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0001 \page ExampleTestEm1 Example TestEm1
0002
0003 - How to count processes.
0004 - How to activate/inactivate processes.
0005 - How to survey the tracking, in particular the range of charged particles.
0006 - How to define a maximum step size.
0007
0008 ## GEOMETRY DEFINITION
0009
0010 It is a simple box which represents a 'semi infinite' homogeneous medium.
0011
0012 Two parameters define the geometry :
0013 - the material of the box,
0014 - the full size of the box.
0015
0016 In addition a transverse uniform magnetic field can be applied.
0017
0018 The default geometry is constructed in DetectorConstruction class, but all of
0019 the above parameters can be changed interactively via the commands defined in
0020 the DetectorMessenger class.
0021
0022 ## PHYSICS LIST
0023
0024 Physics lists are based on modular design. Several modules are instantiated:
0025 1. Transportation
0026 2. EM physics
0027 3. Decays
0028 4. StepMax - for step limitation
0029
0030 EM physics builders can be local (eg. in this example) or from G4 kernel
0031 physics_lists subdirectory.
0032
0033 Local physics builder:
0034 - "local" standard EM physics with current 'best' options setting.
0035 these options are explicited in PhysListEmStandard
0036
0037 From geant4/source/physics_lists/builders:
0038 - "emstandard_opt0" recommended standard EM physics for LHC
0039 - "emstandard_opt1" best CPU performance standard physics for LHC
0040 - "emstandard_opt2" similar fast simulation
0041 - "emstandard_opt3" best standard EM options - analog to "local" above
0042 - "emstandard_opt4" best current advanced EM options standard + lowenergy
0043 - "emstandardSS" standard EM physics and single scattering model
0044 - "emlivermore" low-energy EM physics using Livermore data
0045 - "empenelope" low-energy EM physics implementing Penelope models
0046 - "emlowenergy" low-energy EM physics implementing experimental
0047 low-energy models
0048
0049 Physics lists and options can be (re)set with UI commands
0050
0051 A few commands have been added to PhysicsList, in order to set the production
0052 threshold for secondaries for gamma and e-/e+.
0053
0054 ## AN EVENT : THE PRIMARY GENERATOR
0055
0056 The primary kinematic consists of a single particle starting at the left face
0057 of the box. The type of the particle and its energy are set in the
0058 PrimaryGeneratorAction class, and can be changed via the G4 build-in commands
0059 of G4ParticleGun class (see the macros provided with this example).
0060
0061 In addition one can choose randomly the impact point of the incident particle.
0062 The corresponding interactive command is built in PrimaryGeneratorMessenger.
0063
0064 ## VISUALIZATION
0065
0066 The Visualization Manager is set in the main().
0067 The initialisation of the drawing is done via the commands /vis/... in the
0068 macro vis.mac. To get visualisation:
0069 ```
0070 > /control/execute vis.mac
0071 ```
0072
0073 The detector has a default view which is a longitudinal view of the box.
0074
0075 The tracks are drawn at the end of event, and erased at the end of run.
0076
0077 ## PHYSICS SURVEY
0078
0079 The particle's type and the physics processes which will be available in this
0080 example are set in PhysicsList class.
0081
0082 A set of macros defining various run conditions are provided. The processes
0083 are actived/inactivated together with differents cuts, in order to survey the
0084 processes one by one.
0085
0086 The number of produced secondaries are counted, the number of steps, and the
0087 number of process calls responsible of the step.
0088
0089 ## HOW TO START ?
0090
0091 - Execute TestEm1 in 'batch' mode from macro files
0092 ```
0093 % ./TestEm1 runs.mac
0094 ```
0095
0096 - Execute TestEm1 in 'interactive mode' with visualization
0097 ```
0098 % ./TestEm1
0099 ....
0100 Idle> type your commands
0101 ....
0102 Idle> exit
0103 ```
0104
0105 Macros provided in this example:
0106 - brems.mac: Bremsstrahlung only
0107 - erange.mac: compute the csda range of primary particle
0108 - geantino.mac: geantino as primary particle
0109 - ionis.mac: Ionisation only
0110 - photoelec.mac: 100 keV photon photoelectric effect
0111 - radioactive.mac: use radioactive ion as primary particle
0112 - range.mac: compute the csda range of the primary particle
0113 with or without fluctuations
0114 - erange.mac, pRange.mac, alphaRange.mac, ionRange.mac: variants of range.mac
0115 to play with StepFunction()
0116 - runs.mac: electron 100 MeV; all processes
0117
0118 Macros to be run interactively:
0119 - annihil.mac: To visualise 100 MeV e+ annihilation
0120 - decayinfly.mac: To visualise decay in fly of N16
0121 - etaDecay.mac: to visualise decay of eta particle
0122 - gammaconversion.mac: To visualise gamma conversion and e+ annihilation
0123 - photon.mac: To visualiza p300 keV photon beam
0124 - stepMax.mac: to test command /testem/stepMax
0125 - vis.mac: To activate visualization
0126
0127 ## TRACKING : StepMax
0128
0129 In order to control the accuracy of the deposition, the user can limit
0130 'by hand' the maximum step size of charged particles.
0131 As an example, this limitation is implemented as a 'full' process :
0132 see StepMax class and its Messenger. The 'StepMax process' is registered
0133 in the Physics List.
0134
0135 ## HISTOGRAMS
0136
0137 Testem1 produces several histo which are saved as testem1.root by default.
0138 Content of these histo:
0139 - 1 : track length of primary particle
0140 - 2 : number of steps primary particle
0141 - 3 : step size of primary particle
0142 - 4 : total energy deposit
0143 - 5 : energy of charged secondaries at creation
0144 - 6 : energy of neutral secondaries at creation
0145 - 7 : NIEL energy
0146 - 8 : energy leakage
0147 - 9 : energy deposit + leakage
0148
0149 The histograms are managed by G4AnalysisManager class and its Messenger.
0150 The histos can be individually activated with the command :
0151 /analysis/h1/set id nbBins valMin valMax unit
0152 where unit is the desired unit for the histo (MeV or keV, deg or mrad, etc..)
0153
0154 One can control the name of the histograms file with the command:
0155 ```
0156 /analysis/setFileName name (default testem1)
0157 ```
0158
0159 It is possible to choose the format of the histogram file : root (default),
0160 hdf5, xml, csv, by changing the default file type in HistoManager.cc
0161
0162 It is also possible to print selected histograms on an ascii file:
0163 /analysis/h1/setAscii id
0164 All selected histos will be written on a file name.ascii (default testem1)
