| Geant4 Cross Reference |
>> 1 $Id: README 80190 2014-04-07 10:18:04Z gcosmo $
1 2
2 ========================================= 3 =========================================================
3 Geant4 - an Object-Oriented Toolkit for S 4 Geant4 - an Object-Oriented Toolkit for Simulation in HEP
4 ========================================= 5 =========================================================
5 6
6 Hadr03 7 Hadr03
7 ------ 8 ------
8 9
9 How to compute total cross section from the 10 How to compute total cross section from the direct evaluation of the
10 mean free path ( see below, item Physics). 11 mean free path ( see below, item Physics).
11 How to identify nuclear reactions. 12 How to identify nuclear reactions.
12 How to plot energy spectrum of secondary pa 13 How to plot energy spectrum of secondary particles.
13 14
14 1- GEOMETRY DEFINITION 15 1- GEOMETRY DEFINITION
15 16
16 It is a single box representing a 'semi inf 17 It is a single box representing a 'semi infinite' homogeneous medium.
17 Two parameters define the geometry : 18 Two parameters define the geometry :
18 - the material of the box, 19 - the material of the box,
19 - the (full) size of the box. 20 - the (full) size of the box.
20 21
21 The default geometry (10 m of molybdenum) i 22 The default geometry (10 m of molybdenum) is built in DetectorConstruction,
22 but the above parameters can be changed int 23 but the above parameters can be changed interactively via commands defined
23 in DetectorMessenger. 24 in DetectorMessenger.
24 25
25 2- PHYSICS LIST 26 2- PHYSICS LIST
26 27
27 The PhysicsList contains builders for hadro 28 The PhysicsList contains builders for hadronic interactions.
28 Predefined G4 PhysicsConstructors or 'local 29 Predefined G4 PhysicsConstructors or 'local' PhysicsConstructors can be used
29 (see geant4/source/physics_lists or example 30 (see geant4/source/physics_lists or example runAndEvent/RE04).
30 31
31 In order not to introduce 'artificial' cons 32 In order not to introduce 'artificial' constraints on the step size,
32 electromagnetic processes are not registere 33 electromagnetic processes are not registered: there is no continuous energy
33 loss. 34 loss.
34 35
35 Several hadronic physics options are contro 36 Several hadronic physics options are controlled by environment variables.
36 To select them, see Hadr03.cc. << 37 To trigger them, an envHadronic.csh has been added in this example.
>> 38 One must select the options wished, and do
>> 39 source envHadronic.csh (or sh)
37 40
38 3- AN EVENT : THE PRIMARY GENERATOR 41 3- AN EVENT : THE PRIMARY GENERATOR
39 42
40 The primary kinematic consists of a single 43 The primary kinematic consists of a single particle starting at the edge
41 of the box. The type of the particle and it 44 of the box. The type of the particle and its energy are set in
42 PrimaryGeneratorAction (neutron 1 MeV), and 45 PrimaryGeneratorAction (neutron 1 MeV), and can be changed via the G4
43 build-in commands of ParticleGun class (see 46 build-in commands of ParticleGun class (see the macros provided with
44 this example). 47 this example).
45 48
46 4- PHYSICS 49 4- PHYSICS
47 50
48 An event is killed at the first interaction << 51 An event is killed at the first interaction of the incident paticle.
49 The absorption length, also called mean fre 52 The absorption length, also called mean free path, is computed as
50 the mean value of the track length of the i 53 the mean value of the track length of the incident particle.
51 This is why the medium must be 'infinite' : 54 This is why the medium must be 'infinite' : to be sure that interaction
52 occurs at any events. 55 occurs at any events.
53 56
54 The result is compared with the 'input' val 57 The result is compared with the 'input' value, i.e. with the cross sections
55 given by G4HadronicProcessStore and used by 58 given by G4HadronicProcessStore and used by Geant4.
56 59
57 The list of nuclear reactions that occured 60 The list of nuclear reactions that occured is printed.
58 (the number of gamma of deexcitation is not 61 (the number of gamma of deexcitation is not printed).
59 62
60 Then, comes the total list of generated par 63 Then, comes the total list of generated particles and ions.
61 The energy spectrum of the scattered partic 64 The energy spectrum of the scattered particle (if any) and of the created
62 secondaries are plotted (see SteppingAction 65 secondaries are plotted (see SteppingAction).
63 66
64 Momentum conservation is checked as : 67 Momentum conservation is checked as :
65 momentum balance = modulus(P_out - P_in) 68 momentum balance = modulus(P_out - P_in)
66 69
67 A set of macros defining various run condit 70 A set of macros defining various run conditions are provided.
68 The processes can be actived/inactived in o 71 The processes can be actived/inactived in order to survey the processes
69 individually. 72 individually.
