First attempt to use systemtically TFolders: the geometry object posts itself to...
[u/mrichter/AliRoot.git] / PHOS / AliPHOSv4.cxx
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5f20d3fb 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/* $Id$ */
17
18//_________________________________________________________________________
19// Implementation of the PHOS manager class for fast simulations
20// Tracks particles until the reach a grossly designed PHOS module
21// Modify the particles property (momentum, energy, type) according to
22// the PHOS response function. The result is called a virtual reconstructed
23// particle.
24//
25//*-- Author: Yves Schutz (SUBATECH)
26
27// --- ROOT system ---
28
29#include "TBRIK.h"
30#include "TNode.h"
31#include "TParticle.h"
94de3818 32#include "TTree.h"
33#include "TGeometry.h"
2ab0c725 34#include "TFile.h"
5f20d3fb 35
36// --- Standard library ---
37
38#include <stdio.h>
39
40// --- AliRoot header files ---
cede8016 41#include "AliPHOSFastRecParticle.h"
42#include "AliPHOSGeometry.h"
5f20d3fb 43#include "AliPHOSv4.h"
44#include "AliRun.h"
45#include "AliConst.h"
94de3818 46#include "AliMC.h"
5f20d3fb 47
48ClassImp(AliPHOSv4)
49
50//____________________________________________________________________________
5f20d3fb 51AliPHOSv4::AliPHOSv4(const char *name, const char *title):
52 AliPHOS(name,title)
53{
54 // ctor
55
56 // gets an instance of the geometry parameters class
5cbba5aa 57 if (strcmp(GetTitle(),"") != 0 )
fa7cce36 58 fGeom = AliPHOSGeometry::GetInstance(GetTitle(), "") ;
e04976bd 59
aafe457d 60
fa7cce36 61 SetBigBox(0, GetGeometry()->GetOuterBoxSize(0) ) ;
62 SetBigBox(1, GetGeometry()->GetOuterBoxSize(1) + GetGeometry()->GetCPVBoxSize(1) ) ;
63 SetBigBox(2, GetGeometry()->GetOuterBoxSize(0) );
aafe457d 64
65 fNRecParticles = 0 ;
66 fFastRecParticles = new AliPHOSFastRecParticle::FastRecParticlesList("AliPHOSFastRecParticle", 100) ;
5cbba5aa 67
aafe457d 68 fResPara1 = 0.030 ; // GeV
69 fResPara2 = 0.00003 ;
70 fResPara3 = 0.00001 ;
71
72 fPosParaA0 = 2.87 ; // mm
73 fPosParaA1 = -0.0975 ;
74 fPosParaB0 = 0.257 ;
75 fPosParaB1 = 0.137 ;
76 fPosParaB2 = 0.00619 ;
5f20d3fb 77}
78
79//____________________________________________________________________________
80AliPHOSv4::~AliPHOSv4()
81{
82 // dtor
83
84 fFastRecParticles->Delete() ;
85 delete fFastRecParticles ;
86 fFastRecParticles = 0 ;
87
88}
89
90//____________________________________________________________________________
91void AliPHOSv4::AddRecParticle(const AliPHOSFastRecParticle & rp)
92{
93 // Add a virtually reconstructed particle to the list
94
95 new( (*fFastRecParticles)[fNRecParticles] ) AliPHOSFastRecParticle(rp) ;
96 fNRecParticles++ ;
97}
98
99//____________________________________________________________________________
100void AliPHOSv4::BuildGeometry()
101{
102 // Build the PHOS geometry for the ROOT display
103 //BEGIN_HTML
104 /*
105 <H2>
106 PHOS FAST in ALICE displayed by root
107 </H2>
108 <H4> All Views </H4>
109 <P>
110 <CENTER>
111 <IMG Align=BOTTOM ALT="Fast All Views" SRC="../images/AliPHOSv4AllViews.gif">
112 </CENTER></P>
113 <H4> Front View </H4>
114 <P>
