| Geant4 Cross Reference |
>> 1 $Id: README 81063 2014-05-20 09:14:00Z gcosmo $
1 ---------------------------------------------- 2 -------------------------------------------------------------------
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 gammaray_telescope 8 gammaray_telescope
8 ------------------ 9 ------------------
9 F. Longo, R. Giannitrapan << 10 F.Longo, R.Giannitrapani & G.Santin
10 June 2003 11 June 2003
11 12
12 ---------------------------------------------- << 13 --------------------------------------------------------------
13 Acknowledgments to GEANT4 people, in particula << 14 Acknowledgments to GEANT4 people, in particular to R.Nartallo,
14 A. Pfeiffer, M. G. Pia and G. Cosmo << 15 A.Pfeiffer, M.G.Pia and G.Cosmo
15 ---------------------------------------------- << 16 --------------------------------------------------------------
16 17
17 GammaRayTel is an example of application of Ge 18 GammaRayTel is an example of application of Geant4 in a space
18 environment. It simulates a typical telescope << 19 envinronment. It simulates a typical telescope for gamma ray analysis;
19 the detector setup is composed by a tracker ma 20 the detector setup is composed by a tracker made with silicon planes,
20 subdivided in ladders and strips, a CsI calori 21 subdivided in ladders and strips, a CsI calorimeter and an
21 anticoincidence system. In this version, the t 22 anticoincidence system. In this version, the three detectors are made
22 sensitive but only the hits on the tracker str << 23 sensitive but only the hits on the tracker strips are registered and relevant
23 information (energy deposition, position etc.) << 24 information (energy deposition, position etc) are dumped to an external
24 ASCII file for subsequent analysis. << 25 ASCII file for subsequent analysis.
25 26
26 Relevant information from the simulation is pr 27 Relevant information from the simulation is processed in the GammarayTelAnalysis
27 class and saved, through the G4AnalysisManager << 28 class and saved, through the G4AnalysisManager interface, to Histograms and
28 Tuples. << 29 Tuples.
29 30
30 a) Macros for the visualization of geometry << 31 a) Macros for the visualization of geometry and tracks with
31 OpenGL, VRML and DAWN drivers << 32 OpenGL, VRML and DAWN drivers
32 33
33 b) Implementation of messengers to change so << 34 b) Implementation of messengers to change some parameters of
34 the detector geometry, the particle gener << 35 the detector geometry, the particle generator and the analysis
35 manager (if present) runtime 36 manager (if present) runtime
36 37
37 c) Readout geometry mechanism to describe an << 38 c) Readout geometry mechanism to describe an high number of
38 subdivisions of the planes of the tracker 39 subdivisions of the planes of the tracker (strips) without
39 affecting in a relevant way the simulatio 40 affecting in a relevant way the simulation performances
40 41
41 d) Histogramming facilities are presently pr 42 d) Histogramming facilities are presently provided through the G4AnalysisManager class.
42 43
43 e) User interfaces via Xmotif or normal term 44 e) User interfaces via Xmotif or normal terminal provided
44 45
45 << 46
46 1. Setting up the environment variables 47 1. Setting up the environment variables
47 --------------------------------------- 48 ---------------------------------------
48 49
49 - Setup for storing ASCII data << 50 - Setup for storing ASCII data
50 51
51 If you want to store the output data in an A 52 If you want to store the output data in an ASCII file 'Tracks_x.dat'
52 where x stays for the run number. You should << 53 where x stays for the run number. You should specify the environment
53 variable: 54 variable:
54 55
55 setenv G4STORE_DATA 1 56 setenv G4STORE_DATA 1
56 57
57 - Setup for Visualization << 58 - Setup for Visualization
58 59
59 IMPORTANT: be sure that your Geant4 installa << 60 IMPORTANT: be sure that your Geant4 installation has been done
60 with the proper visualization drivers; for d << 61 with the proper visualization drivers; for details please see the
61 file geant4/source/visualization/README. << 62 file geant4/source/visualization/README.
