[1337] | 1 | $Id: README,v 1.6 2008/05/07 11:47:09 maire Exp $ |
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[807] | 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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[1337] | 138 | be available. See InstallAida.txt |
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