]>
Commit | Line | Data |
---|---|---|
4c039060 | 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 | $Log$ | |
b9d0a01d | 18 | Revision 1.33.6.2 2002/07/24 10:09:31 alibrary |
19 | Updating VirtualMC | |
20 | ||
21 | Revision 1.34 2002/06/13 08:11:56 cblume | |
22 | Add the track references | |
23 | ||
c61f1a66 | 24 | Revision 1.33 2002/02/20 14:01:40 hristov |
25 | Compare a TString with a string, otherwise the conversion cannot be done on Sun | |
26 | ||
e6674585 | 27 | Revision 1.32 2002/02/13 16:58:37 cblume |
28 | Bug fix reported by Jiri. Make atoi input zero terminated in StepManager() | |
29 | ||
593a9fc3 | 30 | Revision 1.31 2002/02/11 14:25:27 cblume |
31 | Geometry update, compressed hit structure | |
32 | ||
332e9569 | 33 | Revision 1.30 2001/05/21 16:45:47 hristov |
34 | Last minute changes (C.Blume) | |
35 | ||
db30bf0f | 36 | Revision 1.29 2001/05/16 14:57:28 alibrary |
37 | New files for folders and Stack | |
38 | ||
9e1a0ddb | 39 | Revision 1.28 2001/05/07 08:03:22 cblume |
40 | Generate also hits in the amplification region | |
41 | ||
f73816f5 | 42 | Revision 1.27 2001/03/30 14:40:15 cblume |
43 | Update of the digitization parameter | |
44 | ||
a3c76cdc | 45 | Revision 1.26 2000/11/30 17:38:08 cblume |
46 | Changes to get in line with new STEER and EVGEN | |
47 | ||
1819f4bb | 48 | Revision 1.25 2000/11/15 14:30:16 cblume |
49 | Fixed bug in calculating detector no. of extra hit | |
50 | ||
990e4068 | 51 | Revision 1.24 2000/11/10 14:58:36 cblume |
52 | Introduce additional hit with amplitude 0 at the chamber borders | |
53 | ||
769257f4 | 54 | Revision 1.23 2000/11/01 14:53:21 cblume |
55 | Merge with TRD-develop | |
56 | ||
793ff80c | 57 | Revision 1.17.2.5 2000/10/15 23:40:01 cblume |
58 | Remove AliTRDconst | |
59 | ||
60 | Revision 1.17.2.4 2000/10/06 16:49:46 cblume | |
61 | Made Getters const | |
62 | ||
63 | Revision 1.17.2.3 2000/10/04 16:34:58 cblume | |
64 | Replace include files by forward declarations | |
65 | ||
66 | Revision 1.17.2.2 2000/09/18 13:50:17 cblume | |
67 | Include TR photon generation and adapt to new AliTRDhit | |
68 | ||
69 | Revision 1.22 2000/06/27 13:08:50 cblume | |
70 | Changed to Copy(TObject &A) to appease the HP-compiler | |
71 | ||
43da34c0 | 72 | Revision 1.21 2000/06/09 11:10:07 cblume |
73 | Compiler warnings and coding conventions, next round | |
74 | ||
dd9a6ee3 | 75 | Revision 1.20 2000/06/08 18:32:58 cblume |
76 | Make code compliant to coding conventions | |
77 | ||
8230f242 | 78 | Revision 1.19 2000/06/07 16:27:32 cblume |
79 | Try to remove compiler warnings on Sun and HP | |
80 | ||
9d0b222b | 81 | Revision 1.18 2000/05/08 16:17:27 cblume |
82 | Merge TRD-develop | |
83 | ||
6f1e466d | 84 | Revision 1.17.2.1 2000/05/08 14:59:16 cblume |
85 | Made inline function non-virtual. Bug fix in setting sensitive chamber | |
86 | ||
87 | Revision 1.17 2000/02/28 19:10:26 cblume | |
88 | Include the new TRD classes | |
89 | ||
851d3db9 | 90 | Revision 1.16.4.1 2000/02/28 18:04:35 cblume |