62 << 63
63 To use the visualization drivers set the fol << 64 To use the visualization drivers set the following variables in
64 your local environment: << 65 your local environment:
65 << 66
66 setenv G4VIS_USE_OPENGLX 1 # OpenGL visuali << 67 setenv G4VIS_USE_OPENGLX 1 # OpenGL visualization
67 setenv G4VIS_USE_DAWNFILE 1 # DAWN file << 68 setenv G4VIS_USE_DAWNFILE 1 # DAWN file
68 setenv G4VIS_USE_VRMLFILE 1 # VRML file << 69 setenv G4VIS_USE_VRMLFILE 1 # VRML file
69 setenv G4VRMLFILE_VIEWER vrmlview # If inst << 70 setenv G4VRMLFILE_VIEWER vrmlview # If installed
70 71
71 - Setup for Xmotif user interface 72 - Setup for Xmotif user interface
>> 73
>> 74 setenv G4UI_USE_XM 1
72 75
73 setenv G4UI_USE_XM 1 << 76 - Set up for analysis
74 <<
75 - Set up for analysis <<
76 77
77 To compile the GammaRayTel example with the << 78 To compile the GammaRayTel example with the analysis tools activated,
78 set the following variables << 79 set the following variables
79 80
80 setenv G4ANALYSIS_USE 1 # Use the analysis t << 81 setenv G4ANALYSIS_USE 1 # Use the analysis tools
81 82
82 2. Sample run 83 2. Sample run
83 ------------- 84 -------------
84 85
85 To run a sample simulation with gamma tracks << 86 To run a sample simulation with gamma tracks interacting with
86 the detector in its standard configuration an 87 the detector in its standard configuration and without any
87 visualization, execute the following command << 88 visualization, execute the following command in the example main
88 directory: 89 directory:
89 90
90 $G4WORKDIR/bin/$G4SYSTEM/GammaRayTel << 91 $G4WORKDIR/bin/$G4SYSTEM/GammaRayTel
91 92
92 It is possible also to run three different co << 93 It is possible also to run three different configuration defined in
93 macro1.mac, macro2.mac and macro3.mac for vis << 94 macro1.mac, macro2.mac and macro3.mac for visualization (OpenGL, VRML
94 and DAWN respectively) with the following com 95 and DAWN respectively) with the following command
95 96
96 $G4WORKDIR/bin/$G4SYSTEM/GammaRayTel macroX.m 97 $G4WORKDIR/bin/$G4SYSTEM/GammaRayTel macroX.mac
97 98
98 where X can be 1, 2 or 3. Be sure to have the 99 where X can be 1, 2 or 3. Be sure to have the right environment (see
99 the preceding section) and the proper visuali 100 the preceding section) and the proper visualization driver enabled in
100 your local G4 installation (see geant4/source 101 your local G4 installation (see geant4/source/visualization/README for
101 more information). 102 more information).
102 103
103 << 104
104 3. Detector description 105 3. Detector description
105 ----------------------- 106 -----------------------
106 107
107 The detector is defined in GammaRayTelDetecto 108 The detector is defined in GammaRayTelDetectorConstruction.cc
108 It is composed of a Payload with three main d 109 It is composed of a Payload with three main detectors, a Tracker (TKR), a
109 Calorimeter (CAL) and an Anticoincidence syst << 110 Calorimeter (CAL) and an Anticoincidence system (ACD).
110 111
111 The standard configuration is made of a TKR o 112 The standard configuration is made of a TKR of 15 Layers of 2 views made of
112 4 * 4 Si single sided silicon detectors with << 113 4*4 Si single sided silicon detectors with Lead converter, and a CAL of
113 5 layers of CsI, each made of 2 views of 12 C 114 5 layers of CsI, each made of 2 views of 12 CsI bars orthogonally posed.
