========================================================= Geant4 - Radioprotection example ========================================================= README --------------------- 0. INTRODUCTION The Radioprotection example derives from a Geant4 application ( look www.ge.infn.it/geant4/space/remsim for more details ) whose scope is to evaluate the dose in astronauts, in vehicle concepts and Moon surface habitat configurations, in a defined interplanetary space radiation environment. 1. GEOMETRY The user can calculate the dose in the astronaut (phantom) in the following set-ups: - Vehicle configuration | ||sh| | | | | |S||ie| |SPE | | | ----> |I||ld| |she | |phantom| beam |H||in| |lter| | | | ||g | | | | | ---------------------------------------> Z axis - The SIH is the Simplified Inflatable Habitat. - The shielding is a layer of water, its scope it to protect the astronaut from Galactic Cosmic Rays (GCR). The user can add, delete this element in the geometrical configuration, change its thickness through UI comands. - The SPE shelter is a water layer (thickness = 75.cm along Z axis), its scope it to protect the astronaut from Solar Particle Events (SPE). The user can add, delete this element in the geometrical configuration through UI comands. - The phantom is the astronaut model; the energy deposit is collected in this geometrical component. The phantom is a box of water, it is 30. cm wide along Z axis, it is voxelised in 30 slices along Z axis. The energy deposit of primary and secondary particles is collected in each voxel. - Moon Habitat configuration _______________________________ | | / |Moon Surface | / | | | x | _________ | |<->|| _____ | | ---->| || |Phan | | <---shelter | beam | || |thom | | | | || |_____| | | \ ||_________| | \ | | pyramid | log| | |______________________________| -------------------------------------------> Z axis - The astronaut/phantom is set in the astronaut habitat (shelter). - The pyramid log is made of moon soil and protects the astronaut from GCR and SPE. The user can add, delete this element in the geometrical configuration, change its thickness (x) through UI comands. - The phantom is the astronaut model; the energy deposit is collected in this geometrical component. The phantom is a box of water, it is 30. cm wide along Z axis, it is voxelised in 30 slices along Z axis. The energy deposit of primary and secondary particles is collected in each voxel. 1.1 UI - The user can change the geometry set-up with the following UI commands: /configuration/choose vehicle -> choose the Vehicle configuration /configuration/choose moon -> choose the Moon Habitat configuration The user can not switch between these two configurations interactively. - The user can select in the vehicle configuration: /configuration/AddShielding On -> set the shielding water layer /configuration/AddShielding Off -> destroy the shielding water layer /shielding/thickness 30.cm -> set the thickness of the shielding layer /configuration/AddSPE On -> set the SPE shelter /configuration/AddSPE Off -> destroy the SPE shelter - The user can select in the Moon surface habitat configuration: /configuration/AddRoof On -> set the pyramid log /configuration/AddRoof Off -> destroy the pyramid log /roof/thickness 1. m -> set the height (x) of the pyramid log 2. PHYSICS LIST The user can select the physics processes to activate interactively as shown in the macro vis.mac. The example is provided of: - Low Energy electromagnetic processes for photons, e- - Standard electromagnetic processes for e+ - Low Energy electromagnetic processes with ICRU parameterisation for p, alpha and ions - Muon electromagnetic processes - Decay - Hadronic processes for p and alpha particles as primary particles. The user can choose the Bertini cascade approach or the binary cascade approach for the modeling of proton hadronic physics. 3. PRIMARY PARTICLES The user can select different set-ups to generate primary particles: - "Basic": monochromatic particle beam (default configuration) - "Interplanetary": particle beam with energy derived from a given energy spectrum. - "Moon": particles generated with energy derived from a given energy spectrum; The primary vertex is generated on a given hemisphere. The default configuration is Basic. The energy spectrum is written is ASCII file: first column: energy in MeV second column: flux The final two rows must look as follows: -1 -1 -2 -2 The flux is used as probability of generating a particle with a particular energy. The sum of the fluxes is normalised to 1 in the RunAction. Examples of ASCII files -- - Galactic Cosmic Rays fluxes (envelope of CREME96 1977 and CREME86 1975 solar minimum spectra): p: gcrZ=1.txt alpha: gcrZ=2.txt carbon ion: gcrZ=6.txt oxygen ion: gcrZ=8.txt silicon ion: gcrZ=14.txt iron ion: gcrZ=26.txt - Solar Particle Events (envelope of CREME96 October 1989 and August 1972 spectra) p: speZ=1.txt alpha: speZ=2.txt 3.1 UI The user can define primary particles with the following command: /gun/particleType proton /gun/particleType alpha /gun/particleType IonC12 /gun/particleType IonO16 /gun/particleType IonSi28 /gun/particleType IonFe52 The user can select interactively the configuration with the following UI commands: /gun/generator Basic /gun/generator Interplanetary /gun/generator Moon In the Basic configuration, the user can change interactively the energy of primary particles: example: /gun/energy 1. MeV 4. STEPPING Available UI command: /step/hadronicVerbose On -> print the hadronic processes undertaken by particles during the run /step/hadronicVerbose Off -> switch off the verbose level 5. ANALYSIS if ANALYSIS_USE = 1 in the variable environment, the output of the simulation is remsim.hbk or remsim.xml. The default output file is remsim.hbk. The user can change the format of the output file interactively as shown in section 5.1 The file contains histograms: - 10 (1) Energy Deposit (MeV)in the phantom (astronaut) versus the depth along Z axis - 20 (1) Initial energy (MeV) of primary particles - 30 (1) Energy Deposit (MeV) in the phantom given by secondaries versus the depth along Z axis - 40 (1) Initial energy (MeV) of primaries reaching the phantom - 50 (1) Initial energy (MeV) of primaries ougoing the phantom - 60 (1) Energy (MeV) of primaries reaching the phantom - 70 (1) Energy (MeV) of primaries outgoing the phantom - 80 (2) Project the coordinate of the hits on the plane xy - 90 (2) Project the energy deposit of the hits on the plane xy 5.1 UI - The user can select the format of the output file if the analysis is active: /analysis/formatFile hbook /analysis/formatFile xml 6.SET-UP - a standard Geant4 example GNUmakefile is provided setup with: compiler = gcc-3.2.3 G4SYSTEM = linux-g++ The following environment variables need to be set for the physics packages: G4LEDATA points to low energy data base - G4EMLOW2.3 G4LEVELGAMMADATA points to PhotoEvaporation data G4RADIOACTIVEDATA points to Radioactive Decay data NeutronHPCrossSections points to neutron data - G4NDL3.7 Setup for analysis: AIDA 3.2.1, PI 1.2.1 Users can download the analysis tools from: http://aida.freehep.org/ http://www.cern.ch/PI 7. HOW TO RUN THE EXAMPLE example macros are provided: - vehicle1.mac, vehicle2.mac are examples of simulation in the vehicle configuration - moon.mac is an example of simulation in the Moon habitat configuration - batch mode: $G4WORDIR/bin/Linux-g++/remsim vehicle1.mac $G4WORDIR/bin/Linux-g++/remsim vehicle2.mac $G4WORDIR/bin/Linux-g++/Brachy moon.mac - Interative mode: $G4WORDIR/bin/Linux-g++/remsim -> the vis.mac is loaded automatically ------------------------------------------------------------------------ Author : Susanna Guatelli for comments, advices, doubts and questions: guatelli@ge.infn.it last modified: Susanna Guatelli 23/11/2004