| Geant4 Cross Reference |
1 ---------------------------------------------- 1 -----------------------------------------------------
2 2
3 ========================================= 3 =========================================================
4 Geant4 - an Object-Oriented Toolkit for S 4 Geant4 - an Object-Oriented Toolkit for Simulation in HEP
5 ========================================= 5 =========================================================
6 6
7 electronScattering 7 electronScattering
8 ------------------ 8 ------------------
9 9
10 Electron scattering benchmark (T. O'Shea and 10 Electron scattering benchmark (T. O'Shea and B. Faddegon)
11 11
12 1- GEOMETRY DEFINITION 12 1- GEOMETRY DEFINITION
13 13
14 The geometry is described in the enclosed doc 14 The geometry is described in the enclosed documument : NRCC_electron_scat.pdf
15 15
16 A "World" volume contains a "Frame" made of A 16 A "World" volume contains a "Frame" made of Air.
17 The Frame contains : ExitWindow, ScatterFoil, 17 The Frame contains : ExitWindow, ScatterFoil, MonitorChbr, Bag.
18 The Bag contains a Gas volume, which contains 18 The Bag contains a Gas volume, which contains 2 aluminium Rings
19 The Scoring plane is the end-plane of the Fra 19 The Scoring plane is the end-plane of the Frame
20 20
21 The default geometry is constructed in Detect 21 The default geometry is constructed in DetectorConstruction class.
22 The parameters of the ScatterFoil (material a 22 The parameters of the ScatterFoil (material and thickness) must be defined
23 via 2 UI commands : see the macro scatter.mac 23 via 2 UI commands : see the macro scatter.mac
24 24
25 2- PHYSICS LIST 25 2- PHYSICS LIST
26 26
27 Physics lists can be local (eg. in this examp 27 Physics lists can be local (eg. in this example) or from G4 kernel
28 physics_lists subdirectory. 28 physics_lists subdirectory.
29 29
30 Local physics lists: 30 Local physics lists:
31 - "local" standard EM physics with current ' 31 - "local" standard EM physics with current 'best' options setting.
32 these options are explicited i 32 these options are explicited in PhysListEmStandard
33 - "standardSS" standard EM physics with singl 33 - "standardSS" standard EM physics with single Coulomb scattering
34 instead of multiple scattering 34 instead of multiple scattering
35 35
36 From geant4/source/physics_lists/builders: 36 From geant4/source/physics_lists/builders:
37 - "emstandard_opt0" recommended standard EM 37 - "emstandard_opt0" recommended standard EM physics for LHC
38 - "emstandard_opt1" best CPU performance sta 38 - "emstandard_opt1" best CPU performance standard physics for LHC
39 - "emstandard_opt2" alternative models 39 - "emstandard_opt2" alternative models
40 - "emstandard_opt3" current state of art for 40 - "emstandard_opt3" current state of art for EM physics
41 analog to "local"above 41 analog to "local"above
42 42
43 Physics lists and options can be (re)set with 43 Physics lists and options can be (re)set with UI commands
44 44
45 Please, notice that options set through G4EmP 45 Please, notice that options set through G4EmProcessOPtions are global, eg
46 for all particle types. In G4 builders, it is 46 for all particle types. In G4 builders, it is shown how to set options per
47 particle type. 47 particle type.
48 48
49 49
50 3- PRIMARY GENERATOR : mono-enegetic pencil b 50 3- PRIMARY GENERATOR : mono-enegetic pencil beam
51 51
52 The primary kinematic consists of a single pa 52 The primary kinematic consists of a single particle which hits the detector
53 perpendicular to the input face (ExitWindow). 53 perpendicular to the input face (ExitWindow). The type of the particle and its
54 energy are set in the PrimaryGeneratorAction 54 energy are set in the PrimaryGeneratorAction class, and can be changed via
55 the G4 build-in commands of ParticleGun class 55 the G4 build-in commands of ParticleGun class.
56 (see the macros provided with this example) 56 (see the macros provided with this example)
57 57
58 The incident beam has a Gaussian-shaped spati 58 The incident beam has a Gaussian-shaped spatial distribution. The rms of the
59 Gaussian can be define with an UI command bui 59 Gaussian can be define with an UI command built in PrimaryGeneratorMessenger.
