| 1 | $Id: README,v 1.21 2007/11/28 12:37:56 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 | TestEm5 |
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| 9 | ------- |
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| 10 | How to study the transmission, absorption and reflexion of particles through |
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| 11 | a single, thin or thick, layer of material. |
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| 12 | In perticular, the effects of the multiple scattering can be ploted. |
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| 13 | |
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| 14 | 1- GEOMETRY DEFINITION |
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| 15 | |
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| 16 | The "absorber" is a box made of a given material. |
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| 17 | |
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| 18 | Three parameters define the absorber : |
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| 19 | - the material of the absorber, |
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| 20 | - the thickness of an absorber, |
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| 21 | - the transverse size of the absorber (the input face is a square). |
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| 22 | |
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| 23 | A volume "World" contains the "absorber". |
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| 24 | |
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| 25 | In addition a transverse uniform magnetic field can be applied. |
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| 26 | |
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| 27 | The default geometry is constructed in DetectorConstruction class, but all the |
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| 28 | parameters can be changed via commands defined in the DetectorMessenger class. |
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| 29 | The parameters of the "World" can be changed, too. |
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| 30 | |
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| 31 | 2- PHYSICS LIST |
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| 32 | |
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| 33 | The following EM physics lists are available in this example: |
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| 34 | - "standard" standard EM physics (default) |
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| 35 | - "livermore" low-energy EM physics using Livermore data |
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| 36 | - "penelope" low-energy EM physics implementing Penelope models |
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| 37 | - "standardSS" standard EM physics with single Coulomb scattering |
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| 38 | instead of multiple scattering |
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| 39 | |
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| 40 | Alternatively, the user may use predefined Geant4 builders: |
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| 41 | - "emstandard" G4EmStandardPhysics builder |
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| 42 | - "emstandard_opt1" G4EmStandardPhysics_option1 builder |
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| 43 | - "emstandard_opt2" G4EmStandardPhysics_option2 builder |
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| 44 | See geant4/source/physics_lists/History for details |
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| 45 | |
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| 46 | 3- 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 absorber |
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| 49 | perpendicular to the input face. The type of the particle and its energy are |
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| 50 | set in the PrimaryGeneratorAction class, and can be changed via the G4 build-in |
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| 51 | commands of ParticleGun class (see the macros provided with this example). |
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| 52 | |
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| 53 | In addition one can choose randomly the impact point of the incident particle. |
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| 54 | The interactive command is built in PrimaryGeneratorMessenger class. |
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| 55 | |
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| 56 | 4- VISUALIZATION |
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| 57 | |
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| 58 | The Visualization Manager is set in the main(). |
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| 59 | The initialisation of the drawing is done via the commands in vis.mac |
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| 60 | In interactive session: |
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| 61 | PreInit or Idle > /control/execute vis.mac |
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| 62 | |
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| 63 | The example has a default view which is a longitudinal view of the detector. |
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| 64 | |
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| 65 | The tracks are drawn at the end of event, and erased at the end of run. |
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| 66 | Optionaly one can choose to draw all particles, only the charged, or none. |
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| 67 | This command is defined in EventActionMessenger class. |
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| 68 | |
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| 69 | 5- TRACKING |
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| 70 | |
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| 71 | During the tracking, one can keep or not the secondaries : see StackingAction |
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| 72 | class and its Messenger. |
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| 73 | One can also limit 'by hand' the step lenght of the particle. As an example, |
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| 74 | this limitation is implemented as a 'full' process : see StepMax class and its |
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| 75 | Messenger. The 'StepMax process' is registered in the Physics List. |
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| 76 | |
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| 77 | 6- DETECTOR RESPONSE |
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| 78 | |
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| 79 | At the end of a run, from the histogram(s), one can study different |
