| Geant4 Cross Reference |
>> 1 $Id$
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2 3
3 ========================================= 4 =========================================================
4 Geant4 - an Object-Oriented Toolkit for S 5 Geant4 - an Object-Oriented Toolkit for Simulation in HEP
5 ========================================= 6 =========================================================
6 7
7 electronScattering 8 electronScattering
8 ------------------ 9 ------------------
9 10
10 Electron scattering benchmark (T. O'Shea and 11 Electron scattering benchmark (T. O'Shea and B. Faddegon)
11 12
12 1- GEOMETRY DEFINITION 13 1- GEOMETRY DEFINITION
13 14
14 The geometry is described in the enclosed doc 15 The geometry is described in the enclosed documument : NRCC_electron_scat.pdf
15 16
16 A "World" volume contains a "Frame" made of A 17 A "World" volume contains a "Frame" made of Air.
17 The Frame contains : ExitWindow, ScatterFoil, 18 The Frame contains : ExitWindow, ScatterFoil, MonitorChbr, Bag.
18 The Bag contains a Gas volume, which contains 19 The Bag contains a Gas volume, which contains 2 aluminium Rings
19 The Scoring plane is the end-plane of the Fra 20 The Scoring plane is the end-plane of the Frame
20 21
21 The default geometry is constructed in Detect 22 The default geometry is constructed in DetectorConstruction class.
22 The parameters of the ScatterFoil (material a 23 The parameters of the ScatterFoil (material and thickness) must be defined
23 via 2 UI commands : see the macro scatter.mac 24 via 2 UI commands : see the macro scatter.mac
24 25
25 2- PHYSICS LIST 26 2- PHYSICS LIST
26 27
27 Physics lists can be local (eg. in this examp 28 Physics lists can be local (eg. in this example) or from G4 kernel
28 physics_lists subdirectory. 29 physics_lists subdirectory.
29 30
30 Local physics lists: 31 Local physics lists:
31 - "local" standard EM physics with current ' 32 - "local" standard EM physics with current 'best' options setting.
32 these options are explicited i 33 these options are explicited in PhysListEmStandard
33 - "standardSS" standard EM physics with singl 34 - "standardSS" standard EM physics with single Coulomb scattering
34 instead of multiple scattering 35 instead of multiple scattering
35 36
36 From geant4/source/physics_lists/builders: 37 From geant4/source/physics_lists/builders:
37 - "emstandard_opt0" recommended standard EM 38 - "emstandard_opt0" recommended standard EM physics for LHC
38 - "emstandard_opt1" best CPU performance sta 39 - "emstandard_opt1" best CPU performance standard physics for LHC
39 - "emstandard_opt2" alternative models 40 - "emstandard_opt2" alternative models
40 - "emstandard_opt3" current state of art for 41 - "emstandard_opt3" current state of art for EM physics
41 analog to "local"above 42 analog to "local"above
42 43
43 Physics lists and options can be (re)set with 44 Physics lists and options can be (re)set with UI commands
44 45
45 Please, notice that options set through G4EmP 46 Please, notice that options set through G4EmProcessOPtions are global, eg
46 for all particle types. In G4 builders, it is 47 for all particle types. In G4 builders, it is shown how to set options per
47 particle type. 48 particle type.
48 49
49 50
50 3- PRIMARY GENERATOR : mono-enegetic pencil b 51 3- PRIMARY GENERATOR : mono-enegetic pencil beam
51 52
52 The primary kinematic consists of a single pa 53 The primary kinematic consists of a single particle which hits the detector
53 perpendicular to the input face (ExitWindow). 54 perpendicular to the input face (ExitWindow). The type of the particle and its
54 energy are set in the PrimaryGeneratorAction 55 energy are set in the PrimaryGeneratorAction class, and can be changed via
55 the G4 build-in commands of ParticleGun class 56 the G4 build-in commands of ParticleGun class.
56 (see the macros provided with this example) 57 (see the macros provided with this example)
57 58
58 The incident beam has a Gaussian-shaped spati 59 The incident beam has a Gaussian-shaped spatial distribution. The rms of the
59 Gaussian can be define with an UI command bui 60 Gaussian can be define with an UI command built in PrimaryGeneratorMessenger.
