| 1 | $Id: README,v 1.11 2009/09/22 14:20:31 maire Exp $ |
|---|
| 2 | ------------------------------------------------------------------- |
|---|
| 3 | |
|---|
| 4 | ========================================================= |
|---|
| 5 | Geant4 - an Object-Oriented Toolkit for Simulation in HEP |
|---|
| 6 | ========================================================= |
|---|
| 7 | |
|---|
| 8 | TestEm11 |
|---|
| 9 | ------- |
|---|
| 10 | |
|---|
| 11 | How to plot a depth dose profile in a rectangular box. |
|---|
| 12 | |
|---|
| 13 | |
|---|
| 14 | 1- GEOMETRY DEFINITION |
|---|
| 15 | |
|---|
| 16 | The geometry consists of a single block of an homogenous material. |
|---|
| 17 | Optionally, the block can be divided in thinner layers (replica) |
|---|
| 18 | |
|---|
| 19 | 4 parameters define the geometry : |
|---|
| 20 | - the material of the box, |
|---|
| 21 | - the thickness of the box (sizeX), |
|---|
| 22 | - the tranverse dimension of the box (sizeYZ). |
|---|
| 23 | - the number of layers (nbOfLayers) |
|---|
| 24 | |
|---|
| 25 | In addition a transverse uniform magnetic field can be applied. |
|---|
| 26 | |
|---|
| 27 | The default geometry is constructed in DetectorConstruction class, |
|---|
| 28 | but all of the above parameters can be changed interactively via |
|---|
| 29 | the commands defined in the DetectorMessenger class. |
|---|
| 30 | |
|---|
| 31 | 2- PHYSICS LIST |
|---|
| 32 | |
|---|
| 33 | Physics lists can be local (eg. in this example) or from G4 kernel |
|---|
| 34 | physics_lists subdirectory. |
|---|
| 35 | |
|---|
| 36 | Local physics lists: |
|---|
| 37 | - "local" standard EM physics with current 'best' options setting. |
|---|
| 38 | these options are explicited in PhysListEmStandard |
|---|
| 39 | |
|---|
| 40 | From geant4/source/physics_lists/builders: |
|---|
| 41 | - "emstandard_opt0" recommended standard EM physics for LHC |
|---|
| 42 | - "emstandard_opt1" best CPU performance standard physics for LHC |
|---|
| 43 | - "emstandard_opt2" |
|---|
| 44 | - "emstandard_opt3" best current advanced EM options. |
|---|
| 45 | analog to "local" above |
|---|
| 46 | - "emlivermore" low-energy EM physics using Livermore data |
|---|
| 47 | - "empenelope" low-energy EM physics implementing Penelope models |
|---|
| 48 | |
|---|
| 49 | Physics lists and options can be (re)set with UI commands |
|---|
| 50 | |
|---|
| 51 | Please, notice that options set through G4EmProcessOPtions are global, eg |
|---|
| 52 | for all particle types. In G4 builders, it is shown how to set options per |
|---|
| 53 | particle type. |
|---|
| 54 | |
|---|
| 55 | |
|---|
| 56 | 3- AN EVENT : THE PRIMARY GENERATOR |
|---|
| 57 | |
|---|
| 58 | The primary kinematic consists of a single particle starting at the |
|---|
| 59 | left face of the box. The type of the particle and its energy are set |
|---|
| 60 | in the PrimaryGeneratorAction class, and can be changed via the G4 |
|---|
| 61 | build-in commands of ParticleGun class (see the macros provided with |
|---|
| 62 | this example). |
|---|
| 63 | |
|---|
| 64 | In addition one can choose randomly the impact point of the incident |
|---|
| 65 | particle. The corresponding interactive command is built in |
|---|
| 66 | PrimaryGeneratorMessenger class. |
|---|
| 67 | |
|---|
| 68 | A RUN is a set of events. |
|---|
| 69 | |
|---|
| 70 | |
|---|
| 71 | 4- VISUALIZATION |
|---|
| 72 | |
|---|
| 73 | The Visualization Manager is set in the main(). |
|---|
| 74 | The initialisation of the drawing is done via the commands |
|---|
| 75 | /vis/... in the macro vis.mac. To get visualisation: |
|---|
| 76 | > /control/execute vis.mac |
|---|
| 77 | |
|---|
| 78 | The detector has a default view which is a longitudinal view of the |
|---|
| 79 | box. |
|---|
| 80 | |
|---|
| 81 | The tracks are drawn at the end of event, and erased at the end of run. |
