source: trunk/examples/extended/radioactivedecay/exrdm/README@ 807

    =========================================================
    Geant4 - an Object-Oriented Toolkit for Simulation in HEP
    =========================================================

                       Extended Example for G4RadioactiveDecay
                       -------------------- 

  The exRDM is created to show how to use the G4RadioactiveDecay process to simulate the decays of radioactive 
  isotopes as well as the induced radioactivity resulted from nuclear interactions. In the example a simple 
  geometry consists of a cylindric target placed in the centre of a tube shaped detector is used. Various primary event
  generation and tallying options are available. More documentations are available at

          http://reat.space.qinetiq.com/septimess/exrdm

  1. GEOMETRY

     Material: There are 7 pre-defined materials: 
        "Vacuum" "Air" "Silicon" "Aluminium" "Lead" "Germanium" and "CsI"

     User can add a new material at the "PreIni" state, using the command
        /geometry/material/add

     For the geometry, the world is filled with "Air" and there are two components in it             
 
       - Target:  A cylinder placed at the origin along the z-axis. The default size of the cylinder is 
                  0.5 cm radius and 1 cm in length, and its default material is "CsI".
                  
       - Detector:A tube cerntred at the origin along the z-axis, with inner radius matching the
                  radius of the target. The default thickness of the tube is 2 cm and it is  
                  5 cm long. The default material is "Germanium".

     The user can change the target/detector size and material at the at the "PreIni" state, using the commands under
                  
                /exrdm/det


  2. PHYSICS

     The following physics processes are included by default:

       - Standard electromagnetic:
           photo-electric effect
           Compton scattering
           pair production
           bremsstrahlung
           ionization
           multiple scattering
           annihilation

       - Decay

       - Radioactive Decay
          By default it is applied through out the geometry. The user can limit it to just the target by 
          commands

                /grdm/noVolumes
                /grdm/selectVolume Target



       - Hadronic processes:
          Hadronic processes are not invoked by default. They can be activated by the user at the "PreIni" 
          state of the execution via the command

                /exrdm/phys/SelectPhysics

          The options are:
 
                "Hadron" - Physicslist comsists of Binary_Cascade, HP_Neutron, QGSP, and LHEP, or
                the standdard hadron physics list avaible in the G4 distribution, i.e. 
                "QGSP_BERT", "QGSP_BIC", "QGSP_HP", "LHEP_BERT", "LHEP_BERT_HP", "LHEP_BIC",
                "LHEP_BIC_HP".


  3. EVENT:

     The event generator is based on the G4GeneralParticleSource (GPS) which allows the user to 
     control all aspects of the initial states of the events. In this example, however, only simple features 
     of the GPS are employed to generate the incident beam or the initial radio-isotopes. By default the 
     incident particle is travelling along the + z-axis and the incident position is at the -Z end 
     of the geometry.      

  4. DETECTOR RESPONSE:

     No Geant4 HITS and SD are defined in this example. All the relevant information of the simulation is extracted
     at the "UserSteppingAction" stage, if the variable "G4ANALYSIS_USE" is defined. These include:

       - Emission particles in the RadioactiveDecay process: 
           particle PDGcode,
           partilce kinetic energy,
           particle creation time,
           particle weight.

        Note: the residual nuclei is not considered as an emitted particle.

       - Radio-Isotopes. All the radioactive isotopes produced in the simulation: 
           isotope  PDGcode,
           isotope  creation time,
           isotope  weight.
 
       - Energy depositions in the target and detector by prodicts of the RadioactiveDecay process: 
           energy depostion (positive volue for target and negative for detector), 
           time,
           weight.
  
  5. VISUALIZATION:
 
     Visualisation of the geometry and the tracks is possible with many of the G4 visualisation packages. An
     example of display the geometry and tracks using VRML is given in the macro file macros/vrml.mac.  

  6. ANALYSIS:

     This example implements an AIDA-compliant analysis system as well as the ROOT file format for 
     histograms and ntuples. If the the user has an AIDA-compliant tool such as 
     AIDAJNI, ANAPHE, or PI installed on his/her system, the analysis part of this example can 
     be activated by 
        
        setenv G4ANALYSIS_USE_AIDA 1

     before building the executable.  The user can also add the "root" file format option by define 
      
       setenv G4ANALYSIS_USE_RROT 1
       
     before the compilation.

     At the completion of a simulation run a file "exrdm.root" by default is produced which contains 
     these data structures. The user can change the name of this output file with the command

        /histo/fileName new-filename

     The output file by default is in "root" format and can be analysed offline using the ROOT tool, 
     which allows the histograms and ntuples to examined, manipulated, saved and printed.

