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27 //
28 ////////////////////////////////////////////////////////////////////////
29 // Optical Photon WaveLength Shifting (WLS) Class Implementation
30 ////////////////////////////////////////////////////////////////////////
31 //
32 // File: G4OpWLS.cc
33 // Description: Discrete Process -- Wavelength Shifting of Optical Photons
34 // Version: 1.0
35 // Created: 2003-05-13
36 // Author: John Paul Archambault
37 // (Adaptation of G4Scintillation and G4OpAbsorption)
38 // Updated: 2005-07-28 - add G4ProcessType to constructor
39 // 2006-05-07 - add G4VWLSTimeGeneratorProfile
40 //
41 ////////////////////////////////////////////////////////////////////////
42
43 #include "G4OpWLS.hh"
44 #include "G4ios.hh"
45 #include "G4PhysicalConstants.hh"
46 #include "G4SystemOfUnits.hh"
47 #include "G4OpProcessSubType.hh"
48 #include "G4Poisson.hh"
49 #include "G4OpticalParameters.hh"
50 #include "G4WLSTimeGeneratorProfileDelta.hh"
51 #include "G4WLSTimeGeneratorProfileExponential.hh"
52
53 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
54 G4OpWLS::G4OpWLS(const G4String& processName, G4ProcessType type)
55 : G4VDiscreteProcess(processName, type)
56 {
57 WLSTimeGeneratorProfile = nullptr;
58 Initialise();
59 SetProcessSubType(fOpWLS);
60 theIntegralTable = nullptr;
61
62 if(verboseLevel > 0)
63 G4cout << GetProcessName() << " is created " << G4endl;
64 }
65
66 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
67 G4OpWLS::~G4OpWLS()
68 {
69 if(theIntegralTable)
70 {
71 theIntegralTable->clearAndDestroy();
72 delete theIntegralTable;
73 }
74 delete WLSTimeGeneratorProfile;
75 }
76
77 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
78 void G4OpWLS::PreparePhysicsTable(const G4ParticleDefinition&) { Initialise(); }
79
80 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
81 void G4OpWLS::Initialise()
82 {
83 G4OpticalParameters* params = G4OpticalParameters::Instance();
84 SetVerboseLevel(params->GetWLSVerboseLevel());
85 UseTimeProfile(params->GetWLSTimeProfile());
86 }
87
88 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
89 G4VParticleChange* G4OpWLS::PostStepDoIt(const G4Track& aTrack,
90 const G4Step& aStep)
91 {
92 std::vector<G4Track*> proposedSecondaries;
93 aParticleChange.Initialize(aTrack);
94 aParticleChange.ProposeTrackStatus(fStopAndKill);
95
96 if(verboseLevel > 1)
97 {
98 G4cout << "\n** G4OpWLS: Photon absorbed! **" << G4endl;
99 }
100
101 G4StepPoint* pPostStepPoint = aStep.GetPostStepPoint();
102 G4MaterialPropertiesTable* MPT =
103 aTrack.GetMaterial()->GetMaterialPropertiesTable();
104 if(!MPT)
105 {
106 return G4VDiscreteProcess::PostStepDoIt(aTrack, aStep);
107 }
108 if(!MPT->GetProperty(kWLSCOMPONENT))
109 {
110 return G4VDiscreteProcess::PostStepDoIt(aTrack, aStep);
111 }
112
113 G4int NumPhotons = 1;
114 if(MPT->ConstPropertyExists(kWLSMEANNUMBERPHOTONS))
115 {
116 G4double MeanNumberOfPhotons = MPT->GetConstProperty(kWLSMEANNUMBERPHOTONS);
117 NumPhotons = G4int(G4Poisson(MeanNumberOfPhotons));
118 if(NumPhotons <= 0)
119 {
120 // return unchanged particle and no secondaries
121 aParticleChange.SetNumberOfSecondaries(0);
122 return G4VDiscreteProcess::PostStepDoIt(aTrack, aStep);
123 }
124 }
125
126 // Retrieve the WLS Integral for this material
127 // new G4PhysicsFreeVector allocated to hold CII's
128 G4double primaryEnergy = aTrack.GetDynamicParticle()->GetKineticEnergy();
129 G4double WLSTime = 0.;
130 G4PhysicsFreeVector* WLSIntegral = nullptr;
131
132 WLSTime = MPT->GetConstProperty(kWLSTIMECONSTANT);
133 WLSIntegral = (G4PhysicsFreeVector*) ((*theIntegralTable)(
134 aTrack.GetMaterial()->GetIndex()));
135
