DetectorConstruction.cc

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// $Id$
//
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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 "G4PropagatorInField.hh"
#include "G4UserLimits.hh"

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

#include "G4UnitsTable.hh"
#include "G4SystemOfUnits.hh"

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DetectorConstruction::DetectorConstruction()
:fBox(0), fBoxSize(500*m), fMaterial(0), fMagField(0)
{
  DefineMaterials();
  SetMaterial("Iron");

  // create UserLimits
  fUserLimits = new G4UserLimits();

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

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

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

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void DetectorConstruction::DefineMaterials()
{
 G4double a, z, density;

 new G4Material("Beryllium", z= 4., a= 9.012182*g/mole, density= 1.848*g/cm3);
 new G4Material("Carbon",    z= 6., a= 12.011*g/mole,   density= 2.265*g/cm3);
 new G4Material("Iron",      z=26., a= 55.85*g/mole,    density= 7.870*g/cm3);

 // define a vacuum with a restgas pressure  typical for accelerators
 G4double const Torr  = atmosphere/760.;         // 1 Torr
 G4double pressure = 10e-9*Torr, temperature = 296.150*kelvin;         // 23  Celsius
 new G4Material("Vacuum", z=7., a=14.01*g/mole, density= 1.516784e-11*kg/m3,
                 kStateGas, temperature, pressure);

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

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

  G4Box*
  sBox = new G4Box("Container",                                //its name
                   fBoxSize/2,fBoxSize/2,fBoxSize/2);        //its dimensions

  G4LogicalVolume*                                           
  lBox = new G4LogicalVolume(sBox,                        //its shape
                             fMaterial,                        //its material
                             fMaterial->GetName());        //its name
                        
  lBox->SetUserLimits(fUserLimits);                        

  fBox = new G4PVPlacement(0,                                //no rotation
                             G4ThreeVector(),                //at (0,0,0)
                           lBox,                        //its logical volume
                           fMaterial->GetName(),        //its name
                           0,                                       //its mother  volume
                           false,                        //no boolean operation
                           0);                                //copy number

  PrintParameters();

  //
  //always return the root volume
  //
  return fBox;
}

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void DetectorConstruction::PrintParameters()
{
  G4cout << "\n The Box is " << G4BestUnit(fBoxSize,"Length")
         << " of " << fMaterial->GetName() << G4endl;
}

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void DetectorConstruction::SetMaterial(G4String materialChoice)
{
  // search the material by its name
  G4Material* pttoMaterial = G4Material::GetMaterial(materialChoice);
  if (pttoMaterial) fMaterial = pttoMaterial;
}

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void DetectorConstruction::SetSize(G4double value)
{
  fBoxSize = value;
}

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

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

  if (fMagField) delete fMagField;        //delete the existing magn field

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

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void DetectorConstruction::SetMaxStepSize(G4double val)
{
  // set the maximum allowed step size
  //
  if (val <= DBL_MIN)
    { G4cout << "\n --->warning from SetMaxStepSize: maxStep "
             << val  << " out of range. Command refused" << G4endl;
      return;
    }
  fUserLimits->SetMaxAllowedStep(val);
}

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void DetectorConstruction::SetMaxStepLength(G4double val)
{
  // set the maximum length of tracking step
  //
  if (val <= DBL_MIN)
    { G4cout << "\n --->warning from SetMaxStepLength: maxStep "
             << val  << " out of range. Command refused" << G4endl;
      return;
    }
  G4TransportationManager* tmanager =
    G4TransportationManager::GetTransportationManager();
  tmanager->GetPropagatorInField()
          ->SetLargestAcceptableStep(val);
}

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#include "G4RunManager.hh"

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

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