A01RootDetectorConstruction.cxx

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//------------------------------------------------
// The Virtual Monte Carlo examples
// Copyright (C) 2007 - 2014 Ivana Hrivnacova
// All rights reserved.
//
// For the licensing terms see geant4_vmc/LICENSE.
// Contact: root-vmc@cern.ch
//-------------------------------------------------
 
/// \file A01RootDetectorConstruction.cxx
/// \brief Implementation of the A01RootDetectorConstruction class
///
/// Geant4 ExampleA01 adapted to Virtual Monte Carlo \n
///
/// \date 12/05/2012
/// \author I. Hrivnacova; IPN, Orsay
 
#include <Riostream.h>
#include <TGeoManager.h>
#include <TList.h>
#include <TVirtualMC.h>
 
#include "A01LocalMagField.h"
#include "A01RootDetectorConstruction.h"
 
/// \cond CLASSIMP
ClassImp(A01RootDetectorConstruction)
  /// \endcond
 
  //_____________________________________________________________________________
  A01RootDetectorConstruction::A01RootDetectorConstruction(
    const TString& geometryFileName)
  : TObject(), fGeometryFileName(geometryFileName), fUseLocalMagField(false)
{
  /// Standard constuctor
  /// \param geometryFileName The root geometry file name
}
 
//_____________________________________________________________________________
A01RootDetectorConstruction::~A01RootDetectorConstruction()
{
  /// Destructor
}
 
//
// public methods
//
 
//_____________________________________________________________________________
void A01RootDetectorConstruction::ConstructGeometry()
{
  /// Contruct volumes using TGeo modeller
 
  TGeoManager::Import(fGeometryFileName.Data());
 
  // Update media parameters (needed for Geant3)
  TList* media = gGeoManager->GetListOfMedia();
  TIter next(media);
  while (TObject* obj = next()) {
    TGeoMedium* medium = (TGeoMedium*)obj;
    medium->SetParam(1, 2);    // ifield - User defined magnetic field
    medium->SetParam(2, 10);   // fieldm - Maximum field value (in kiloGauss)
    medium->SetParam(6, .001); // epsil - Tracking precision
  }
 
  // Create local magnetic field
  if (fUseLocalMagField) {
    // Constant magnetic field (in kiloGauss)
    // field value: 1.0*tesla (= 10.0 kiloGauss) in y
    TVirtualMagField* magField = new A01LocalMagField(0, 10.0, 0);
 
    // set the field to "magneticLogical" volume
    TGeoVolume* magneticVolume = gGeoManager->FindVolumeFast("magneticLogical");
    if (magneticVolume) {
      magneticVolume->SetField(magField);
    }
    else {
      std::cerr << "The Tube volume was not found in geometry." << std::endl;
      std::cerr << "Local magnetic field has not been set." << std::endl;
      delete magField;
    }
  }
  // notify VMC about Root geometry
  gMC->SetRootGeometry();
}