91 | Change to new hit version, introduce geometry class, and move digitization and clustering to AliTRDdigitizer/AliTRDclusterizerV1 | |
92 | ||
93 | Revision 1.16 1999/11/05 22:50:28 fca | |
94 | Do not use Atan, removed from ROOT too | |
95 | ||
90f8d287 | 96 | Revision 1.15 1999/11/02 17:20:19 fca |
97 | initialise nbytes before using it | |
98 | ||
036da493 | 99 | Revision 1.14 1999/11/02 17:15:54 fca |
100 | Correct ansi scoping not accepted by HP compilers | |
101 | ||
0549c011 | 102 | Revision 1.13 1999/11/02 17:14:51 fca |
103 | Correct ansi scoping not accepted by HP compilers | |
104 | ||
9c767df4 | 105 | Revision 1.12 1999/11/02 16:35:56 fca |
106 | New version of TRD introduced | |
107 | ||
5c7f4665 | 108 | Revision 1.11 1999/11/01 20:41:51 fca |
109 | Added protections against using the wrong version of FRAME | |
110 | ||
ab76897d | 111 | Revision 1.10 1999/09/29 09:24:35 fca |
112 | Introduction of the Copyright and cvs Log | |
113 | ||
4c039060 | 114 | */ |
115 | ||
fe4da5cc | 116 | /////////////////////////////////////////////////////////////////////////////// |
117 | // // | |
769257f4 | 118 | // Transition Radiation Detector version 1 -- slow simulator // |
fe4da5cc | 119 | // // |
120 | //Begin_Html | |
121 | /* | |
5c7f4665 | 122 | <img src="picts/AliTRDfullClass.gif"> |
fe4da5cc | 123 | */ |
124 | //End_Html | |
125 | // // | |
126 | // // | |
127 | /////////////////////////////////////////////////////////////////////////////// | |
128 | ||
769257f4 | 129 | #include <stdlib.h> |
130 | ||
fe4da5cc | 131 | #include <TMath.h> |
fe4da5cc | 132 | #include <TVector.h> |
5c7f4665 | 133 | #include <TRandom.h> |
793ff80c | 134 | #include <TF1.h> |
1819f4bb | 135 | #include <TLorentzVector.h> |
fe4da5cc | 136 | |
fe4da5cc | 137 | #include "AliRun.h" |
fe4da5cc | 138 | #include "AliMC.h" |
d3f347ff | 139 | #include "AliConst.h" |
5c7f4665 | 140 | |
851d3db9 | 141 | #include "AliTRDv1.h" |
793ff80c | 142 | #include "AliTRDhit.h" |
851d3db9 | 143 | #include "AliTRDmatrix.h" |
144 | #include "AliTRDgeometry.h" | |
793ff80c | 145 | #include "AliTRDsim.h" |
851d3db9 | 146 | |
fe4da5cc | 147 | ClassImp(AliTRDv1) |
8230f242 | 148 | |
149 | //_____________________________________________________________________________ | |
150 | AliTRDv1::AliTRDv1():AliTRD() | |
151 | { | |
152 | // | |
153 | // Default constructor | |
154 | // | |
155 | ||
8230f242 | 156 | fSensSelect = 0; |
157 | fSensPlane = -1; | |
158 | fSensChamber = -1; | |
159 | fSensSector = -1; | |
160 | fSensSectorRange = 0; | |
161 | ||
162 | fDeltaE = NULL; | |
793ff80c | 163 | fTR = NULL; |
8230f242 | 164 | |
165 | } | |
166 | ||
fe4da5cc | 167 | //_____________________________________________________________________________ |
168 | AliTRDv1::AliTRDv1(const char *name, const char *title) | |
169 | :AliTRD(name, title) | |
170 | { | |
171 | // | |
851d3db9 | 172 | // Standard constructor for Transition Radiation Detector version 1 |
fe4da5cc | 173 | // |
82bbf98a | 174 | |
