B2a/src/DetectorConstruction.cc

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0025 //
0026 /// \file DetectorConstruction.cc
0027 /// \brief Implementation of the B2a::DetectorConstruction class
0028
0029 #include "DetectorConstruction.hh"
0030
0031 #include "DetectorMessenger.hh"
0032 #include "TrackerSD.hh"
0033
0034 #include "G4AutoDelete.hh"
0035 #include "G4Box.hh"
0036 #include "G4Colour.hh"
0037 #include "G4GeometryManager.hh"
0038 #include "G4GeometryTolerance.hh"
0039 #include "G4GlobalMagFieldMessenger.hh"
0040 #include "G4LogicalVolume.hh"
0041 #include "G4Material.hh"
0042 #include "G4NistManager.hh"
0043 #include "G4PVPlacement.hh"
0044 #include "G4SDManager.hh"
0045 #include "G4SystemOfUnits.hh"
0046 #include "G4Tubs.hh"
0047 #include "G4UserLimits.hh"
0048 #include "G4VisAttributes.hh"
0049
0050 using namespace B2;
0051
0052 namespace B2a
0053 {
0054
0055 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0056
0057 G4ThreadLocal G4GlobalMagFieldMessenger* DetectorConstruction::fMagFieldMessenger = nullptr;
0058
0059 DetectorConstruction::DetectorConstruction()
0060 {
0061   fMessenger = new DetectorMessenger(this);
0062
0063   fNbOfChambers = 5;
0064   fLogicChamber = new G4LogicalVolume*[fNbOfChambers];
0065 }
0066
0067 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0068
0069 DetectorConstruction::~DetectorConstruction()
0070 {
0071   delete[] fLogicChamber;
0072   delete fStepLimit;
0073   delete fMessenger;
0074 }
0075
0076 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0077
0078 G4VPhysicalVolume* DetectorConstruction::Construct()
0079 {
0080   // Define materials
0081   DefineMaterials();
0082
0083   // Define volumes
0084   return DefineVolumes();
0085 }
0086
0087 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0088
0089 void DetectorConstruction::DefineMaterials()
0090 {
0091   // Material definition
0092
0093   G4NistManager* nistManager = G4NistManager::Instance();
0094
0095   // Air defined using NIST Manager
0096   nistManager->FindOrBuildMaterial("G4_AIR");
0097
0098   // Lead defined using NIST Manager
0099   fTargetMaterial = nistManager->FindOrBuildMaterial("G4_Pb");
0100
0101   // Xenon gas defined using NIST Manager
0102   fChamberMaterial = nistManager->FindOrBuildMaterial("G4_Xe");
0103
0104   // Print materials
0105   G4cout << *(G4Material::GetMaterialTable()) << G4endl;
0106 }
0107
0108 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0109
0110 G4VPhysicalVolume* DetectorConstruction::DefineVolumes()
0111 {
0112   G4Material* air = G4Material::GetMaterial("G4_AIR");
0113
0114   // Sizes of the principal geometrical components (solids)
0115
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 = (fNbOfChambers + 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   // Visualization attributes
0189
0190   G4VisAttributes boxVisAtt(G4Colour::White());
0191   G4VisAttributes chamberVisAtt(G4Colour::Yellow());
0192
0193   worldLV->SetVisAttributes(boxVisAtt);
0194   fLogicTarget->SetVisAttributes(boxVisAtt);
0195   trackerLV->SetVisAttributes(boxVisAtt);
0196
0197   // Tracker segments
0198
0199   G4cout << "There are " << fNbOfChambers << " chambers in the tracker region. " << G4endl
0200          << "The chambers are " << chamberWidth / cm << " cm of " << fChamberMaterial->GetName()
0201          << G4endl << "The distance between chamber is " << chamberSpacing / cm << " cm" << G4endl;
0202
0203   G4double firstPosition = -trackerSize + chamberSpacing;
0204   G4double firstLength = trackerLength / 10;
0205   G4double lastLength = trackerLength;
0206
0207   G4double halfWidth = 0.5 * chamberWidth;
0208   G4double rmaxFirst = 0.5 * firstLength;
0209
0210   G4double rmaxIncr = 0.0;
0211   if (fNbOfChambers > 0) {
0212     rmaxIncr = 0.5 * (lastLength - firstLength) / (fNbOfChambers - 1);
0213     if (chamberSpacing < chamberWidth) {
0214       G4Exception("DetectorConstruction::DefineVolumes()", "InvalidSetup", FatalException,
0215                   "Width>Spacing");
0216     }
0217   }
0218
0219   for (G4int copyNo = 0; copyNo < fNbOfChambers; copyNo++) {
0220     G4double Zposition = firstPosition + copyNo * chamberSpacing;
0221     G4double rmax = rmaxFirst + copyNo * rmaxIncr;
0222
0223     auto chamberS = new G4Tubs("Chamber_solid", 0, rmax, halfWidth, 0. * deg, 360. * deg);
0224
0225     fLogicChamber[copyNo] =
0226       new G4LogicalVolume(chamberS, fChamberMaterial, "Chamber_LV", nullptr, nullptr, nullptr);
0227
0228     fLogicChamber[copyNo]->SetVisAttributes(chamberVisAtt);
