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The user can select different set-ups to generate primary particles:
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- "Basic": monochromatic particle beam (default configuration)
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- "Interplanetary": particle beam with energy derived from a given
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energy spectrum.
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- "Moon": particles generated with energy derived from a given
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energy spectrum; The primary vertex is generated on a given hemisphere.
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The default configuration is Basic.
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The energy spectrum is written is ASCII file:
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first column: energy in MeV
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second column: flux
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The final two rows must look as follows:
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-1 -1
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-2 -2
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The flux is used as probability of generating a particle with a particular
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energy. The sum of the fluxes is normalised to 1 in the RunAction.
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Examples of ASCII files --
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- Galactic Cosmic Rays fluxes (envelope of CREME96 1977 and CREME86 1975 solar
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minimum spectra):
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p: gcrZ=1.txt
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alpha: gcrZ=2.txt
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carbon ion: gcrZ=6.txt
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oxygen ion: gcrZ=8.txt
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silicon ion: gcrZ=14.txt
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iron ion: gcrZ=26.txt
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- Solar Particle Events (envelope of CREME96 October 1989 and
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August 1972 spectra)
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p: speZ=1.txt
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alpha: speZ=2.txt
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3.1 UI
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The user can define primary particles with the following command:
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/gun/particle proton
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/gun/particle alpha
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/gun/particle IonC12
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/gun/particle IonO16
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/gun/particle IonSi28
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/gun/particle IonFe52
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The user can select interactively the configuration with the following
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UI commands:
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/gun/generator Basic
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/gun/generator Interplanetary
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/gun/generator Moon
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In the Basic configuration, the user can change interactively the
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energy of primary particles:
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example: /gun/energy 1.MeV
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4. STEPPING
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Available UI command:
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/step/hadronicVerbose On -> print the hadronic processes undertaken by
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particles during the run
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/step/hadronicVerbose Off -> switch off the verbose level
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5. ANALYSIS
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if ANALYSIS_USE = 1 in the variable environment, the output of
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the simulation is remsim.hbk
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The file contains histograms:
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- 10 (1) Energy Deposit (MeV)in the phantom (astronaut) versus
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the depth along Z axis
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- 20 (1) Initial energy (MeV) of primary particles
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- 30 (1) Energy Deposit (MeV) in the phantom given by secondaries
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versus the depth along Z axis
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- 40 (1) Initial energy (MeV) of primaries reaching the phantom
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- 50 (1) Initial energy (MeV) of primaries ougoing the phantom
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- 60 (1) Energy (MeV) of primaries reaching the phantom
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- 70 (1) Energy (MeV) of primaries outgoing the phantom
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6.SET-UP
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- a standard Geant4 example GNUmakefile is provided
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setup with:
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compiler = gcc-3.2.3
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G4SYSTEM = linux-g++
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The following environment variables need to be set for the physics packages:
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G4LEDATA points to low energy data base - G4EMLOW2.3
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G4LEVELGAMMADATA points to PhotoEvaporation data
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G4RADIOACTIVEDATA points to Radioactive Decay data
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NeutronHPCrossSections points to neutron data - G4NDL3.7
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Setup for analysis: AIDA 3.2.1, PI 1.2.1
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Users can download the analysis tools from:
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http://aida.freehep.org/
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http://www.cern.ch/PI
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7. HOW TO RUN THE EXAMPLE
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example macros are provided:
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- vehicle1.mac, vehicle2.mac are examples of simulation in the
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vehicle configuration
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- moon.mac is an example of simulation in the Moon habitat configuration
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- batch mode:
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$G4WORDIR/bin/Linux-g++/remsim vehicle1.mac
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$G4WORDIR/bin/Linux-g++/remsim vehicle2.mac
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$G4WORDIR/bin/Linux-g++/Brachy moon.mac
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- Interative mode:
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$G4WORDIR/bin/Linux-g++/remsim
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-> the vis.mac is loaded automatically |
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------------------------------------------------------------------------
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Author : Susanna Guatelli
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for comments, advices, doubts and questions: guatelli@ge.infn.it
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last modified: Susanna Guatelli 27/5/2004
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