| Geant4 Cross Reference |
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4 Geant4 - X-Ray Telescope Exampl
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8 Introduction
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10 XrayTel is an advanced Geant4 example based on
11 an X-ray Telescope. It is based on work carri
12 experts to simulate the interaction between X-
13 and Chandra with low energy protons present in
14 background. The X-ray mirrors are designed to
15 grazing-incidence angles and focus them onto d
16 However, this mechanism also seems to work for
17 if they reach the detectors in sufficient numb
18 In this example, the geometry has been simplif
19 shell and no baffles, but all the dimensions a
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21 The aim of this advanced example is to illustr
22 GUI, visualisation, particle generation and an
23 in Geant4:
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25 - macros are provided to display the geometry
26 OpenGL, DAWN Postscript or VRML visualisati
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28 - the generation of particles is done via the
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30 - histograming facilities are available throu
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32 In order to be able to use any of these packag
33 necessary and a number of environment variable
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36 NOTE: The geometry is refreshed on the viewer
37 but the tracks are plotted only in case
38 This is the case only for about 1 every
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42 2. Run
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44 To execute a sample simulation with visualisat
45 reaching the detector run:
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47 XrayTel
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49 execute command "/control/execute test.mac"
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51 To enable visualisation, uncomment one line fr
52 /control/execute vis.mac
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54 If the analysis options are set, histograms wi
55 automatically created and the corresponding fi
56 A 1D histogram will display the energy distrib
57 that reach the detector at the end of the run.
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60 3. Detector description
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62 The telescope and detector geometry is defined
63 XrayTelDetectorConstruction.cc
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66 4. Physics processes
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68 The physics processes are in XrayTelPhysicsLis
69 The main process in this example is G4hMultipl
70 off the mirror surfaces.
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73 5. Event generation
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75 This is done using the new General Particle So
76 this can be found in:
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78 http://reat.space.qinetiq.com/gps/
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81 6. Analysis
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83 Relevant information from the simulation is pr
84 class and saved, through the G4AnalysisManager
85 Tuples. The output file is written in Root for
86 No external software is required (apart from t
87