[807] | 1 | $Id: README,v 1.22 2007/11/12 15:48:58 maire Exp $ |
---|
| 2 | ------------------------------------------------------------------- |
---|
| 3 | |
---|
| 4 | ========================================================= |
---|
| 5 | Geant4 - an Object-Oriented Toolkit for Simulation in HEP |
---|
| 6 | ========================================================= |
---|
| 7 | |
---|
| 8 | TestEm1 |
---|
| 9 | ------- |
---|
| 10 | How to count processes. |
---|
| 11 | How to activate/inactivate processes. |
---|
| 12 | How to survey the tracking, in perticular the range of charged particles. |
---|
| 13 | How to define a maximum step size. |
---|
| 14 | |
---|
| 15 | 1 - GEOMETRY DEFINITION |
---|
| 16 | |
---|
| 17 | It is a simple box which represente an 'semi infinite' homogeneous medium. |
---|
| 18 | |
---|
| 19 | Two parameters define the geometry : |
---|
| 20 | - the material of the box, |
---|
| 21 | - the full size of the box. |
---|
| 22 | |
---|
| 23 | In addition a transverse uniform magnetic field can be applied. |
---|
| 24 | |
---|
| 25 | The default geometry is constructed in DetectorConstruction class, but all of |
---|
| 26 | the above parameters can be changed interactively via the commands defined in |
---|
| 27 | the DetectorMessenger class. |
---|
| 28 | |
---|
| 29 | 2 - PHYSICS LIST |
---|
| 30 | |
---|
| 31 | The particle list is the one of novice/exampleN03. |
---|
| 32 | The physics list contains the 'standard' electromagnetic processes, and decay. |
---|
| 33 | |
---|
| 34 | Few commands have been added to PhysicsList, in order to set the production |
---|
| 35 | threshold for secondaries for gamma and e-/e+. |
---|
| 36 | |
---|
| 37 | 3 - AN EVENT : THE PRIMARY GENERATOR |
---|
| 38 | |
---|
| 39 | The primary kinematic consists of a single particle starting at the left face |
---|
| 40 | of the box. The type of the particle and its energy are set in the |
---|
| 41 | PrimaryGeneratorAction class, and can be changed via the G4 build-in commands |
---|
| 42 | of ParticleGun class (see the macros provided with this example). |
---|
| 43 | |
---|
| 44 | In addition one can choose randomly the impact point of the incident particle. |
---|
| 45 | The corresponding interactive command is built in PrimaryGeneratorMessenger. |
---|
| 46 | |
---|
| 47 | 4 - VISUALIZATION |
---|
| 48 | |
---|
| 49 | The Visualization Manager is set in the main(). |
---|
| 50 | The initialisation of the drawing is done via the commands /vis/... in the |
---|
| 51 | macro vis.mac. To get visualisation: |
---|
| 52 | > /control/execute vis.mac |
---|
| 53 | |
---|
| 54 | The detector has a default view which is a longitudinal view of the box. |
---|
| 55 | |
---|
| 56 | The tracks are drawn at the end of event, and erased at the end of run. |
---|
| 57 | Optionaly one can choose to draw all particles, only the charged, or none. |
---|
| 58 | This command is defined in EventActionMessenger class. |
---|
| 59 | |
---|
| 60 | 5 - PHYSICS SURVEY |
---|
| 61 | |
---|
| 62 | The particle's type and the physic processes which will be available in this |
---|
| 63 | example are set in PhysicsList class. |
---|
| 64 | |
---|
| 65 | A set of macros defining various run conditions are provided. The processes |
---|
| 66 | are actived/inactived together with differents cuts, in order to survey the |
---|
| 67 | processes one by one. |
---|
| 68 | |
---|
| 69 | The number of produced secondaries are counted, the number of steps, and the |
---|
| 70 | number of process calls responsible of the step. |
---|
| 71 | |
---|
| 72 | 6 - HOW TO START ? |
---|
| 73 | |
---|
| 74 | - compile and link to generate an executable |
---|
| 75 | % cd geant4/examples/extended/electromagnetic/TestEm1 |
---|
| 76 | % gmake |
---|
| 77 | |
---|
| 78 | - execute TestEm1 in 'batch' mode from macro files |
---|
| 79 | % TestEm1 run10.mac |
---|
| 80 | |
---|
| 81 | - execute TestEm1 in 'interactive mode' with visualization |
---|
| 82 | % TestEm1 |
---|
| 83 | .... |
---|
| 84 | Idle> type your commands |
---|
| 85 | .... |
---|
| 86 | Idle> exit |
---|
| 87 | |
---|
| 88 | 7 - TRACKING : StepMax |