136 // Max WLS Integral
137 G4double CIImax = WLSIntegral->GetMaxValue();
138 G4int NumberOfPhotons = NumPhotons;
139
140 for(G4int i = 0; i < NumPhotons; ++i)
141 {
142 G4double sampledEnergy;
143 // Make sure the energy of the secondary is less than that of the primary
144 for(G4int j = 1; j <= 100; ++j)
145 {
146 // Determine photon energy
147 G4double CIIvalue = G4UniformRand() * CIImax;
148 sampledEnergy = WLSIntegral->GetEnergy(CIIvalue);
149 if(sampledEnergy <= primaryEnergy)
150 break;
151 }
152 // If no such energy can be sampled, return one less secondary, or none
153 if(sampledEnergy > primaryEnergy)
154 {
155 if(verboseLevel > 1)
156 {
157 G4cout << " *** G4OpWLS: One less WLS photon will be returned ***"
158 << G4endl;
159 }
160 NumberOfPhotons--;
161 if(NumberOfPhotons == 0)
162 {
163 if(verboseLevel > 1)
164 {
165 G4cout
166 << " *** G4OpWLS: No WLS photon can be sampled for this primary ***"
167 << G4endl;
168 }
169 // return unchanged particle and no secondaries
170 aParticleChange.SetNumberOfSecondaries(0);
171 return G4VDiscreteProcess::PostStepDoIt(aTrack, aStep);
172 }
173 continue;
174 }
175 else if(verboseLevel > 1)
176 {
177 G4cout << "G4OpWLS: Created photon with energy: " << sampledEnergy
178 << G4endl;
179 }
180
181 // Generate random photon direction
182 G4double cost = 1. - 2. * G4UniformRand();
183 G4double sint = std::sqrt((1. - cost) * (1. + cost));
184 G4double phi = twopi * G4UniformRand();
185 G4double sinp = std::sin(phi);
186 G4double cosp = std::cos(phi);
187 G4ParticleMomentum photonMomentum(sint * cosp, sint * sinp, cost);
188
189 G4ThreeVector photonPolarization(cost * cosp, cost * sinp, -sint);
190 G4ThreeVector perp = photonMomentum.cross(photonPolarization);
191
192 phi = twopi * G4UniformRand();
193 sinp = std::sin(phi);
194 cosp = std::cos(phi);
195 photonPolarization = (cosp * photonPolarization + sinp * perp).unit();
196
197 // Generate a new photon:
198 auto sec_dp =
199 new G4DynamicParticle(G4OpticalPhoton::OpticalPhoton(), photonMomentum);
200 sec_dp->SetPolarization(photonPolarization);
201 sec_dp->SetKineticEnergy(sampledEnergy);
202
203 G4double secTime = pPostStepPoint->GetGlobalTime() +
204 WLSTimeGeneratorProfile->GenerateTime(WLSTime);
205 G4ThreeVector secPos = pPostStepPoint->GetPosition();
206 G4Track* secTrack = new G4Track(sec_dp, secTime, secPos);
207
208 secTrack->SetTouchableHandle(aTrack.GetTouchableHandle());
209 secTrack->SetParentID(aTrack.GetTrackID());
210
211 proposedSecondaries.push_back(secTrack);
212 }
213
214 aParticleChange.SetNumberOfSecondaries((G4int)proposedSecondaries.size());
215 for(auto sec : proposedSecondaries)
216 {
217 aParticleChange.AddSecondary(sec);
218 }
219 if(verboseLevel > 1)
220 {
221 G4cout << "\n Exiting from G4OpWLS::DoIt -- NumberOfSecondaries = "
222 << aParticleChange.GetNumberOfSecondaries() << G4endl;
223 }
224
225 return G4VDiscreteProcess::PostStepDoIt(aTrack, aStep);
226 }
227
228 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
229 void G4OpWLS::BuildPhysicsTable(const G4ParticleDefinition&)
230 {
231 if(theIntegralTable)
232 {
233 theIntegralTable->clearAndDestroy();
234 delete theIntegralTable;
235 theIntegralTable = nullptr;
236 }
237
238 const G4MaterialTable* materialTable = G4Material::GetMaterialTable();
239 std::size_t numOfMaterials = G4Material::GetNumberOfMaterials();
240 theIntegralTable = new G4PhysicsTable(numOfMaterials);
241
242 // loop for materials
243 for(std::size_t i = 0; i < numOfMaterials; ++i)
244 {
245 auto physVector = new G4PhysicsFreeVector();
246
247 // Retrieve vector of WLS wavelength intensity for
248 // the material from the material's optical properties table.
