Merged ITS-working with HEAD. Improved some of the documentation and
[u/mrichter/AliRoot.git] / PHOS / AliPHOSvFast.cxx
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3decf5cb 1/**************************************************************************
2 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
3 * *
4 * Author: The ALICE Off-line Project. *
5 * Contributors are mentioned in the code where appropriate. *
6 * *
7 * Permission to use, copy, modify and distribute this software and its *
8 * documentation strictly for non-commercial purposes is hereby granted *
9 * without fee, provided that the above copyright notice appears in all *
10 * copies and that both the copyright notice and this permission notice *
11 * appear in the supporting documentation. The authors make no claims *
12 * about the suitability of this software for any purpose. It is *
13 * provided "as is" without express or implied warranty. *
14 **************************************************************************/
15
16//_________________________________________________________________________
17// Manager class for PHOS version for fast simulations
18//*-- Author : Y. Schutz SUBATECH
19//////////////////////////////////////////////////////////////////////////////
20
21// --- ROOT system ---
22
23#include "TBRIK.h"
24#include "TNode.h"
25#include "TParticle.h"
26
27// --- Standard library ---
28
29#include <cstdio>
30#include <cassert>
31
32// --- AliRoot header files ---
33
34#include "AliPHOSvFast.h"
3decf5cb 35#include "AliRun.h"
36#include "AliConst.h"
37
38ClassImp(AliPHOSvFast)
39
40//____________________________________________________________________________
41AliPHOSvFast::AliPHOSvFast()
42{
a73f33f0 43 fFastRecParticles = 0 ;
3decf5cb 44 fNRecParticles = 0 ;
45}
46
47//____________________________________________________________________________
48AliPHOSvFast::AliPHOSvFast(const char *name, const char *title):
49 AliPHOS(name,title)
50{
51 // gets an instance of the geometry parameters class
52
53 fGeom = AliPHOSGeometry::GetInstance(title, "") ;
54
55 if (fGeom->IsInitialized() )
56 cout << "AliPHOSvFast : PHOS geometry intialized for " << fGeom->GetName() << endl ;
57 else
58 cout << "AliPHOSvFast : PHOS geometry initialization failed !" << endl ;
59
60 SetBigBox(0, fGeom->GetOuterBoxSize(0) ) ;
61 SetBigBox(1, fGeom->GetOuterBoxSize(1) + fGeom->GetPPSDBoxSize(1) ) ;
62 SetBigBox(2, fGeom->GetOuterBoxSize(0) );
63
64 fNRecParticles = 0 ;
a73f33f0 65 fFastRecParticles = new FastRecParticlesList("AliPHOSFastRecParticle", 100) ;
66
b1aa729d 67 fResPara1 = 0.030 ; // GeV
68 fResPara2 = 0.00003 ;
69 fResPara3 = 0.00001 ;
70
71 fPosParaA0 = 2.87 ; // mm
72 fPosParaA1 = -0.0975 ;
73 fPosParaB0 = 0.257 ;
74 fPosParaB1 = 0.137 ;
75 fPosParaB2 = 0.00619 ;
3decf5cb 76}
77
78//____________________________________________________________________________
79AliPHOSvFast::~AliPHOSvFast()
80{
81
a73f33f0 82 fFastRecParticles->Delete() ;
83 delete fFastRecParticles ;
84 fFastRecParticles = 0 ;
3decf5cb 85
86}
87
88//____________________________________________________________________________