9d0b222b | 175 | fSensSelect = 0; |
176 | fSensPlane = -1; | |
177 | fSensChamber = -1; | |
178 | fSensSector = -1; | |
8230f242 | 179 | fSensSectorRange = 0; |
5c7f4665 | 180 | |
9d0b222b | 181 | fDeltaE = NULL; |
793ff80c | 182 | fTR = NULL; |
5c7f4665 | 183 | |
184 | SetBufferSize(128000); | |
185 | ||
186 | } | |
187 | ||
8230f242 | 188 | //_____________________________________________________________________________ |
dd9a6ee3 | 189 | AliTRDv1::AliTRDv1(const AliTRDv1 &trd) |
8230f242 | 190 | { |
191 | // | |
192 | // Copy constructor | |
193 | // | |
194 | ||
dd9a6ee3 | 195 | ((AliTRDv1 &) trd).Copy(*this); |
8230f242 | 196 | |
197 | } | |
198 | ||
5c7f4665 | 199 | //_____________________________________________________________________________ |
200 | AliTRDv1::~AliTRDv1() | |
201 | { | |
dd9a6ee3 | 202 | // |
203 | // AliTRDv1 destructor | |
204 | // | |
82bbf98a | 205 | |
5c7f4665 | 206 | if (fDeltaE) delete fDeltaE; |
793ff80c | 207 | if (fTR) delete fTR; |
82bbf98a | 208 | |
fe4da5cc | 209 | } |
210 | ||
dd9a6ee3 | 211 | //_____________________________________________________________________________ |
212 | AliTRDv1 &AliTRDv1::operator=(const AliTRDv1 &trd) | |
213 | { | |
214 | // | |
215 | // Assignment operator | |
216 | // | |
217 | ||
218 | if (this != &trd) ((AliTRDv1 &) trd).Copy(*this); | |
219 | return *this; | |
220 | ||
221 | } | |
8230f242 | 222 | |
223 | //_____________________________________________________________________________ | |
43da34c0 | 224 | void AliTRDv1::Copy(TObject &trd) |
8230f242 | 225 | { |
226 | // | |
227 | // Copy function | |
228 | // | |
229 | ||
43da34c0 | 230 | ((AliTRDv1 &) trd).fSensSelect = fSensSelect; |
231 | ((AliTRDv1 &) trd).fSensPlane = fSensPlane; | |
232 | ((AliTRDv1 &) trd).fSensChamber = fSensChamber; | |
233 | ((AliTRDv1 &) trd).fSensSector = fSensSector; | |
234 | ((AliTRDv1 &) trd).fSensSectorRange = fSensSectorRange; | |
8230f242 | 235 | |
793ff80c | 236 | fDeltaE->Copy(*((AliTRDv1 &) trd).fDeltaE); |
237 | fTR->Copy(*((AliTRDv1 &) trd).fTR); | |
8230f242 | 238 | |
239 | } | |
240 | ||
fe4da5cc | 241 | //_____________________________________________________________________________ |
242 | void AliTRDv1::CreateGeometry() | |
243 | { | |
244 | // | |
851d3db9 | 245 | // Create the GEANT geometry for the Transition Radiation Detector - Version 1 |
5c7f4665 | 246 | // This version covers the full azimuth. |
d3f347ff | 247 | // |
248 | ||
82bbf98a | 249 | // Check that FRAME is there otherwise we have no place where to put the TRD |
8230f242 | 250 | AliModule* frame = gAlice->GetModule("FRAME"); |
251 | if (!frame) return; | |
d3f347ff | 252 | |
82bbf98a | 253 | // Define the chambers |
254 | AliTRD::CreateGeometry(); | |
d3f347ff | 255 | |
fe4da5cc | 256 | } |
257 | ||
258 | //_____________________________________________________________________________ | |
259 | void AliTRDv1::CreateMaterials() | |
260 | { | |
261 | // | |
851d3db9 | 262 | // Create materials for the Transition Radiation Detector version 1 |
