1 | $Id: README,v 1.5 2006/05/18 08:16:42 grichine 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 | TestEm10 |
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9 | -------- |
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10 | |
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11 | Test for investigation of ionisation in thin absorbers, transition |
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12 | and synchrotron radiations. Default setup for "TestEm10.in" and "TestEm10.large_N.in" is |
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13 | the experiment for XTR with NIM A294 (1990) 465-472 (fig. 11) setup |
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14 | |
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15 | |
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16 | 0- INTRODUCTION |
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17 | |
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18 | The parameterisations models can be changed simply with: |
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19 | |
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20 | Idle> /XTRdetector/setModel i (i = 1 to 10) |
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21 | |
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22 | It is NOT needed (and not recommended) to issue the command |
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23 | /XTRdetector/update if just the model is changed. |
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24 | |
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25 | See macro file "TestEm10.in" for an example. |
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26 | |
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27 | |
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28 | 1- GEOMETRY DEFINITION |
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29 | |
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30 | The "absorber" is a tube made of a given material. |
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31 | |
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32 | Three parameters define the absorber : |
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33 | - the material of the absorber, |
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34 | - the thickness of an absorber, |
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35 | - the transverse size of the absorber (the input face is a square). |
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36 | |
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37 | The volume "World" contains the "absorber". |
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38 | In this test the parameters of the "World" can be changed , too. |
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39 | |
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40 | In addition a transverse uniform magnetic field can be applied. |
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41 | |
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42 | The default geometry is constructed in DetectorConstruction class, |
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43 | but all the parameters can be changed via |
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44 | the commands defined in the DetectorMessenger class. |
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45 | |
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46 | 2- AN EVENT : THE PRIMARY GENERATOR |
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47 | |
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48 | The primary kinematic consists of a single particle which hits the |
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49 | absorber perpendicular to the input face. The type of the particle |
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50 | and its energy are set in the PrimaryGeneratorAction class, and can |
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51 | be changed via the G4 build-in commands of ParticleGun class (see |
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52 | the macros provided with this example). |
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53 | |
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54 | A RUN is a set of events. |
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55 | |
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56 | 3- DETECTOR RESPONSE |
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57 | |
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58 | Here we test G4PAIionisation , G4IonisationByLogicalVolume and |
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59 | transition radiation processes |
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60 | |
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61 | A HIT is a record, event per event , of all the |
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62 | informations needed to simulate and analyse the detector response. |
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63 | |
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64 | In this example a CalorHit is defined as a set of 2 informations: |
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65 | - the total energy deposit in the absorber, |
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66 | - the total tracklength of all charged particles in the absorber, |
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67 | |
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68 | Therefore the absorber is declared |
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69 | 'sensitive detector' (SD), which means they can contribute to the hit. |
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70 | |
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71 | At the end of a run, from the histogram(s), one can study |
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72 | different physics quantities such as : |
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73 | - angle distribution, |
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74 | - energy deposit, |
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75 | - transmission/backscattering, |
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76 | - ... |
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77 | |
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78 | The test contains 10 built-in histograms, which can be activated by |
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79 | interactive commands (see the macros runxx.mac for details). |
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80 | |
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81 | The histogram files can be viewed using PAW e.g with the commands |
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82 | |
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83 | paw> h/file 1 geant4.plot01 or g4.p11 |
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84 | paw> option stat |
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85 | paw> h/pl 1 |
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86 | |
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87 | |
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88 | |
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89 | 4- PHYSICS DEMO |
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90 | |
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91 | The particle's type and the physic processes which will be available |
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92 | in this example are set in PhysicsList class. |
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93 | |
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94 | The messenger classes introduce interactive commands . Using these |
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95 | commands the geometry of the detector, the data of the primary |
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96 | particle, the limits of the histograms , etc. can be changed. |
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97 | |
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98 | |
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99 | 5- HOW TO START ? |
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100 | |
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101 | - compile and link to generate an executable |
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102 | % cd TestEm10 |
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103 | % gmake |
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104 | |
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105 | - execute TestEm10 in 'batch' mode from macro files e.g. |
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106 | % $(G4INSTALL)/bin/$(G4SYSTEM)/TestEm10 run11.mac |
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107 | |
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108 | - execute TestEm10 in 'interactive' mode with visualization e.g. |
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109 | % $(G4INSTALL)/bin/$(G4SYSTEM)/TestEm10 |
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110 | .... |
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111 | Idle> type your commands |
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112 | .... |
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113 | |
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114 | List of the built-in histograms |
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115 | ------------------------------- |
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116 | |
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117 | 1. number of (tracking) steps/event |
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118 | 2. energy deposit distribution in the absorber (in MeV) |
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119 | 3. angle distribution of the primary particle at the exit |
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120 | of the absorber (deg) |
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121 | 4. distribution of the lateral displacement at exit(mm) |
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122 | 5. kinetic energy of the transmitted primaries (MeV) |
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123 | 6. angle distribution of the backscattered primaries (deg) |
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124 | 7. kinetic energy of the backscattered primary particles (MeV) |
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125 | 8. kinetic energy of the charged secondary particles (MeV) |
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126 | 9. z distribution of the secondary charged vertices (mm) |
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127 | 10. kinetic energy of the photons escaping the absorber (MeV) |
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128 | |
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129 | |
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130 | Using histograms |
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131 | ---------------- |
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132 | |
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133 | By default the histograms are not activated. To activate histograms |
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134 | the environment variable G4ANALYSIS_USE should be defined. For instance |
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135 | uncomment the flag G4ANALYSIS_USE in GNUmakefile. |
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136 | |
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137 | To use histograms any of implementations of AIDA interfaces should |
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138 | be available (see http://aida.freehep.org). |
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139 | |
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140 | A package including AIDA and extended interfaces also using Python |
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141 | is PI, available from: http://cern.ch/pi . |
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142 | |
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143 | Once installed PI or PI-Lite in a specified local area $MYPY, it is |
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144 | required to add the installation path to $PATH, i.e. for example, |
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145 | for release 1.2.1 of PI: |
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146 | |
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147 | setenv PATH ${PATH}:$MYPI/1.2.1/app/releases/PI/PI_1_2_1/rh73_gcc32/bin |
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148 | |
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149 | CERN users can use the PATH to the LCG area on AFS. |
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150 | |
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151 | Before compilation of the example it is optimal to clean up old |
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152 | files: |
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153 | |
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154 | gmake histclean |
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155 | gmake |
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156 | |
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157 | Before running the example the command should be issued: |
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158 | |
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159 | eval `aida-config --runtime csh` |
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160 | |
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161 | It is possible to choose the format of the output file with |
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162 | histograms using UI command: |
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163 | |
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164 | /testem/histo/setFileType type |
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165 | |
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166 | The following types are available: hbook, root, xml. |
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