Geant4 Cross Reference |
1 ---------------------------------------------- 2 3 ========================================= 4 Geant4 - an Object-Oriented Toolkit for S 5 ========================================= 6 7 TestEm13 8 -------- 9 10 How to compute cross sections from the trans 11 ( see below, item Physics). 12 13 1- GEOMETRY DEFINITION 14 15 It is a single box representing a layer of f 16 homogeneous material. 17 Two parameters define the geometry : 18 - the material of the box, 19 - the (full) size of the box. 20 21 The default geometry (1 cm of water) is cons 22 DetectorConstruction, but the above paramete 23 interactively via the commands defined in De 24 25 2- PHYSICS LIST 26 27 The physics list contains the standard elect 28 In order not to introduce 'artificial' const 29 multiple scattering is not instanciated, and 30 registered as discrete : there is no continu 31 32 3- AN EVENT : THE PRIMARY GENERATOR 33 34 The primary kinematic consists of a single p 35 of the box. The type of the particle and its 36 PrimaryGeneratorAction (1 MeV gamma), and ca 37 build-in commands of ParticleGun class (see 38 this example). 39 40 4- PHYSICS 41 42 An event is killed at the first step of the 43 Either the particle has interacted or is tra 44 The cross section, also called absorption co 45 the rate of unaltered transmitted incident p 46 47 The result is compared with the 'input' data 48 sections stored in the PhysicsTables and use 49 50 A set of macros defining various run conditi 51 The processes are actived/inactived in order 52 individually. 53 54 55 6- VISUALIZATION 56 57 The Visualization Manager is set in the main 58 The initialisation of the drawing is done vi 59 /vis/... in the macro vis.mac. To get visual 60 > /control/execute vis.mac 61 62 The detector has a default view which is a l 63 box. 64 65 The tracks are drawn at the end of event, an 66 67 7- HOW TO START ? 68 69 execute TestEm13 in 'batch' mode from macro 70 % TestEm13 compt.mac 71 72 execute TestEm13 in 'interactive mode' with 73 % TestEm13 74 Idle> control/execute vis.mac 75 .... 76 Idle> type your commands 77 .... 78 Idle> exit 79 80 Macros provided in this example: 81 - anni.mac: e+ (10 MeV) on 5 cm Alumin 82 - compton.mac: gamma (300 keV) on 1 cm Alu 83 - conv.mac: gamma (20 MeV) on 5 mm Lead 84 - electron.mac: e- (100 MeV) on 1 cm Alumin 85 - gamma.mac: gamma (100 keV) on 1 cm Wat 86 - photoelec.mac: gamma (100 keV) on 1 cm Iro 87 - proton.mac: proton (1 GeV) on 1 cm Wate