fe4da5cc | 263 | // |
82bbf98a | 264 | |
d3f347ff | 265 | AliTRD::CreateMaterials(); |
82bbf98a | 266 | |
fe4da5cc | 267 | } |
268 | ||
793ff80c | 269 | //_____________________________________________________________________________ |
270 | void AliTRDv1::CreateTRhit(Int_t det) | |
271 | { | |
272 | // | |
273 | // Creates an electron cluster from a TR photon. | |
274 | // The photon is assumed to be created a the end of the radiator. The | |
275 | // distance after which it deposits its energy takes into account the | |
276 | // absorbtion of the entrance window and of the gas mixture in drift | |
277 | // volume. | |
278 | // | |
279 | ||
280 | // PDG code electron | |
281 | const Int_t kPdgElectron = 11; | |
282 | ||
283 | // Ionization energy | |
284 | const Float_t kWion = 22.04; | |
285 | ||
286 | // Maximum number of TR photons per track | |
287 | const Int_t kNTR = 50; | |
288 | ||
289 | TLorentzVector mom, pos; | |
793ff80c | 290 | |
793ff80c | 291 | // Create TR at the entrance of the chamber |
292 | if (gMC->IsTrackEntering()) { | |
293 | ||
f73816f5 | 294 | // Create TR only for electrons |
295 | Int_t iPdg = gMC->TrackPid(); | |
296 | if (TMath::Abs(iPdg) != kPdgElectron) return; | |
297 | ||
793ff80c | 298 | Float_t eTR[kNTR]; |
299 | Int_t nTR; | |
300 | ||
301 | // Create TR photons | |
302 | gMC->TrackMomentum(mom); | |
303 | Float_t pTot = mom.Rho(); | |
304 | fTR->CreatePhotons(iPdg,pTot,nTR,eTR); | |
305 | if (nTR > kNTR) { | |
306 | printf("AliTRDv1::CreateTRhit -- "); | |
307 | printf("Boundary error: nTR = %d, kNTR = %d\n",nTR,kNTR); | |
308 | exit(1); | |
309 | } | |
310 | ||
311 | // Loop through the TR photons | |
312 | for (Int_t iTR = 0; iTR < nTR; iTR++) { | |
313 | ||
314 | Float_t energyMeV = eTR[iTR] * 0.001; | |
315 | Float_t energyeV = eTR[iTR] * 1000.0; | |
316 | Float_t absLength = 0; | |
317 | Float_t sigma = 0; | |
318 | ||
319 | // Take the absorbtion in the entrance window into account | |
320 | Double_t muMy = fTR->GetMuMy(energyMeV); | |
321 | sigma = muMy * fFoilDensity; | |
322 | absLength = gRandom->Exp(sigma); | |
323 | if (absLength < AliTRDgeometry::MyThick()) continue; | |
324 | ||
325 | // The absorbtion cross sections in the drift gas | |
326 | if (fGasMix == 1) { | |
327 | // Gas-mixture (Xe/CO2) | |
328 | Double_t muXe = fTR->GetMuXe(energyMeV); | |
329 | Double_t muCO = fTR->GetMuCO(energyMeV); | |
db30bf0f | 330 | sigma = (0.85 * muXe + 0.15 * muCO) * fGasDensity; |
793ff80c | 331 | } |
332 | else { | |
333 | // Gas-mixture (Xe/Isobutane) | |
334 | Double_t muXe = fTR->GetMuXe(energyMeV); | |
335 | Double_t muBu = fTR->GetMuBu(energyMeV); | |
336 | sigma = (0.97 * muXe + 0.03 * muBu) * fGasDensity; | |
337 | } | |
338 | ||
339 | // The distance after which the energy of the TR photon | |
340 | // is deposited. | |
341 | absLength = gRandom->Exp(sigma); | |
342 | if (absLength > AliTRDgeometry::DrThick()) continue; | |
343 | ||
344 | // The position of the absorbtion | |