114 4 lateral panels and a top layer of plastic s << 115 4 lateral panels and a top layer of plastic scintillator (ACL and ACT)
115 complete the configuration. 116 complete the configuration.
116 The Si detectors are composed of two silicon 117 The Si detectors are composed of two silicon planes subdivided in strips
117 aligned along the X axis in one plane and alo 118 aligned along the X axis in one plane and along the Y axis for the other.
118 119
119 The following baseline configuration is adopt 120 The following baseline configuration is adopted:
>> 121
>> 122 GEOMETRICAL PARAMETER VALUE
120 123
121 GEOMETRICAL PARAMETER VALUE << 124 Converter thickness 300 microns
122 << 125 Silicon Thickness 400 microns
123 Converter Thickness 300 micron << 126 Silicon Tile Size XY 9 cm
124 Silicon Thickness 400 micron << 127 Silicon Pitch 200.micrometer
125 Silicon Tile Size XY 9 cm << 128 Views Distance 1. mm
126 Silicon Pitch 200. micrometer << 129 CAL Bar Thickness 1.5 cm
127 Views Distance 1. mm << 130 ACD Thickness 1. cm
128 CAL Bar Thickness 1.5 cm << 131
129 ACD Thickness 1. cm << 132 It is possible to modify in some way this configuration using the
130 << 133 commands defined in GammaRayTelDetectorMessenger.
131 It is possible to modify in some way this con << 134 This feature is available in the UI throught the commands subtree
132 commands defined in GammaRayTelDetectorMessen <<
133 This feature is available in the UI through t <<
134 "/payload/" (see the help command in the UI f 135 "/payload/" (see the help command in the UI for more information).
135 136
136 4. Physics processes 137 4. Physics processes
137 -------------------- 138 --------------------
138 139
139 This example uses a modular physics list, wit << 140 This example uses a modular physics list, with a sample of Hadronic processes
140 (see the web page http://cmsdoc.cern.ch/~hpw/ 141 (see the web page http://cmsdoc.cern.ch/~hpw/GHAD/HomePage/ for more adeguate
141 physics lists), the Standard or the LowEnergy 142 physics lists), the Standard or the LowEnergy Electromagnetic processes.
142 143
143 5. Particle Generator 144 5. Particle Generator
144 --------------------- 145 ---------------------
145 146
146 The GammaRayTelParticleGenerationAction and i 147 The GammaRayTelParticleGenerationAction and its Messenger let the user define
147 the incident flux of particles, from a specif << 148 the incident flux of particles, from a specific direction or from an
148 isotropic background. In the first case parti << 149 isotropic background. In the first case particles are generated on a spherical
149 surface which diameter is perpendicular to th 150 surface which diameter is perpendicular to the arrival direction. In the second
150 case the arrival directions are isotropic. 151 case the arrival directions are isotropic.
151 152
152 The user can define also between two spectral 153 The user can define also between two spectral options:
153 monochromatic or with a power-law dependence. 154 monochromatic or with a power-law dependence. The particle
154 generator parameters are accessible through t << 155 generator parameters are accessible throught the UI tree "/gun/" (use the
155 UI help for more information). We are plannin 156 UI help for more information). We are planning to include, in the next
156 releases of this example, the General Particl 157 releases of this example, the General Particle Source module of G4.
157 << 158
158 6. Hit 159 6. Hit
159 ------ 160 ------
160 161
161 In this version the hits from the TKR the CAL << 162 In this version the hits from the TKR the CAL and the ACD are generated.
