| 1 | $Id: README,v 1.22 2007/11/12 15:48:58 maire Exp $
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| 2 | -------------------------------------------------------------------
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| 3 |
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| 4 | =========================================================
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| 5 | Geant4 - an Object-Oriented Toolkit for Simulation in HEP
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| 6 | =========================================================
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| 7 |
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| 8 | TestEm1
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| 9 | -------
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| 10 | How to count processes.
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| 11 | How to activate/inactivate processes.
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| 12 | How to survey the tracking, in perticular the range of charged particles.
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| 13 | How to define a maximum step size.
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| 14 |
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| 15 | 1 - GEOMETRY DEFINITION
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| 16 |
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| 17 | It is a simple box which represente an 'semi infinite' homogeneous medium.
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| 18 |
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| 19 | Two parameters define the geometry :
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| 20 | - the material of the box,
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| 21 | - the full size of the box.
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| 22 |
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| 23 | In addition a transverse uniform magnetic field can be applied.
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| 24 |
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| 25 | The default geometry is constructed in DetectorConstruction class, but all of
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| 26 | the above parameters can be changed interactively via the commands defined in
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| 27 | the DetectorMessenger class.
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| 28 |
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| 29 | 2 - PHYSICS LIST
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| 30 |
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| 31 | The particle list is the one of novice/exampleN03.
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| 32 | The physics list contains the 'standard' electromagnetic processes, and decay.
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| 33 |
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| 34 | Few commands have been added to PhysicsList, in order to set the production
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| 35 | threshold for secondaries for gamma and e-/e+.
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| 36 |
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| 37 | 3 - AN EVENT : THE PRIMARY GENERATOR
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| 38 |
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| 39 | The primary kinematic consists of a single particle starting at the left face
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| 40 | of the box. The type of the particle and its energy are set in the
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| 41 | PrimaryGeneratorAction class, and can be changed via the G4 build-in commands
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| 42 | of ParticleGun class (see the macros provided with this example).
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| 43 |
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| 44 | In addition one can choose randomly the impact point of the incident particle.
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| 45 | The corresponding interactive command is built in PrimaryGeneratorMessenger.
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| 46 |
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| 47 | 4 - VISUALIZATION
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| 48 |
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| 49 | The Visualization Manager is set in the main().
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| 50 | The initialisation of the drawing is done via the commands /vis/... in the
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| 51 | macro vis.mac. To get visualisation:
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| 52 | > /control/execute vis.mac
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| 53 |
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| 54 | The detector has a default view which is a longitudinal view of the box.
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| 55 |
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| 56 | The tracks are drawn at the end of event, and erased at the end of run.
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| 57 | Optionaly one can choose to draw all particles, only the charged, or none.
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| 58 | This command is defined in EventActionMessenger class.
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| 59 |
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| 60 | 5 - PHYSICS SURVEY
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| 61 |
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| 62 | The particle's type and the physic processes which will be available in this
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| 63 | example are set in PhysicsList class.
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| 64 |
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| 65 | A set of macros defining various run conditions are provided. The processes
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| 66 | are actived/inactived together with differents cuts, in order to survey the
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| 67 | processes one by one.
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| 68 |
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| 69 | The number of produced secondaries are counted, the number of steps, and the
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| 70 | number of process calls responsible of the step.
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| 71 |
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| 72 | 6 - HOW TO START ?
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| 73 |
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| 74 | - compile and link to generate an executable
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| 75 | % cd geant4/examples/extended/electromagnetic/TestEm1
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| 76 | % gmake
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| 77 |
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| 78 | - execute TestEm1 in 'batch' mode from macro files
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| 79 | % TestEm1 run10.mac
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| 80 |
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| 81 | - execute TestEm1 in 'interactive mode' with visualization
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| 82 | % TestEm1
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| 83 | ....
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| 84 | Idle> type your commands
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| 85 | ....
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| 86 | Idle> exit
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| 87 |
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| 88 | 7 - TRACKING : StepMax
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| 89 |
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| 90 | In order to control the accuracy of the deposition, the user can limit
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| 91 | 'by hand' the maximum step size of charged particles.
