| Geant4 Cross Reference |
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4 Geant4 - an Object-Oriented Toolkit for S
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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