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26 //
27 /// \file B2/B2a/src/DetectorConstruction.cc
28 /// \brief Implementation of the B2a::DetectorConstruction class
29
30 #include "DetectorConstruction.hh"
31
32 #include "DetectorMessenger.hh"
33 #include "TrackerSD.hh"
34
35 #include "G4AutoDelete.hh"
36 #include "G4Box.hh"
37 #include "G4Colour.hh"
38 #include "G4GeometryManager.hh"
39 #include "G4GeometryTolerance.hh"
40 #include "G4GlobalMagFieldMessenger.hh"
41 #include "G4LogicalVolume.hh"
42 #include "G4Material.hh"
43 #include "G4NistManager.hh"
44 #include "G4PVPlacement.hh"
45 #include "G4SDManager.hh"
46 #include "G4SystemOfUnits.hh"
47 #include "G4Tubs.hh"
48 #include "G4UserLimits.hh"
49 #include "G4VisAttributes.hh"
50
51 using namespace B2;
52
53 namespace B2a
54 {
55
56 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
57
58 G4ThreadLocal G4GlobalMagFieldMessenger* DetectorConstruction::fMagFieldMessenger = nullptr;
59
60 DetectorConstruction::DetectorConstruction()
61 {
62 fMessenger = new DetectorMessenger(this);
63
64 fNbOfChambers = 5;
65 fLogicChamber = new G4LogicalVolume*[fNbOfChambers];
66 }
67
68 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
69
70 DetectorConstruction::~DetectorConstruction()
71 {
72 delete[] fLogicChamber;
73 delete fStepLimit;
74 delete fMessenger;
75 }
76
77 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
78
79 G4VPhysicalVolume* DetectorConstruction::Construct()
80 {
81 // Define materials
82 DefineMaterials();
83
84 // Define volumes
85 return DefineVolumes();
86 }
87
88 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
89
90 void DetectorConstruction::DefineMaterials()
91 {
92 // Material definition
93
94 G4NistManager* nistManager = G4NistManager::Instance();
95
96 // Air defined using NIST Manager
97 nistManager->FindOrBuildMaterial("G4_AIR");
98
99 // Lead defined using NIST Manager
100 fTargetMaterial = nistManager->FindOrBuildMaterial("G4_Pb");
101
102 // Xenon gas defined using NIST Manager
103 fChamberMaterial = nistManager->FindOrBuildMaterial("G4_Xe");
104
105 // Print materials
106 G4cout << *(G4Material::GetMaterialTable()) << G4endl;
107 }
108
109 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
110
111 G4VPhysicalVolume* DetectorConstruction::DefineVolumes()
112 {
113 G4Material* air = G4Material::GetMaterial("G4_AIR");
114
115 // Sizes of the principal geometrical components (solids)
116
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 = (fNbOfChambers + 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 // Visualization attributes
190
191 G4VisAttributes boxVisAtt(G4Colour::White());
192 G4VisAttributes chamberVisAtt(G4Colour::Yellow());
193
194 worldLV->SetVisAttributes(boxVisAtt);
195 fLogicTarget->SetVisAttributes(boxVisAtt);
196 trackerLV->SetVisAttributes(boxVisAtt);
197
198 // Tracker segments
199
200 G4cout << "There are " << fNbOfChambers << " chambers in the tracker region. " << G4endl
201 << "The chambers are " << chamberWidth / cm << " cm of " << fChamberMaterial->GetName()
202 << G4endl << "The distance between chamber is " << chamberSpacing / cm << " cm" << G4endl;
203
204 G4double firstPosition = -trackerSize + chamberSpacing;
205 G4double firstLength = trackerLength / 10;
206 G4double lastLength = trackerLength;
207
208 G4double halfWidth = 0.5 * chamberWidth;
209 G4double rmaxFirst = 0.5 * firstLength;
210
211 G4double rmaxIncr = 0.0;
212 if (fNbOfChambers > 0) {
213 rmaxIncr = 0.5 * (lastLength - firstLength) / (fNbOfChambers - 1);
214 if (chamberSpacing < chamberWidth) {
215 G4Exception("DetectorConstruction::DefineVolumes()", "InvalidSetup", FatalException,
216 "Width>Spacing");
217 }
218 }
219
220 for (G4int copyNo = 0; copyNo < fNbOfChambers; copyNo++) {
221 G4double Zposition = firstPosition + copyNo * chamberSpacing;
222 G4double rmax = rmaxFirst + copyNo * rmaxIncr;
223
224 auto chamberS = new G4Tubs("Chamber_solid", 0, rmax, halfWidth, 0. * deg, 360. * deg);
225
226 fLogicChamber[copyNo] =
