source: trunk/examples/extended/exoticphysics/monopole/src/DetectorConstruction.cc

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// $Id: DetectorConstruction.cc,v 1.2 2010/06/04 19:03:36 vnivanch Exp $
// GEANT4 tag $Name: geant4-09-04-beta-01 $
//
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#include "DetectorConstruction.hh"
#include "DetectorMessenger.hh"

#include "G4Material.hh"
#include "G4Box.hh"
#include "G4LogicalVolume.hh"
#include "G4PVPlacement.hh"
#include "G4UniformMagField.hh"

#include "G4GeometryManager.hh"
#include "G4UserLimits.hh"
#include "G4PhysicalVolumeStore.hh"
#include "G4LogicalVolumeStore.hh"
#include "G4SolidStore.hh"

#include "G4UnitsTable.hh"
#include "G4NistManager.hh"

#include "G4MonopoleFieldSetup.hh"
#include "G4FieldManager.hh"
#include "G4TransportationManager.hh"

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DetectorConstruction::DetectorConstruction()
{
  // default parameter values
  absorSizeX = absorSizeYZ = 10 * cm;
  worldSizeX = worldSizeYZ = 1.2 * absorSizeX;
  maxStepSize = 5 * mm;

  worldMaterial = absorMaterial = 0;
  magField = 0;
  lAbsor   = 0;
  fMFieldSetup = 0;

  DefineMaterials();
  SetMaterial("G4_Al");

  // create commands for interactive definition of the detector
  detectorMessenger = new DetectorMessenger(this);
}

DetectorConstruction::~DetectorConstruction()
{
  delete detectorMessenger;
}

G4VPhysicalVolume* DetectorConstruction::Construct()
{ 
  return ConstructVolumes();
}

void DetectorConstruction::DefineMaterials()
{ 
  /***********************     define Elements     *********************/
  G4double z, a;

  G4Element* N = new G4Element("Nitrogen", "N", z= 7, a= 14.01*g/mole);
  G4Element* O = new G4Element("Oxygen"  , "O", z= 8, a= 16.00*g/mole);

  /***********************    define Materials    **********************/
  G4double density, temperature, pressure;
  G4int    ncomponents;
  G4double fractionmass;
 
  G4Material* Air = new G4Material("Air"  , density = 1.290 * mg/cm3, ncomponents=2);
  Air->AddElement(N, fractionmass = 0.7);
  Air->AddElement(O, fractionmass = 0.3);

  density     = universe_mean_density;    //from PhysicalConstants.h
  pressure    = 3.e-18 * pascal;
  temperature = 2.73 * kelvin;

  G4Material* vacuum = new G4Material("Galactic", z = 1, a = 1.008 * g/mole, density,
                          kStateGas, temperature, pressure);

  G4cout << *(G4Material::GetMaterialTable()) << G4endl;

  //default materials
  worldMaterial = vacuum;
}


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G4VPhysicalVolume* DetectorConstruction::ConstructVolumes()
{
  G4GeometryManager::GetInstance()->OpenGeometry();
  G4PhysicalVolumeStore::GetInstance()->Clean();
  G4LogicalVolumeStore::GetInstance()->Clean();
  G4SolidStore::GetInstance()->Clean();

  /****************************    World   *****************************/
  G4Box * sWorld = new G4Box("world",                                   //name
               worldSizeX / 2, worldSizeYZ / 2, worldSizeYZ / 2);       //dimensions

  G4LogicalVolume * lWorld = new G4LogicalVolume(sWorld,                //shape
                                                worldMaterial,          //material
                                                "world");               //name

  G4VPhysicalVolume * pWorld = new G4PVPlacement(0,     //no rotation
                           G4ThreeVector(),             //at (0,0,0)
                           lWorld,                      //logical volume
                           "world",                     //name
                           0,                           //mother  volume
                           false,                       //no boolean operation
                           0);                          //copy number


  /**************************    Absorber    ***************************/
  G4Box * sAbsor = new G4Box("Absorber",                        //name
                   absorSizeX / 2, absorSizeYZ / 2, absorSizeYZ / 2);   //dimensions
                                                              
  lAbsor = new G4LogicalVolume(sAbsor,                  //shape
                               absorMaterial,           //material
                              "Absorber");              //name
  
                              
           new G4PVPlacement(0,                         //no rotation
                           G4ThreeVector(),             //at (0,0,0)
                           lAbsor,                      //logical volume
                           "Absorber",                  //name
                           lWorld,                      //mother  volume
                           false,                       //no boolean operation
                           0);                          //copy number
  lAbsor->SetUserLimits(new G4UserLimits(maxStepSize));

  PrintParameters();

  /************     always return the World volume     *****************/
  return pWorld;
}



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void DetectorConstruction::PrintParameters()
{
  G4cout << "\n---------------------------------------------------------\n";
  G4cout << "---> The Absorber is " << G4BestUnit(absorSizeX, "Length")
         << " of " << absorMaterial->GetName() << G4endl;
  G4cout << "\n---------------------------------------------------------\n";

}


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void DetectorConstruction::SetSizeX(G4double value)
{
  absorSizeX = value; worldSizeX = 1.2 * absorSizeX;
}
  

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void DetectorConstruction::SetSizeYZ(G4double value)
{
  absorSizeYZ = value; 
  worldSizeYZ = 1.2 * absorSizeYZ;
}  


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void DetectorConstruction::SetMaterial(G4String materialChoice)
{
  // search the material by its name   
  G4Material * pttoMaterial = G4NistManager::Instance()->FindOrBuildMaterial(materialChoice);
  if (pttoMaterial) absorMaterial = pttoMaterial;
  else  G4cout << "Material does not exist in DB" << G4endl;
}


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void DetectorConstruction::SetMagField(G4double fieldValue)
{
  //apply a global uniform magnetic field along Z axis
  G4FieldManager * fieldMgr = 
    G4TransportationManager::GetTransportationManager()->GetFieldManager();
    
  if (magField) { delete magField; }    //delete the existing magn field

  //fMFieldSetup = G4MonopoleFieldSetup::GetMonopoleFieldSetup(); // create the field

  
  if (fieldValue != 0.)                 // create a new one if non nul
    {
      magField = new G4UniformMagField(G4ThreeVector(0., 0., fieldValue));        
      fieldMgr->SetDetectorField(magField);
      fieldMgr->CreateChordFinder(magField);
    }
   else
    {
      magField = 0;
      fieldMgr->SetDetectorField(magField);
    }
}

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void DetectorConstruction::SetMaxStepSize(G4double step_)
{
  maxStepSize = step_;
  if(lAbsor) lAbsor->SetUserLimits(new G4UserLimits(maxStepSize));
}


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#include "G4RunManager.hh" 

void DetectorConstruction::UpdateGeometry()
{
  G4RunManager::GetRunManager()->DefineWorldVolume(ConstructVolumes());
}

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