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| 80 | physics quantities such as : |
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| 81 | - energy deposit in the absorber, |
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| 82 | - energy spectrum of secondaries at creation, |
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| 83 | - energy spectrum and angle distribution of particles at exit, |
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| 84 | - transmission and backscattering coefficients, |
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| 85 | - ... |
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| 86 | |
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| 87 | 7- List of the built-in histograms |
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| 88 | ---------------------------------- |
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| 89 | |
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| 90 | The test contains more than 20 built-in 1D histograms, which are managed by the |
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| 91 | HistoManager class and its Messenger. The histos can be individually activated |
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| 92 | with the command : |
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| 93 | /testem/histo/setHisto id nbBins valMin valMax unit |
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| 94 | where unit is the desired unit for the histo (MeV or keV, deg or mrad, etc..) |
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| 95 | (see the macros xxxx.mac). |
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| 96 | |
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| 97 | 1 "energy deposit in absorber" |
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| 98 | 2 "energy of charged secondaries at creation" |
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| 99 | 3 "energy of gammas at creation (log10(Ekin/MeV))" |
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| 100 | 4 "x_vertex of charged secondaries (all)" |
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| 101 | 5 "x_vertex of charged secondaries (not absorbed)" |
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| 102 | 10 "(transmit, charged) : kinetic energy at exit" |
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| 103 | 11 "(transmit, charged) : ener fluence: dE(MeV)/dOmega" |
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| 104 | 12 "(transmit, charged) : space angle dN/dOmega" |
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| 105 | 13 "(transmit, charged) : projected angle at exit" |
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| 106 | 14 "(transmit, charged) : projected position at exit" |
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| 107 | 15 "(transmit, charged) : radius at exit" |
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| 108 | 20 "(transmit, neutral) : kinetic energy at exit" |
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| 109 | 21 "(transmit, neutral) : ener fluence: dE(MeV)/dOmega" |
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| 110 | 22 "(transmit, neutral) : space angle dN/dOmega" |
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| 111 | 23 "(transmit, neutral) : projected angle at exit" |
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| 112 | 30 "(reflect , charged) : kinetic energy at exit" |
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| 113 | 31 "(reflect , charged) : ener fluence: dE(MeV)/dOmega" |
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| 114 | 32 "(reflect , charged) : space angle dN/dOmega" |
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| 115 | 33 "(reflect , charged) : projected angle at exit" |
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| 116 | 40 "(reflect , neutral) : kinetic energy at exit" |
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| 117 | 41 "(reflect , neutral) : ener fluence: dE(MeV)/dOmega" |
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| 118 | 42 "(reflect , neutral) : space angle dN/dOmega" |
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| 119 | 43 "(reflect , neutral) : projected angle at exit" |
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| 120 | |
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| 121 | The histograms can be viewed using PAW. See below the note on ANAPHE+AIDA. |
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| 122 | |
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| 123 | One can control the name of the histograms file with the command: |
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| 124 | /testem/histo/setFileName name (default testem5.hbook) |
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| 125 | |
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| 126 | It is also possible to print selected histograms on an ascii file: |
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| 127 | /testem/histo/printHisto id |
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| 128 | All selected histos will be written on a file name.ascii (default testem5) |
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| 129 | |
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| 130 | Note that, by default, histograms are disabled. To activate them, uncomment |
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| 131 | the flag G4ANALYSIS_USE in GNUmakefile. |
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| 132 | |
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| 133 | 8- GEANT4/GEANT3/DATA COMPARISON |
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| 134 | |
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| 135 | A Geant4/Geant3/exp. data comparison is given here for a few cases. |
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| 136 | These cases can be classified as follow: |
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| 137 | - e-/e+ incident particles versus protons and others. |
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| 138 | - 3 energy regimes: low: < 1MeV; medium: 1MeV -> few 10MeV; high: > 100MeV |
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| 139 | |
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| 140 | We indicate here the corresponding macros. |
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| 141 | |
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| 142 | | low energy | medium energy | high energy |
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| 143 | -------------------------------------------------------- |
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| 144 | | acosta.mac | | |
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| 145 | e-+ | berger.mac | hanson.mac | |
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| 146 | | hunger.mac | kulchi.mac | |
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| 147 | | tavola.mac | | |
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| 148 | -------------------------------------------------------- |