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| 92 | As an example, this limitation is implemented as a 'full' process :
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| 93 | see StepMax class and its Messenger. The 'StepMax process' is registered
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| 94 | in the Physics List.
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| 95 |
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| 96 | 8 - HISTOGRAMS
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| 97 |
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| 98 | Testem1 produces several histo which are saved as testem1.hbook by default.
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| 99 | Content of these histo:
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| 100 | 1 : track length of primary particle
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| 101 | 2 : number of steps primary particle
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| 102 | 3 : step size of primary particle
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| 103 |
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| 104 | The histograms are managed by the HistoManager class and its Messenger.
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| 105 | The histos can be individually activated with the command :
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| 106 | /testem/histo/setHisto id nbBins valMin valMax unit
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| 107 | where unit is the desired unit for the histo (MeV or keV, deg or mrad, etc..)
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| 108 |
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| 109 | One can control the name of the histograms file with the command:
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| 110 | /testem/histo/setFileName name (default testem1)
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| 111 |
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| 112 | It is possible to choose the format of the histogram file (hbook, root, XML)
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| 113 | with the command /testem/histo/setFileType (hbook by default)
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| 114 |
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| 115 | It is also possible to print selected histograms on an ascii file:
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| 116 | /testem/histo/printHisto id
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| 117 | All selected histos will be written on a file name.ascii (default testem1)
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| 118 |
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| 119 | Note that, by default, histograms are disabled. To activate them, uncomment
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| 120 | the flag G4ANALYSIS_USE in GNUmakefile.
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| 121 |
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| 122 | Before compilation of the example it is optimal to clean up old files:
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| 123 | gmake histclean
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| 124 | gmake
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| 125 |
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| 126 | 9 - USING HISTOGRAMS
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| 127 |
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| 128 | To use histograms, at least one of the AIDA implementations should be
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| 129 | available (see http://aida.freehep.org).
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| 130 |
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| 131 | 9a - PI
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| 132 |
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| 133 | A package including AIDA and extended interfaces also using Python is PI,
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| 134 | available from: http://cern.ch/pi
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| 135 |
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| 136 | Once installed PI or PI-Lite in a specified local area $MYPY, it is required
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| 137 | to add the installation path to $PATH, i.e. for example, for release 1.2.1 of
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| 138 | PI:
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| 139 | setenv PATH ${PATH}:$MYPI/1.2.1/app/releases/PI/PI_1_2_1/rh73_gcc32/bin
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| 140 |
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| 141 | CERN users can use the PATH to the LCG area on AFS.
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| 142 | Before running the example the command should be issued:
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| 143 | eval `aida-config --runtime csh`
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| 144 |
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| 145 | 9b - OpenScientist
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| 146 |
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| 147 | OpenScientist is available at http://OpenScientist.lal.in2p3.fr.
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| 148 |
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| 149 | You have to "setup" the OpenScientist AIDA implementation before compiling
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| 150 | (then with G4ANALYSIS_USE set) and running your Geant4 application.
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| 151 |
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| 152 | On UNIX you setup, with a csh flavoured shell :
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| 153 | csh> source <<OpenScientist install path>/aida-setup.csh
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| 154 | or with a sh flavoured shell :
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| 155 | sh> . <<OpenScientist install path>/aida-setup.sh
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| 156 | On Windows :
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| 157 | DOS> call <<OpenScientist install path>/aida-setup.bat
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| 158 |
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| 159 | You can use various file formats for writing (AIDA-XML, hbook, root).
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| 160 | These formats are readable by the Lab onx interactive program
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| 161 | or the OpenPAW application. See the web pages.
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| 162 |
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| 163 |
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| 164 | With OpenPAW, on a run.hbook file, one can view the histograms
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| 165 | with something like :
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| 166 | OS> opaw
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| 167 | opaw> h/file 1 run.hbook ( or opaw> h/file 1 run.aida or run.root)
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| 168 | opaw> zone 2 2
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| 169 | opaw> h/plot 1
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| 170 | opaw> h/plot 2
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