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26 //
27 /// \file B2/B2b/src/DetectorConstruction.cc
28 /// \brief Implementation of the B2b::DetectorConstruction class
29
30 #include "DetectorConstruction.hh"
31
32 #include "ChamberParameterisation.hh"
33 #include "DetectorMessenger.hh"
34 #include "TrackerSD.hh"
35
36 #include "G4AutoDelete.hh"
37 #include "G4Box.hh"
38 #include "G4Colour.hh"
39 #include "G4GeometryManager.hh"
40 #include "G4GeometryTolerance.hh"
41 #include "G4GlobalMagFieldMessenger.hh"
42 #include "G4LogicalVolume.hh"
43 #include "G4Material.hh"
44 #include "G4NistManager.hh"
45 #include "G4PVParameterised.hh"
46 #include "G4PVPlacement.hh"
47 #include "G4SDManager.hh"
48 #include "G4SystemOfUnits.hh"
49 #include "G4ThreeVector.hh"
50 #include "G4Tubs.hh"
51 #include "G4UserLimits.hh"
52 #include "G4VisAttributes.hh"
53
54 using namespace B2;
55
56 namespace B2b
57 {
58
59 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
60
61 G4ThreadLocal G4GlobalMagFieldMessenger* DetectorConstruction::fMagFieldMessenger = nullptr;
62
63 DetectorConstruction::DetectorConstruction()
64 {
65 fMessenger = new DetectorMessenger(this);
66 }
67
68 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
69
70 DetectorConstruction::~DetectorConstruction()
71 {
72 delete fStepLimit;
73 delete fMessenger;
74 }
75
76 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
77
78 G4VPhysicalVolume* DetectorConstruction::Construct()
79 {
80 // Define materials
81 DefineMaterials();
82
83 // Define volumes
84 return DefineVolumes();
85 }
86
87 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
88
89 void DetectorConstruction::DefineMaterials()
90 {
91 // Material definition
92
93 G4NistManager* nistManager = G4NistManager::Instance();
94
95 // Air defined using NIST Manager
96 nistManager->FindOrBuildMaterial("G4_AIR");
97
98 // Lead defined using NIST Manager
99 fTargetMaterial = nistManager->FindOrBuildMaterial("G4_Pb");
100
101 // Xenon gas defined using NIST Manager
102 fChamberMaterial = nistManager->FindOrBuildMaterial("G4_Xe");
103
104 // Print materials
105 G4cout << *(G4Material::GetMaterialTable()) << G4endl;
106 }
107
108 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
109
110 G4VPhysicalVolume* DetectorConstruction::DefineVolumes()
111 {
112 G4Material* air = G4Material::GetMaterial("G4_AIR");
113
114 // Sizes of the principal geometrical components (solids)
115
116 G4int NbOfChambers = 5;
117 G4double chamberSpacing = 80 * cm; // from chamber center to center!
118
119 G4double chamberWidth = 20.0 * cm; // width of the chambers
120 G4double targetLength = 5.0 * cm; // full length of Target
121
122 G4double trackerLength = (NbOfChambers + 1) * chamberSpacing;
123
124 G4double worldLength = 1.2 * (2 * targetLength + trackerLength);
125
126 G4double targetRadius = 0.5 * targetLength; // Radius of Target
127 targetLength = 0.5 * targetLength; // Half length of the Target
128 G4double trackerSize = 0.5 * trackerLength; // Half length of the Tracker
129
130 // Definitions of Solids, Logical Volumes, Physical Volumes
131
132 // World
133
134 G4GeometryManager::GetInstance()->SetWorldMaximumExtent(worldLength);
135
136 G4cout << "Computed tolerance = "
137 << G4GeometryTolerance::GetInstance()->GetSurfaceTolerance() / mm << " mm" << G4endl;
138
139 auto worldS = new G4Box("world", // its name
140 worldLength / 2, worldLength / 2, worldLength / 2); // its size
141 auto worldLV = new G4LogicalVolume(worldS, // its solid
142 air, // its material
143 "World"); // its name
144
145 // Must place the World Physical volume unrotated at (0,0,0).