     User can also change the output file format to "hbook"  or "xml" using the commands
        
        /histo/fileType hbook  
        /histo/fileType xml
     
     The output file, in "xml" or "hbook" or "root" format, conatins the 3 ntuples (100,200,300) whose details have been 
     described in section 4. In addition, there are 7 histograms in the file:

        histogram 10: The Pulse Height Spectrum (PHS) of the target.
        histogram 11: The PHS of the detector.
        histogram 12: The combined PHS of the target and detector.
        histogram 13: The anti-coincidece PHS of the target.
        histogram 14: The anti-coincidece PHS of the detector.
        histogram 15: The coincidece PHS between the target and detector.
        histogram 16: The emitted particle energy spectrum.

     The binnings of each histogram can be changed with the command 
        
        /histo/setHisto

     It is assumed the detector and target pulses both have an integration time of 1 micro-second, and the 
     coincidence gate is 2 microsecond wide. The target and detctor have a threshold of 10 keV in the 
     anti-/coincidence modes.        

     Histograms 10-15 were derived from the same data stored in ntuple-300(the energy depositions), while
     Histogram 16 is obtained with data in ntuple-100 (the emission particles). The user should be able to
     reproduce these histograms, or new histograms, with the ntuple data in an analyis tool such as JAS3. 
        

  7. GETTING STARTED:

     i) If you have an AIDA-compliant analysis system installed than you shall switch on the analysis part of
     example by 

        setenv G4ANALYSIS_USE_AIDA 1
 
     in addition if you want to add the ROOT file format, do
       
        setenv G4ANALYSIS_USE_ROOT 1

     otherwise make sure the G4ANALYSIS_USE_AIDA and G4ANALYSIS_USE_ROOT are not definded
 
        unsetenv G4ANALYSIS_USE_AIDA
        unsetenv G4ANALYSIS_USE_ROOT
         
     ii) Build the exRDM executable:

         cd to exrdm
         gmake clean
         gmake

     gmake will create tmp and bin directories in your $G4TMP and $G4BIN directories. 
     The executable, named exRDM, will be in $G4BIN/$G4SYSTEM/ directory.

     iii) Run the executable: while in the exrdm directory do 

         $G4BIN/$G4SYSTEM/exRDM exrdm.in

     If all goes well, the execution shall be terminated in a few seconds. If G4ANALYSIS_USE_ROOT is 
     defined, there will be a proton.root file in the current directory.

     One can use ROOT to exam the file.

 8. FURTHER EXAMPLES:

    There are a number of g4mac files in the ./macros subdirectory, to show the features of the G4RadioactiveDecay
    process. Most of them will lead to the creation of an aida file in the same name of the micro file, which can 
    be examed and analysed with an analysis tool such as ROOT.
 
        vrml.mac:  to visulise the geometry and the incident of one 100 MeV Cf240 isotope and its decay. A vrml
                   file (g4_xx.vrml) is created at the end. If a default vrml viewer has been set, one shall  
                   see the geometru and track displayed automatically.

        u238c.mac: shows the decays of the U238 chain in analogue MC mode.

        th234c-b.mac: shows the decays of Th234 in variance reduction MC mode. All its secondaies in along the 
                      decay chains are generated. The default source profile and decay biasing schemes are used
                      to determine the decay times and weights of the secondaries.

        proton-1gev.mac: simulation of 1 GeV protons incident on a lead target. The decays of the radio-siotopes 
                         created in the proton-lead interactions are simulated with RadioactiveDecay in analogue 
                         MC mode.   

        proton-b.mac: same as proton-1geV.mac, but the decays of the radio-siotopes created in the  proton-lead 
                      interactions are simulated with RadioactiveDecay in variance reduction MC mode. The isotopes 
                      and those along the decay chains are forced to decay in the time windows specified by the 
                      user in file measures.data, and the weights of the decay products are determined by the 
                      beam profile as defined in the beam.data file and their decay times. 

        one-iso.mac: simple macro file to show how to simulate the decay of a specific radio-isotope. User can 
                     edit it to simulate which ever isotope he/she likes to try.

        neutron.mac: macrofile to show the incident of low energy neutrons on an user specified NaI target and 
                     the decays of the induced radio-isotopes. This shows how to define a new material in exrdm.

        ne24.mac: this shows the decays of Ne-24 to Na-24 in variance reduction MC mode. Further decays of Na-24 
                  are not simulated by applying the nucleuslimits in RadioactiveDecay. Two runs are carried out.
                  One with the bracjing ratio biasing applied and one without. 

        multiple-source.mac: to show the decays of different isotopes uniformly distributed through the target 
                             volume in a single run. 

        isotopes.mac: to show the decays of a number of different isotopes in a single macro file.


        f24.mac: to show the different treatments one can apply to the decays of F24. i) the complete decay chain 
                 from F24 to Mg24, in analogue mode; ii) the complete chain, but in variance reduction mode; 
                 iii) restrict to the decay of F24 only in analogue mode; iv) restrict to the decay of F24 only but
                 in variance reduction mode.

        as74.mac: The decays of As74 which has a rather complicated decay scheme. i) in analogue MC mode; ii) in 
                  variance reduction MC mode.

        test.mac: macro used to check if the right physics processes are assigned to different particles.