162 Only the hit from the TRK are saved. Each TKR << 163 Only the hit from the TRK are saved. Each TKR hit contains the following
163 information 164 information
164 165
165 a) ID of the event (this is important for mu 166 a) ID of the event (this is important for multiple events run)
166 b) Energy deposition of the particle in the 167 b) Energy deposition of the particle in the strip (keV)
167 c) Number of the strip << 168 c) Number of the strip
168 d) Number of the plane 169 d) Number of the plane
169 e) Type of the plane (1=X 0=Y) 170 e) Type of the plane (1=X 0=Y)
170 f) Position of the hit (x, y, z) in the refe << 171 f) Position of the hit (x,y,z) in the reference frame of the payload
171 172
172 The hit information are saved on an ASCII fil << 173 The hit information are saved on an ASCII file named Tracks_N.dat, where
173 N is the progressive ID number associated to << 174 N is the progressive ID number associated to the run.
174 175
175 7. Analysis 176 7. Analysis
176 ----------- << 177 ----------------
177 << 178
178 Relevant information from the simulation is pr 179 Relevant information from the simulation is processed in the GammarayTelAnalysis
179 class and saved, through the G4AnalysisManager << 180 class and saved, through the G4AnalysisManager interface, to Histograms and
180 Tuples. The output file is written in ROOT for << 181 Tuples. The output file is written in ROOT format, but one can easily switch to
181 XML (or Hbook) by changing the appropriate #in 182 XML (or Hbook) by changing the appropriate #include in GammarayTelAnalysis.hh
182 No external software is required (apart from t << 183 No external software is required (apart from the hbook case, in which the CERNLIB
183 must be installed and a FORTRAN compiler must 184 must be installed and a FORTRAN compiler must be present)
184 185
185 Keep in mind that the actual implementation o 186 Keep in mind that the actual implementation of the analysis tools in GammaRayTel
186 is of a pedagogical nature, so we kept it as << 187 is of a pedagogical nature, so we kept it as simple as possible.
187 188
188 The actual analysis produces some histograms << 189 The actual analysis produces some histograms (see next section) and an ntuple.
189 Both the histograms and the ntuple are saved << 190 Both the histograms and the ntuple are saved at the end of the run in the file
190 "gammaraytel.root". Please note that in a mul << 191 "gammaraytel.root". Please note that in a multiple run session,
191 the last run always override the root file. 192 the last run always override the root file.
192 193
193 8. Histogramming 194 8. Histogramming
194 ---------------- 195 ----------------
195 196
196 The 1D histograms contain the energy depositi << 197 The 1D histograms contain the energy deposition in the last X plane of
197 the TKR and the hits distribution along the X << 198 the TKR and the hits distribution along the X planes of the TKR
198 (note again that these histograms have been c << 199 (note again that these histograms have been chosen more for pedagogical
199 motivation than for physical one). 200 motivation than for physical one).
200 201
201 These histograms are filled and updated at ev << 202 These histograms are filled and updated at every event and are initialized
202 with each new run; the scale of the histogram << 203 with each new run; the scale of the histograms is automatically derived from
203 the detector geometry. << 204 the detector geometry.
204 205
205 Through a messenger it is possible to set som << 206 Throught a messenger it is possible to set some options with
206 the UI subtree "/analysis/" (use the UI help << 207 the UI subtree "/analysis/" (use the UI help for more info);
207 208
208 In this example we only show the use of very << 209 In this example we only show the use of very basic feature of this new
209 simulation/analysis framework. 210 simulation/analysis framework.
210 211
211 9. Digi 212 9. Digi
212 ------- << 213 --------
213 214
214 For the TKR also the digits corresponding to << 215 For the TKR also the digits corresponding to the Hits are generated.
215 A digi is generated when the hit energy depos << 216 A digi is generated when the hit energy deposit is greater than a threshold
216 (in this example setted at 120 keV). << 217 (in this example setted at 120 keV).