345 | Float_t posHit[3]; | |
346 | gMC->TrackPosition(pos); | |
347 | posHit[0] = pos[0] + mom[0] / pTot * absLength; | |
348 | posHit[1] = pos[1] + mom[1] / pTot * absLength; | |
349 | posHit[2] = pos[2] + mom[2] / pTot * absLength; | |
350 | ||
351 | // Create the charge | |
352 | Int_t q = ((Int_t) (energyeV / kWion)); | |
353 | ||
354 | // Add the hit to the array. TR photon hits are marked | |
355 | // by negative charge | |
332e9569 | 356 | AddHit(gAlice->CurrentTrack(),det,posHit,-q,kTRUE); |
793ff80c | 357 | |
358 | } | |
359 | ||
360 | } | |
361 | ||
362 | } | |
363 | ||
5c7f4665 | 364 | //_____________________________________________________________________________ |
365 | void AliTRDv1::Init() | |
366 | { | |
367 | // | |
368 | // Initialise Transition Radiation Detector after geometry has been built. | |
5c7f4665 | 369 | // |
370 | ||
371 | AliTRD::Init(); | |
372 | ||
9e1a0ddb | 373 | if(fDebug) printf("%s: Slow simulator\n",ClassName()); |
851d3db9 | 374 | if (fSensSelect) { |
375 | if (fSensPlane >= 0) | |
376 | printf(" Only plane %d is sensitive\n",fSensPlane); | |
377 | if (fSensChamber >= 0) | |
378 | printf(" Only chamber %d is sensitive\n",fSensChamber); | |
9d0b222b | 379 | if (fSensSector >= 0) { |
380 | Int_t sens1 = fSensSector; | |
381 | Int_t sens2 = fSensSector + fSensSectorRange; | |
793ff80c | 382 | sens2 -= ((Int_t) (sens2 / AliTRDgeometry::Nsect())) |
383 | * AliTRDgeometry::Nsect(); | |
9d0b222b | 384 | printf(" Only sectors %d - %d are sensitive\n",sens1,sens2-1); |
385 | } | |
851d3db9 | 386 | } |
793ff80c | 387 | if (fTR) |
9e1a0ddb | 388 | printf("%s: TR simulation on\n",ClassName()); |
793ff80c | 389 | else |
9e1a0ddb | 390 | printf("%s: TR simulation off\n",ClassName()); |
851d3db9 | 391 | printf("\n"); |
5c7f4665 | 392 | |
393 | // First ionization potential (eV) for the gas mixture (90% Xe + 10% CO2) | |
394 | const Float_t kPoti = 12.1; | |
395 | // Maximum energy (50 keV); | |
396 | const Float_t kEend = 50000.0; | |
397 | // Ermilova distribution for the delta-ray spectrum | |
8230f242 | 398 | Float_t poti = TMath::Log(kPoti); |
399 | Float_t eEnd = TMath::Log(kEend); | |
793ff80c | 400 | fDeltaE = new TF1("deltae",Ermilova,poti,eEnd,0); |
5c7f4665 | 401 | |
9e1a0ddb | 402 | if(fDebug) { |
403 | printf("%s: ",ClassName()); | |
404 | for (Int_t i = 0; i < 80; i++) printf("*"); | |
405 | printf("\n"); | |
406 | } | |
5c7f4665 | 407 | |
fe4da5cc | 408 | } |
409 | ||
793ff80c | 410 | //_____________________________________________________________________________ |
411 | AliTRDsim *AliTRDv1::CreateTR() | |
412 | { | |
413 | // | |
414 | // Enables the simulation of TR | |
415 | // | |
416 | ||
417 | fTR = new AliTRDsim(); | |
418 | return fTR; | |
419 | ||
420 | } | |
421 | ||
5c7f4665 | 422 | //_____________________________________________________________________________ |
423 | void AliTRDv1::SetSensPlane(Int_t iplane) | |
424 | { | |
425 | // | |
851d3db9 | 426 | // Defines the hit-sensitive plane (0-5) |
