B2b/src/DetectorConstruction.cc

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0025 //
0026 /// \file DetectorConstruction.cc
0027 /// \brief Implementation of the B2b::DetectorConstruction class
0028
0029 #include "DetectorConstruction.hh"
0030
0031 #include "ChamberParameterisation.hh"
0032 #include "DetectorMessenger.hh"
0033 #include "TrackerSD.hh"
0034
0035 #include "G4AutoDelete.hh"
0036 #include "G4Box.hh"
0037 #include "G4Colour.hh"
0038 #include "G4GeometryManager.hh"
0039 #include "G4GeometryTolerance.hh"
0040 #include "G4GlobalMagFieldMessenger.hh"
0041 #include "G4LogicalVolume.hh"
0042 #include "G4Material.hh"
0043 #include "G4NistManager.hh"
0044 #include "G4PVParameterised.hh"
0045 #include "G4PVPlacement.hh"
0046 #include "G4SDManager.hh"
0047 #include "G4SystemOfUnits.hh"
0048 #include "G4ThreeVector.hh"
0049 #include "G4Tubs.hh"
0050 #include "G4UserLimits.hh"
0051 #include "G4VisAttributes.hh"
0052
0053 using namespace B2;
0054
0055 namespace B2b
0056 {
0057
0058 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0059
0060 G4ThreadLocal G4GlobalMagFieldMessenger* DetectorConstruction::fMagFieldMessenger = nullptr;
0061
0062 DetectorConstruction::DetectorConstruction()
0063 {
0064   fMessenger = new DetectorMessenger(this);
0065 }
0066
0067 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0068
0069 DetectorConstruction::~DetectorConstruction()
0070 {
0071   delete fStepLimit;
0072   delete fMessenger;
0073 }
0074
0075 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0076
0077 G4VPhysicalVolume* DetectorConstruction::Construct()
0078 {
0079   // Define materials
0080   DefineMaterials();
0081
0082   // Define volumes
0083   return DefineVolumes();
0084 }
0085
0086 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0087
0088 void DetectorConstruction::DefineMaterials()
0089 {
0090   // Material definition
0091
0092   G4NistManager* nistManager = G4NistManager::Instance();
0093
0094   // Air defined using NIST Manager
0095   nistManager->FindOrBuildMaterial("G4_AIR");
0096
0097   // Lead defined using NIST Manager
0098   fTargetMaterial = nistManager->FindOrBuildMaterial("G4_Pb");
0099
0100   // Xenon gas defined using NIST Manager
0101   fChamberMaterial = nistManager->FindOrBuildMaterial("G4_Xe");
0102
0103   // Print materials
0104   G4cout << *(G4Material::GetMaterialTable()) << G4endl;
0105 }
0106
0107 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0108
0109 G4VPhysicalVolume* DetectorConstruction::DefineVolumes()
0110 {
0111   G4Material* air = G4Material::GetMaterial("G4_AIR");
0112
0113   // Sizes of the principal geometrical components (solids)
0114
0115   G4int NbOfChambers = 5;
0116   G4double chamberSpacing = 80 * cm;  // from chamber center to center!
0117
0118   G4double chamberWidth = 20.0 * cm;  // width of the chambers
0119   G4double targetLength = 5.0 * cm;  // full length of Target
0120
0121   G4double trackerLength = (NbOfChambers + 1) * chamberSpacing;
0122
0123   G4double worldLength = 1.2 * (2 * targetLength + trackerLength);
0124
0125   G4double targetRadius = 0.5 * targetLength;  // Radius of Target
0126   targetLength = 0.5 * targetLength;  // Half length of the Target
0127   G4double trackerSize = 0.5 * trackerLength;  // Half length of the Tracker
0128
0129   // Definitions of Solids, Logical Volumes, Physical Volumes
0130
0131   // World
0132
0133   G4GeometryManager::GetInstance()->SetWorldMaximumExtent(worldLength);
0134
0135   G4cout << "Computed tolerance = "
0136          << G4GeometryTolerance::GetInstance()->GetSurfaceTolerance() / mm << " mm" << G4endl;
0137
0138   auto worldS = new G4Box("world",  // its name
0139                           worldLength / 2, worldLength / 2, worldLength / 2);  // its size
0140   auto worldLV = new G4LogicalVolume(worldS,  // its solid
0141                                      air,  // its material
0142                                      "World");  // its name
0143
0144   //  Must place the World Physical volume unrotated at (0,0,0).
