| Geant4 Cross Reference |
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2
3 =========================================
4 Geant4 - an Object-Oriented Toolkit for S
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6
7 purgin_magnet
8 -------------
9 s. Larsson, May 2004
10
11 ----------------------------------------------
12 Acknowledgments to the GEANT4 Collaboration, i
13 J Generowicz, G. Folger, Vladimir Ivanchenko,
14 S. Guatelli.
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16
17 0. Introduction
18 ----------------
19
20 This example simulates electrons traveling thr
21
22 The Purging Magnet example is an application o
23 environment. It simulates a strong purging mag
24 The geometry is very simplified. The major ide
25 implement an external magnetic field grid and
26 electrons are as expected in this particular f
27 energy and momentum) are collected in a measur
28 stored in a CSV file (or, optionally in a ROOT
29 the G4AnalysisManager default file type in Pur
30
31 <<<<<<< HEAD
32
33 =======
34 >>>>>>> Migration to G4RunManagerFactory done.
35 1. Setting up the environment variables
36 ---------------------------------------
37
38 The following environment variables need to be
39
40 G4LEDATA: points to low energy data base
41
42 The required data-file for the detailed field
43 http://cern.ch/geant4-data/datasets/PurgMag
44
45
46 2. How to run the example
47 -------------------------
48
49 - Run the "PurgMag" executable.
50 - File PurgMag.TABLE needs to be available in
51 - For visualisation use vis.mac.
52 - Interactive or batch modes possible.
53 Default: Interactive mode.
54
55 To run a certain number of events in interacti
56 type the following at the "idle>" prompt:
57
58 idle> run/beamOn NumberOfEvents
59 idle> exit
60
61 - Simulation histogram output is stored in pur
62 purgmag_102.cvs (gammas), purgman_103.cvs (e+
63
64 1)Ntuple with position, energy and momentum fo
65 2)Ntuple with position, energy and momentum fo
66 (not needed in this example, will be used in
67 3)Ntuple with position, energy and momentum fo
68 (not needed in this example, will be used in
69
70 A default visualisation macro (vis.mac) is pre
71 Executing it from the build directory:
72 $ ./PurgMag
73 runs vis.mac before giving you an interactive
74
75
76 3. Detector description
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78
79 Simply a measurement volume. All particles ent
80
81
82 4. Physics processes
83 --------------------
84
85 This example uses the standard Electromagnetic
86
87
88 5. Particle Generator
89 ----------------------
90
91 The PurgMagPrimaryGeneratorAction sets the ini
92
93 -electrons 50MeV
94 -Start position (0, 0, 15cm)
95 -Momentum direction (0, 0, -1)
96
97
98 6. Geometry and materials
99 --------------------------
100
101 The world consists of Vacuum to minimize inter
102 with the medium. The purging magnet is impleme
103 of field values and geometerically as a pole g
104 measurement volume also contains vacuum.
105
106 The field is interpolated using a simple linea
107 dimensions (z and rho).
108
109 7. Comparison
110 --------------
111
112 The design of the magnetic field was made with
113 which is an electromagnetic finite element and
114 analysis software. The deviation in the y-dire
115 has also been calculated in the OPERA 3D modul
116
117 TOSCA: deviation y-direction: 35.112 cm
118 GEANT4: deviation y-direction: 35.170 cm (upda
119
120 **********************************************
121 *
122 * More information about the setup and geometr
123 *
124 **********************************************