a73f33f0 89void AliPHOSvFast::AddRecParticle(const AliPHOSFastRecParticle & rp)
90{
f96d3dc7 91 new( (*fFastRecParticles)[fNRecParticles] ) AliPHOSFastRecParticle(rp) ;
92 fNRecParticles++ ;
3decf5cb 93}
94
95//____________________________________________________________________________
96void AliPHOSvFast::BuildGeometry()
97{
98
99 // Build the PHOS geometry for the ROOT display
100
101 const Int_t kColorPHOS = kRed ;
102
103 Double_t const kRADDEG = 180.0 / kPI ;
104
105 new TBRIK( "BigBox", "PHOS box", "void", GetBigBox(0)/2,
106 GetBigBox(1)/2,
107 GetBigBox(2)/2 );
108
109 // position PHOS into ALICE
110
111 Float_t r = fGeom->GetIPtoOuterCoverDistance() + GetBigBox(1) / 2.0 ;
112 Int_t number = 988 ;
113 Float_t pphi = TMath::ATan( GetBigBox(0) / ( 2.0 * fGeom->GetIPtoOuterCoverDistance() ) ) ;
114 pphi *= kRADDEG ;
115 TNode * top = gAlice->GetGeometry()->GetNode("alice") ;
116
117 char * nodename = new char[20] ;
118 char * rotname = new char[20] ;
119
120 for( Int_t i = 1; i <= fGeom->GetNModules(); i++ ) {
121 Float_t angle = pphi * 2 * ( i - fGeom->GetNModules() / 2.0 - 0.5 ) ;
122 sprintf(rotname, "%s%d", "rot", number++) ;
123 new TRotMatrix(rotname, rotname, 90, angle, 90, 90 + angle, 0, 0);
124 top->cd();
125 sprintf(nodename,"%s%d", "Module", i) ;
126 Float_t x = r * TMath::Sin( angle / kRADDEG ) ;
127 Float_t y = -r * TMath::Cos( angle / kRADDEG ) ;
128 TNode * bigboxnode = new TNode(nodename, nodename, "BigBox", x, y, 0, rotname ) ;
129 bigboxnode->SetLineColor(kColorPHOS) ;
130 fNodes->Add(bigboxnode) ;
131 }
132 delete[] nodename ;
133 delete[] rotname ;
134}
135
136//____________________________________________________________________________
137void AliPHOSvFast::CreateGeometry()
138{
139
140 AliPHOSvFast *phostmp = (AliPHOSvFast*)gAlice->GetModule("PHOS") ;
141
142 if ( phostmp == NULL ) {
143
144 fprintf(stderr, "PHOS detector not found!\n") ;
145 return ;
146
147 }
148
149 // Get pointer to the array containing media indeces
150 Int_t *idtmed = fIdtmed->GetArray() - 699 ;
151
152 Float_t bigbox[3] ;
153 bigbox[0] = GetBigBox(0) / 2.0 ;
154 bigbox[1] = GetBigBox(1) / 2.0 ;
155 bigbox[2] = GetBigBox(2) / 2.0 ;
156
157 gMC->Gsvolu("PHOS", "BOX ", idtmed[798], bigbox, 3) ;
158
159 // --- Position PHOS mdules in ALICE setup ---
160
161 Int_t idrotm[99] ;
162 Double_t const kRADDEG = 180.0 / kPI ;
163
164 for( Int_t i = 1; i <= fGeom->GetNModules(); i++ ) {
165
166 Float_t angle = fGeom->GetPHOSAngle(i) ;
167 AliMatrix(idrotm[i-1], 90.0, angle, 90.0, 90.0+angle, 0.0, 0.0) ;
168
169 Float_t r = fGeom->GetIPtoOuterCoverDistance() + GetBigBox(1) / 2.0 ;
170
171 Float_t xP1 = r * TMath::Sin( angle / kRADDEG ) ;
172 Float_t yP1 = -r * TMath::Cos( angle / kRADDEG ) ;
3decf5cb 173 gMC->Gspos("PHOS", i, "ALIC", xP1, yP1, 0.0, idrotm[i-1], "ONLY") ;
174
175 } // for GetNModules
176
177}
178
179
180//____________________________________________________________________________
181void AliPHOSvFast::Init(void)
182{
183
184 Int_t i;
185
186 printf("\n");
187 for(i=0;i<35;i++) printf("*");
188 printf(" FAST PHOS_INIT ");
189 for(i=0;i<35;i++) printf("*");
190 printf("\n");
191
192 // Here the PHOS initialisation code (if any!)
