| Geant4 Cross Reference |
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2 Geant4 - an Object-Oriented Toolkit f
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4
5 WLS
6 ----------
7
8 This application simulates the propagation o
9 Wave Length Shifting (WLS) fiber.
10
11
12 1- Geometry Definition
13
14 The default geometry is as follow:
15
16 - A perfect, bare (or clad), PMMA fiber: 0.5mm
17 center (0,0,0) of the World.
18 - A circular MPPC with 0.5mm radius at the +z
19 - World and coupling materials are G4_AIR
20 - Photons will always refracted out to couplin
21 reaching MPPC
22 - There are many flexible parameters that the
23 They are under the /WLS directory of help.
24
25
26 2- Material Choices
27
28 There are several materials that the user ca
29 world and coupling.
30
31 They are:
32
33 - Vacuum (G4_Galactic)
34 - Air (G4_AIR)
35 - PMMA, refractive index n = 1.60
36 - Pethylene, n = 1.49
37 - FPethylene, n = 1.42
38 - Polystyrene, n = 1.60
39 - Silicone, n = 1.46
40
41
42 3- Photon Source
43
44 This program uses the General Particle Sourc
45 provided by Geant4 for generating particles.
46 optical photon must be within the range 2.00
47
48
49 4- Hit
50
51 A hit is registered when an optical photon i
52 surface. Information stored in a hit includ
53 location the optical photon is absorbed on t
54 where the optical photon left the fiber, the
55 photon, and the energy of the optical photon
56
57
58 5- Stepping Action
59
60 The stepping action keeps track of the numbe
61 gone through. In order to prevent infinite
62 rays taking up computing time, there is a li
63 bounces that an optical photon can go throug
64 The default limit is 100,000. The user can
65 the /stepping/setBounceLimit command. A val
66 limit. All optical photons artificially kil
67 on in their UserTrackInformation.
68
69
70 6- Visualization
71
72 To visualize particle trajectories, simply u
73 interactive mode or in your own macro.
74
75
76 7- main()
77
78 - execute wls in 'batch' mode from macro file
79 - you can enter an optional integer seed for
80 % wls electron.mac (optional: enter a
81
82 - wls in 'interactive mode' with visualizatio
83 % wls
84 ....
85 Idle> /control/execute
86 Idle> /run/beamOn 1
87 ....
88 Idle> exit
89
90 8- Macros provided
91
92 - electron.mac: Sets up the geometry and conf
93 Primary particle is a 10 MeV
94 - vis.mac: macro for visualization; called au
95 given on command line.