60 60
61 4- VISUALIZATION 61 4- VISUALIZATION
62 62
63 The Visualization Manager is set in the main( 63 The Visualization Manager is set in the main().
64 The initialisation of the drawing is done via 64 The initialisation of the drawing is done via the commands in vis.mac
65 In interactive session: 65 In interactive session:
66 PreInit or Idle > /control/execute vis.mac 66 PreInit or Idle > /control/execute vis.mac
67 67
68 The example has a default view which is a lon 68 The example has a default view which is a longitudinal view of the detector.
69 69
70 The tracks are drawn at the end of event, and 70 The tracks are drawn at the end of event, and erased at the end of run.
71 Optionaly one can choose to draw all particle 71 Optionaly one can choose to draw all particles, only the charged, or none.
72 This command is defined in EventActionMesseng 72 This command is defined in EventActionMessenger class.
73 73
74 5- TRACKING 74 5- TRACKING
75 75
76 One can limit 'by hand' the step lenght of t 76 One can limit 'by hand' the step lenght of the particle. As an example,
77 this limitation is implemented as a 'full' pr 77 this limitation is implemented as a 'full' process : see StepMax class and its
78 Messenger. The 'StepMax process' is registere 78 Messenger. The 'StepMax process' is registered in the Physics List.
79 79
80 6- DETECTOR RESPONSE 80 6- DETECTOR RESPONSE
81 81
82 At the end of a run, from the histogram(s), o 82 At the end of a run, from the histogram(s), one can study different
83 physics quantities, via the histograms define 83 physics quantities, via the histograms defined below.
84 84
85 An ascii file corresponding to histo 4 (see b 85 An ascii file corresponding to histo 4 (see below) is automatically written.
86 86
87 87
88 7- List of the built-in histograms 88 7- List of the built-in histograms
89 ---------------------------------- 89 ----------------------------------
90 90
91 The test contains 4 built-in 1D histograms, w 91 The test contains 4 built-in 1D histograms, which are managed by
92 G4AnalysisManager class and its Messenger. Th 92 G4AnalysisManager class and its Messenger. The histos can be individually activated
93 with the command : 93 with the command :
94 /analysis/h1/set id nbBins valMin valMax uni 94 /analysis/h1/set id nbBins valMin valMax unit
95 where unit is the desired unit for the histo 95 where unit is the desired unit for the histo (MeV or keV, deg or mrad, etc..)
96 (see the macros xxxx.mac). 96 (see the macros xxxx.mac).
97 97
98 1 "(charged particles): projected angle at S 98 1 "(charged particles): projected angle at Scoring plane"
99 2 "(charged particles): dN/dS at Scoring pla 99 2 "(charged particles): dN/dS at Scoring plane"
100 3 "(charged particles): d(N/cost)/dS at Scor 100 3 "(charged particles): d(N/cost)/dS at Scoring plane"
101 4 "(charged particles): normalized d(N/cost) 101 4 "(charged particles): normalized d(N/cost)/dS at Scoring plane"
102 5 "(charged particles); scatteri 102 5 "(charged particles); scattering angle theta"
103 6 "(charged particles); measured 103 6 "(charged particles); measured scattering angle theta"
104 104
105 The histograms can be viewed using ROOT or PA 105 The histograms can be viewed using ROOT or PAW.
106 106
107 One can control the name and format of the hi 107 One can control the name and format of the histograms file with the command:
108 /analysis/setFileName name (default nrccBen 108 /analysis/setFileName name (default nrccBenchmark)
109 It is possible to choose the format of the hi 109 It is possible to choose the format of the histogram file : root (default),
110 xml, csv, by using namespace in HistoManager. 110 xml, csv, by using namespace in HistoManager.hh
111 It is also possible to print selected histogr 111 It is also possible to print selected histograms on an ascii file:
112 /analysis/h1/setAscii id 112 /analysis/h1/setAscii id
113 All selected histos will be written on a file 113 All selected histos will be written on a file name.ascii (default nrccBenchmark)
114 114
115 115
116 8- HOW TO START ? 116 8- HOW TO START ?
117 117
118 - execute electronScattering in 'batch' mode 118 - execute electronScattering in 'batch' mode from macro files e.g.
119 % electronScattering myMacro.mac 119 % electronScattering myMacro.mac
120 120
121 - execute electronScattering in 'interactive' 121 - execute electronScattering in 'interactive' mode with visualization e.g.
122 % electronScattering 122 % electronScattering
123 Then type your commands, for instance : 123 Then type your commands, for instance :
124 Idle> control/execute vis.mac 124 Idle> control/execute vis.mac
125 Idle> run/beamOn 5 125 Idle> run/beamOn 5
126 .... 126 ....