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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