146 //
147 auto worldPV = new G4PVPlacement(nullptr, // no rotation
148 G4ThreeVector(), // at (0,0,0)
149 worldLV, // its logical volume
150 "World", // its name
151 nullptr, // its mother volume
152 false, // no boolean operations
153 0, // copy number
154 fCheckOverlaps); // checking overlaps
155
156 // Target
157
158 G4ThreeVector positionTarget = G4ThreeVector(0, 0, -(targetLength + trackerSize));
159
160 auto targetS = new G4Tubs("target", 0., targetRadius, targetLength, 0. * deg, 360. * deg);
161 fLogicTarget = new G4LogicalVolume(targetS, fTargetMaterial, "Target", nullptr, nullptr, nullptr);
162 new G4PVPlacement(nullptr, // no rotation
163 positionTarget, // at (x,y,z)
164 fLogicTarget, // its logical volume
165 "Target", // its name
166 worldLV, // its mother volume
167 false, // no boolean operations
168 0, // copy number
169 fCheckOverlaps); // checking overlaps
170
171 G4cout << "Target is " << 2 * targetLength / cm << " cm of " << fTargetMaterial->GetName()
172 << G4endl;
173
174 // Tracker
175
176 G4ThreeVector positionTracker = G4ThreeVector(0, 0, 0);
177
178 auto trackerS = new G4Tubs("tracker", 0, trackerSize, trackerSize, 0. * deg, 360. * deg);
179 auto trackerLV = new G4LogicalVolume(trackerS, air, "Tracker", nullptr, nullptr, nullptr);
180 new G4PVPlacement(nullptr, // no rotation
181 positionTracker, // at (x,y,z)
182 trackerLV, // its logical volume
183 "Tracker", // its name
184 worldLV, // its mother volume
185 false, // no boolean operations
186 0, // copy number
187 fCheckOverlaps); // checking overlaps
188
189 // Tracker segments
190
191 // An example of Parameterised volumes
192 // Dummy values for G4Tubs -- modified by parameterised volume
193
194 auto chamberS = new G4Tubs("tracker", 0, 100 * cm, 100 * cm, 0. * deg, 360. * deg);
195 fLogicChamber =
196 new G4LogicalVolume(chamberS, fChamberMaterial, "Chamber", nullptr, nullptr, nullptr);
197
198 G4double firstPosition = -trackerSize + chamberSpacing;
199 G4double firstLength = trackerLength / 10;
200 G4double lastLength = trackerLength;
201
202 G4VPVParameterisation* chamberParam =
203 new ChamberParameterisation(NbOfChambers, // NoChambers
204 firstPosition, // Z of center of first
205 chamberSpacing, // Z spacing of centers
206 chamberWidth, // chamber width
207 firstLength, // initial length
208 lastLength); // final length
209
210 // dummy value : kZAxis -- modified by parameterised volume
211
212 new G4PVParameterised("Chamber", // their name
213 fLogicChamber, // their logical volume
214 trackerLV, // Mother logical volume
215 kZAxis, // Are placed along this axis
216 NbOfChambers, // Number of chambers
217 chamberParam, // The parametrisation
218 fCheckOverlaps); // checking overlaps
219
220 G4cout << "There are " << NbOfChambers << " chambers in the tracker region. " << G4endl
221 << "The chambers are " << chamberWidth / cm << " cm of " << fChamberMaterial->GetName()
222 << G4endl << "The distance between chamber is " << chamberSpacing / cm << " cm" << G4endl;
223
224 // Visualization attributes
225
226 G4VisAttributes boxVisAtt(G4Colour::White());
227
228 worldLV->SetVisAttributes(boxVisAtt);
229 fLogicTarget->SetVisAttributes(boxVisAtt);
230 trackerLV->SetVisAttributes(boxVisAtt);
231
232 G4VisAttributes chamberVisAtt(G4Colour::Yellow());