193
194 for(i=0;i<80;i++) printf("*");
195 printf("\n");
196
197}
198
199//___________________________________________________________________________
200Float_t AliPHOSvFast::GetBigBox(Int_t index)
201{
202 Float_t rv = 0 ;
203
204 switch (index) {
205 case 0:
206 rv = fBigBoxX ;
207 break ;
208 case 1:
209 rv = fBigBoxY ;
210 break ;
211 case 2:
212 rv = fBigBoxZ ;
213 break ;
214 }
215 return rv ;
216}
217
218//___________________________________________________________________________
219void AliPHOSvFast::MakeBranch(Option_t* opt)
220{
221 //
222 // Create a new branch in the current Root Tree
f96d3dc7 223
3decf5cb 224 AliDetector::MakeBranch(opt) ;
225
226 char branchname[10];
227 sprintf(branchname,"%s",GetName());
a73f33f0 228 char *cd = strstr(opt,"R");
3decf5cb 229
a73f33f0 230 if (fFastRecParticles && gAlice->TreeR() && cd) {
231 gAlice->TreeR()->Branch(branchname, &fFastRecParticles, fBufferSize);
3decf5cb 232 }
233}
234
a73f33f0 235//____________________________________________________________________________
236Double_t AliPHOSvFast::MakeEnergy(const Double_t energy)
237{
b1aa729d 238 Double_t sigma = SigmaE(energy) ;
239 return fRan.Gaus(energy, sigma) ;
a73f33f0 240}
241
242//____________________________________________________________________________
b1aa729d 243TVector3 AliPHOSvFast::MakePosition(const Double_t energy, const TVector3 pos, const Double_t theta, const Double_t phi)
a73f33f0 244{
b1aa729d 245 TVector3 newpos ;
246 Double_t sigma = SigmaP( energy, theta*180./TMath::Pi() ) ;
247 Double_t x = fRan.Gaus( pos.X(), sigma ) ;
248 sigma = SigmaP( energy, phi*180./TMath::Pi() ) ;
249 Double_t z = fRan.Gaus( pos.Z(), sigma ) ;
250 Double_t y = pos.Y() ;
251
252 newpos.SetX(x) ;
253 newpos.SetY(y) ;
254 newpos.SetZ(z) ;
255
256 return newpos ;
257}
a73f33f0 258
b1aa729d 259//____________________________________________________________________________
260void AliPHOSvFast::MakeRecParticle(const Int_t modid, const TVector3 pos, AliPHOSFastRecParticle & rp)
261{
a73f33f0 262 // get the detected type of particle
b1aa729d 263
264 Int_t type = MakeType( rp ) ;
a73f33f0 265 rp.SetType(type) ;
266
267
268 // get the detected energy
269
270 TLorentzVector momentum ;
271 rp.Momentum(momentum) ;
272 Double_t kineticenergy = TMath::Sqrt( TMath::Power(momentum.E(), 2) - TMath::Power(rp.GetMass(), 2) ) ;
273 Double_t modifiedkineticenergy = MakeEnergy(kineticenergy ) ;
b1aa729d 274 Double_t modifiedenergy = TMath::Sqrt( TMath::Power(modifiedkineticenergy, 2)
275 + TMath::Power( rp.GetMass(), 2) ) ;
276
277 // get the angle of incidence
278
279 Double_t incidencetheta = 90. * TMath::Pi() /180 - rp.Theta() ;
280 Double_t incidencephi = ( 270 + fGeom->GetPHOSAngle(modid) ) * TMath::Pi() / 180. - rp.Phi() ;
281
282 // get the detected direction
283
284 TVector3 modifiedposition = MakePosition(kineticenergy, pos, incidencetheta, incidencephi) ;
285 modifiedposition *= modifiedkineticenergy / modifiedposition.Mag() ;
286
287 // Set the modified 4-momentum of the reconstructed particle
288
289 rp.SetMomentum(modifiedposition.X(), modifiedposition.Y(), modifiedposition.Z(), modifiedenergy) ;
290
a73f33f0 291 }
292
293//____________________________________________________________________________
b1aa729d 294Int_t AliPHOSvFast::MakeType(AliPHOSFastRecParticle & rp )
a73f33f0 295{
296 Int_t rv = kUNDEFINED ;
b1aa729d 297 Int_t charge = (Int_t)rp.GetPDG()->Charge() ;
298 Int_t test ;
299 Float_t ran ;
f96d3dc7 300 if ( charge != 0 && ( TMath::Abs(rp.GetPdgCode()) != 11 ) )
b1aa729d 301 test = - 1 ;
302 else
