Ex02DetectorConstruction.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 Ex02DetectorConstruction.cxx
/// \brief Implementation of the Ex02DetectorConstruction class
///
/// Geant4 ExampleN02 adapted to Virtual Monte Carlo \n
/// Id: Ex02DetectorConstruction.cc,v 1.11 2002/01/09 17:24:09 ranjard Exp \n
/// GEANT4 tag Name: geant4-04-00-patch-02
///
/// \date 21/04/2002
/// \author I. Hrivnacova; IPN, Orsay
 
#include <iostream>
 
#include <TGeoManager.h>
#include <TThread.h>
#include <TVirtualMC.h>
 
#include "Ex02ChamberParameterisation.h"
#include "Ex02DetectorConstruction.h"
 
/// \cond CLASSIMP
ClassImp(Ex02DetectorConstruction)
  /// \endcond
 
  using namespace std;
 
//_____________________________________________________________________________
Ex02DetectorConstruction::Ex02DetectorConstruction()
  : TObject(),
    fWorldLength(0.),
    fTargetLength(0.),
    fTrackerLength(0.),
    fNofChambers(0),
    fChamberWidth(0.),
    fChamberSpacing(0.),
    fImedAir(0),
    fImedPb(0),
    fImedXe(0)
{
  /// Default constuctor
 
  // fpMagField = new ExN02MagneticField();
 
  //--------- Sizes of the principal geometrical components (solids)  ---------
 
  fNofChambers = 5;
  fChamberWidth = 20;
  fChamberSpacing = 80;
 
  fTrackerLength =
    (fNofChambers + 1) * fChamberSpacing; // Full length of Tracker
  fTargetLength = 5.0;                    // Full length of Target
  fWorldLength = 1.2 * (fTargetLength + fTrackerLength);
}
 
//_____________________________________________________________________________
Ex02DetectorConstruction::~Ex02DetectorConstruction()
{
  /// Destructor
 
  // delete fpMagField;
}
 
//_____________________________________________________________________________
void Ex02DetectorConstruction::ConstructMaterials()
{
  /// Construct materials using TGeo modeller
 
  //--------- Material definition ---------
 
  // Create Root geometry manager
  new TGeoManager("E02_geometry", "E02 VMC example geometry");
 
  Double_t a;       // Mass of a mole in g/mole
  Double_t z;       // Atomic number
  Double_t density; // Material density in g/cm3
 
  // Elements
 
  TGeoElement* elN = new TGeoElement("Nitrogen", "N", z = 7., a = 14.01);
  TGeoElement* elO = new TGeoElement("Oxygen", "O", z = 8., a = 16.00);
 
  // Materials
 
  TGeoMixture* matAir = new TGeoMixture("Air", 2, density = 1.29e-03);
  matAir->AddElement(elN, 0.7);
  matAir->AddElement(elO, 0.3);
 
  TGeoMaterial* matLead =
    new TGeoMaterial("Lead", a = 207.19, z = 82., density = 11.35);
 
  TGeoMaterial* matXe =
    new TGeoMaterial("XenonGas", a = 131.29, z = 54., density = 5.458e-03);
 
  Double_t atmosphere = 6.32421e+08;
  Double_t pressure = 1. * atmosphere;
  Double_t temperature = 293.15;
  matXe->SetPressure(pressure);
  matXe->SetTemperature(temperature);
  matXe->SetState(TGeoMaterial::kMatStateGas);
 
  // Tracking media
 
  Double_t param[20];
  param[0] = 0;     // isvol  - Not used
  param[1] = 2;     // ifield - User defined magnetic field
  param[2] = 10.;   // fieldm - Maximum field value (in kiloGauss)
  param[3] = -20.;  // tmaxfd - Maximum angle due to field deflection
  param[4] = -0.01; // stemax - Maximum displacement for multiple scat
  param[5] = -.3;   // deemax - Maximum fractional energy loss, DLS
  param[6] = .001;  // epsil - Tracking precision
  param[7] = -.8;   // stmin
  for (Int_t i = 8; i < 20; ++i) param[i] = 0.;
 
  fImedAir = 1;
  new TGeoMedium("Air", fImedAir, matAir, param);
 
  fImedPb = 2;
  new TGeoMedium("Lead", fImedPb, matLead, param);
 
  fImedXe = 3;
  new TGeoMedium("XenonGas", fImedXe, matXe, param);
}
 
//_____________________________________________________________________________
void Ex02DetectorConstruction::ConstructGeometry()
{
  /// Contruct volumes using TGeo modeller
 
  //--------- Sizes of the principal geometrical components (solids)  ---------
 
  Int_t targetMater = fImedPb;
  Int_t chamberMater = fImedXe;
 
  Double_t targetSize = 0.5 * fTargetLength;   // Half length of the Target
  Double_t trackerSize = 0.5 * fTrackerLength; // Half length of the Tracker
 
  Double_t* ubuf = 0;
 
  //--------- Definitions of Solids, Logical Volumes, Physical Volumes ---------
 
  //------------------------------
  // World
  //------------------------------
 
  Double_t halfWorldLength = 0.5 * fWorldLength;
 
  Double_t world[3];
  world[0] = halfWorldLength;
  world[1] = halfWorldLength;
  world[2] = halfWorldLength;
  TGeoVolume* top = gGeoManager->Volume("WRLD", "BOX", fImedAir, world, 3);
  gGeoManager->SetTopVolume(top);
 