217 The TKR digi information are stored on the sa 218 The TKR digi information are stored on the same file Tracks_N.dat and contain:
218 219
219 a) ID of the event (this is important for mu 220 a) ID of the event (this is important for multiple events run)
220 b) Number of the strip << 221 b) Number of the strip
221 c) Number of the plane 222 c) Number of the plane
222 d) Type of the plane (1=X 0=Y) 223 d) Type of the plane (1=X 0=Y)
223 224
224 10. Classes Overview 225 10. Classes Overview
225 -------------------- << 226 -------------------
226 227
227 This is the overview of the classes defined i 228 This is the overview of the classes defined in this example
228 << 229
229 GammaRayTelPrimaryGeneratorAction << 230 GammaRayTelPrimaryGeneratorAction
230 User action for primaries generator << 231 User action for primaries generator
231 232
232 GammaRayTelPrimaryGeneratorMessenger 233 GammaRayTelPrimaryGeneratorMessenger
233 Messenger for interactive particle generat << 234 Messenger for interactive particle generator
234 parameters modification via the User Inter << 235 parameters modification via the User Interface
235 << 236
236 GammaRayTelPhysicsList 237 GammaRayTelPhysicsList
237 Determination of modular physics classes << 238 Determination of modular physics classes
238 239
239 GammaRayTelDetectorConstruction << 240 GammaRayTelGeneralPhysics
240 Geometry and material definitions for the << 241 Decay processes
241 242
242 GammaRayTelDetectorMessenger << 243 GammaRayTelEMPhysics
243 Messenger for interactive geometry paramet << 244 Std and LowE physics processes (for gamma & e-/e+)
244 modification via the User Interface << 245
>> 246 GammaRayTelMuonPhysics
>> 247 Muon & its processes
>> 248
>> 249 GammaRayTelIonPhysics
>> 250 Ions and their processes
245 251
>> 252 GammaRayTelHadronPhysics
>> 253 Sample of hadronic processes
>> 254
>> 255 GammaRayTelTelVisManager
>> 256 Visualization manager class
>> 257
>> 258 GammaRayTelDetectorConstruction
>> 259 Geometry and material definitions for the detector
>> 260
>> 261 GammaRayTelDetectorMessenger
>> 262 Messenger for interactive geometry parameters
>> 263 modification via the User Interface
>> 264
246 GammaRayTelAnalysis 265 GammaRayTelAnalysis
247 Analysis manager class (experimental) << 266 Analysis manager class (experimental)
248 267
249 GammaRayTelAnalysisMessenger 268 GammaRayTelAnalysisMessenger
250 Messenger for interactive analysis options << 269 Messenger for interactive analysis options modification
251 via the User Interface << 270 via the User Interface
252 271
253 GammaRayTelRunAction 272 GammaRayTelRunAction
254 User run action class << 273 User run action class
255 274
256 GammaRayTelEventAction 275 GammaRayTelEventAction
257 User event action class << 276 User event action class
258 277
259 GammaRayTelTrackerHit 278 GammaRayTelTrackerHit
260 Description of the hits on the tracker << 279 Description of the hits on the tracker
261 280
262 GammaRayTelDigi 281 GammaRayTelDigi
263 Description of the digi on the tracker << 282 Description of the digi on the tracker
264 283
265 GammaRayTelDigitizer 284 GammaRayTelDigitizer
266 Description of the digitizer for the track << 285 Description of the digitizer for the tracker
267 286
268 GammaRayTelTrackerSD 287 GammaRayTelTrackerSD
269 Description of the TKR sensitive detector << 288 Description of the TKR sensitive detector
270 289
271 GammaRayTelAnticoincidenceHit 290 GammaRayTelAnticoincidenceHit
272 Description of the hits on the anticoincid << 291 Description of the hits on the anticoincidence
273 292
274 GammaRayTelAnticoincidenceSD 293 GammaRayTelAnticoincidenceSD
275 Description of the ACD sensitive detector << 294 Description of the ACD sensitive detector
276 295
277 GammaRayTelCalorimeterHit 296 GammaRayTelCalorimeterHit
278 Description of the hits on the calorimeter << 297 Description of the hits on the calorimeter
279 298
280 GammaRayTelCalorimeterSD 299 GammaRayTelCalorimeterSD
281 Description of the CAL sensitive detector << 300 Description of the CAL sensitive detector
>> 301
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