4 // Author: I. Hrivnacova
6 // Class AliPrimaryGeneratorAction
7 // -------------------------------
8 // See the class description in the header file.
10 #include "AliPrimaryGeneratorAction.h"
11 #include "AliPrimaryGeneratorMessenger.h"
12 #include "AliTrackingAction.h"
13 #include "AliParticleGun.h"
14 #include "AliGunParticle.h"
15 #include "AliGlobals.h"
17 #include "AliGenerator.h"
19 #include "TG4G3Units.h"
22 #include <G4ParticleTable.hh>
23 #include <G4ParticleDefinition.hh>
25 #include <Randomize.hh>
27 #include <TParticle.h>
29 //_____________________________________________________________________________
30 AliPrimaryGeneratorAction::AliPrimaryGeneratorAction()
31 : AliVerbose("primaryGeneratorAction"),
32 fGenerator(kAliGenerator),
39 //_____________________________________________________________________________
40 AliPrimaryGeneratorAction::~AliPrimaryGeneratorAction() {
46 //_____________________________________________________________________________
47 void AliPrimaryGeneratorAction::ConstructGenerator()
49 // Constructs selected generator.
54 // gun is constructed interactively
57 ConstructGeantinoGenerator(false);
59 case kChargedGeantino:
60 ConstructGeantinoGenerator(true);
63 ConstructAliGenerator();
68 //_____________________________________________________________________________
69 void AliPrimaryGeneratorAction::ConstructGeantinoGenerator(G4bool isCharged)
71 // Geantino with random momentum direction
72 // (the default generator).
78 G4ParticleTable* particleTable
79 = G4ParticleTable::GetParticleTable();
81 for (G4int i=0; i< fNofGunParticles; i++)
83 G4ParticleDefinition* particleDef = 0;
85 particleDef = particleTable->FindParticle("geantino");
87 particleDef = particleTable->FindParticle("chargedgeantino");
90 G4String text = "AliPrimaryGeneratorAction::GenerateGeantino:\n";
91 text = text + " G4ParticleTable::FindParticle() failed.";
92 AliGlobals::Exception(text);
96 RandFlat::shootArray(3,rn);
100 G4ThreeVector momentumDir(px, py, pz);
102 G4double energy = 1.*GeV;
103 G4ThreeVector position(0.,0.,0.);
105 G4ThreeVector polarization(0.,0.,0.);
107 AliGunParticle * gunParticle
108 = new AliGunParticle(particleDef, momentumDir, energy, position, time,
111 fParticleGun.AddParticle(gunParticle);
113 if (VerboseLevel() > 1) {
114 G4cout << "Geantino generator has been built." << G4endl;
118 //_____________________________________________________________________________
119 void AliPrimaryGeneratorAction::ConstructAliGenerator()
121 // Generator from AliRoot
122 // AliGenerator::Generate() fills the AliRun::fParticles array.
125 // check if AliGenerator is set
126 AliGenerator* generator = gAlice->Generator();
128 G4String text = "AliPrimaryGeneratorAction::ConstructGenerator:\n";
129 text = text + " No AliGenerator is defined in gAlice.";
130 AliGlobals::Exception(text);
132 // fill AliRun::fParticleMap array
133 generator->Generate();
136 //_____________________________________________________________________________
137 void AliPrimaryGeneratorAction::GenerateAliGeneratorPrimaries(G4Event* event)
139 // Creates a new G4PrimaryVertex objects for each TParticle
140 // in fParticles array.
