source: trunk/examples/extended/electromagnetic/TestEm5/README@ 807

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[807]1$Id: README,v 1.21 2007/11/28 12:37:56 maire Exp $
2-----------------------------------------------------
3
4 =========================================================
5 Geant4 - an Object-Oriented Toolkit for Simulation in HEP
6 =========================================================
7
8 TestEm5
9 -------
10 How to study the transmission, absorption and reflexion of particles through
11 a single, thin or thick, layer of material.
12 In perticular, the effects of the multiple scattering can be ploted.
13
14 1- GEOMETRY DEFINITION
15
16 The "absorber" is a box made of a given material.
17
18 Three parameters define the absorber :
19 - the material of the absorber,
20 - the thickness of an absorber,
21 - the transverse size of the absorber (the input face is a square).
22
23 A volume "World" contains the "absorber".
24
25 In addition a transverse uniform magnetic field can be applied.
26
27 The default geometry is constructed in DetectorConstruction class, but all the
28 parameters can be changed via commands defined in the DetectorMessenger class.
29 The parameters of the "World" can be changed, too.
30
31 2- PHYSICS LIST
32
33 The following EM physics lists are available in this example:
34 - "standard" standard EM physics (default)
35 - "livermore" low-energy EM physics using Livermore data
36 - "penelope" low-energy EM physics implementing Penelope models
37 - "standardSS" standard EM physics with single Coulomb scattering
38 instead of multiple scattering
39
40 Alternatively, the user may use predefined Geant4 builders:
41 - "emstandard" G4EmStandardPhysics builder
42 - "emstandard_opt1" G4EmStandardPhysics_option1 builder
43 - "emstandard_opt2" G4EmStandardPhysics_option2 builder
44 See geant4/source/physics_lists/History for details
45
46 3- AN EVENT : THE PRIMARY GENERATOR
47
48 The primary kinematic consists of a single particle which hits the absorber
49 perpendicular to the input face. The type of the particle and its energy are
50 set in the PrimaryGeneratorAction class, and can be changed via the G4 build-in
51 commands of ParticleGun class (see the macros provided with this example).
52
53 In addition one can choose randomly the impact point of the incident particle.
54 The interactive command is built in PrimaryGeneratorMessenger class.
55
56 4- VISUALIZATION
57
58 The Visualization Manager is set in the main().
59 The initialisation of the drawing is done via the commands in vis.mac
60 In interactive session:
61 PreInit or Idle > /control/execute vis.mac
62
63 The example has a default view which is a longitudinal view of the detector.
64
65 The tracks are drawn at the end of event, and erased at the end of run.
66 Optionaly one can choose to draw all particles, only the charged, or none.
67 This command is defined in EventActionMessenger class.
68
69 5- TRACKING
70
71 During the tracking, one can keep or not the secondaries : see StackingAction
72 class and its Messenger.
73 One can also limit 'by hand' the step lenght of the particle. As an example,
74 this limitation is implemented as a 'full' process : see StepMax class and its
75 Messenger. The 'StepMax process' is registered in the Physics List.
76
77 6- DETECTOR RESPONSE
78
79 At the end of a run, from the histogram(s), one can study different
80 physics quantities such as :
81 - energy deposit in the absorber,
82 - energy spectrum of secondaries at creation,
83 - energy spectrum and angle distribution of particles at exit,
84 - transmission and backscattering coefficients,
85 - ...
86
87 7- List of the built-in histograms
88 ----------------------------------
89
90 The test contains more than 20 built-in 1D histograms, which are managed by the
91 HistoManager class and its Messenger. The histos can be individually activated
92 with the command :
93 /testem/histo/setHisto id nbBins valMin valMax unit
94 where unit is the desired unit for the histo (MeV or keV, deg or mrad, etc..)
95 (see the macros xxxx.mac).
96
97 1 "energy deposit in absorber"
98 2 "energy of charged secondaries at creation"
99 3 "energy of gammas at creation (log10(Ekin/MeV))"
100 4 "x_vertex of charged secondaries (all)"
101 5 "x_vertex of charged secondaries (not absorbed)"
102 10 "(transmit, charged) : kinetic energy at exit"
103 11 "(transmit, charged) : ener fluence: dE(MeV)/dOmega"
104 12 "(transmit, charged) : space angle dN/dOmega"
105 13 "(transmit, charged) : projected angle at exit"
106 14 "(transmit, charged) : projected position at exit"
107 15 "(transmit, charged) : radius at exit"
108 20 "(transmit, neutral) : kinetic energy at exit"
109 21 "(transmit, neutral) : ener fluence: dE(MeV)/dOmega"
110 22 "(transmit, neutral) : space angle dN/dOmega"
111 23 "(transmit, neutral) : projected angle at exit"
112 30 "(reflect , charged) : kinetic energy at exit"
113 31 "(reflect , charged) : ener fluence: dE(MeV)/dOmega"
114 32 "(reflect , charged) : space angle dN/dOmega"
115 33 "(reflect , charged) : projected angle at exit"
116 40 "(reflect , neutral) : kinetic energy at exit"
117 41 "(reflect , neutral) : ener fluence: dE(MeV)/dOmega"
118 42 "(reflect , neutral) : space angle dN/dOmega"
119 43 "(reflect , neutral) : projected angle at exit"
