Gabriele Cosmo
106 lines
3.2 KiB
Plaintext
106 lines
3.2 KiB
Plaintext
-------------------------------------------------------------------
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=========================================================
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Geant4 - an Object-Oriented Toolkit for Simulation in HEP
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=========================================================
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ExUCN
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-----
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Peter Gumplinger
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TRIUMF, Vancouver, Canada
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This example exhibits the functionality of UCN physics
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1- GEOMETRY DEFINITION
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The geometry consists of a single hollow pipe (cylinder)
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placed in a world.
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Default World Size: G4Box - 1m x 1m x 100m
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The pipe wall is made of G4_Ni while the world and, hence,
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the inside of the pipe is made from G4_Galactic
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The G4UCNMaterialPropertiesTable properties are:
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"REFLECTIVITY" = 1
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"DIFFUSION" = 0.1
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"FERMIPOT" = 252.0 neV
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"SPINFLIP"= 0.
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"LOSS" = 12.5e-5
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"LOSSCS" = 0.
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"ABSCS"= 4.49 // 1/v loss cross-section at room temp.
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"SCATCS" = 18.5 // (incoherent) "elastic" scattering cross-section
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The MicroRoughnessParameters are:
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Roughness correlation length w = 30nm
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Surface roughness b = 1nm
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# of angles theta_i in the look-up tables: 180
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# of energie bins in the look-up tables: 1000
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min. and max. values of theta_i: 0*degree and 90*degree
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min. and max values of Energy: 1neV and 1000neV
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# of angles theta_o in the look-up table calculation: 15
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# of angels phi_o in the look-up table calculation: 15
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angular cut: 0.01*degree
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The default step limits in the vacuum is 1mm and maxTime is 100s
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The simulation is in a G4UniformGravityField
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2- PHYSICS LIST
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The ExUCNPhysicsList defines only G4Neutron, G4Proton, G4Electron,
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G4AntiNeutrinoE, G4MuonPlus, G4MuonMinus and G4GenericIon
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Through ExUCNExtraPhysics the following processes are instantiated:
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G4StepLimiter
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G4UserSpecialCuts
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and in ConstructUCN()
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G4UCNLoss
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G4UCNAbsorption
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G4UCNMultiScattering
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3- AN EVENT : THE PRIMARY GENERATOR
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The primary kinematic consists of a single ultra-colde neutron
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(uniform between 1neV and 100neV from the origin uniform into 4pi
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A RUN is a set of events.
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4- VISUALIZATION
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The Visualization Manager is set in the main() for interactive session.
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The initialisation of the drawing is done via the command
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/control/execute vis.mac
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5- HOW TO START ?
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This example handles the program arguments in a new way.
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It can be run with the following optional arguments:
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% ExUCN [-m macro ] [-u UIsession] [-t nThreads]
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The -t option is available only in multi-threading mode
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and it allows the user to override the Geant4 default number of
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threads. The number of threads can be also set via G4FORCENUMBEROFTHREADS
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environment variable which has the top priority.
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- execute ExUCN in 'batch' mode from macro files e.g.
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% ExUCN -m ExUCN.in > ExUCN.out &
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- execute ExUCN in 'interactive' mode with visualization e.g.
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% ExUCN
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....
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Idle> type your commands, for example:
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Idle> run/beamOn 1
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....
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6- HISTOGRAMS
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- no histograms for now
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