$Id: README,v 1.6 2008/05/07 11:47:09 maire Exp $ ------------------------------------------------------------------- ========================================================= Geant4 - an Object-Oriented Toolkit for Simulation in HEP ========================================================= TestEm10 -------- Test for investigation of ionisation in thin absorbers, transition and synchrotron radiations. Default setup for "TestEm10.in" and "TestEm10.large_N.in" is the experiment for XTR with NIM A294 (1990) 465-472 (fig. 11) setup 0- INTRODUCTION The parameterisations models can be changed simply with: Idle> /XTRdetector/setModel i (i = 1 to 10) It is NOT needed (and not recommended) to issue the command /XTRdetector/update if just the model is changed. See macro file "TestEm10.in" for an example. 1- GEOMETRY DEFINITION The "absorber" is a tube made of a given material. Three parameters define the absorber : - the material of the absorber, - the thickness of an absorber, - the transverse size of the absorber (the input face is a square). The volume "World" contains the "absorber". In this test the parameters of the "World" can be changed , too. In addition a transverse uniform magnetic field can be applied. The default geometry is constructed in DetectorConstruction class, but all the parameters can be changed via the commands defined in the DetectorMessenger class. 2- AN EVENT : THE PRIMARY GENERATOR The primary kinematic consists of a single particle which hits the absorber perpendicular to the input face. The type of the particle and its energy are set in the PrimaryGeneratorAction class, and can be changed via the G4 build-in commands of ParticleGun class (see the macros provided with this example). A RUN is a set of events. 3- DETECTOR RESPONSE Here we test G4PAIionisation , G4IonisationByLogicalVolume and transition radiation processes A HIT is a record, event per event , of all the informations needed to simulate and analyse the detector response. In this example a CalorHit is defined as a set of 2 informations: - the total energy deposit in the absorber, - the total tracklength of all charged particles in the absorber, Therefore the absorber is declared 'sensitive detector' (SD), which means they can contribute to the hit. At the end of a run, from the histogram(s), one can study different physics quantities such as : - angle distribution, - energy deposit, - transmission/backscattering, - ... The test contains 10 built-in histograms, which can be activated by interactive commands (see the macros runxx.mac for details). The histogram files can be viewed using PAW e.g with the commands paw> h/file 1 geant4.plot01 or g4.p11 paw> option stat paw> h/pl 1 4- PHYSICS DEMO The particle's type and the physic processes which will be available in this example are set in PhysicsList class. The messenger classes introduce interactive commands . Using these commands the geometry of the detector, the data of the primary particle, the limits of the histograms , etc. can be changed. 5- HOW TO START ? - compile and link to generate an executable % cd TestEm10 % gmake - execute TestEm10 in 'batch' mode from macro files e.g. % $(G4INSTALL)/bin/$(G4SYSTEM)/TestEm10 run11.mac - execute TestEm10 in 'interactive' mode with visualization e.g. % $(G4INSTALL)/bin/$(G4SYSTEM)/TestEm10 .... Idle> type your commands .... List of the built-in histograms ------------------------------- 1. number of (tracking) steps/event 2. energy deposit distribution in the absorber (in MeV) 3. angle distribution of the primary particle at the exit of the absorber (deg) 4. distribution of the lateral displacement at exit(mm) 5. kinetic energy of the transmitted primaries (MeV) 6. angle distribution of the backscattered primaries (deg) 7. kinetic energy of the backscattered primary particles (MeV) 8. kinetic energy of the charged secondary particles (MeV) 9. z distribution of the secondary charged vertices (mm) 10. kinetic energy of the photons escaping the absorber (MeV) Using histograms ---------------- By default the histograms are not activated. To activate histograms the environment variable G4ANALYSIS_USE should be defined. For instance uncomment the flag G4ANALYSIS_USE in GNUmakefile. To use histograms any of implementations of AIDA interfaces should be available. See InstallAida.txt