115 <CENTER>
116 <IMG Align=BOTTOM ALT="Fast Front View" SRC="../images/AliPHOSv4FrontView.gif">
117 </CENTER></P>
118 */
119 //END_HTML
120
121 const Int_t kColorPHOS = kRed ;
122
123 Double_t const kRADDEG = 180.0 / kPI ;
124
125 new TBRIK( "BigBox", "PHOS box", "void", GetBigBox(0)/2,
126 GetBigBox(1)/2,
127 GetBigBox(2)/2 );
128
129 // position PHOS into ALICE
130
fa7cce36 131 Float_t r = GetGeometry()->GetIPtoCrystalSurface() + GetBigBox(1) / 2.0 ;
5f20d3fb 132 Int_t number = 988 ;
fa7cce36 133 Float_t pphi = TMath::ATan( GetBigBox(0) / ( 2.0 * GetGeometry()->GetIPtoCrystalSurface() ) ) ;
5f20d3fb 134 pphi *= kRADDEG ;
135 TNode * top = gAlice->GetGeometry()->GetNode("alice") ;
136
137 char * nodename = new char[20] ;
138 char * rotname = new char[20] ;
139
fa7cce36 140 for( Int_t i = 1; i <= GetGeometry()->GetNModules(); i++ ) {
141 Float_t angle = pphi * 2 * ( i - GetGeometry()->GetNModules() / 2.0 - 0.5 ) ;
5f20d3fb 142 sprintf(rotname, "%s%d", "rot", number++) ;
143 new TRotMatrix(rotname, rotname, 90, angle, 90, 90 + angle, 0, 0);
144 top->cd();
145 sprintf(nodename,"%s%d", "Module", i) ;
146 Float_t x = r * TMath::Sin( angle / kRADDEG ) ;
147 Float_t y = -r * TMath::Cos( angle / kRADDEG ) ;
148 TNode * bigboxnode = new TNode(nodename, nodename, "BigBox", x, y, 0, rotname ) ;
149 bigboxnode->SetLineColor(kColorPHOS) ;
150 fNodes->Add(bigboxnode) ;
151 }
152 delete[] nodename ;
153 delete[] rotname ;
154}
155
156//____________________________________________________________________________
157void AliPHOSv4::CreateGeometry()
158{
159 // Create the geometry for GEANT
160
161 AliPHOSv4 *phostmp = (AliPHOSv4*)gAlice->GetModule("PHOS") ;
162
163 if ( phostmp == NULL ) {
164
165 fprintf(stderr, "PHOS detector not found!\n") ;
166 return ;
167
168 }
169
170 // Get pointer to the array containing media indeces
171 Int_t *idtmed = fIdtmed->GetArray() - 699 ;
172
173 Float_t bigbox[3] ;
174 bigbox[0] = GetBigBox(0) / 2.0 ;
175 bigbox[1] = GetBigBox(1) / 2.0 ;
176 bigbox[2] = GetBigBox(2) / 2.0 ;
177
178 gMC->Gsvolu("PHOS", "BOX ", idtmed[798], bigbox, 3) ;
179
180 // --- Position PHOS mdules in ALICE setup ---
181
182 Int_t idrotm[99] ;
183 Double_t const kRADDEG = 180.0 / kPI ;
184
fa7cce36 185 for( Int_t i = 1; i <= GetGeometry()->GetNModules(); i++ ) {
5f20d3fb 186
fa7cce36 187 Float_t angle = GetGeometry()->GetPHOSAngle(i) ;
5f20d3fb 188 AliMatrix(idrotm[i-1], 90.0, angle, 90.0, 90.0+angle, 0.0, 0.0) ;
189
fa7cce36 190 Float_t r = GetGeometry()->GetIPtoCrystalSurface() + GetBigBox(1) / 2.0 ;
5f20d3fb 191
192 Float_t xP1 = r * TMath::Sin( angle / kRADDEG ) ;
193 Float_t yP1 = -r * TMath::Cos( angle / kRADDEG ) ;
194 gMC->Gspos("PHOS", i, "ALIC", xP1, yP1, 0.0, idrotm[i-1], "ONLY") ;
195
196 } // for GetNModules
197
198}
199
200
201//____________________________________________________________________________
202void AliPHOSv4::Init(void)
203{
204 // Prints out an information message
205
206 Int_t i;
207
208 printf("\n");
209 for(i=0;i<35;i++) printf("*");
210 printf(" FAST PHOS_INIT ");
211 for(i=0;i<35;i++) printf("*");
212 printf("\n");
213
214 // Here the PHOS initialisation code (if any!)
