a design study for a cobra upgrade to - Institut für Kern- und ...

More documents

Recommendations

Info

98 B SECOND APPENDIX B.2 Geant4 Geant4 is an object-oriented toolkit for the simulation of the passage of particles through matter, written in C++. It provides a realistic reproduction of physical processes for an energy region from 250 eV up to a few GeV. The necessary cross sections for the simulations are interpolated from stored values in evaluated databases. The final state depends on the angle and energy distributions and will be calculated with the corresponding theoretical model or interpolated from the database [44]. A main method with two toolkit classes (G4Runmanager and G4UImanager) and three classes, which are derived from toolkit classes (G4Detectorconstruction, G4PhysicsList and G4PrimaryGeneratorAction) are required for building a simulation. The G4Runmanager controls the flow of the program. It manages the initialisation procedures like detector construction, definition of particles and physics processes or initialisation of primary particles. In the user initialised class DetectorConstruction, the geometry and material of the detector are defined by the user. In the PhysicsList, the user defines the particles and physical processes, which shall be regarded. The initial state of the event is defined with the PrimaryGeneratorAction. This implies the particle type, energy, position, direction and number of initialised particles. A RUN is defined as a set of events. The user has control at the Begin and End of each run (class RunAction), the Begin and End of each event (class EventAction), the begin and End of each track (class TrackingAction) and at the End of each step (class SteppingAction). A HIT is a record, track per track (and even step per step), of a set of user defined information needed to simulate and analyse the detector response. Only interactions in volumes, specified as sensitive detectors can be handled as hits and be stored in the HitsCollection. The HitsCollection is printed at the end of event (via the method TrackerSD::EndOfEvent()), under the control of the command:/hits/verbose 1. A visualisation of the event is possible with the G4VisManager. Used visualisation systems are OpenGL, Heprep or Dawn. Geant4 applications can run in batch mode, where macro commands, being read at the beginning of a run, can be used. An interactive mode, driven by command lines or via a graphical user interface is also possible. [48] VENOM is the Cobra simulation framework, first developed by H. Kiel [8] and redesigned by J. Wilson and B. Morgan [53]. It is a
B.2 Geant4 99 Geant4 application, enabling reproducible simulations of signal and background physics processes in the detector for all COBRA collaborators. Venom contains packages, which can be added and extended by the user. All packages use the same physics class (VXPhysicsList) and material class (VXMaterials). Geometry, action, readout and generator classes can be added by writing new packages. Venom uses factory classes to enable runtime configurations of the geometry, the run action, the data readout and the event generator. A granular build system makes compiling of individual packages possible before linking them to the main application. The main application contains the VXDetectorConstruction, VXPrimaryGeneratorAction, VXPhysicsList, VXVisManager and VXActionManager classes. This is the minimal set of classes required by Geant4 to run. The VXDetectorConstruction constructs the VXMaterials class and only places the world logical volume. The construction of the world logical volume and all subvolumes is performed by VXVGeoComponent. This is an abstract base class, which places the component, and again leaves the construction of the components (which can consist of subcomponents) to their individual classes. The VXPrimaryGeneratorAction generates the primary events. The particle guns Decay0, Bkkgen, Chaingen and GPS can be chosen by using the SetPrimaryGenerator() method. The