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0001 \page ExampleTestEm17 Example TestEm17
0002
0003 This example is intended to check implementation of the processes
0004 of muon interactions: ionization, direct (e+,e-) production, mu+mu-
0005 pair production, bremsstrahlung, and mu-nuclear interaction.
0006 It allows to compute differential cross sections (as function of the
0007 energy transfered to secondaries), total cross sections, and to compare
0008 with analytic calculations.
0009
0010 ## GEOMETRY DEFINITION
0011
0012 It is a single box of homogeneous medium.
0013 Two parameters define the geometry :
0014 - the material of the box,
0015 - the (full) size of the box.
0016
0017 The default geometry (1 m of Iron) is constructed in
0018 DetectorConstruction, but the above parameters can be changed
0019 interactively via the commands defined in DetectorMessenger.
0020
0021 ## PHYSICS LIST
0022
0023 The Physics List of the example uses the main physics constructor
0024 (builder) called "local", which includes only muon, pion, and proton
0025 processes under study. As an alternative standard "emstandard_opt0"
0026 and "emstandard_opt4" constructors may be used.
0027
0028 Default energy range for EM processes in this example
0029 is from 100*eV to 1000*PeV.
0030
0031 Optionally "muNucl" builder, MuNuclearBuilder, may be added activating muon-nuclear
0032 inelastic interaction.
0033
0034 ## AN EVENT : THE PRIMARY GENERATOR
0035
0036 The primary kinematic consists of a single particle starting at the edge
0037 of the box. The type of the particle and its energy are set in
0038 PrimaryGeneratorAction (mu+ 10 TeV), and can be changed via the G4
0039 build-in commands of ParticleGun class (see the macros provided with
0040 this example).
0041
0042 ## PHYSICS
0043
0044 The incident particle is a muon. During the tracking, secondary
0045 particles are killed.
0046
0047 The number of interactions are plotted as a function of the energy
0048 transfered to the secondaries.
0049 The total number of interactions is recorded, and the total cross section
0050 computed from this.
0051
0052 At RunAction::EndOfRun(..), the above results are compared with analytical
0053 calculations. The functions computing the theoretical cross sections have been
0054 provided by the G4 MEPhI group, and implemented in MuCrossSections class.
0055
0056 ## HISTOGRAMS
0057
0058 The test contains 8 built-in 1D histograms, which are managed by the
0059 HistoManager class and its messenger, HistoMessenger.
0060
0061 - 1 Relative muon transferred energy distribution
0062 (log10(eps/Emu kin) for knock-on electrons (ionization)
0063 - 2 ... direct (e+,e-) pair production by muons
0064 - 3 ... bremsstrahlung by muons
0065 - 4 ... nuclear interaction by muons
0066 - 5 ... ionistion for hadrons
0067 - 6 ... (e+,e-) pair production by hadrons
0068 - 7 ... bremsstrahlung by hadrons
0069 - 8 ... direct mu+,mu- pair production by muons
0070
0071
0072 The histos can be activated individually with the command :
0073 ```
0074 /testem/histo/setHisto id nbBins valMin valMax
0075 ```
0076 min and max values of log10(eps/Emu kin).
0077
0078 At RunAction::EndOfRunAction() the corresponding histos for analytic calculations are
0079 automatically created and filled (histo 11 to 14, and 18).
0080
0081 One can control the name and the type of the histograms file with
0082 the command:
0083 ```
0084 /testem/histo/setFileName name (default testem17)
0085 ```
0086
0087 It is possible to choose the format of the histogram file :
0088 root (default), xml, csv by changing the default file type in HistoManager.cc.
0089
0090 ## VISUALIZATION
0091
0092 The Visualization Manager is set in the main().
0093 The initialisation of the drawing is done via the commands
0094 /vis/... in the macro vis.mac. To get visualisation:
0095 ```
0096 > /control/execute vis.mac
0097 ```
0098
0099 The detector has a default view which is a longitudinal view of the
0100 box.
0101
0102 The tracks are drawn at the end of event, and erased at the end of run.
0103
0104 ## HOW TO START ?
0105
0106 - Execute TestEm17 in 'batch' mode from macro files :
0107 ```
0108 % ./TestEm17 allproc.mac
0109 ```
0110
0111 - Execute TestEm17 in 'interactive mode' with visualization :
0112 ```
0113 % ./TestEm17
0114 Idle> control/execute vis.mac
0115 ....
0116 Idle> type your commands
0117 ....
0118 Idle> exit
0119 ```
0120