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| 149 | others| bichsel.mac | vincour.mac | shen1.mac shen2.mac |
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| 150 | | | gottsch.mac | tramu.mac |
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| 151 | -------------------------------------------------------- |
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| 152 | |
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| 153 | The relevant part of the GEANT3 code is in the subdirectory geant3 together |
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| 154 | with the xxxx.dat input files. |
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| 155 | |
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| 156 | 9- HOW TO START ? |
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| 157 | |
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| 158 | - compile and link to generate an executable |
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| 159 | % cd TestEm5 |
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| 160 | % gmake |
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| 161 | |
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| 162 | - execute TestEm5 in 'batch' mode from macro files e.g. |
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| 163 | % $(G4INSTALL)/bin/$(G4SYSTEM)/TestEm5 myMacro.mac |
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| 164 | |
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| 165 | - execute TestEm5 in 'interactive' mode with visualization e.g. |
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| 166 | % $(G4INSTALL)/bin/$(G4SYSTEM)/TestEm5 |
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| 167 | Then type your commands, for instance : |
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| 168 | Idle> control/execute vis.mac |
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| 169 | Idle> run/beamOn 5 |
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| 170 | .... |
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| 171 | |
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| 172 | 10- USING HISTOGRAMS |
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| 173 | |
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| 174 | Note that, by default, histograms are disabled. To activate them, uncomment |
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| 175 | the flag G4ANALYSIS_USE in GNUmakefile. |
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| 176 | |
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| 177 | Before compilation of the example it is optimal to clean up old files: |
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| 178 | gmake histclean |
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| 179 | gmake |
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| 180 | To use histograms, at least one of the AIDA implementations should be |
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| 181 | available (see http://aida.freehep.org). |
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| 182 | |
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| 183 | 8a - PI |
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| 184 | |
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| 185 | A package including AIDA and extended interfaces also using Python is PI, |
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| 186 | available from: http://cern.ch/pi |
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| 187 | |
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| 188 | Once installed PI or PI-Lite in a specified local area $MYPY, it is required |
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| 189 | to add the installation path to $PATH, i.e. for example, for release 1.2.1 of |
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| 190 | PI: |
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| 191 | setenv PATH ${PATH}:$MYPI/1.2.1/app/releases/PI/PI_1_2_1/rh73_gcc32/bin |
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| 192 | |
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| 193 | CERN users can use the PATH to the LCG area on AFS. |
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| 194 | Before running the example the command should be issued: |
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| 195 | eval `aida-config --runtime csh` |
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| 196 | |
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| 197 | 8b - OpenScientist |
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| 198 | |
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| 199 | OpenScientist is available at http://OpenScientist.lal.in2p3.fr. |
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| 200 | |
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| 201 | You have to "setup" the OpenScientist AIDA implementation before compiling |
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| 202 | (then with G4ANALYSIS_USE set) and running your Geant4 application. |
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| 203 | |
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| 204 | On UNIX you setup, with a csh flavoured shell : |
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| 205 | csh> source <<OpenScientist install path>/aida-setup.csh |
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| 206 | or with a sh flavoured shell : |
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| 207 | sh> . <<OpenScientist install path>/aida-setup.sh |
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| 208 | On Windows : |
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| 209 | DOS> call <<OpenScientist install path>/aida-setup.bat |
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| 210 | |
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| 211 | You can use various file formats for writing (AIDA-XML, hbook, root). |
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| 212 | These formats are readable by the Lab onx interactive program |
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| 213 | or the OpenPAW application. See the web pages. |
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| 214 | |
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| 215 | |
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| 216 | With OpenPAW, on a run.hbook file, one can view the histograms |
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| 217 | with something like : |
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| 218 | OS> opaw |
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| 219 | opaw> h/file 1 run.hbook ( or opaw> h/file 1 run.aida or run.root) |
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| 220 | opaw> zone 2 2 |
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| 221 | opaw> h/plot 1 |
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| 222 | opaw> h/plot 2 |
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