120
121 The histograms can be viewed using PAW. See below the note on ANAPHE+AIDA.
122
123 One can control the name of the histograms file with the command:
124 /testem/histo/setFileName name (default testem5.hbook)
125
126 It is also possible to print selected histograms on an ascii file:
127 /testem/histo/printHisto id
128 All selected histos will be written on a file name.ascii (default testem5)
129
130 Note that, by default, histograms are disabled. To activate them, uncomment
131 the flag G4ANALYSIS_USE in GNUmakefile.
132
133 8- GEANT4/GEANT3/DATA COMPARISON
134
135 A Geant4/Geant3/exp. data comparison is given here for a few cases.
136 These cases can be classified as follow:
137 - e-/e+ incident particles versus protons and others.
138 - 3 energy regimes: low: < 1MeV; medium: 1MeV -> few 10MeV; high: > 100MeV
139
140 We indicate here the corresponding macros.
141
142 | low energy | medium energy | high energy
143 --------------------------------------------------------
144 | acosta.mac | |
145 e-+ | berger.mac | hanson.mac |
146 | hunger.mac | kulchi.mac |
147 | tavola.mac | |
148 --------------------------------------------------------
149 others| bichsel.mac | vincour.mac | shen1.mac shen2.mac
150 | | gottsch.mac | tramu.mac
151 --------------------------------------------------------
152
153 The relevant part of the GEANT3 code is in the subdirectory geant3 together
154 with the xxxx.dat input files.
155
156 9- HOW TO START ?
157
158 - compile and link to generate an executable
159 % cd TestEm5
160 % gmake
161
162 - execute TestEm5 in 'batch' mode from macro files e.g.
163 % $(G4INSTALL)/bin/$(G4SYSTEM)/TestEm5 myMacro.mac
164
165 - execute TestEm5 in 'interactive' mode with visualization e.g.
166 % $(G4INSTALL)/bin/$(G4SYSTEM)/TestEm5
167 Then type your commands, for instance :
168 Idle> control/execute vis.mac
169 Idle> run/beamOn 5
170 ....
171
172 10- USING HISTOGRAMS
173
174 Note that, by default, histograms are disabled. To activate them, uncomment
175 the flag G4ANALYSIS_USE in GNUmakefile.
176
177 Before compilation of the example it is optimal to clean up old files:
178 gmake histclean
179 gmake
180 To use histograms, at least one of the AIDA implementations should be
181 available (see http://aida.freehep.org).
182
183 8a - PI
184
185 A package including AIDA and extended interfaces also using Python is PI,
186 available from: http://cern.ch/pi
187
188 Once installed PI or PI-Lite in a specified local area $MYPY, it is required
189 to add the installation path to $PATH, i.e. for example, for release 1.2.1 of
190 PI:
191 setenv PATH ${PATH}:$MYPI/1.2.1/app/releases/PI/PI_1_2_1/rh73_gcc32/bin
192
193 CERN users can use the PATH to the LCG area on AFS.
194 Before running the example the command should be issued:
195 eval `aida-config --runtime csh`
196
197 8b - OpenScientist
198
199 OpenScientist is available at http://OpenScientist.lal.in2p3.fr.
200
201 You have to "setup" the OpenScientist AIDA implementation before compiling
202 (then with G4ANALYSIS_USE set) and running your Geant4 application.
203
204 On UNIX you setup, with a csh flavoured shell :
205 csh> source <<OpenScientist install path>/aida-setup.csh
206 or with a sh flavoured shell :
207 sh> . <<OpenScientist install path>/aida-setup.sh
208 On Windows :
209 DOS> call <<OpenScientist install path>/aida-setup.bat
210
211 You can use various file formats for writing (AIDA-XML, hbook, root).
212 These formats are readable by the Lab onx interactive program
213 or the OpenPAW application. See the web pages.
214
215
216 With OpenPAW, on a run.hbook file, one can view the histograms
217 with something like :
218 OS> opaw
219 opaw> h/file 1 run.hbook ( or opaw> h/file 1 run.aida or run.root)
220 opaw> zone 2 2
221 opaw> h/plot 1
222 opaw> h/plot 2
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