227 new G4LogicalVolume(chamberS, fChamberMaterial, "Chamber_LV", nullptr, nullptr, nullptr);
228
229 fLogicChamber[copyNo]->SetVisAttributes(chamberVisAtt);
230
231 new G4PVPlacement(nullptr, // no rotation
232 G4ThreeVector(0, 0, Zposition), // at (x,y,z)
233 fLogicChamber[copyNo], // its logical volume
234 "Chamber_PV", // its name
235 trackerLV, // its mother volume
236 false, // no boolean operations
237 copyNo, // copy number
238 fCheckOverlaps); // checking overlaps
239 }
240
241 // Example of User Limits
242 //
243 // Below is an example of how to set tracking constraints in a given
244 // logical volume
245 //
246 // Sets a max step length in the tracker region, with G4StepLimiter
247
248 G4double maxStep = 0.5 * chamberWidth;
249 fStepLimit = new G4UserLimits(maxStep);
250 trackerLV->SetUserLimits(fStepLimit);
251
252 /// Set additional contraints on the track, with G4UserSpecialCuts
253 ///
254 /// G4double maxLength = 2*trackerLength, maxTime = 0.1*ns, minEkin = 10*MeV;
255 /// trackerLV->SetUserLimits(new G4UserLimits(maxStep,
256 /// maxLength,
257 /// maxTime,
258 /// minEkin));
259
260 // Always return the physical world
261
262 return worldPV;
263 }
264
265 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
266
267 void DetectorConstruction::ConstructSDandField()
268 {
269 // Sensitive detectors
270
271 G4String trackerChamberSDname = "/TrackerChamberSD";
272 auto trackerSD = new TrackerSD(trackerChamberSDname, "TrackerHitsCollection");
273 G4SDManager::GetSDMpointer()->AddNewDetector(trackerSD);
274 // Setting trackerSD to all logical volumes with the same name
275 // of "Chamber_LV".
276 SetSensitiveDetector("Chamber_LV", trackerSD, true);
277
278 // Create global magnetic field messenger.
279 // Uniform magnetic field is then created automatically if
280 // the field value is not zero.
281 G4ThreeVector fieldValue = G4ThreeVector();
282 fMagFieldMessenger = new G4GlobalMagFieldMessenger(fieldValue);
283 fMagFieldMessenger->SetVerboseLevel(1);
284
285 // Register the field messenger for deleting
286 G4AutoDelete::Register(fMagFieldMessenger);
287 }
288
289 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
290
291 void DetectorConstruction::SetTargetMaterial(G4String materialName)
292 {
293 G4NistManager* nistManager = G4NistManager::Instance();
294
295 G4Material* pttoMaterial = nistManager->FindOrBuildMaterial(materialName);
296
297 if (fTargetMaterial != pttoMaterial) {
298 if (pttoMaterial) {
299 fTargetMaterial = pttoMaterial;
300 if (fLogicTarget) fLogicTarget->SetMaterial(fTargetMaterial);
301 G4cout << G4endl << "----> The target is made of " << materialName << G4endl;
302 }
303 else {
304 G4cout << G4endl << "--> WARNING from SetTargetMaterial : " << materialName << " not found"
305 << G4endl;
306 }
307 }
308 }
309
310 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
311
312 void DetectorConstruction::SetChamberMaterial(G4String materialName)
313 {
314 G4NistManager* nistManager = G4NistManager::Instance();
315
316 G4Material* pttoMaterial = nistManager->FindOrBuildMaterial(materialName);
317
318 if (fChamberMaterial != pttoMaterial) {
319 if (pttoMaterial) {
320 fChamberMaterial = pttoMaterial;
321 for (G4int copyNo = 0; copyNo < fNbOfChambers; copyNo++) {
322 if (fLogicChamber[copyNo]) fLogicChamber[copyNo]->SetMaterial(fChamberMaterial);
323 }
324 G4cout << G4endl << "----> The chambers are made of " << materialName << G4endl;
325 }
326 else {
327 G4cout << G4endl << "--> WARNING from SetChamberMaterial : " << materialName << " not found"
328 << G4endl;
329 }
330 }
331 }
332
333 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
334
335 void DetectorConstruction::SetMaxStep(G4double maxStep)
336 {
337 if ((fStepLimit) && (maxStep > 0.)) fStepLimit->SetMaxAllowedStep(maxStep);
338 }
339
340 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
341
342 void DetectorConstruction::SetCheckOverlaps(G4bool checkOverlaps)
343 {
344 fCheckOverlaps = checkOverlaps;
345 }
346
347 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
348
349 } // namespace B2a