60 61
61 4- VISUALIZATION 62 4- VISUALIZATION
62 63
63 The Visualization Manager is set in the main( 64 The Visualization Manager is set in the main().
64 The initialisation of the drawing is done via 65 The initialisation of the drawing is done via the commands in vis.mac
65 In interactive session: 66 In interactive session:
66 PreInit or Idle > /control/execute vis.mac 67 PreInit or Idle > /control/execute vis.mac
67 68
68 The example has a default view which is a lon 69 The example has a default view which is a longitudinal view of the detector.
69 70
70 The tracks are drawn at the end of event, and 71 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 72 Optionaly one can choose to draw all particles, only the charged, or none.
72 This command is defined in EventActionMesseng 73 This command is defined in EventActionMessenger class.
73 74
74 5- TRACKING 75 5- TRACKING
75 76
76 One can limit 'by hand' the step lenght of t 77 One can limit 'by hand' the step lenght of the particle. As an example,
77 this limitation is implemented as a 'full' pr 78 this limitation is implemented as a 'full' process : see StepMax class and its
78 Messenger. The 'StepMax process' is registere 79 Messenger. The 'StepMax process' is registered in the Physics List.
79 80
80 6- DETECTOR RESPONSE 81 6- DETECTOR RESPONSE
81 82
82 At the end of a run, from the histogram(s), o 83 At the end of a run, from the histogram(s), one can study different
83 physics quantities, via the histograms define 84 physics quantities, via the histograms defined below.
84 85
85 An ascii file corresponding to histo 4 (see b 86 An ascii file corresponding to histo 4 (see below) is automatically written.
86 87
87 88
88 7- List of the built-in histograms 89 7- List of the built-in histograms
89 ---------------------------------- 90 ----------------------------------
90 91
91 The test contains 4 built-in 1D histograms, w 92 The test contains 4 built-in 1D histograms, which are managed by
92 G4AnalysisManager class and its Messenger. Th 93 G4AnalysisManager class and its Messenger. The histos can be individually activated
93 with the command : 94 with the command :
94 /analysis/h1/set id nbBins valMin valMax uni 95 /analysis/h1/set id nbBins valMin valMax unit
95 where unit is the desired unit for the histo 96 where unit is the desired unit for the histo (MeV or keV, deg or mrad, etc..)
96 (see the macros xxxx.mac). 97 (see the macros xxxx.mac).
97 98
98 1 "(charged particles): projected angle at S 99 1 "(charged particles): projected angle at Scoring plane"
99 2 "(charged particles): dN/dS at Scoring pla 100 2 "(charged particles): dN/dS at Scoring plane"
100 3 "(charged particles): d(N/cost)/dS at Scor 101 3 "(charged particles): d(N/cost)/dS at Scoring plane"
101 4 "(charged particles): normalized d(N/cost) 102 4 "(charged particles): normalized d(N/cost)/dS at Scoring plane"
102 5 "(charged particles); scatteri 103 5 "(charged particles); scattering angle theta"
103 6 "(charged particles); measured 104 6 "(charged particles); measured scattering angle theta"
104 105
105 The histograms can be viewed using ROOT or PA 106 The histograms can be viewed using ROOT or PAW.
106 107
107 One can control the name and format of the hi 108 One can control the name and format of the histograms file with the command:
108 /analysis/setFileName name (default nrccBen 109 /analysis/setFileName name (default nrccBenchmark)
109 It is possible to choose the format of the hi 110 It is possible to choose the format of the histogram file : root (default),
110 xml, csv, by using namespace in HistoManager. 111 xml, csv, by using namespace in HistoManager.hh
111 It is also possible to print selected histogr 112 It is also possible to print selected histograms on an ascii file:
112 /analysis/h1/setAscii id 113 /analysis/h1/setAscii id
113 All selected histos will be written on a file 114 All selected histos will be written on a file name.ascii (default nrccBenchmark)
114 115
115 116
116 8- HOW TO START ? 117 8- HOW TO START ?
117 118
118 - execute electronScattering in 'batch' mode 119 - execute electronScattering in 'batch' mode from macro files e.g.
119 % electronScattering myMacro.mac 120 % electronScattering myMacro.mac
120 121
121 - execute electronScattering in 'interactive' 122 - execute electronScattering in 'interactive' mode with visualization e.g.
122 % electronScattering 123 % electronScattering
123 Then type your commands, for instance : 124 Then type your commands, for instance :
124 Idle> control/execute vis.mac 125 Idle> control/execute vis.mac
125 Idle> run/beamOn 5 126 Idle> run/beamOn 5
126 .... 127 ....