1 | $Id: README,v 1.1 2006/05/09 16:22:19 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 | TestEm17 |
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9 | -------- |
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10 | This example is intended to check implementation of the processes |
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11 | of muon interactions: ionization, direct (e+,e-) production, |
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12 | bremsstrahlung, mu-nuclear interaction. |
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13 | It allows to compute differential cross sections (as function of the |
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14 | energy tranfered to secondaries), total cross sections and to compare |
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15 | with analytic calculations. |
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16 | |
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17 | 1- GEOMETRY DEFINITION |
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18 | |
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19 | It is a single box of homogeneous medium. |
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20 | Two parameters define the geometry : |
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21 | - the material of the box, |
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22 | - the (full) size of the box. |
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23 | |
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24 | The default geometry (1 m of Iron) is constructed in |
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25 | DetectorConstruction, but the above parameters can be changed |
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26 | interactively via the commands defined in DetectorMessenger. |
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27 | |
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28 | 2- PHYSICS LIST |
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29 | |
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30 | The physics list contains only electromagnetic processes for muon, |
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31 | adding G4MuNuclearInteraction and seting of upper energy range limit |
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32 | to 1000 PeV). |
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33 | |
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34 | Standard (default) and g4v52 (frozen at the release Geant4 v.5.2) |
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35 | physics can be choosen. |
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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 edge |
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40 | of the box. The type of the particle and its energy are set in |
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41 | PrimaryGeneratorAction (mu+ 10 TeV), and can be changed via the G4 |
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42 | build-in commands of ParticleGun class (see the macros provided with |
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43 | this example). |
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44 | |
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45 | 4- PHYSICS |
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46 | |
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47 | The incident particle is a muon. During the tracking, secondary |
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48 | particles are killed. |
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49 | |
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50 | The number of interactions are plotted as a function of the energy |
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51 | transfered to the secondaries. |
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52 | The total number of interactions is recorded, and the total crossSection |
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53 | computed from this. |
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54 | |
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55 | At EndOfRun, the above results are compared with analytic calculations. |
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56 | The functions which compute the theoritical crossSections have been |
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57 | provided by the G4 MEPhI group, and grouped in MuCrossSection class. |
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58 | |
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59 | 5- HISTOGRAMS |
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60 | |
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61 | The test contains 4 built-in 1D histograms, which are managed by the |
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62 | HistoManager class and its Messenger. |
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63 | |
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64 | 1 Monte-Carlo relative transferred energy distribution histo |
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65 | (log10(eps/Emu kin) for knock-on electrons (ionization) |
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66 | 2 -"- direct (e+,e-) pair production |
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67 | 3 -"- bremsstrahlung |
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68 | 4 -"- nuclear interaction |
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69 | |
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70 | The histos can be activated individually with the command : |
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71 | /testem/histo/setHisto id nbBins valMin valMax : min and max values of |
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72 | log10(eps/Emu kin). |
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73 | |
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74 | At EndOfRun the corresponding histos for analytic calculations are |
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75 | automatically created anf filled (histo 6 to 9), and the comparison |
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76 | (G4 divided by theory) is done in histos 11 to 14. |
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77 | |
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78 | One can control the name and the type of the histograms file with |
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79 | the commands: |
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80 | /testem/histo/setFileName name (default testem17) |
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81 | /testem/histo/setFileType name (default hbook) |
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82 | |
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83 | Note that, by default, histograms are disabled. To activate them, |
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84 | uncomment the flag G4ANALYSIS_USE in GNUmakefile. |
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85 | |
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86 | 6- VISUALIZATION |
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87 | |
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88 | The Visualization Manager is set in the main(). |
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89 | The initialisation of the drawing is done via the commands |
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90 | /vis/... in the macro vis.mac. To get visualisation: |
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91 | > /control/execute vis.mac |
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92 | |
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93 | The detector has a default view which is a longitudinal view of the |
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94 | box. |
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95 | |
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96 | The tracks are drawn at the end of event, and erased at the end of run. |
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97 | |
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98 | 7- HOW TO START ? |
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99 | |
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100 | compile and link to generate an executable |
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101 | % cd geant4/examples/extended/electromagnetic/TestEm17 |
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102 | % gmake |
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103 | |
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104 | execute TestEm17 in 'batch' mode from macro files : |
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105 | % TestEm17 allproc.mac |
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106 | |
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107 | execute TestEm17 in 'interactive mode' with visualization : |
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108 | % TestEm17 |
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109 | Idle> control/execute vis.mac |
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110 | .... |
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111 | Idle> type your commands |
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112 | .... |
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113 | Idle> exit |
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114 | |
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115 | 8- USING HISTOGRAMS |
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116 | |
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117 | By default the histograms are not activated. To activate histograms |
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118 | the environment variable G4ANALYSIS_USE should be defined. For instance |
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119 | uncomment the flag G4ANALYSIS_USE in GNUmakefile. |
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120 | |
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121 | Before compilation of the example it is optimal to clean up old files: |
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122 | gmake histclean |
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123 | gmake |
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124 | |
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125 | To use histograms, at least one of the AIDA implementations should be |
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126 | available (see http://aida.freehep.org). |
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127 | |
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128 | 8a - PI |
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129 | |
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130 | A package including AIDA and extended interfaces also using Python is PI, |
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131 | available from: http://cern.ch/pi |
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132 | |
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133 | Once installed PI or PI-Lite in a specified local area $MYPY, it is required |
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134 | to add the installation path to $PATH, i.e. for example, for release 1.2.1 of |
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135 | PI: |
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136 | setenv PATH ${PATH}:$MYPI/1.2.1/app/releases/PI/PI_1_2_1/rh73_gcc32/bin |
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137 | |
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138 | CERN users can use the PATH to the LCG area on AFS. |
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139 | Before running the example the command should be issued: |
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140 | eval `aida-config --runtime csh` |
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141 | |
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142 | 8b - OpenScientist |
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143 | |
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144 | OpenScientist is available at http://OpenScientist.lal.in2p3.fr. |
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145 | |
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146 | You have to "setup" the OpenScientist AIDA implementation before compiling |
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147 | (then with G4ANALYSIS_USE set) and running your Geant4 application. |
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148 | |
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149 | On UNIX you setup, with a csh flavoured shell : |
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150 | csh> source <<OpenScientist install path>/aida-setup.csh |
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151 | or with a sh flavoured shell : |
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152 | sh> . <<OpenScientist install path>/aida-setup.sh |
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153 | On Windows : |
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154 | DOS> call <<OpenScientist install path>/aida-setup.bat |
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155 | |
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156 | You can use various file formats for writing (AIDA-XML, hbook, root). |
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157 | These formats are readable by the Lab onx interactive program |
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158 | or the OpenPAW application. See the web pages. |
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159 | |
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160 | |
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161 | With OpenPAW, on a run.hbook file, one can view the histograms |
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162 | with something like : |
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163 | OS> opaw |
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164 | opaw> h/file 1 run.hbook ( or opaw> h/file 1 run.aida or run.root) |
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165 | opaw> zone 2 2 |
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166 | opaw> h/plot 1 |
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167 | opaw> h/plot 2 |
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