0145   //
0146   auto worldPV = new G4PVPlacement(nullptr,  // no rotation
0147                                    G4ThreeVector(),  // at (0,0,0)
0148                                    worldLV,  // its logical volume
0149                                    "World",  // its name
0150                                    nullptr,  // its mother  volume
0151                                    false,  // no boolean operations
0152                                    0,  // copy number
0153                                    fCheckOverlaps);  // checking overlaps
0154
0155   // Target
0156
0157   G4ThreeVector positionTarget = G4ThreeVector(0, 0, -(targetLength + trackerSize));
0158
0159   auto targetS = new G4Tubs("target", 0., targetRadius, targetLength, 0. * deg, 360. * deg);
0160   fLogicTarget = new G4LogicalVolume(targetS, fTargetMaterial, "Target", nullptr, nullptr, nullptr);
0161   new G4PVPlacement(nullptr,  // no rotation
0162                     positionTarget,  // at (x,y,z)
0163                     fLogicTarget,  // its logical volume
0164                     "Target",  // its name
0165                     worldLV,  // its mother volume
0166                     false,  // no boolean operations
0167                     0,  // copy number
0168                     fCheckOverlaps);  // checking overlaps
0169
0170   G4cout << "Target is " << 2 * targetLength / cm << " cm of " << fTargetMaterial->GetName()
0171          << G4endl;
0172
0173   // Tracker
0174
0175   G4ThreeVector positionTracker = G4ThreeVector(0, 0, 0);
0176
0177   auto trackerS = new G4Tubs("tracker", 0, trackerSize, trackerSize, 0. * deg, 360. * deg);
0178   auto trackerLV = new G4LogicalVolume(trackerS, air, "Tracker", nullptr, nullptr, nullptr);
0179   new G4PVPlacement(nullptr,  // no rotation
0180                     positionTracker,  // at (x,y,z)
0181                     trackerLV,  // its logical volume
0182                     "Tracker",  // its name
0183                     worldLV,  // its mother  volume
0184                     false,  // no boolean operations
0185                     0,  // copy number
0186                     fCheckOverlaps);  // checking overlaps
0187
0188   // Tracker segments
0189
0190   // An example of Parameterised volumes
0191   // Dummy values for G4Tubs -- modified by parameterised volume
0192
0193   auto chamberS = new G4Tubs("tracker", 0, 100 * cm, 100 * cm, 0. * deg, 360. * deg);
0194   fLogicChamber =
0195     new G4LogicalVolume(chamberS, fChamberMaterial, "Chamber", nullptr, nullptr, nullptr);
0196
0197   G4double firstPosition = -trackerSize + chamberSpacing;
0198   G4double firstLength = trackerLength / 10;
0199   G4double lastLength = trackerLength;
0200
0201   G4VPVParameterisation* chamberParam =
0202     new ChamberParameterisation(NbOfChambers,  // NoChambers
0203                                 firstPosition,  // Z of center of first
0204                                 chamberSpacing,  // Z spacing of centers
0205                                 chamberWidth,  // chamber width
0206                                 firstLength,  // initial length
0207                                 lastLength);  // final length
0208
0209   // dummy value : kZAxis -- modified by parameterised volume
0210
0211   new G4PVParameterised("Chamber",  // their name
0212                         fLogicChamber,  // their logical volume
0213                         trackerLV,  // Mother logical volume
0214                         kZAxis,  // Are placed along this axis
0215                         NbOfChambers,  // Number of chambers
0216                         chamberParam,  // The parametrisation
0217                         fCheckOverlaps);  // checking overlaps
0218
0219   G4cout << "There are " << NbOfChambers << " chambers in the tracker region. " << G4endl
0220          << "The chambers are " << chamberWidth / cm << " cm of " << fChamberMaterial->GetName()
0221          << G4endl << "The distance between chamber is " << chamberSpacing / cm << " cm" << G4endl;