143 G4PrimaryVertex* previousVertex = 0;
144 G4ThreeVector previousPosition = G4ThreeVector();
145 G4double previousTime = 0.;
147 G4int nofParticles = gAlice->GetNtrack();
149 //G4cout << " nofParticles: " << nofParticles << G4endl;
150 for( G4int i=0; i<nofParticles; i++ ) {
152 // get the particle from AliRun stack
153 TParticle* particle = gAlice->Particle(i);
156 if (!particle->TestBit(kDoneBit)) {
157 // only particles that didn't die (decay) in primary generator
158 // will be transformed to G4 objects
160 // get particle definition from G4ParticleTable
161 G4int pdgEncoding = particle->GetPdgCode();
162 G4ParticleTable* particleTable
163 = G4ParticleTable::GetParticleTable();
164 G4ParticleDefinition* particleDefinition = 0;
165 if (pdgEncoding != 0)
166 particleDefinition = particleTable->FindParticle(pdgEncoding);
168 G4String name = particle->GetName();
169 if (name == "Rootino")
170 particleDefinition = particleTable->FindParticle("geantino");
173 if (particleDefinition==0) {
174 G4cout << "pdgEncoding: " << pdgEncoding << G4endl;
176 "AliPrimaryGeneratorAction::GenerateAliGeneratorPrimaries:\n";
177 text = text + " G4ParticleTable::FindParticle() failed.";
178 AliGlobals::Exception(text);
182 G4ThreeVector position
183 = G4ThreeVector(particle->Vx()*TG4G3Units::Length(),
184 particle->Vy()*TG4G3Units::Length(),
185 particle->Vz()*TG4G3Units::Length());
186 G4double time = particle->T()*TG4G3Units::Time();
187 G4PrimaryVertex* vertex;
188 if ( i==0 || position != previousPosition || time != previousTime ) {
189 // create a new vertex
190 // in case position and time of gun particle are different from
192 // (vertex objects are destroyed in G4EventManager::ProcessOneEvent()
193 // when event is deleted)
194 vertex = new G4PrimaryVertex(position, time);
195 event->AddPrimaryVertex(vertex);
197 previousVertex = vertex;
198 previousPosition = position;
202 vertex = previousVertex;
204 // create a primary particle and add it to the vertex
205 // (primaryParticle objects are destroyed in G4EventManager::ProcessOneEvent()
206 // when event and then vertex is deleted)
207 G4double px = particle->Px()*TG4G3Units::Energy();
208 G4double py = particle->Py()*TG4G3Units::Energy();
209 G4double pz = particle->Pz()*TG4G3Units::Energy();
210 G4PrimaryParticle* primaryParticle
211 = new G4PrimaryParticle(particleDefinition, px, py, pz);
214 TVector3 polarization;
215 particle->GetPolarisation(polarization);
217 ->SetPolarization(polarization.X(), polarization.Y(), polarization.Z());
219 // add primary particle to the vertex
220 vertex->SetPrimary(primaryParticle);
227 //_____________________________________________________________________________
228 void AliPrimaryGeneratorAction::GeneratePrimaries(G4Event* event)
230 // Generates primary particles by the selected generator.
234 gAlice->BeginEvent();
236 // fill particle gun/particle array
237 ConstructGenerator();
239 // generate primary vertices
240 if (fGenerator == kAliGenerator) {
241 // use AliGenerator if set
242 GenerateAliGeneratorPrimaries(event);
244 // do not save primary particles
245 // (they would be stored twice)
246 AliTrackingAction* trackingAction
247 = AliTrackingAction::Instance();
248 if (trackingAction) trackingAction->SetSavePrimaries(false);
251 // use particle gun otherwise
252 fParticleGun.GeneratePrimaryVertex(event);
254 // primary particles have to be saved
255 AliTrackingAction* trackingAction
256 = AliTrackingAction::Instance();
257 if (trackingAction) trackingAction->SetSavePrimaries(true);
261 //_____________________________________________________________________________
262 void AliPrimaryGeneratorAction::SetGenerator(AliPrimaryGenerator generator)
267 fGenerator = generator;
270 //_____________________________________________________________________________
271 void AliPrimaryGeneratorAction::SetNofGunParticles(G4int nofParticles)
273 // Sets number of primary particles.
274 // This method is applied only to "gun" type generators
275 // (and not to AliGenerator from AliRoot).
278 fNofGunParticles = nofParticles;