example from AnaEx01

This example is a modified version of the AnaEx01 in the "extended" folder of the Geant4 examples.

Examples AnaEx01, AnaEx02 and AnaEx03 show the usage of histogram and tuple manipulations using G4Analysis, ROOT and AIDA compliant systems on the same scenario. All analysis manipulations (histo booking, filling, saving histos in a file, etc...) are located in one class : HistoManager, implementation of which is different in each example. All the other classes are same in all three examples.

This example shows the usage of histogram and tuple manipulations using G4Analysis system.

The example is an adaptation of examples/novice/N03. It describes a simple sampling calorimeter setup.

Detector description

The calorimeter is a box made of a given number of layers. A layer consists of an absorber plate and of a detection gap. The layer is replicated.

Six parameters define the calorimeter : * the material of the absorber, * the thickness of an absorber plate, * the material of the detection gap, * the thickness of a gap, * the number of layers, * the transverse size of the calorimeter (the input face is a square).

The default geometry is constructed in DetectorConstruction class, but all of the above parameters can be modified interactively via the commands defined in the DetectorMessenger class.

        |<----layer 0---------->|<----layer 1---------->|<----layer 2---------->|
        |                       |                       |                       |
        ==========================================================================
        ||              |       ||              |       ||              |       ||
        ||              |       ||              |       ||              |       ||
 beam   ||   absorber   |  gap  ||   absorber   |  gap  ||   absorber   |  gap  ||
======> ||              |       ||              |       ||              |       ||
        ||              |       ||              |       ||              |       ||
        ==========================================================================

Physics list

The particle's type and the physic processes which will be available in this example are set in the FTFP_BERT physics list.

Action Initialization

A newly introduced class, ActionInitialization, instantiates and registers to Geant4 kernel all user action classes which are defined thread-local and a run action class which is defined both thread-local and global.

The thread-local action classes are defined in ActionInitialization::Build() and the global run action class is defined in ActionInitialization::BuildForMaster(). Note that ActionInitialization::Build() is also used to instatiate user action clasess in sequential mode.

An event: PrimaryGeneratorAction

Primaries are generated with the General Particle Source (GPS) http://geant4-userdoc.web.cern.ch/geant4-userdoc/UsersGuides/ForApplicationDeveloper/html/GettingStarted/generalParticleSource.html therefore all the configuration of the primaries can be done via macro

Histograms

AnaEx01 can produce 4 histograms :

EAbs : total energy deposit in absorber per event EGap : total energy deposit in gap per event
LAbs : total track length of charged particles in absorber per event LGap : total track length of charged particles in gap per event

And 2 Ntuples :

• Ntuple1: ..* one row per event : EnergyAbs EnergyGap
• Ntuple2: ..* one row per event : TrackLAbs TrackLGap

These histos and ntuples are booked in HistoManager and filled from EventAction.

One can control the name of the histograms file and its format: default name : AnaEx01
The format of the histogram file can be : root (default), xml, csv. Include correct g4nnn.hh in HistoManager.hh

How to build

mkdir <build dir>

cd <build dir>

cmake ../AnaEx01

make