| Geant4 Cross Reference |
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2
3 =========================================
4 Geant4 - an Object-Oriented Toolkit for S
5 =========================================
6
7 fanoCavity
8 ----------
9
10 This program computes the dose deposited i
11 monoenergetic photon beam.
12 The geometry of the chamber satisfies the
13 equilibrium. Hence, under idealized condit
14 deposited over the beam energy fluence mus
15 mass_energy_transfer coefficient of the wa
16
17 E.Poon and al, Phys. Med. Biol. 50 (2005)
18 I.Kawrakow, Med. Phys. 27-3 (2000) 499
19
20 1- GEOMETRY
21
22 The chamber is modelized as a cylinder wit
23
24 6 parameters define the geometry :
25 - the material of the wall of the chambe
26 - the radius of the chamber and the thic
27 - the material of the cavity
28 - the radius and the thickness of the ca
29
30 Wall and cavity must be made of the same m
31 density
32
33 All above parameters can be redifined via
34 DetectorMessenger class
35
36 -----------------
37 | |
38 | wall |
39 | ----- |
40 | | | |
41 | | <-+-----+--- cavit
42 ------> | | | |
43 ------> | | | |
44 beam -------------------------------- c
45 ------> | | | |
46 ------> | | | |
47 | | | |
48 | | | |
49 | ----- |
50 | |
51 | |
52 -----------------
53
54 2- BEAM
55
56 Monoenergetic incident photon beam is unif
57 to the flat end of the chamber. The beam r
58 UI command built in PrimaryGeneratorMessen
59 chamber radius.
60
61 Beam regeneration : after each Compton int
62 reset to its initial state, energy and dir
63 sites are uniformly distribued within the
64
65 This modification must be done in the Part
66 of the Compton scattering interaction. The
67 (MyKleinNishinaCompton) is assigned to the
68 PhysicsList. MyKleinNishinaCompton inherit
69 only the function SampleSecondaries() is o
70
71 3- PURPOSE OF THE PROGRAM
72
73 The program computes the dose deposited in
74 Dose/Beam_energy_fluence. This ratio is co
75 coefficient of the wall material.
76
77 The mass_energy_transfer coefficient needs
78 - the photon total cross section, whic
79 by G4EmCalculator (see EndOfRunActio
80 - the average kinetic energy of charge
81 wall during the run.
82
83 The program needs high statistic to reach
84 The UI command /run/printProgress allows t
85 the kineticEnergy and dose calculations.
86
87 In addition, to increase the program effic
88 which have no chance to reach the cavity a
89 StackinAction). This feature can be switch
90 StackingMessenger).
91
92 The simplest way to study the effect of e-
93 deposition is to use the command /testem/s
94
95 4- PHYSICS
96
97 The physics lists contains the standard el
98 modifications listed here.
99
100 - Compton scattering : as explained above,
101 MyKleinNishinaCompton class.
102
103 In order to make the program more efficien
104 cross section via the function SetCSFactor
105 associated UI command. Default is factor=1
106
107 - Bremsstrahlung : Fano conditions imply n
108 bremsstrahlung radiation. Therefore this p
109 physics list. However, it is always possib
110 See PhysListEmStandard class.
111
112 - Ionisation : In order to have same stopp
113 must cancel the density correction term in
114 a specific MollerBhabha model (MyMollerBha
115 G4MollerBhabhaModel.
116
117 To prevent explicit generation of delta-ra
118 threshold (i.e. cut) is set to 10 km (CSDA
119
120 The finalRange of the step function is set
121 correspond to a tracking cut in water of a
122 Once again, the above parameters can be co
123
124 - Multiple scattering : is switched in sin
125 boundaries. This is selected via EM option
126 controled with UI commands.
127
128 - All PhysicsTables are built with 100 bin
129
130 5- HISTOGRAMS
131
132 fanoCavity has several predefined 1D histog
133
134 1 : emission point of e+-
135 2 : energy spectrum of e+-
136 3 : theta distribution of e+-
137 4 : emission point of e+- hitting cavity
138 5 : energy spectrum of e+- when entering
139 6 : theta distribution of e+- before ent
140 7 : theta distribution of e+- at first s
141 8 : track segment of e+- in cavity
142 9 : step size of e+- in wall
143 10 : step size of e+- in cavity
144 11 : energy deposit in cavity per track
145
146 The histograms are managed by G4AnalysisMan
147 The histos can be individually activated wi
148 /analysis/h1/set id nbBins valMin valMax u
149 where unit is the desired unit for the hist
150
151 One can control the name of the histograms
152 /analysis/setFileName name (default fanoC
153
154 It is possible to choose the format of the
155 hdf5, xml, csv, by changing the default fil
156
157 It is also possible to print selected histo
158 /analysis/h1/setAscii id
159 All selected histos will be written on a fi
160
161 6- HOW TO START ?
162
163 - execute fanoCavity in 'batch' mode from
164 % fanoCavity run01.mac
165
166 - execute fanoCavity in 'interactive mode'
167 % fanoCavity
168 ....
169 Idle> type your commands
170 ....
171 Idle> exit
172
173 Alternative macro file:
174 basic.mac - disabled multiple scattering a