| 1 | $Id: README,v 1.8 2007/11/12 18:19:30 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 | fanoCavity2 |
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| 9 | ----------- |
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| 10 | |
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| 11 | This program computes the dose deposited in an ionization chamber by an |
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| 12 | extended (one dimensional) monoenergetic electron source. |
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| 13 | The geometry of the chamber satisfies the conditions of charged particle |
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| 14 | equilibrium. Hence, under idealized conditions, the ratio of the dose |
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| 15 | deposited over the beam energy fluence must be equal to 1. |
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| 16 | This variante of the Fano cavity test make use of an reciprocity theorem. |
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| 17 | |
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| 18 | J.Sempau and P.Andreo, Phys. Med. Biol. 51 (2006) 3533 |
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| 19 | |
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| 20 | 1- GEOMETRY |
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| 21 | |
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| 22 | The chamber is modelized as a cylinder with a cavity in it. |
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| 23 | |
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| 24 | 5 parameters define the geometry : |
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| 25 | - the radius of the chamber (must be big) |
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| 26 | - the material of the wall |
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| 27 | - the thickness of the wall |
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| 28 | - the material of the cavity |
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| 29 | - the thickness of the cavity |
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| 30 | |
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| 31 | Wall and cavity must be made of the same material, but with different |
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| 32 | density. |
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| 33 | Radius must be bigger than range of electrons in cavity. |
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| 34 | |
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| 35 | All above parameters can be redifined via the UI commands built in |
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| 36 | DetectorMessenger class. |
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| 37 | |
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| 38 | _________________ |
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| 39 | radius (infinite) | | | | |
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| 40 | | | | | |
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| 41 | | | | | |
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| 42 | | | | | |
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| 43 | | | <-+-----+--- cavity |
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| 44 | | | | | |
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| 45 | | | | | |
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| 46 | ---------------------------- cylinder axis = e- source |
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| 47 | | | | | |
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| 48 | | | | | |
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| 49 | | | | | |
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| 50 | |wall | |wall | |
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| 51 | | | | | |
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| 52 | | | | | |
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| 53 | | | | | |
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| 54 | ----------------- |
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| 55 | |
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| 56 | 2- BEAM |
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| 57 | |
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| 58 | Monoenergetic (E0) incident electron source is uniformly distribued along |
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| 59 | cylinder axis, within wall and cavity, with constant lineic density |
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| 60 | per mass: I. |
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| 61 | An effective wall thickness is defined from the range of e- at energy E0. |
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| 62 | |
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| 63 | Beam_energy_fluence is E0*I |
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| 64 | |
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| 65 | 3- PURPOSE OF THE PROGRAM |
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| 66 | |
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| 67 | The program computes the dose deposited in the cavity and the ratio |
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| 68 | Dose/Beam_energy_fluence. This ratio must be 1. |
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| 69 | |
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| 70 | The program needs high statistic to reach precision on the computed dose. |
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| 71 | The UI command /testem/event/printModulo allows to survey the convergence of |
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| 72 | the dose calculation. |
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| 73 | |
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| 74 | The simplest way to study the effect of e- tracking parameters on dose |
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| 75 | deposition is to use the command /testem/stepMax. |
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| 76 | |
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| 77 | 4- PHYSICS |
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| 78 | |
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| 79 | The physics list contains the standard electromagnetic processes, with few |
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| 80 | modifications listed here. |
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| 81 | |
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| 82 | - Bremsstrahlung : Fano conditions imply no energy transfer via |
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| 83 | bremsstrahlung radiation. Therefore this process is not registered in the |
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| 84 | physics list. However, it is always possible to include it via an UI |
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| 85 | command. See PhysicsListMessenger class. |
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| 86 | |
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| 87 | - Ionization : In order to have same stopping power in wall and cavity, one |
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| 88 | must cancel the density correction term in the dedx formula. This is done in |
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| 89 | a specific MollerBhabha model (MyMollerBhabhaModel) which inherites from |
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| 90 | G4MollerBhabhaModel. |
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| 91 | |
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| 92 | To prevent explicit generation of delta-rays, the default production |
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| 93 | threshold (i.e. cut) is set to 10 km (CSDA condition). |
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| 94 | |
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| 95 | The finalRange of the step function is set to 10 um, which more on less |
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| 96 | correspond to a tracking cut in water of about 20 keV. See emOptions. |
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| 97 | Once again, the above parameters can be controled via UI commands. |
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| 98 | |
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| 99 | - Multiple scattering : is switched in single Coulomb scattering mode near |
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| 100 | boundaries. This is selected via EM options in PhysicsList, and can be |
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| 101 | controled with UI commands. |
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| 102 | |
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| 103 | - All PhysicsTables are built with 100 bins per decade. |
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| 104 | |