303 test = rp.GetPdgCode() ;
304
305 switch (test) {
306
307 case 22: // it's a photon
308 ran = fRan.Rndm() ;
309 if ( ran <= 0.5 ) // 50 %
310 rv = kGAMMA ;
311 else {
312 ran = fRan.Rndm() ;
313 if( ran <= 0.9498 )
314 rv = kNEUTRALEM ;
315 else
316 rv = kNEUTRALHADRON ;
317 }
318 break ;
319
320 case 2112: // it's a neutron
321 ran = fRan.Rndm() ;
322 if ( ran <= 0.9998 )
323 rv = kNEUTRALHADRON ;
324 else
325 rv = kNEUTRALEM ;
326 break ;
327
328 case -2112: // it's a anti-neutron
329 ran = fRan.Rndm() ;
330 if ( ran <= 0.9984 )
331 rv = kNEUTRALHADRON ;
332 else
333 rv = kNEUTRALEM ;
334 break ;
335
336 case 11: // it's a electron
337 ran = fRan.Rndm() ;
338 if ( ran <= 0.9996 )
339 rv = kELECTRON ;
340 else
341 rv = kCHARGEDHADRON ;
342 break;
343
f96d3dc7 344 case -11: // it's a positon
b1aa729d 345 ran = fRan.Rndm() ;
346 if ( ran <= 0.9996 )
347 rv = kELECTRON ;
348 else
349 rv = kCHARGEDHADRON ;
350 break;
351
352 case -1: // it's a charged
353 ran = fRan.Rndm() ;
354 if ( ran <= 0.9996 )
355 rv = kCHARGEDHADRON ;
356 else
357 rv = kGAMMA ;
358
359 break ;
360 }
361
362
a73f33f0 363 return rv ;
364}
365
3decf5cb 366//___________________________________________________________________________
f96d3dc7 367void AliPHOSvFast::ResetPoints()
368{
369 ResetFastRecParticles() ;
370}
371
372//___________________________________________________________________________
373void AliPHOSvFast::ResetFastRecParticles()
374{
375 if (fFastRecParticles)
376 fFastRecParticles->Clear() ;
377 fNRecParticles = 0 ;
378}
379
380//___________________________________________________________________________
3decf5cb 381void AliPHOSvFast::SetBigBox(Int_t index, Float_t value)
382{
383
384 switch (index) {
385 case 0:
386 fBigBoxX = value ;
387 break ;
388 case 1:
389 fBigBoxY = value ;
390 break ;
391 case 2:
392 fBigBoxZ = value ;
393 break ;
394 }
395
396}
397
398//____________________________________________________________________________
a73f33f0 399Double_t AliPHOSvFast::SigmaE(Double_t energy)
400{
401 Double_t rv = -1 ;
402
403 rv = TMath::Sqrt( TMath::Power(fResPara1/energy, 2)
404 + TMath::Power(fResPara2/TMath::Sqrt(energy), 2)
405 + TMath::Power(fResPara3, 2) ) ;
406
407 return rv * energy ;
408}
409
410//____________________________________________________________________________
b1aa729d 411Double_t AliPHOSvFast::SigmaP(Double_t energy, Int_t incidence)
412{
413
414 Double_t paraA = fPosParaA0 + fPosParaA1 * incidence ;
415 Double_t paraB = fPosParaB0 + fPosParaB1 * incidence + fPosParaB2 * incidence * incidence ;
416
417 return ( paraA / TMath::Sqrt(energy) + paraB ) * 0.1 ; // in cm
418}
419
420//____________________________________________________________________________
3decf5cb 421void AliPHOSvFast::StepManager(void)
422{
423
424 Int_t primary = gAlice->GetPrimary( gAlice->CurrentTrack() );
a73f33f0 425 TLorentzVector lv ;
426 gMC->TrackPosition(lv) ;
b1aa729d 427 TVector3 pos = lv.Vect() ;
428 Int_t modid ;
429 gMC->CurrentVolID(modid);
a73f33f0 430
431 // Makes a reconstructed particle from the primary particle
3decf5cb 432
a73f33f0 433 TClonesArray * particlelist = gAlice->Particles() ;
434 TParticle * part = (TParticle *)particlelist->At(primary) ;
435
436 AliPHOSFastRecParticle rp(*part) ;
437
438 // Adds the response of PHOS to the particle
b1aa729d 439
440 MakeRecParticle(modid, pos, rp) ;
3decf5cb 441
a73f33f0 442 // add the primary particle to the FastRecParticles list
b1aa729d 443
a73f33f0 444 AddRecParticle(rp) ;
445
446 // stop the track as soon PHOS is reached
b1aa729d 447
3decf5cb 448 gMC->StopTrack() ;
449
450}
451