215
216 for(i=0;i<80;i++) printf("*");
217 printf("\n");
218
219}
220
221//___________________________________________________________________________
baef0810 222Float_t AliPHOSv4::GetBigBox(Int_t index) const
5f20d3fb 223{
224 // Get the X, Y or Z dimension of the box describing a PHOS module
225
226 Float_t rv = 0 ;
227
228 switch (index) {
229 case 0:
230 rv = fBigBoxX ;
231 break ;
232 case 1:
233 rv = fBigBoxY ;
234 break ;
235 case 2:
236 rv = fBigBoxZ ;
237 break ;
238 }
239 return rv ;
240}
241
242//___________________________________________________________________________
9e1a0ddb 243void AliPHOSv4::MakeBranch(Option_t* opt, const char *file)
5f20d3fb 244{
245 // Create new branch in the current reconstructed Root Tree
246
2ab0c725 247 AliDetector::MakeBranch(opt,file) ;
5f20d3fb 248
249 char branchname[10];
250 sprintf(branchname,"%s",GetName());
5cf7bbad 251 const char *cd = strstr(opt,"R");
5f20d3fb 252
253 if (fFastRecParticles && gAlice->TreeR() && cd) {
9e1a0ddb 254 MakeBranchInTree(gAlice->TreeR(),
255 branchname, &fFastRecParticles, fBufferSize, file);
5f20d3fb 256 }
257}
258
259//____________________________________________________________________________
260Double_t AliPHOSv4::MakeEnergy(const Double_t energy)
261{
262 // Smears the energy according to the energy dependent energy resolution.
263 // A gaussian distribution is assumed
264
265 Double_t sigma = SigmaE(energy) ;
266 return fRan.Gaus(energy, sigma) ;
267}
268
269//____________________________________________________________________________
270TVector3 AliPHOSv4::MakePosition(const Double_t energy, const TVector3 pos, const Double_t theta, const Double_t phi)
271{
272 // Smears the impact position according to the energy dependent position resolution
273 // A gaussian position distribution is assumed
274
275 TVector3 newpos ;
276 Double_t sigma = SigmaP( energy, theta*180./TMath::Pi() ) ;
277 Double_t x = fRan.Gaus( pos.X(), sigma ) ;
278 sigma = SigmaP( energy, phi*180./TMath::Pi() ) ;
279 Double_t z = fRan.Gaus( pos.Z(), sigma ) ;
280 Double_t y = pos.Y() ;
281
282 newpos.SetX(x) ;
283 newpos.SetY(y) ;
284 newpos.SetZ(z) ;
285
286 return newpos ;
287}
288
289//____________________________________________________________________________
290void AliPHOSv4::MakeRecParticle(const Int_t modid, const TVector3 pos, AliPHOSFastRecParticle & rp)
291{
292 // Modify the primary particle properties according
293 // 1. the response function of PHOS
294 // 2. the performance of the EMC+PPSD setup
295
296 Int_t type = MakeType( rp ) ;
297 rp.SetType(type) ;
298
299
300 // get the detected energy
301
302 TLorentzVector momentum ;
303 rp.Momentum(momentum) ;
304 Double_t kineticenergy = TMath::Sqrt( TMath::Power(momentum.E(), 2) - TMath::Power(rp.GetMass(), 2) ) ;
305 Double_t modifiedkineticenergy = MakeEnergy(kineticenergy ) ;