233 fLogicChamber->SetVisAttributes(chamberVisAtt);
234
235 // Example of User Limits
236 //
237 // Below is an example of how to set tracking constraints in a given
238 // logical volume
239 //
240 // Sets a max step length in the tracker region, with G4StepLimiter
241
242 G4double maxStep = 0.5 * chamberWidth;
243 fStepLimit = new G4UserLimits(maxStep);
244 trackerLV->SetUserLimits(fStepLimit);
245
246 /// Set additional contraints on the track, with G4UserSpecialCuts
247 ///
248 /// G4double maxLength = 2*trackerLength, maxTime = 0.1*ns, minEkin = 10*MeV;
249 /// trackerLV->SetUserLimits(new G4UserLimits(maxStep,
250 /// maxLength,
251 /// maxTime,
252 /// minEkin));
253
254 // Always return the physical world
255
256 return worldPV;
257 }
258
259 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
260
261 void DetectorConstruction::ConstructSDandField()
262 {
263 // Sensitive detectors
264
265 G4String trackerChamberSDname = "B2/TrackerChamberSD";
266 auto trackerSD = new TrackerSD(trackerChamberSDname, "TrackerHitsCollection");
267 G4SDManager::GetSDMpointer()->AddNewDetector(trackerSD);
268 SetSensitiveDetector(fLogicChamber, trackerSD);
269
270 // Create global magnetic field messenger.
271 // Uniform magnetic field is then created automatically if
272 // the field value is not zero.
273 G4ThreeVector fieldValue = G4ThreeVector();
274 fMagFieldMessenger = new G4GlobalMagFieldMessenger(fieldValue);
275 fMagFieldMessenger->SetVerboseLevel(1);
276
277 // Register the field messenger for deleting
278 G4AutoDelete::Register(fMagFieldMessenger);
279 }
280
281 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
282
283 void DetectorConstruction::SetTargetMaterial(G4String materialName)
284 {
285 G4NistManager* nistManager = G4NistManager::Instance();
286
287 G4Material* pttoMaterial = nistManager->FindOrBuildMaterial(materialName);
288
289 if (fTargetMaterial != pttoMaterial) {
290 if (pttoMaterial) {
291 fTargetMaterial = pttoMaterial;
292 if (fLogicTarget) fLogicTarget->SetMaterial(fTargetMaterial);
293 G4cout << G4endl << "----> The target is made of " << materialName << G4endl;
294 }
295 else {
296 G4cout << G4endl << "--> WARNING from SetTargetMaterial : " << materialName << " not found"
297 << G4endl;
298 }
299 }
300 }
301
302 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
303
304 void DetectorConstruction::SetChamberMaterial(G4String materialName)
305 {
306 G4NistManager* nistManager = G4NistManager::Instance();
307
308 G4Material* pttoMaterial = nistManager->FindOrBuildMaterial(materialName);
309
310 if (fChamberMaterial != pttoMaterial) {
311 if (pttoMaterial) {
312 fChamberMaterial = pttoMaterial;
313 if (fLogicChamber) fLogicChamber->SetMaterial(fChamberMaterial);
314 G4cout << G4endl << "----> The chambers are made of " << materialName << G4endl;
315 }
316 else {
317 G4cout << G4endl << "--> WARNING from SetChamberMaterial : " << materialName << " not found"
318 << G4endl;
319 }
320 }
321 }
322
323 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
324
325 void DetectorConstruction::SetMaxStep(G4double maxStep)
326 {
327 if ((fStepLimit) && (maxStep > 0.)) fStepLimit->SetMaxAllowedStep(maxStep);
328 }
329
330 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
331
332 } // namespace B2b
333