249 G4MaterialPropertiesTable* MPT =
250 (*materialTable)[i]->GetMaterialPropertiesTable();
251 if(MPT)
252 {
253 G4MaterialPropertyVector* wlsVector = MPT->GetProperty(kWLSCOMPONENT);
254 if(wlsVector)
255 {
256 // Retrieve the first intensity point in vector
257 // of (photon energy, intensity) pairs
258 G4double currentIN = (*wlsVector)[0];
259 if(currentIN >= 0.0)
260 {
261 // Create first (photon energy)
262 G4double currentPM = wlsVector->Energy(0);
263 G4double currentCII = 0.0;
264 physVector->InsertValues(currentPM, currentCII);
265
266 // Set previous values to current ones prior to loop
267 G4double prevPM = currentPM;
268 G4double prevCII = currentCII;
269 G4double prevIN = currentIN;
270
271 // loop over all (photon energy, intensity)
272 // pairs stored for this material
273 for(std::size_t j = 1; j < wlsVector->GetVectorLength(); ++j)
274 {
275 currentPM = wlsVector->Energy(j);
276 currentIN = (*wlsVector)[j];
277 currentCII =
278 prevCII + 0.5 * (currentPM - prevPM) * (prevIN + currentIN);
279
280 physVector->InsertValues(currentPM, currentCII);
281
282 prevPM = currentPM;
283 prevCII = currentCII;
284 prevIN = currentIN;
285 }
286 }
287 }
288 }
289 theIntegralTable->insertAt(i, physVector);
290 }
291 }
292
293 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
294 G4double G4OpWLS::GetMeanFreePath(const G4Track& aTrack, G4double,
295 G4ForceCondition*)
296 {
297 G4double thePhotonEnergy = aTrack.GetDynamicParticle()->GetTotalEnergy();
298 G4double attLength = DBL_MAX;
299 G4MaterialPropertiesTable* MPT =
300 aTrack.GetMaterial()->GetMaterialPropertiesTable();
301
302 if(MPT)
303 {
304 G4MaterialPropertyVector* attVector = MPT->GetProperty(kWLSABSLENGTH);
305 if(attVector)
306 {
307 attLength = attVector->Value(thePhotonEnergy, idx_wls);
308 }
309 }
310 return attLength;
311 }
312
313 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
314 void G4OpWLS::UseTimeProfile(const G4String name)
315 {
316 if(WLSTimeGeneratorProfile)
317 {
318 delete WLSTimeGeneratorProfile;
319 WLSTimeGeneratorProfile = nullptr;
320 }
321 if(name == "delta")
322 {
323 WLSTimeGeneratorProfile = new G4WLSTimeGeneratorProfileDelta("delta");
324 }
325 else if(name == "exponential")
326 {
327 WLSTimeGeneratorProfile =
328 new G4WLSTimeGeneratorProfileExponential("exponential");
329 }
330 else
331 {
332 G4Exception("G4OpWLS::UseTimeProfile", "em0202", FatalException,
333 "generator does not exist");
334 }
335 G4OpticalParameters::Instance()->SetWLSTimeProfile(name);
336 }
337
338 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
339 void G4OpWLS::SetVerboseLevel(G4int verbose)
340 {
341 verboseLevel = verbose;
342 G4OpticalParameters::Instance()->SetWLSVerboseLevel(verboseLevel);
343 }
344