306 Double_t modifiedenergy = TMath::Sqrt( TMath::Power(modifiedkineticenergy, 2)
307 + TMath::Power( rp.GetMass(), 2) ) ;
308
309 // get the angle of incidence
310
311 Double_t incidencetheta = 90. * TMath::Pi() /180 - rp.Theta() ;
fa7cce36 312 Double_t incidencephi = ( 270 + GetGeometry()->GetPHOSAngle(modid) ) * TMath::Pi() / 180. - rp.Phi() ;
5f20d3fb 313
314 // get the detected direction
315
316 TVector3 modifiedposition = MakePosition(kineticenergy, pos, incidencetheta, incidencephi) ;
317 modifiedposition *= modifiedkineticenergy / modifiedposition.Mag() ;
318
319 // Set the modified 4-momentum of the reconstructed particle
320
321 rp.SetMomentum(modifiedposition.X(), modifiedposition.Y(), modifiedposition.Z(), modifiedenergy) ;
322
323 }
324
325//____________________________________________________________________________
326Int_t AliPHOSv4::MakeType(AliPHOSFastRecParticle & rp )
327{
328 // Generate a particle type using the performance of the EMC+PPSD setup
329
330 Int_t rv = AliPHOSFastRecParticle::kUNDEFINED ;
331 Int_t charge = (Int_t)rp.GetPDG()->Charge() ;
332 Int_t test ;
333 Float_t ran ;
334 if ( charge != 0 && ( TMath::Abs(rp.GetPdgCode()) != 11 ) )
335 test = - 1 ;
336 else
337 test = rp.GetPdgCode() ;
338
339 switch (test) {
340
341 case 22: // it's a photon
342 ran = fRan.Rndm() ;
343 if ( ran <= 0.5 ) // 50 %
344 rv = AliPHOSFastRecParticle::kGAMMA ;
345 else {
346 ran = fRan.Rndm() ;
347 if( ran <= 0.9498 )
348 rv = AliPHOSFastRecParticle::kNEUTRALEM ;
349 else
350 rv = AliPHOSFastRecParticle::kNEUTRALHA ;
351 }
352 break ;
353
354 case 2112: // it's a neutron
355 ran = fRan.Rndm() ;
356 if ( ran <= 0.9998 )
357 rv = AliPHOSFastRecParticle::kNEUTRALHA ;
358 else
359 rv = AliPHOSFastRecParticle::kNEUTRALEM ;
360 break ;
361
362 case -2112: // it's a anti-neutron
363 ran = fRan.Rndm() ;
364 if ( ran <= 0.9984 )
365 rv = AliPHOSFastRecParticle::kNEUTRALHA ;
366 else
367 rv = AliPHOSFastRecParticle::kNEUTRALEM ;
368 break ;
369
370 case 11: // it's a electron
371 ran = fRan.Rndm() ;
372 if ( ran <= 0.9996 )
373 rv = AliPHOSFastRecParticle::kELECTRON ;
374 else
375 rv = AliPHOSFastRecParticle::kCHARGEDHA ;
376 break;
377
378 case -11: // it's a positon
379 ran = fRan.Rndm() ;
380 if ( ran <= 0.9996 )
381 rv = AliPHOSFastRecParticle::kELECTRON ;
382 else
383 rv = AliPHOSFastRecParticle::kCHARGEDHA ;
384 break;
385
386 case -1: // it's a charged
387 ran = fRan.Rndm() ;
388 if ( ran <= 0.9996 )
389 rv = AliPHOSFastRecParticle::kCHARGEDHA ;
390 else
391 rv = AliPHOSFastRecParticle::kGAMMA ;
392
393 break ;
394 }
395
396
397 return rv ;
398}
399
400//___________________________________________________________________________
401void AliPHOSv4::ResetPoints()
402{
403 // This overloads the method in AliDetector
404
405 ResetFastRecParticles() ;
406}
407
408//___________________________________________________________________________