|---|
| 82 | Optionaly one can choose to draw all particles, only the charged one, |
|---|
| 83 | or none. This command is defined in EventActionMessenger class. |
|---|
| 84 | |
|---|
| 85 | |
|---|
| 86 | 5- HOW TO START ? |
|---|
| 87 | |
|---|
| 88 | - compile and link to generate an executable |
|---|
| 89 | % cd geant4/examples/extended/electromagnetic/TestEm1 |
|---|
| 90 | % gmake |
|---|
| 91 | |
|---|
| 92 | - execute TestEm11 in 'batch' mode from macro files |
|---|
| 93 | % TestEm11 run01.mac |
|---|
| 94 | |
|---|
| 95 | - execute TestEm11 in 'interactive mode' with visualization |
|---|
| 96 | % TestEm11 |
|---|
| 97 | .... |
|---|
| 98 | Idle> type your commands |
|---|
| 99 | .... |
|---|
| 100 | Idle> exit |
|---|
| 101 | |
|---|
| 102 | |
|---|
| 103 | 6- TRACKING and STEP MAX |
|---|
| 104 | |
|---|
| 105 | Testem11 computes the total energy deposited along the trajectory of |
|---|
| 106 | the incident particle : the so-called longitudinal energy profile, |
|---|
| 107 | or depth dose distribution. |
|---|
| 108 | The energy deposited (edep) is randomly distribued along the step (see |
|---|
| 109 | SteppingAction). |
|---|
| 110 | |
|---|
| 111 | In order to control the accuracy of the deposition, the maximum step size |
|---|
| 112 | of charged particles is computed automatically from the binning of |
|---|
| 113 | histogram 1 and 8 (see HistoManager). |
|---|
| 114 | |
|---|
| 115 | As an example, this limitation is implemented as a 'full' process : |
|---|
| 116 | see StepMax class and its Messenger. The 'StepMax process' is registered |
|---|
| 117 | in the Physics List. |
|---|
| 118 | |
|---|
| 119 | In RunAction::BeginOfRun() the stepMax value is passed from the |
|---|
| 120 | HistoManager to the StepMax process. |
|---|
| 121 | A boolean UI command allows to desactivate this mechanism. |
|---|
| 122 | |
|---|
| 123 | 7- HISTOGRAMS |
|---|
| 124 | |
|---|
| 125 | Testem11 has several predefined 1D histograms : |
|---|
| 126 | |
|---|
| 127 | 1 : longitudinal energy profile (in MeV/mm and per event) |
|---|
| 128 | 2 : total energy deposited in the absorber |
|---|
| 129 | 3 : total track length of the primary track |
|---|
| 130 | 4 : step size of the primary track |
|---|
| 131 | 5 : projected range of the primary track |
|---|
| 132 | 6 : total track length of charged secondary tracks |
|---|
| 133 | 7 : step size of charged secondary tracks |
|---|
| 134 | 8 : longitudinal energy profile (in MeV.cm2/g), as a function of x/r0 |
|---|
| 135 | where r0 is the range of the primary particle |
|---|
| 136 | |
|---|
| 137 | The histograms are managed by the HistoManager class and its Messenger. |
|---|
| 138 | The histos can be individually activated with the command : |
|---|
| 139 | /testem/histo/setHisto id nbBins valMin valMax unit |
|---|
| 140 | where unit is the desired unit for the histo (MeV or keV, deg or mrad, etc..) |
|---|
| 141 | |
|---|
| 142 | One can control the name of the histograms file with the command: |
|---|
| 143 | /testem/histo/setFileName name (default testem11) |
|---|
| 144 | |
|---|
| 145 | It is possible to choose the format of the histogram file (hbook, root, XML) |
|---|
| 146 | with the command /testem/histo/setFileType (root by default) |
|---|
| 147 | |
|---|
| 148 | It is also possible to print selected histograms on an ascii file: |
|---|
| 149 | /testem/histo/printHisto id |
|---|
| 150 | All selected histos will be written on a file name.ascii (default testem11) |
|---|
| 151 | |
|---|
| 152 | Note that, by default, histograms are disabled. To activate them, uncomment |
|---|
| 153 | the flag G4ANALYSIS_USE in GNUmakefile. |
|---|
| 154 | |
|---|
| 155 | |
|---|
| 156 | 8- USING HISTOGRAMS |
|---|
| 157 | |
|---|
| 158 | To use histograms, at least one of the AIDA implementations should be |
|---|
| 159 | available. See InstallAida.txt |
|---|
