| 1 | $Id: README,v 1.12 2008/08/22 14:35:12 vnivanch 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 | TestEm9 |
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| 9 | ------- |
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| 10 | Demonstrate electromagnetic physics in crystal calorimeters. |
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| 11 | How to define cut-per-region. |
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| 12 | |
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| 13 | 1- GEOMETRY DEFINITION |
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| 14 | |
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| 15 | The geometry consists of the vertex detector (VD), the electromagnetic |
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| 16 | calorimeter (EM), and the muon identifier (MU). Detector layout along |
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| 17 | the axis Z. |
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| 18 | |
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| 19 | VD consisted of 3 layers of Si with pads structured along the axis X. |
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| 20 | Between VD and EM there are 2 active absorbers (scintillators). |
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| 21 | EM is the matrix 5x5 of heavy crystals. MU consist of 2 active absorbers |
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| 22 | (scintillators) and the iron plate between. |
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| 23 | |
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| 24 | 2 additional to the World regions are defined: VertexDetector and |
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| 25 | MuonDetector. For testing purposes first absorber of MU is included in |
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| 26 | the region of VD. |
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| 27 | |
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| 28 | Material of calorimiter and absorber can be choosen: |
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| 29 | Air Water lAr Al Fe BGO PbWO4 Pb. |
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| 30 | eg: /testem/det/CalMat PbWO4 |
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| 31 | /testem/det/AbsMat Al |
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| 32 | |
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| 33 | The size of the detector can be changed also. |
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| 34 | |
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| 35 | eg: /testem/det/EcalLength 20 cm |
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| 36 | /testem/det/EcalWidth 5 cm |
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| 37 | /testem/det/update ---> rebuild the geometry |
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| 38 | |
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| 39 | 2- PHYSICS LISTS |
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| 40 | |
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| 41 | Physics Lists are based on modular design. Few modules are instantiated: |
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| 42 | 1. Transporatation |
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| 43 | 2. EM physics |
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| 44 | 3. Decays |
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| 45 | 4. StepMax - for steplimitation |
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| 46 | |
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| 47 | The following options for EM physics using builders from physics_lists |
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| 48 | sub-package are available: |
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| 49 | - "emstandard" (default) |
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| 50 | - "emstandard_opt1" (EMV) |
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| 51 | - "emstandard_opt2" (EMX) |
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| 52 | - "emstandard_opt3" recommended for medical and space applications |
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| 53 | |
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| 54 | There are local to this example variants of EM physics: |
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| 55 | - "emstandard_local" close to opt3 |
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| 56 | - "standardIG" close to opt2 |
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| 57 | - "standardLPM" relativistic bremsstrahlung model added to opt1 |
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| 58 | - "Livermore" low-energy EM physics using Livermore data |
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| 59 | - "Penelope" low-energy EM physics implementing Penelope models |
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| 60 | |
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| 61 | Optional components can be added: |
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| 62 | - "elastic" elastic scattering of hadrons |
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| 63 | - "binary" QBBC configuration of hadron/ion inelastic models |
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| 64 | - "gamma_nuc" gamma- and electro-nuclear processes |
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| 65 | - "stopping" stopping processes |
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| 66 | |
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| 67 | 3- AN EVENT : THE PRIMARY GENERATOR |
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| 68 | |
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| 69 | The primary kinematic consists of a single particle which hits the |
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| 70 | cylinder perpendicular to the input face. The type of the particle |
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| 71 | and its energy are set in the PrimaryGeneratorAction class, and can |
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| 72 | changed via the G4 build-in commands of ParticleGun class. |
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| 73 | |
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| 74 | 4- OUTPUT |
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| 75 | |
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| 76 | The batch regime of simulation can be started |
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| 77 | $G4WORKDIR/bin/$G4SYSTEM/TestEm9 TestEm9.in |
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| 78 | where TestEm9.in is the example of macro file for batch job. |
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| 79 | |
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| 80 | As a result of simulation the number of secondaries produced |
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| 81 | in different regions are averaged. The average energy depositions |
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| 82 | in active absorbers and EM as well as RMS of these values are shown. |
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| 83 | The number of hits in pads of VD is printed out. |
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| 84 | |
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| 85 | 5- VISUALISATION |
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| 86 | |
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| 87 | To use visualisation the environment variable G4_VIS_USE should be |
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| 88 | defined. An interactive session starts if no macro file is specified |
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| 89 | in the command line: |
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| 90 | $G4WORKDIR/bin/$G4SYSTEM/TestEm9 |
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| 91 | |
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| 92 | To start visualisation one can issur |
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| 93 | >/control/execute vis.mac |
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| 94 | >/run/beamOn 1 |
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| 95 | |
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| 96 | 6- ANALYSIS |
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| 97 | |
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| 98 | To create histograms/ntuple for further analysis one should define |
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| 99 | environment variable G4ANALYSIS_USE and setup local AIDA implementation. |
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| 100 | The example should be recompiled: |
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| 101 | |
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| 102 | gmake histclean |
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| 103 | gmake |
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| 104 | |
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| 105 | The macro file csi.mac can be used as exmple of macro for analysis. It |
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| 106 | can be executed in the following way: |
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| 107 | $G4WORKDIR/bin/$G4SYSTEM/TestEm9 csi.mac |
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| 108 | |
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| 109 | |
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| 110 | 7- Using histograms |
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| 111 | ------------------- |
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| 112 | |
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| 113 | By default the histograms are not activated. To activate histograms |
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| 114 | the environment variable G4ANALYSIS_USE should be defined. For instance |
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| 115 | uncomment the flag G4ANALYSIS_USE in GNUmakefile. |
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| 116 | |
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| 117 | To use histograms any of implementations of AIDA interfaces should |
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| 118 | be available. See InstallAida.txt |
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