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26 //
27 /// \file exoticphysics/ucn/src/ExUCNDetectorConstruction.cc
28 /// \brief Implementation of the ExUCNDetectorConstruction class
29 //
30
31 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
32 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
33
34 #include "ExUCNDetectorConstruction.hh"
35
36 #include "G4Box.hh"
37 #include "G4Colour.hh"
38 #include "G4FieldManager.hh"
39 #include "G4GeometryManager.hh"
40 #include "G4LogicalVolume.hh"
41 #include "G4LogicalVolumeStore.hh"
42 #include "G4Material.hh"
43 #include "G4NistManager.hh"
44 #include "G4PVPlacement.hh"
45 #include "G4PhysicalConstants.hh"
46 #include "G4PhysicalVolumeStore.hh"
47 #include "G4RepleteEofM.hh"
48 #include "G4SolidStore.hh"
49 #include "G4SystemOfUnits.hh"
50 #include "G4TransportationManager.hh"
51 #include "G4Tubs.hh"
52 #include "G4UCNMaterialPropertiesTable.hh"
53 #include "G4UniformGravityField.hh"
54 #include "G4UserLimits.hh"
55 #include "G4VPhysicalVolume.hh"
56 #include "G4VisAttributes.hh"
57 // #include "G4EqGravityField.hh"
58
59 #include "G4ChordFinder.hh"
60 #include "G4ClassicalRK4.hh"
61 #include "G4MagIntegratorStepper.hh"
62 #include "G4PropagatorInField.hh"
63
64 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
65
66 ExUCNDetectorConstruction::ExUCNDetectorConstruction() : fVacuum(0), fGuideMaterial(0)
67 {
68 // materials
69 DefineMaterials();
70 }
71
72 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
73
74 ExUCNDetectorConstruction::~ExUCNDetectorConstruction()
75 {
76 if (fField) delete fField;
77 }
78
79 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
80
81 void ExUCNDetectorConstruction::DefineMaterials()
82 {
83 G4NistManager* nistMan = G4NistManager::Instance();
84
85 fVacuum = nistMan->FindOrBuildMaterial("G4_Galactic");
86 fGuideMaterial = nistMan->FindOrBuildMaterial("G4_Ni");
87
88 // --- Ni diffuse 10%
89
90 G4UCNMaterialPropertiesTable* MPT = new G4UCNMaterialPropertiesTable();
91
92 // MPT->AddConstProperty("REFLECTIVITY",1.);
93 // Commented out above line as REFLECTIVITY=1 by default in
94 // G4OpBoundaryProcess. Also use AddProperty to set REFLECTIVITY if needed
95 MPT->AddConstProperty("DIFFUSION", 0.1);
96 MPT->AddConstProperty("FERMIPOT", 252.0); // Gollub, Table 2.1 in neV
97 MPT->AddConstProperty("SPINFLIP", 0.);
98 MPT->AddConstProperty("LOSS", 12.5e-5); // Gollub, Table 2.1
99 MPT->AddConstProperty("LOSSCS", 0.);
100 MPT->AddConstProperty("ABSCS", 4.49); // 1/v loss cross-section at room temp.
101 MPT->AddConstProperty("SCATCS", 18.5); // (incoherent) "elastic" scattering cs
102
103 G4double neV = 1.e-9 * eV;
104
105 MPT->SetMicroRoughnessParameters(30 * nm, 1 * nm, 180, 1000, 0 * degree, 90 * degree, 1 * neV,
106 1000 * neV, 15, 15, 0.01 * degree);
107
108 fGuideMaterial->SetMaterialPropertiesTable(MPT);
109
110 G4cout << *(G4Material::GetMaterialTable()) << G4endl;
111 }
112
113 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
114
115 G4VPhysicalVolume* ExUCNDetectorConstruction::Construct()
116 {
117 //
118 // World
119 //
120
121 G4double worldSizeX = 1. * m;
122 G4double worldSizeY = 1. * m;
123 G4double worldSizeZ = 100. * m;
124
125 G4Box* solidWorld = new G4Box("World", worldSizeX / 2., worldSizeY / 2., worldSizeZ / 2.);
126
127 G4LogicalVolume* logicWorld = new G4LogicalVolume(solidWorld, fVacuum, "World");
128
129 G4VPhysicalVolume* physiWorld =
130 new G4PVPlacement(0, G4ThreeVector(), "World", logicWorld, 0, false, 0);
131
132 // --------------------------------- Guide -------------------------------------
133
134 G4double GuideR = 35. * mm;
135 G4double GuideW = 2. * mm;