70 73
71 5- HISTOGRAMS 74 5- HISTOGRAMS
72 75
73 The test contains 12 built-in 1D histograms 76 The test contains 12 built-in 1D histograms, which are managed by
74 G4AnalysisManager and its Messenger. The hi 77 G4AnalysisManager and its Messenger. The histos can be individually
75 activated with the command : 78 activated with the command :
76 /analysis/h1/set id nbBins valMin valMax u 79 /analysis/h1/set id nbBins valMin valMax unit
77 where unit is the desired unit for the hist 80 where unit is the desired unit for the histo (MeV or keV, etc..)
78 (see the macros xxxx.mac). 81 (see the macros xxxx.mac).
79 82
80 1 "kinetic energy of scattered pri << 83 1 "kinetic energy of scattered primary particle"
81 2 "kinetic energy of gamma" 84 2 "kinetic energy of gamma"
82 3 "kinetic energy of e-" << 85 3 "kinetic energy of neutrons"
83 4 "kinetic energy of neutrons" << 86 4 "kinetic energy of protons"
84 5 "kinetic energy of protons" << 87 5 "kinetic energy of deuterons"
85 6 "kinetic energy of deuterons" << 88 6 "kinetic energy of alphas"
86 7 "kinetic energy of alphas" << 89 7 "kinetic energy of nuclei"
87 8 "kinetic energy of nuclei" << 90 8 "kinetic energy of mesons"
88 9 "kinetic energy of mesons" << 91 9 "kinetic energy of baryons"
89 10 "kinetic energy of baryons" << 92 10 "Q = Ekin out - Ekin in"
90 11 "Q = Ekin out - Ekin in" << 93 11 "Pbalance = mag(P_out - P_in)"
91 12 "Pbalance = mag(P_out - P_in)" << 94 12 "atomic mass of nuclei"
92 13 "atomic mass of nuclei" <<
93 95
94 The histograms are managed by the HistoMana 96 The histograms are managed by the HistoManager class and its Messenger.
95 The histos can be individually activated wi 97 The histos can be individually activated with the command :
96 /analysis/h1/set id nbBins valMin valMax u 98 /analysis/h1/set id nbBins valMin valMax unit
97 where unit is the desired unit for the hist 99 where unit is the desired unit for the histo (MeV or keV, deg or mrad, etc..)
98 100
99 One can control the name of the histograms 101 One can control the name of the histograms file with the command:
100 /analysis/setFileName name (default Hadr0 102 /analysis/setFileName name (default Hadr03)
101 103
102 It is possible to choose the format of the 104 It is possible to choose the format of the histogram file : root (default),
103 xml, csv, by using namespace in HistoManage 105 xml, csv, by using namespace in HistoManager.hh
104 106
105 It is also possible to print selected histo 107 It is also possible to print selected histograms on an ascii file:
106 /analysis/h1/setAscii id 108 /analysis/h1/setAscii id
107 All selected histos will be written on a fi 109 All selected histos will be written on a file name.ascii (default Hadr03)
108 110
109 6- VISUALIZATION 111 6- VISUALIZATION
110 112
111 The Visualization Manager is set in the mai 113 The Visualization Manager is set in the main().
112 The initialisation of the drawing is done v 114 The initialisation of the drawing is done via the commands
113 /vis/... in the macro vis.mac. To get visua 115 /vis/... in the macro vis.mac. To get visualisation:
114 > /control/execute vis.mac 116 > /control/execute vis.mac
115 117
116 The detector has a default view which is a 118 The detector has a default view which is a longitudinal view of the box.
117 The tracks are drawn at the end of event, a 119 The tracks are drawn at the end of event, and erased at the end of run.
118 120
119 7- HOW TO START ? 121 7- HOW TO START ?
120 122
121 Execute Hadr03 in 'batch' mode from macro f 123 Execute Hadr03 in 'batch' mode from macro files :
122 % Hadr03 inelastic.mac 124 % Hadr03 inelastic.mac
123 125
124 Execute Hadr03 in 'interactive mode' with v 126 Execute Hadr03 in 'interactive mode' with visualization :
125 % Hadr03 127 % Hadr03
126 Idle> control/execute vis.mac 128 Idle> control/execute vis.mac
127 .... 129 ....
128 Idle> type your commands 130 Idle> type your commands
129 .... 131 ....
130 Idle> exit 132 Idle> exit
131 <<
132 Macros provided in this example: <<
133 - hadr03.in: macro used in Geant4 testing <<
134 - Au196.mac: neutron (1 MeV) on Au195 <<
135 - elastic.mac: proton (10 MeV) on Mo100. Ela <<
136 - fusion.mac: deuteron (400 keV) on tritium <<
137 - gamma.mac: gamma (10 MeV) on Au196 <<
138 - inelastic.mac: proton (10 MaV) on Mo98. In <<
139 - ion.mac: Li7 (140 MeV) on Be9 <<
140 - nCapture.mac: neutron (1 eV) on Boron. Cap <<
141 - nFission.mac: neutron (1 eV) on U235. Fis <<
142 - neutron.mac: neutron (1 MeV) on Boron <<
143 <<
144 Macros to be run interactively: <<
145 - debug.mac: proton (10 MeV) on Boron <<
146 - vis.mac: To activate visualization <<