5c7f4665 | 427 | // |
82bbf98a | 428 | |
851d3db9 | 429 | if ((iplane < 0) || (iplane > 5)) { |
5c7f4665 | 430 | printf("Wrong input value: %d\n",iplane); |
431 | printf("Use standard setting\n"); | |
851d3db9 | 432 | fSensPlane = -1; |
433 | fSensSelect = 0; | |
5c7f4665 | 434 | return; |
435 | } | |
82bbf98a | 436 | |
5c7f4665 | 437 | fSensSelect = 1; |
438 | fSensPlane = iplane; | |
82bbf98a | 439 | |
5c7f4665 | 440 | } |
441 | ||
442 | //_____________________________________________________________________________ | |
443 | void AliTRDv1::SetSensChamber(Int_t ichamber) | |
444 | { | |
445 | // | |
851d3db9 | 446 | // Defines the hit-sensitive chamber (0-4) |
5c7f4665 | 447 | // |
448 | ||
851d3db9 | 449 | if ((ichamber < 0) || (ichamber > 4)) { |
5c7f4665 | 450 | printf("Wrong input value: %d\n",ichamber); |
451 | printf("Use standard setting\n"); | |
851d3db9 | 452 | fSensChamber = -1; |
453 | fSensSelect = 0; | |
5c7f4665 | 454 | return; |
455 | } | |
456 | ||
457 | fSensSelect = 1; | |
458 | fSensChamber = ichamber; | |
459 | ||
460 | } | |
461 | ||
462 | //_____________________________________________________________________________ | |
463 | void AliTRDv1::SetSensSector(Int_t isector) | |
464 | { | |
465 | // | |
851d3db9 | 466 | // Defines the hit-sensitive sector (0-17) |
5c7f4665 | 467 | // |
468 | ||
9d0b222b | 469 | SetSensSector(isector,1); |
470 | ||
471 | } | |
472 | ||
473 | //_____________________________________________________________________________ | |
474 | void AliTRDv1::SetSensSector(Int_t isector, Int_t nsector) | |
475 | { | |
476 | // | |
477 | // Defines a range of hit-sensitive sectors. The range is defined by | |
478 | // <isector> (0-17) as the starting point and <nsector> as the number | |
479 | // of sectors to be included. | |
480 | // | |
481 | ||
851d3db9 | 482 | if ((isector < 0) || (isector > 17)) { |
9d0b222b | 483 | printf("Wrong input value <isector>: %d\n",isector); |
5c7f4665 | 484 | printf("Use standard setting\n"); |
9d0b222b | 485 | fSensSector = -1; |
486 | fSensSectorRange = 0; | |
487 | fSensSelect = 0; | |
5c7f4665 | 488 | return; |
489 | } | |
490 | ||
9d0b222b | 491 | if ((nsector < 1) || (nsector > 18)) { |
492 | printf("Wrong input value <nsector>: %d\n",nsector); | |
493 | printf("Use standard setting\n"); | |
494 | fSensSector = -1; | |
495 | fSensSectorRange = 0; | |
496 | fSensSelect = 0; | |
497 | return; | |
498 | } | |
499 | ||
500 | fSensSelect = 1; | |
501 | fSensSector = isector; | |
502 | fSensSectorRange = nsector; | |
5c7f4665 | 503 | |
504 | } | |
505 | ||
506 | //_____________________________________________________________________________ | |
507 | void AliTRDv1::StepManager() | |
508 | { | |
509 | // | |
5c7f4665 | 510 | // Slow simulator. Every charged track produces electron cluster as hits |
511 | // along its path across the drift volume. The step size is set acording | |
512 | // to Bethe-Bloch. The energy distribution of the delta electrons follows | |