136 G4double GuideL = 6. * m;
137
138 G4Tubs* solidGuide = new G4Tubs("SolidGuide", GuideR, GuideR + GuideW, GuideL / 2., 0., twopi);
139
140 G4LogicalVolume* logicGuide = new G4LogicalVolume(solidGuide, fGuideMaterial, "Guide");
141
142 new G4PVPlacement(0, G4ThreeVector(), "Guide", logicGuide, physiWorld, false, 0);
143
144 // ------------------------------ End Plate -----------------------------------
145
146 G4Tubs* solidEndPlate = new G4Tubs("EndPlate", 0., GuideR, GuideW / 2., 0., twopi);
147
148 G4LogicalVolume* logicEndPlate = new G4LogicalVolume(solidEndPlate, fVacuum, "EndPlate");
149
150 G4ThreeVector endPlatePos = G4ThreeVector(0., 0., GuideL / 2. + GuideW / 2.);
151
152 new G4PVPlacement(0, endPlatePos, "EndPlate", logicEndPlate, physiWorld, false, 0);
153
154 G4double maxStep = 1.0 * mm;
155 G4double maxTime = 100. * s;
156
157 G4UserLimits* stepLimit = new G4UserLimits(maxStep, DBL_MAX, maxTime);
158
159 logicWorld->SetUserLimits(stepLimit);
160
161 //
162 // Visualization attributes
163 //
164
165 G4VisAttributes* guideColor = new G4VisAttributes(G4Colour(0.0, 0.0, 1.0));
166 guideColor->SetVisibility(true);
167 guideColor->SetForceWireframe(true);
168
169 G4VisAttributes* endPlateColor = new G4VisAttributes(G4Colour(1.0, 0.0, 0.0));
170 endPlateColor->SetVisibility(true);
171 endPlateColor->SetForceSolid(true);
172
173 logicWorld->SetVisAttributes(G4VisAttributes::GetInvisible());
174 logicGuide->SetVisAttributes(guideColor);
175 logicEndPlate->SetVisAttributes(endPlateColor);
176
177 //
178 // always return the physical World
179 //
180 return physiWorld;
181 }
182
183 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
184
185 G4ThreadLocal G4UniformGravityField* ExUCNDetectorConstruction::fField = 0;
186
187 void ExUCNDetectorConstruction::ConstructSDandField()
188 {
189 if (!fField) {
190 fField = new G4UniformGravityField();
191
192 G4RepleteEofM* equation = new G4RepleteEofM(fField);
193 // G4RepleteEofM* equation = new G4RepleteEofM(fField,12);
194 // G4EqGravityField* equation = new G4EqGravityField(fField);
195
196 G4FieldManager* fieldManager =
197 G4TransportationManager::GetTransportationManager()->GetFieldManager();
198 fieldManager->SetDetectorField(fField);
199
200 G4MagIntegratorStepper* stepper = new G4ClassicalRK4(equation, 8);
201 // G4MagIntegratorStepper* stepper = new G4ClassicalRK4(equation,12);
202
203 G4double minStep = 0.01 * mm;
204
205 G4ChordFinder* chordFinder = new G4ChordFinder((G4MagneticField*)fField, minStep, stepper);
206
207 // Set accuracy parameters
208 G4double deltaChord = 3.0 * mm;
209 chordFinder->SetDeltaChord(deltaChord);
210
211 G4double deltaOneStep = 0.01 * mm;
212 fieldManager->SetAccuraciesWithDeltaOneStep(deltaOneStep);
213
214 G4double deltaIntersection = 0.1 * mm;
215 fieldManager->SetDeltaIntersection(deltaIntersection);
216
217 G4TransportationManager* transportManager = G4TransportationManager::GetTransportationManager();
218
219 G4PropagatorInField* fieldPropagator = transportManager->GetPropagatorInField();
220
221 // Dimensionless limits for relative accuracy of integration
222 G4double epsMin = 2.5e-7;
223 G4double epsMax = 0.001; // Will soon be maximum without warning.
224 // The relative accuracy used for a step of length 'l'
225 // a.) epsMin if deltaOneStep / l < epsMin
226 // epsilon_step = b.) epsMax if deltaOneStep / l > epsMax
227 // c.) deltaOneStep / l otherwise
228
229 fieldPropagator->SetMinimumEpsilonStep(epsMin);
230 fieldPropagator->SetMaximumEpsilonStep(epsMax);
231
232 fieldManager->SetChordFinder(chordFinder);
233 }
234 }
235
236 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
237