Gabriele Cosmo
154 lines
5.1 KiB
Plaintext
154 lines
5.1 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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rdecay01
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--------
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Survey G4RadioactiveDecay process. See Physics Reference Manual, chapter 36.
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See also http://ie.lbl.gov/decay.html
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1- Geometry construction
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---------------------
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It is a simple box which represente an 'infinite' homogeneous medium.
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2- Physics list
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------------
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PhysicsList.cc defines only G4RadioactiveDecay, G4Transportation processes,
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and relevant particle definitions.
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Therefore, once created, particles or ions travel as geantino.
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3- Primary generator
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-----------------
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Default kinematic is an ion (Ne24), at rest, at coordinate origin.
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Can be changed with particleGun commands.
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4- Physics
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-------
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As said above, all particles and ions behave as geantino, eg. no energy loss.
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A flag, /rdecay01/fullChain (true or false), allows to limit to
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single decay or full decay chain (default).
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In case of full decay chain, G4TrackStatus of ions is set to fStopButAlive
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in order to force decay at rest.
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In case of single decay, G4TrackStatus of secondary ion is set to fStopAndKill.
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At each decay, one counts and plots energy spectrum of created particles and
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ions, and energy-momentum balance of that decay.
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Total time of life of decay chain is plotted. Activity is computed.
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The command /rdecay01/timeWindow allows to survey activity of each nuclide in a specified
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time window [t1,t2] : population at t1 and t2, nb of decays within [t1,t2], mean activity.
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See timeWindow.mac
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Few macros are given in example. Debug.mac is to be run in interactive mode.
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4-a User data files
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-------------------
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Users can redefine RadioactiveDecay and PhotonEvaporation data, via commands:
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/grdm/setRadioactiveDecayFile
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/grdm/setPhotoEvaporationFile
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Examples of such files are given in subdirectory UserData.
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Formats are described in readme
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Examples in macros Cf238.mac and No252.mac
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4-b example of biasing
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----------------------
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macro timeWindowBiased.mac illustrates one of the biasing capabilities of the
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radioactiveDecay package. Ca47 is "forced" to decay within 20 days
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(eg. 1728000 seconds in data file).
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It is instructive to plot time of life (histo 8) with and without the weight of the track:
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see lines 189/190 of TrackingAction.cc
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And also to compare with analog decay mode : comment out /grdm/ commands in the macro.
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5- Visualisation
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-------------
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Visualization Manager is set in the main().
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Initialisation of the drawing is done via the commands
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/vis/.. in the macro vis.mac. This macro is automatically read from the main
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in case of interactive running mode.
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e- red
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e+ blue
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nu_e white
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anti_nu_e white
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gamma green
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alpha yellow
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GenericIon grey
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6- How to start ?
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--------------
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- Execute rdecay01 in 'batch' mode from macro files
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% rdecay01 singleDecay.mac
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- Execute rdecay01 in 'interactive mode' with visualization
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% rdecay01
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....
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Idle> ---> type your commands. For instance:
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Idle> /control/execute debug.mac
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....
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Idle> /run/beamOn 1
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....
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Idle> exit
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Macros provided in this example:
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- Co60.mac: Co60
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- Gd158.mac: Gd158 excited state
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- No158.mac: read user data file
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- Po212.mac: Po212 excited state
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- Ra228.mac: Ra228 excited state
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- alpha.mac: Po212 alpha decay
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- atomicDeexcitation.mac: plot Auger cascade
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- fullChain.mac: U238
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- neutron.mac: Li10 neutron emission
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- proton.mac: Co53 proton emission
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- singleDecay.mac: Ne10
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- timeWindow.mac: print activity within a given time window
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- timeWindowBiased.mac: force decay within a given time window
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Macros to be run interactively:
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- Cf238.mac: read user data file
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- debug.mac: Pb210
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- electronicCapture.mac: Fe55 electronic capture
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- vis.mac: To activate visualization
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7- Histograms
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----------
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rdecay01 produces several 1D histograms which are saved as
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rdecay01.root by default.
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1 : energy spectrum: e+ e-
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2 : energy spectrum: nu_e anti_nu_ev
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3 : energy spectrum: gamma
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4 : energy spectrum: alpha
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5 : energy spectrum: ions
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6 : total kinetic energy (Q)
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7 : momentum balance
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8 : total time of life of decay chain
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9 : total visible energy
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The histograms are managed by G4AnalysisManager and its Messenger.
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The histos can be individually activated with the command :
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/analysis/h1/set id nbBins valMin valMax unit
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where unit is the desired unit for the histo (MeV or keV, deg or mrad, etc..)
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One can control the name of the histograms file with the command:
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/analysis/setFileName name (default rdecay1)
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It is possible to choose the format of the histogram file : root (default),
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xml, csv, by using namespace in HistoManager.hh
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It is also possible to print selected histograms on an ascii file:
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/analysis/h1/setAscii id
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All selected histos will be written on a file name.ascii (default rdecay1)
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