particle gun Decay0 uses the input files of the Decay0 software, initialising the energy and angular distributions of the electrons, positrons of gamma rays of double beta decays. The Bkkgen initialises decays of single isotopes, whereas Chaingen sets decays belonging to decay chains and GPS initialises particles. The VXVisManager is a standard visualisation manager supporting OpenGl, Heprep and Dawn. The VXActionManager allows to change run, event, stepping, stacking and tracking action classes at run time. Venom provides no time information. The deposited energy in each sensitive detector volume is written to a Root file. The Array64 Root output file consist of a tree containing four leaves, the deposited energy edep, the shelf-ID and board-ID (used for K64Array) and the crystal ID. The crystal Id ranges from 1 to 16 and the shelf-ID from 1 to 4. THE SCINT64 PACKAGE was written as part of this diploma thesis. It is a new Venom package, constructing the previously described simplified scintillator upgrade. The Scint64 package uses the class array64paintedcrystal from the Array64 package and contains the classes scint64Nest, scint64Scintillator, scint64PaintedScintillator, scint64ScintillatorCube, scint64PaintedScintillator-
Page 1 and 2:
A DESIGN STUDY FOR A COBRA UPGRADE
Page 3:
I hereby declare that I have create
Page 6 and 7:
vi Abstract
Page 8 and 9:
viii Überblick
Page 10 and 11:
x Contents 4.1.2 Scintillation proc
Page 12 and 13:
xii Contents
Page 14 and 15:
2 1 Introduction The CdZnTe detecto
Page 16 and 17:
4 2 Neutrino physics mass scales no
Page 18 and 19:
6 2 Neutrino physics Ground states
Page 20 and 21:
8 2 Neutrino physics mi: 〈mνe〉
Page 22 and 23:
10 2 Neutrino physics
Page 24 and 25:
12 3 The COBRA experiment CdZnTe (C
Page 26 and 27:
14 3 The COBRA experiment 1420:480:
Page 28 and 29:
16 3 The COBRA experiment Figure 3.
Page 30 and 31:
18 3 The COBRA experiment They are
Page 32 and 33:
20 3 The COBRA experiment Therefore
Page 34 and 35:
22 4 Scintillation detectors search
Page 36 and 37:
24 4 Scintillation detectors Figure
Page 38 and 39:
26 4 Scintillation detectors spectr
Page 40 and 41:
28 4 Scintillation detectors SCINTI
Page 42 and 43:
30 4 Scintillation detectors emissi
Page 44 and 45:
32 4 Scintillation detectors activa
Page 46 and 47:
34 4 Scintillation detectors descri
Page 48 and 49:
Page 50 and 51:
38 4 Scintillation detectors group
Page 52 and 53:
Page 54 and 55:
Page 56 and 57:
44 4 Scintillation detectors AVALAN
Page 58 and 59:
Page 60 and 61: 48 4 Scintillation detectors gap. T
Page 62 and 63: 50 4 Scintillation detectors photoc
Page 64 and 65: 52 5 Scintillator upgrade ergy phys
Page 66 and 67: 54 5 Scintillator upgrade event ID
Page 68 and 69: 56 5 Scintillator upgrade Ephoton (
Page 70 and 71: 58 5 Scintillator upgrade back side
Page 72 and 73: 60 5 Scintillator upgrade three dif
Page 74 and 75: 62 5 Scintillator upgrade vice. The
Page 76 and 77: 64 5 Scintillator upgrade lecting e
Page 78 and 79: 66 5 Scintillator upgrade Figure 5.
Page 84 and 85: 72 5 Scintillator upgrade In 3.1 %
Page 86 and 87: 74 5 Scintillator upgrade were repo
Page 90 and 91: 78 5 Scintillator upgrade crystal p
Page 92 and 93: 80 5 Scintillator upgrade and gamma
Page 94 and 95: 82 5 Scintillator upgrade Backgroun
Page 96 and 97: 84 5 Scintillator upgrade source of
Page 98 and 99: 86 6 Summary and future work dimens
Page 100 and 101: 88 A FIRST APPENDIX Scintillator De
Page 102 and 103: 90 A FIRST APPENDIX A.2 Reports abo
Page 104 and 105: 92 A FIRST APPENDIX trons than a st
Page 106 and 107: 94 B SECOND APPENDIX Figure B.1: Am
Page 108 and 109: 96 B SECOND APPENDIX Figure B.5: Am
Page 112 and 113: 100 B SECOND APPENDIX Cube, scint64
Page 114 and 115: 102 B SECOND APPENDIX
Page 116 and 117: 104 Bibliography [13] H. V. Klapdor
Page 118 and 119: 106 Bibliography [43] T. Y. Kim et
Page 120: Typeset September 29, 2010
show all

a design study for a cobra upgrade to - Institut für Kern- und ...

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?