0229
0230     new G4PVPlacement(nullptr,  // no rotation
0231                       G4ThreeVector(0, 0, Zposition),  // at (x,y,z)
0232                       fLogicChamber[copyNo],  // its logical volume
0233                       "Chamber_PV",  // its name
0234                       trackerLV,  // its mother  volume
0235                       false,  // no boolean operations
0236                       copyNo,  // copy number
0237                       fCheckOverlaps);  // checking overlaps
0238   }
0239
0240   // Example of User Limits
0241   //
0242   // Below is an example of how to set tracking constraints in a given
0243   // logical volume
0244   //
0245   // Sets a max step length in the tracker region, with G4StepLimiter
0246
0247   G4double maxStep = 0.5 * chamberWidth;
0248   fStepLimit = new G4UserLimits(maxStep);
0249   trackerLV->SetUserLimits(fStepLimit);
0250
0251   /// Set additional contraints on the track, with G4UserSpecialCuts
0252   ///
0253   /// G4double maxLength = 2*trackerLength, maxTime = 0.1*ns, minEkin = 10*MeV;
0254   /// trackerLV->SetUserLimits(new G4UserLimits(maxStep,
0255   ///                                           maxLength,
0256   ///                                           maxTime,
0257   ///                                           minEkin));
0258
0259   // Always return the physical world
0260
0261   return worldPV;
0262 }
0263
0264 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0265
0266 void DetectorConstruction::ConstructSDandField()
0267 {
0268   // Sensitive detectors
0269
0270   G4String trackerChamberSDname = "/TrackerChamberSD";
0271   auto trackerSD = new TrackerSD(trackerChamberSDname, "TrackerHitsCollection");
0272   G4SDManager::GetSDMpointer()->AddNewDetector(trackerSD);
0273   // Setting trackerSD to all logical volumes with the same name
0274   // of "Chamber_LV".
0275   SetSensitiveDetector("Chamber_LV", trackerSD, true);
0276
0277   // Create global magnetic field messenger.
0278   // Uniform magnetic field is then created automatically if
0279   // the field value is not zero.
0280   G4ThreeVector fieldValue = G4ThreeVector();
0281   fMagFieldMessenger = new G4GlobalMagFieldMessenger(fieldValue);
0282   fMagFieldMessenger->SetVerboseLevel(1);
0283
0284   // Register the field messenger for deleting
0285   G4AutoDelete::Register(fMagFieldMessenger);
0286 }
0287
0288 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0289
0290 void DetectorConstruction::SetTargetMaterial(G4String materialName)
0291 {
0292   G4NistManager* nistManager = G4NistManager::Instance();
0293
0294   G4Material* pttoMaterial = nistManager->FindOrBuildMaterial(materialName);
0295
0296   if (fTargetMaterial != pttoMaterial) {
0297     if (pttoMaterial) {
0298       fTargetMaterial = pttoMaterial;
0299       if (fLogicTarget) fLogicTarget->SetMaterial(fTargetMaterial);
0300       G4cout << G4endl << "----> The target is made of " << materialName << G4endl;
0301     }
0302     else {
0303       G4cout << G4endl << "-->  WARNING from SetTargetMaterial : " << materialName << " not found"
0304              << G4endl;
0305     }
0306   }
0307 }
0308
0309 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0310
0311 void DetectorConstruction::SetChamberMaterial(G4String materialName)
0312 {
0313   G4NistManager* nistManager = G4NistManager::Instance();
0314
0315   G4Material* pttoMaterial = nistManager->FindOrBuildMaterial(materialName);
0316
0317   if (fChamberMaterial != pttoMaterial) {
0318     if (pttoMaterial) {
0319       fChamberMaterial = pttoMaterial;
0320       for (G4int copyNo = 0; copyNo < fNbOfChambers; copyNo++) {
0321         if (fLogicChamber[copyNo]) fLogicChamber[copyNo]->SetMaterial(fChamberMaterial);
0322       }
0323       G4cout << G4endl << "----> The chambers are made of " << materialName << G4endl;
0324     }
0325     else {
0326       G4cout << G4endl << "-->  WARNING from SetChamberMaterial : " << materialName << " not found"
0327              << G4endl;
0328     }
0329   }
0330 }
0331
0332 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0333
0334 void DetectorConstruction::SetMaxStep(G4double maxStep)
0335 {
0336   if ((fStepLimit) && (maxStep > 0.)) fStepLimit->SetMaxAllowedStep(maxStep);
0337 }
0338
0339 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0340
0341 void DetectorConstruction::SetCheckOverlaps(G4bool checkOverlaps)
0342 {
0343   fCheckOverlaps = checkOverlaps;
0344 }
0345
0346 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
0347
0348 }  // namespace B2a