---|
| 89 | |
---|
| 90 | In order to control the accuracy of the deposition, the user can limit |
---|
| 91 | 'by hand' the maximum step size of charged particles. |
---|
| 92 | As an example, this limitation is implemented as a 'full' process : |
---|
| 93 | see StepMax class and its Messenger. The 'StepMax process' is registered |
---|
| 94 | in the Physics List. |
---|
| 95 | |
---|
| 96 | 8 - HISTOGRAMS |
---|
| 97 | |
---|
| 98 | Testem1 produces several histo which are saved as testem1.hbook by default. |
---|
| 99 | Content of these histo: |
---|
| 100 | 1 : track length of primary particle |
---|
| 101 | 2 : number of steps primary particle |
---|
| 102 | 3 : step size of primary particle |
---|
| 103 | |
---|
| 104 | The histograms are managed by the HistoManager class and its Messenger. |
---|
| 105 | The histos can be individually activated with the command : |
---|
| 106 | /testem/histo/setHisto id nbBins valMin valMax unit |
---|
| 107 | where unit is the desired unit for the histo (MeV or keV, deg or mrad, etc..) |
---|
| 108 | |
---|
| 109 | One can control the name of the histograms file with the command: |
---|
| 110 | /testem/histo/setFileName name (default testem1) |
---|
| 111 | |
---|
| 112 | It is possible to choose the format of the histogram file (hbook, root, XML) |
---|
| 113 | with the command /testem/histo/setFileType (hbook by default) |
---|
| 114 | |
---|
| 115 | It is also possible to print selected histograms on an ascii file: |
---|
| 116 | /testem/histo/printHisto id |
---|
| 117 | All selected histos will be written on a file name.ascii (default testem1) |
---|
| 118 | |
---|
| 119 | Note that, by default, histograms are disabled. To activate them, uncomment |
---|
| 120 | the flag G4ANALYSIS_USE in GNUmakefile. |
---|
| 121 | |
---|
| 122 | Before compilation of the example it is optimal to clean up old files: |
---|
| 123 | gmake histclean |
---|
| 124 | gmake |
---|
| 125 | |
---|
| 126 | 9 - USING HISTOGRAMS |
---|
| 127 | |
---|
| 128 | To use histograms, at least one of the AIDA implementations should be |
---|
| 129 | available (see http://aida.freehep.org). |
---|
| 130 | |
---|
| 131 | 9a - PI |
---|
| 132 | |
---|
| 133 | A package including AIDA and extended interfaces also using Python is PI, |
---|
| 134 | available from: http://cern.ch/pi |
---|
| 135 | |
---|
| 136 | Once installed PI or PI-Lite in a specified local area $MYPY, it is required |
---|
| 137 | to add the installation path to $PATH, i.e. for example, for release 1.2.1 of |
---|
| 138 | PI: |
---|
| 139 | setenv PATH ${PATH}:$MYPI/1.2.1/app/releases/PI/PI_1_2_1/rh73_gcc32/bin |
---|
| 140 | |
---|
| 141 | CERN users can use the PATH to the LCG area on AFS. |
---|
| 142 | Before running the example the command should be issued: |
---|
| 143 | eval `aida-config --runtime csh` |
---|
| 144 | |
---|
| 145 | 9b - OpenScientist |
---|
| 146 | |
---|
| 147 | OpenScientist is available at http://OpenScientist.lal.in2p3.fr. |
---|
| 148 | |
---|
| 149 | You have to "setup" the OpenScientist AIDA implementation before compiling |
---|
| 150 | (then with G4ANALYSIS_USE set) and running your Geant4 application. |
---|
| 151 | |
---|
| 152 | On UNIX you setup, with a csh flavoured shell : |
---|
| 153 | csh> source <<OpenScientist install path>/aida-setup.csh |
---|
| 154 | or with a sh flavoured shell : |
---|
| 155 | sh> . <<OpenScientist install path>/aida-setup.sh |
---|
| 156 | On Windows : |
---|
| 157 | DOS> call <<OpenScientist install path>/aida-setup.bat |
---|
| 158 | |
---|
| 159 | You can use various file formats for writing (AIDA-XML, hbook, root). |
---|
| 160 | These formats are readable by the Lab onx interactive program |
---|
| 161 | or the OpenPAW application. See the web pages. |
---|
| 162 | |
---|
| 163 | |
---|
| 164 | With OpenPAW, on a run.hbook file, one can view the histograms |
---|
| 165 | with something like : |
---|
| 166 | OS> opaw |
---|
| 167 | opaw> h/file 1 run.hbook ( or opaw> h/file 1 run.aida or run.root) |
---|
| 168 | opaw> zone 2 2 |
---|
| 169 | opaw> h/plot 1 |
---|
| 170 | opaw> h/plot 2 |
---|