0222
0223   // Visualization attributes
0224
0225   G4VisAttributes boxVisAtt(G4Colour::White());
0226
0227   worldLV->SetVisAttributes(boxVisAtt);
0228   fLogicTarget->SetVisAttributes(boxVisAtt);
0229   trackerLV->SetVisAttributes(boxVisAtt);
0230
0231   G4VisAttributes chamberVisAtt(G4Colour::Yellow());
0232   fLogicChamber->SetVisAttributes(chamberVisAtt);
0233
0234   // Example of User Limits
0235   //
0236   // Below is an example of how to set tracking constraints in a given
0237   // logical volume
0238   //
0239   // Sets a max step length in the tracker region, with G4StepLimiter
0240
0241   G4double maxStep = 0.5 * chamberWidth;
0242   fStepLimit = new G4UserLimits(maxStep);
0243   trackerLV->SetUserLimits(fStepLimit);
0244
0245   /// Set additional contraints on the track, with G4UserSpecialCuts
0246   ///
0247   /// G4double maxLength = 2*trackerLength, maxTime = 0.1*ns, minEkin = 10*MeV;
0248   /// trackerLV->SetUserLimits(new G4UserLimits(maxStep,
0249   ///                                           maxLength,
0250   ///                                           maxTime,
0251   ///                                           minEkin));
0252
0253   // Always return the physical world
0254
0255   return worldPV;
0256 }
0257
0258 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0259
0260 void DetectorConstruction::ConstructSDandField()
0261 {
0262   // Sensitive detectors
0263
0264   G4String trackerChamberSDname = "B2/TrackerChamberSD";
0265   auto trackerSD = new TrackerSD(trackerChamberSDname, "TrackerHitsCollection");
0266   G4SDManager::GetSDMpointer()->AddNewDetector(trackerSD);
0267   SetSensitiveDetector(fLogicChamber, trackerSD);
0268
0269   // Create global magnetic field messenger.
0270   // Uniform magnetic field is then created automatically if
0271   // the field value is not zero.
0272   G4ThreeVector fieldValue = G4ThreeVector();
0273   fMagFieldMessenger = new G4GlobalMagFieldMessenger(fieldValue);
0274   fMagFieldMessenger->SetVerboseLevel(1);
0275
0276   // Register the field messenger for deleting
0277   G4AutoDelete::Register(fMagFieldMessenger);
0278 }
0279
0280 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0281
0282 void DetectorConstruction::SetTargetMaterial(G4String materialName)
0283 {
0284   G4NistManager* nistManager = G4NistManager::Instance();
0285
0286   G4Material* pttoMaterial = nistManager->FindOrBuildMaterial(materialName);
0287
0288   if (fTargetMaterial != pttoMaterial) {
0289     if (pttoMaterial) {
0290       fTargetMaterial = pttoMaterial;
0291       if (fLogicTarget) fLogicTarget->SetMaterial(fTargetMaterial);
0292       G4cout << G4endl << "----> The target is made of " << materialName << G4endl;
0293     }
0294     else {
0295       G4cout << G4endl << "-->  WARNING from SetTargetMaterial : " << materialName << " not found"
0296              << G4endl;
0297     }
0298   }
0299 }
0300
0301 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0302
0303 void DetectorConstruction::SetChamberMaterial(G4String materialName)
0304 {
0305   G4NistManager* nistManager = G4NistManager::Instance();
0306
0307   G4Material* pttoMaterial = nistManager->FindOrBuildMaterial(materialName);
0308
0309   if (fChamberMaterial != pttoMaterial) {
0310     if (pttoMaterial) {
0311       fChamberMaterial = pttoMaterial;
0312       if (fLogicChamber) fLogicChamber->SetMaterial(fChamberMaterial);
0313       G4cout << G4endl << "----> The chambers are made of " << materialName << G4endl;
0314     }
0315     else {
0316       G4cout << G4endl << "-->  WARNING from SetChamberMaterial : " << materialName << " not found"
0317              << G4endl;
0318     }
0319   }
0320 }
0321
0322 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0323
0324 void DetectorConstruction::SetMaxStep(G4double maxStep)
0325 {
0326   if ((fStepLimit) && (maxStep > 0.)) fStepLimit->SetMaxAllowedStep(maxStep);
0327 }
0328
0329 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0330
0331 }  // namespace B2b