513 | // a spectrum taken from Ermilova et al. | |
514 | // | |
515 | ||
851d3db9 | 516 | Int_t pla = 0; |
517 | Int_t cha = 0; | |
518 | Int_t sec = 0; | |
793ff80c | 519 | Int_t det = 0; |
851d3db9 | 520 | Int_t iPdg; |
793ff80c | 521 | Int_t qTot; |
5c7f4665 | 522 | |
793ff80c | 523 | Float_t hits[3]; |
b9d0a01d | 524 | Double_t random[1]; |
5c7f4665 | 525 | Float_t charge; |
526 | Float_t aMass; | |
527 | ||
f73816f5 | 528 | Double_t pTot = 0; |
5c7f4665 | 529 | Double_t eDelta; |
530 | Double_t betaGamma, pp; | |
f73816f5 | 531 | Double_t stepSize; |
5c7f4665 | 532 | |
332e9569 | 533 | Bool_t drRegion = kFALSE; |
534 | Bool_t amRegion = kFALSE; | |
535 | ||
536 | TString cIdCurrent; | |
537 | TString cIdSensDr = "J"; | |
538 | TString cIdSensAm = "K"; | |
593a9fc3 | 539 | Char_t cIdChamber[3]; |
540 | cIdChamber[2] = 0; | |
332e9569 | 541 | |
5c7f4665 | 542 | TLorentzVector pos, mom; |
82bbf98a | 543 | |
332e9569 | 544 | const Int_t kNplan = AliTRDgeometry::Nplan(); |
545 | const Double_t kBig = 1.0E+12; | |
5c7f4665 | 546 | |
547 | // Ionization energy | |
a3c76cdc | 548 | const Float_t kWion = 22.04; |
549 | // Maximum momentum for e+ e- g | |
550 | const Float_t kPTotMaxEl = 0.002; | |
f73816f5 | 551 | // Minimum energy for the step size adjustment |
552 | const Float_t kEkinMinStep = 1.0e-5; | |
5c7f4665 | 553 | // Plateau value of the energy-loss for electron in xenon |
554 | // taken from: Allison + Comb, Ann. Rev. Nucl. Sci. (1980), 30, 253 | |
555 | //const Double_t kPlateau = 1.70; | |
556 | // the averaged value (26/3/99) | |
a3c76cdc | 557 | const Float_t kPlateau = 1.55; |
5c7f4665 | 558 | // dN1/dx|min for the gas mixture (90% Xe + 10% CO2) |
a3c76cdc | 559 | const Float_t kPrim = 48.0; |
5c7f4665 | 560 | // First ionization potential (eV) for the gas mixture (90% Xe + 10% CO2) |
a3c76cdc | 561 | const Float_t kPoti = 12.1; |
851d3db9 | 562 | |
563 | // PDG code electron | |
8230f242 | 564 | const Int_t kPdgElectron = 11; |
5c7f4665 | 565 | |
566 | // Set the maximum step size to a very large number for all | |
567 | // neutral particles and those outside the driftvolume | |
568 | gMC->SetMaxStep(kBig); | |
569 | ||
570 | // Use only charged tracks | |
571 | if (( gMC->TrackCharge() ) && | |
572 | (!gMC->IsTrackStop() ) && | |
573 | (!gMC->IsTrackDisappeared())) { | |
fe4da5cc | 574 | |
5c7f4665 | 575 | // Inside a sensitive volume? |
332e9569 | 576 | drRegion = kFALSE; |
577 | amRegion = kFALSE; | |
578 | cIdCurrent = gMC->CurrentVolName(); | |
e6674585 | 579 | if (cIdSensDr == cIdCurrent[1]) { |
332e9569 | 580 | drRegion = kTRUE; |
581 | } | |
e6674585 | 582 | if (cIdSensAm == cIdCurrent[1]) { |
332e9569 | 583 | amRegion = kTRUE; |
584 | } | |
585 | if (drRegion || amRegion) { | |
fe4da5cc | 586 | |
5c7f4665 | 587 | // The hit coordinates and charge |
588 | gMC->TrackPosition(pos); | |
589 | hits[0] = pos[0]; | |
590 | hits[1] = pos[1]; | |
591 | hits[2] = pos[2]; | |
5c7f4665 | 592 | |
851d3db9 | 593 | // The sector number (0 - 17) |