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| 105 | 5- HISTOGRAMS |
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| 106 | |
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| 107 | fanoCavity2 has several predefined 1D histograms : |
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| 108 | |
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| 109 | 1 : emission point of e+- |
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| 110 | 2 : energy spectrum of e+- |
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| 111 | 3 : theta distribution of e+- |
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| 112 | 4 : emission point of e+- hitting cavity |
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| 113 | 5 : energy spectrum of e+- when entering in cavity |
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| 114 | 6 : theta distribution of e+- before enter in cavity |
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| 115 | 7 : theta distribution of e+- at first step in cavity |
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| 116 | 8 : track segment of e+- in cavity |
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| 117 | 9 : step size of e+- in wall |
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| 118 | 10 : step size of e+- in cavity |
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| 119 | 11 : energy deposit in cavity per track |
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| 120 | |
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| 121 | The histograms are managed by the HistoManager class and its Messenger. |
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| 122 | The histos can be individually activated with the command : |
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| 123 | /testem/histo/setHisto id nbBins valMin valMax unit |
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| 124 | where unit is the desired unit for the histo (MeV or keV, deg or mrad, etc..) |
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| 125 | |
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| 126 | One can control the name of the histograms file with the command: |
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| 127 | /testem/histo/setFileName name (default fanoCavity) |
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| 128 | |
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| 129 | It is possible to choose the format of the histogram file (hbook, root, XML) |
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| 130 | with the command /testem/histo/setFileType (hbook by default) |
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| 131 | |
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| 132 | It is also possible to print selected histograms on an ascii file: |
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| 133 | /testem/histo/printHisto id |
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| 134 | All selected histos will be written on a file name.ascii (default fanocavity2) |
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| 135 | |
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| 136 | Note that, by default, histograms are disabled. To activate them, uncomment |
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| 137 | the flag G4ANALYSIS_USE in GNUmakefile. |
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| 138 | |
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| 139 | 6- HOW TO START ? |
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| 140 | |
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| 141 | - compile and link to generate an executable |
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| 142 | % cd geant4/examples/extended/medical/fanoCavity2 |
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| 143 | % gmake |
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| 144 | |
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| 145 | - execute fanoCavity2 in 'batch' mode from macro files |
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| 146 | % fanoCavity2 run01.mac |
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| 147 | |
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| 148 | - execute fanoCavity2 in 'interactive mode' with visualization |
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| 149 | % fanoCavity2 |
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| 150 | .... |
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| 151 | Idle> type your commands |
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| 152 | .... |
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| 153 | Idle> exit |
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| 154 | |
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| 155 | 7- USING HISTOGRAMS |
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| 156 | |
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| 157 | To use histograms, at least one of the AIDA implementations should be |
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| 158 | available (see http://aida.freehep.org). |
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| 159 | |
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| 160 | 8a - PI |
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| 161 | |
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| 162 | A package including AIDA and extended interfaces also using Python is PI, |
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| 163 | available from: http://cern.ch/pi |
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| 164 | |
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| 165 | Once installed PI or PI-Lite in a specified local area $MYPY, it is required |
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| 166 | to add the installation path to $PATH, i.e. for example, for release 1.2.1 of |
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| 167 | PI: |
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| 168 | setenv PATH ${PATH}:$MYPI/1.2.1/app/releases/PI/PI_1_2_1/rh73_gcc32/bin |
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| 169 | |
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| 170 | CERN users can use the PATH to the LCG area on AFS. |
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| 171 | Before running the example the command should be issued: |
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| 172 | eval `aida-config --runtime csh` |
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| 173 | |
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| 174 | 8b - OpenScientist |
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| 175 | |
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| 176 | OpenScientist is available at http://OpenScientist.lal.in2p3.fr. |
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| 177 | |
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| 178 | You have to "setup" the OpenScientist AIDA implementation before compiling |
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| 179 | (then with G4ANALYSIS_USE set) and running your Geant4 application. |
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| 180 | |
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| 181 | On UNIX you setup, with a csh flavoured shell : |
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| 182 | csh> source <<OpenScientist install path>/aida-setup.csh |
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| 183 | or with a sh flavoured shell : |
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| 184 | sh> . <<OpenScientist install path>/aida-setup.sh |
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| 185 | On Windows : |
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| 186 | DOS> call <<OpenScientist install path>/aida-setup.bat |
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| 187 | |
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| 188 | You can use various file formats for writing (AIDA-XML, hbook, root). |
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| 189 | These formats are readable by the Lab onx interactive program |
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| 190 | or the OpenPAW application. See the web pages. |
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| 191 | |
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| 192 | |
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| 193 | With OpenPAW, on a run.hbook file, one can view the histograms |
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| 194 | with something like : |
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| 195 | OS> opaw |
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| 196 | opaw> h/file 1 run.hbook ( or opaw> h/file 1 run.aida or run.root) |
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| 197 | opaw> zone 2 2 |
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| 198 | opaw> h/plot 1 |
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| 199 | opaw> h/plot 2 |
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