| 1 | $Id: README,v 1.2 2007/05/15 17:46:43 japost 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 | field02 (based on field01)
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| 9 | -------------------------
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| 10 |
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| 11 | Test for investigation of tracking in electric field
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| 12 | and field dependent electromagnetic processes.
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| 13 |
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| 14 |
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| 15 | 1- GEOMETRY DEFINITION
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| 16 |
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| 17 | The "absorber" is a solid made of a given material.
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| 18 |
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| 19 | Three parameters define the absorber :
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| 20 | - the material of the absorber,
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| 21 | - the thickness of an absorber,
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| 22 | - the transverse size of the absorber (the input face is a square).
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| 23 |
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| 24 | The volume "World" contains the "absorber".
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| 25 | In this test the parameters of the "World" can be changed , too.
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| 26 |
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| 27 | In addition a transverse uniform magnetic field can be applied.
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| 28 |
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| 29 | The default geometry is constructed in DetectorConstruction class,
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| 30 | but all the parameters can be changed via
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| 31 | the commands defined in the DetectorMessenger class.
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| 32 |
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| 33 | 2- AN EVENT : THE PRIMARY GENERATOR
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| 34 |
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| 35 | The primary kinematic consists of a single particle which hits the
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| 36 | absorber perpendicular to the input face. The type of the particle
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| 37 | and its energy are set in the PrimaryGeneratorAction class, and can
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| 38 | be changed via the G4 build-in commands of ParticleGun class (see
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| 39 | the macros provided with this example).
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| 40 |
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| 41 | A RUN is a set of events.
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| 42 |
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| 43 | 3- DETECTOR RESPONSE
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| 44 |
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| 45 | A HIT is a record, event per event , of all the
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| 46 | informations needed to simulate and analyse the detector response.
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| 47 |
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| 48 | Therefore the absorber is declared
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| 49 | 'sensitive detector' (SD), which means they can contribute to the hit.
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| 50 |
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| 51 | At the end of a run, from the histogram(s), one can study
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| 52 | different physics quantities such as :
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| 53 | - angle distribution,
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| 54 | - energy deposit,
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| 55 | - transmission/backscattering,
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| 56 | - ...
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| 57 |
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| 58 | The test contains 10 built-in histograms, which can be activated by
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| 59 | interactive commands (see the macros runxx.mac for details).
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| 60 | The histograms/plots are in printed form in the corresponding
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| 61 | resultxx (for GEANT4) and outxx (for GEANT3) files, and they are
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| 62 | saved as geant4.plotxx and geant3.plotxx histogram files, too.
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| 63 |
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| 64 | The histogram files can be viewed using PAW e.g with the commands
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| 65 |
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| 66 | paw> h/file 1 geant4.plot01 or g4.p11
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| 67 | paw> option stat
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| 68 | paw> h/pl 1
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| 69 |
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| 70 |
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| 71 |
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| 72 | 4- PHYSICS DEMO
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| 73 |
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| 74 | The particle's type and the physic processes which will be available
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| 75 | in this example are set in PhysicsList class.
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| 76 |
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| 77 | The messenger classes introduce interactive commands . Using these
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| 78 | commands the geometry of the detector, the data of the primary
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| 79 | particle, the limits of the histograms , etc. can be changed.
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| 80 |
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| 81 |
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| 82 | 5- HOW TO START ?
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| 83 |
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| 84 | - compile and link to generate an executable
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| 85 | % cd $G4INSTALL/example/extended/field/field01
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| 86 | % gmake
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| 87 |
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| 88 | - execute field01 in 'batch' mode from macro files e.g.
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| 89 | % $(G4INSTALL)/bin/$(G4SYSTEM)/field01 run11.mac
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| 90 |
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| 91 | - execute field01 in 'interactive' mode with visualization e.g.
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| 92 | % $(G4INSTALL)/bin/$(G4SYSTEM)/field01
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| 93 | ....
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| 94 | Idle> type your commands
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| 95 | ....
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| 96 |
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| 97 | 6- GEANT4/GEANT3/exp.data comparison
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| 98 |
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| 99 | A GEANT4/GEANT3/exp. data comparison is given here for a few cases.
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| 100 |
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| 101 | The GEANT4 results can be found in the results/ directory, the resultxx
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| 102 | output was obtained with the runxx.mac macro.
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| 103 |
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| 104 | The relevant part of the GEANT3 code is in the geant3/ directory
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| 105 | together with the runxx.dat input files. The outputs of the GEANT3 runs
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| 106 | geant3/results subdirectory.
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| 107 |
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| 108 | In order to make an executable of GEANT3 the gmakeB command should be
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| 109 | used in the geant3/ subdirectory.To run this executable with a given
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| 110 | input file the input file name should be given when it is being asked
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| 111 | by the program.(see geant3/README)
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| 112 |
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| 113 | The expdata/ directory contains some information
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| 114 | on the experimental data.
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| 115 |
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| 116 |
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| 117 | List of the built-in histograms
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| 118 | -------------------------------
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| 119 |
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| 120 | 1. number of (tracking) steps/event
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| 121 | 2. energy deposit distribution in the absorber (in MeV)
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| 122 | 3. angle distribution of the primary particle at the exit
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| 123 | of the absorber (deg)
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| 124 | 4. distribution of the lateral displacement at exit(mm)
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| 125 | 5. kinetic energy of the transmitted primaries (MeV)
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| 126 | 6. angle distribution of the backscattered primaries (deg)
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| 127 | 7. kinetic energy of the backscattered primary particles (MeV)
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| 128 | 8. kinetic energy of the charged secondary particles (MeV)
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| 129 | 9. z distribution of the secondary charged vertices (mm)
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| 130 | 10. kinetic energy of the photons escaping the absorber (MeV)
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| 131 |
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