  //------------------------------
  // Target
  //------------------------------
 
  Double_t target[3];
  target[0] = targetSize;
  target[1] = targetSize;
  target[2] = targetSize;
  gGeoManager->Volume("TARG", "BOX", targetMater, target, 3);
 
  Double_t posX = 0.;
  Double_t posY = 0.;
  Double_t posZ = -(targetSize + trackerSize);
  gGeoManager->Node("TARG", 1, "WRLD", posX, posY, posZ, 0, kTRUE, ubuf);
 
  cout << "Target is " << fTargetLength
       << " cm"
       //<< " of " << TargetMater->GetName()
       << " of lead " << endl;
 
  //------------------------------
  // Tracker
  //------------------------------
 
  Double_t tracker[3];
  tracker[0] = trackerSize;
  tracker[1] = trackerSize;
  tracker[2] = trackerSize;
  gGeoManager->Volume("TRAK", "BOX", fImedAir, tracker, 3);
 
  posX = 0.;
  posY = 0.;
  posZ = 0.;
  gGeoManager->Node("TRAK", 1, "WRLD", posX, posY, posZ, 0, kTRUE, ubuf);
 
  //------------------------------
  // Tracker segments
  //------------------------------
  //
  // An example of Parameterised volumes
  // dummy values for G4Box -- modified by parameterised volume
  // - implemented using Gsposp
 
  Double_t chamber[3];
  chamber[0] = -1;
  chamber[1] = -1;
  chamber[2] = -1;
  gGeoManager->Volume("CHMB", "BOX", chamberMater, chamber, 0);
 
  Double_t firstPosition = -trackerSize + 0.5 * fChamberWidth;
  Double_t firstLength = fTrackerLength / 10;
  Double_t lastLength = fTrackerLength;
  Ex02ChamberParameterisation* chamberParam =
    new Ex02ChamberParameterisation(fNofChambers, // NoChambers
      firstPosition,                              // Z of center of first
      fChamberSpacing,                            // Z spacing of centers
      fChamberWidth,                              // Width Chamber
      firstLength,                                // lengthInitial
      lastLength);                                // lengthFinal
  for (Int_t i = 0; i < fNofChambers; i++) {
    Double_t pos[3];
    Double_t dim[3];
    chamberParam->ComputeTransformation(i, pos);
    chamberParam->ComputeDimensions(i, dim);
    gGeoManager->Node(
      "CHMB", i, "TRAK", pos[0], pos[1], pos[2], 0, kTRUE, dim, 3);
  }
 
  cout << "There are " << fNofChambers << " chambers in the tracker region. "
       << "The chambers are " << fChamberWidth * 10.
       << " mm of "
       //<< ChamberMater->GetName()
       << "Xenon gas"
       << "\n The distance between chamber is " << fChamberSpacing << " cm"
       << endl;
 
  // close geometry
  gGeoManager->CloseGeometry();
 
  // notify VMC about Root geometry
  gMC->SetRootGeometry();
 
  //------------------------------------------------
  // Sensitive detectors
  //------------------------------------------------
  /*
 
    G4SDManager* SDman = G4SDManager::GetSDMpointer();
 
    G4String trackerChamberSDname = "ExN02/TrackerChamberSD";
    ExN02TrackerSD* aTrackerSD = new ExN02TrackerSD( trackerChamberSDname );
    SDman->AddNewDetector( aTrackerSD );
    logicChamber->SetSensitiveDetector( aTrackerSD );
  */
 
  //--------- Visualization attributes -------------------------------
  /*
    G4VisAttributes* BoxVisAtt= new G4VisAttributes(G4Colour(1.0,1.0,1.0));
    logicWorld  ->SetVisAttributes(BoxVisAtt);
    logicTarget ->SetVisAttributes(BoxVisAtt);
    logicTracker->SetVisAttributes(BoxVisAtt);
 
    G4VisAttributes* ChamberVisAtt = new G4VisAttributes(G4Colour(1.0,1.0,0.0));
    logicChamber->SetVisAttributes(ChamberVisAtt);
  */
  //--------- example of User Limits -------------------------------
 
  // below is an example of how to set tracking constraints in a given
  // logical volume(see also in N02PhysicsList how to setup the process
  // G4UserSpecialCuts).
  // Sets a max Step length in the tracker region
  // Double_t maxStep = 0.5*fChamberWidth, maxLength = 2*fTrackerLength;
  // Double_t maxTime = 0.1*ns, minEkin = 10*MeV;
  // logicTracker->SetUserLimits(new G4UserLimits(maxStep,maxLength,maxTime,
  //                                               minEkin));
}
 
//_____________________________________________________________________________
void Ex02DetectorConstruction::SetTargetMaterial(
  const TString& /*materialName*/)
{
  /// Set target material (not available with VMC)
 
  Warning("SetTargetMaterial", "Not available in virtual Monte Carlo");
}
 
//_____________________________________________________________________________
void Ex02DetectorConstruction::SetChamberMaterial(
  const TString& /*materialName*/)
{
  /// Set chamber material (not available with VMC)
 
  Warning("SetTargetMaterial", "Not available in virtual Monte Carlo");
}