409void AliPHOSv4::ResetFastRecParticles()
410{
411 // Resets the list of virtual reconstructed particles
412
413 if (fFastRecParticles)
414 fFastRecParticles->Clear() ;
415 fNRecParticles = 0 ;
416}
417
418//___________________________________________________________________________
419void AliPHOSv4::SetBigBox(Int_t index, Float_t value)
420{
421 // Set the size of the Box describing a PHOS module
422
423 switch (index) {
424 case 0:
425 fBigBoxX = value ;
426 break ;
427 case 1:
428 fBigBoxY = value ;
429 break ;
430 case 2:
431 fBigBoxZ = value ;
432 break ;
433 }
434
435}
436
437//____________________________________________________________________________
438Double_t AliPHOSv4::SigmaE(Double_t energy)
439{
440 // Calculates the energy dependent energy resolution
441
442 Double_t rv = -1 ;
443
444 rv = TMath::Sqrt( TMath::Power(fResPara1/energy, 2)
445 + TMath::Power(fResPara2/TMath::Sqrt(energy), 2)
446 + TMath::Power(fResPara3, 2) ) ;
447
448 return rv * energy ;
449}
450
451//____________________________________________________________________________
452Double_t AliPHOSv4::SigmaP(Double_t energy, Int_t incidence)
453{
454 // Calculates the energy dependent position resolution
455
456 Double_t paraA = fPosParaA0 + fPosParaA1 * incidence ;
457 Double_t paraB = fPosParaB0 + fPosParaB1 * incidence + fPosParaB2 * incidence * incidence ;
458
459 return ( paraA / TMath::Sqrt(energy) + paraB ) * 0.1 ; // in cm
460}
461
462//____________________________________________________________________________
463void AliPHOSv4::StepManager(void)
464{
465 // Only verifies if the particle reaches PHOS and stops the tracking
5cbba5aa 466
5f20d3fb 467 Int_t primary = gAlice->GetPrimary( gAlice->CurrentTrack() );
5cbba5aa 468
5f20d3fb 469 TLorentzVector lv ;
470 gMC->TrackPosition(lv) ;
471 TVector3 pos = lv.Vect() ;
472 Int_t modid ;
473 gMC->CurrentVolID(modid);
474
2f04ed65 475 Float_t energy = gMC->Etot() ; //Total energy of current track
5cbba5aa 476
477 //Calculating mass of current particle
2f04ed65 478 TDatabasePDG * pdg = TDatabasePDG::Instance() ;
479 TParticlePDG * partPDG = pdg->GetParticle(gMC->TrackPid()) ;
5cbba5aa 480 Float_t mass = partPDG->Mass() ;
5f20d3fb 481
2f04ed65 482 if(energy > mass){
483 pos.SetMag(TMath::Sqrt(energy*energy-mass*mass)) ;
484 TLorentzVector pTrack(pos, energy) ;
5cbba5aa 485
486 TParticle * part = new TParticle(gMC->TrackPid(), 0,-1,-1,-1,-1, pTrack, lv) ;
487
488 AliPHOSFastRecParticle rp(*part) ;
489 rp.SetPrimary(primary) ;
490
491 // Adds the response of PHOS to the particle
492 MakeRecParticle(modid, pos, rp) ;
493
494 // add the `track' particle to the FastRecParticles list
5f20d3fb 495
5cbba5aa 496 AddRecParticle(rp) ;
5f20d3fb 497
5cbba5aa 498 part->Delete() ;
499 }
5f20d3fb 500 // stop the track as soon PHOS is reached
501
502 gMC->StopTrack() ;
503
504}
505