| Geant4 Cross Reference |
1 2 ========================================================= 3 Geant4 - ULTRA-based air shower example 4 ========================================================= 5 6 README 7 --------------------- 8 9 ------------------------------------------------------------------------ 10 ----> Introduction. 11 12 The ULTRA detector is a hybrid 2-component system consisting of: 13 14 15 1) an UV detection system - the UVscope 16 2) an array of scintillator detectors - the ETscope 17 18 The UVscope detects Cherenkov light associated to cosmic ray showers 19 when it is diffusively reflected on ground. 20 The ETscope detects in coincidence the charged particles of the shower. 21 22 In the current version only the UVscope simulation is included 23 ------------------------------------------------------------------------ 24 ----> Description 25 26 The UVscope consists of a Fresnel lens and a PMT located in the focal 27 plane, enclosed in a cylindrical aluminum housing. The lens is 457 mm 28 in diameter and is made of UV transmitting acrylic with 5.6 grooves 29 per mm. The description of the geometry of the Fresnel lens makes use 30 of object parameterisation/replication capabilities. 31 32 The primary vertex generator describes a plane circular source of UV 33 (3eV, about 400 nm) optical photons. 34 Depending on the selected detector configuration, the source can be 35 positioned such that the photons are fired 36 to a reflecting surface or, by default, directly to the UVscope 37 (no reflecting surface is present in this case). 38 Reflection at the surface can be chosen to be specular or diffuse. 39 In both cases the normal to the surface makes an angle of 45 degrees 40 with the UVscope axis and the photons are emitted at an angle of 41 90 degrees with the UVscope axis. 42 If none of these variables is set no reflecting surface is used 43 and the photons source is positioned at the UVscope axis. 44 45 The definition of the relevant optical boundaries, parameters and 46 processes is made. 47 48 ------------------------------------------------------------------------ 49 ----> SET-UP 50 51 A standard Geant4 example GNUmakefile and a CMakeLists.txt file are 52 provided, for building with cmake 53 54 The following environment variable can be set in order to get 55 additional verbosity during program running: 56 57 1) GNUmakefile 58 59 setenv ULTRA_VERBOSE 60 61 or 62 63 2) cmake -DULTRA_VERBOSE=ON "path to source" 64 65 66 ------------------------------------------------------------------------ 67 68 The analysis is performed using the native Geant4 analysis tools 69 (g4tools). In the default case, the output histograms are written 70 in a ROOT file. 71 72 The output file can be written in other formats (csv, xml, hdf5) by 73 changing the G4AnalysisManager default file type in UltraRunAction::BeginOfRunAction(). 74 75 ----------------------------------------------------------------------- 76 ----> How to run the example. 77 78 From the directory where the Ultra binary resides : 79 80 ./Ultra "macro name" for running in batch mode 81 82 ./Ultra for running in interative mode. 83 The macro VisDirect.mac is executed. 84 85 Several macros are available for interactive visualisation. 86 While in interactive mode type the command 87 /control/execute "name_of_macro", 88 where "name_of_macro" is one of the following: 89 90 Direct.mac - a beam of photons is shot directly to the telescope. 91 Mirror.mac - the beam is directed to a specular reflecing surface 92 Ground.mac - the beam is directed to a diffusively reflecting surface 93 94 ------------------------------------------------------------------------ 95 ----> Simulation output 96 97 the output is ultra.root 98 It contains: 99 1)1Dhistogram with the detected photons energy (eV) 100 2)1Dhistogram with the number of detected photons per event 101 102 103 To plot these histograms run the ROOT macro 'do_plots.C' : 104 > root do_plots.C 105 ------------------------------------------------------------------------ 106 107 for comments and questions: bernardo@lip.pt 108 for more info http://www.ge.infn.it/geant4/examples/ 109 110 last modified: B. Tome 08/11/2019 111 created by : B. Tome and M.C. Espirito Santo 20/05/2004