594 | // The numbering goes clockwise and starts at y = 0 | |
595 | Float_t phi = kRaddeg*TMath::ATan2(pos[0],pos[1]); | |
596 | if (phi < 90.) | |
597 | phi = phi + 270.; | |
598 | else | |
599 | phi = phi - 90.; | |
600 | sec = ((Int_t) (phi / 20)); | |
82bbf98a | 601 | |
332e9569 | 602 | // The plane and chamber number |
603 | cIdChamber[0] = cIdCurrent[2]; | |
604 | cIdChamber[1] = cIdCurrent[3]; | |
605 | Int_t idChamber = atoi(cIdChamber); | |
606 | cha = ((Int_t) idChamber / kNplan); | |
607 | pla = ((Int_t) idChamber % kNplan); | |
82bbf98a | 608 | |
5c7f4665 | 609 | // Check on selected volumes |
610 | Int_t addthishit = 1; | |
611 | if (fSensSelect) { | |
6f1e466d | 612 | if ((fSensPlane >= 0) && (pla != fSensPlane )) addthishit = 0; |
613 | if ((fSensChamber >= 0) && (cha != fSensChamber)) addthishit = 0; | |
9d0b222b | 614 | if (fSensSector >= 0) { |
615 | Int_t sens1 = fSensSector; | |
616 | Int_t sens2 = fSensSector + fSensSectorRange; | |
793ff80c | 617 | sens2 -= ((Int_t) (sens2 / AliTRDgeometry::Nsect())) |
618 | * AliTRDgeometry::Nsect(); | |
9d0b222b | 619 | if (sens1 < sens2) { |
620 | if ((sec < sens1) || (sec >= sens2)) addthishit = 0; | |
621 | } | |
622 | else { | |
623 | if ((sec < sens1) && (sec >= sens2)) addthishit = 0; | |
624 | } | |
625 | } | |
5c7f4665 | 626 | } |
627 | ||
628 | // Add this hit | |
629 | if (addthishit) { | |
630 | ||
f73816f5 | 631 | // The detector number |
793ff80c | 632 | det = fGeometry->GetDetector(pla,cha,sec); |
633 | ||
f73816f5 | 634 | // Special hits and TR photons only in the drift region |
332e9569 | 635 | if (drRegion) { |
f73816f5 | 636 | |
c61f1a66 | 637 | // Create a track reference at the entrance and |
638 | // exit of each chamber that contain the | |
639 | // momentum components of the particle | |
f73816f5 | 640 | if (gMC->IsTrackEntering() || gMC->IsTrackExiting()) { |
641 | gMC->TrackMomentum(mom); | |
c61f1a66 | 642 | AddTrackReference(gAlice->CurrentTrack(),mom,pos); |
f73816f5 | 643 | } |
644 | ||
645 | // Create the hits from TR photons | |
646 | if (fTR) CreateTRhit(det); | |
647 | ||
648 | } | |
649 | ||
650 | // Calculate the energy of the delta-electrons | |
651 | eDelta = TMath::Exp(fDeltaE->GetRandom()) - kPoti; | |
652 | eDelta = TMath::Max(eDelta,0.0); | |
653 | ||
654 | // The number of secondary electrons created | |
655 | qTot = ((Int_t) (eDelta / kWion) + 1); | |
656 | ||
657 | // Create a new dEdx hit | |
332e9569 | 658 | if (drRegion) { |
659 | AddHit(gAlice->CurrentTrack(),det,hits,qTot,kTRUE); | |
f73816f5 | 660 | } |
5c7f4665 | 661 | else { |
332e9569 | 662 | AddHit(gAlice->CurrentTrack(),det,hits,qTot,kFALSE); |
f73816f5 | 663 | } |
664 | ||
5c7f4665 | 665 | // Calculate the maximum step size for the next tracking step |
f73816f5 | 666 | // Produce only one hit if Ekin is below cutoff |
667 | aMass = gMC->TrackMass(); | |
668 | if ((gMC->Etot() - aMass) > kEkinMinStep) { | |
669 | ||
670 | // The energy loss according to Bethe Bloch | |
671 | iPdg = TMath::Abs(gMC->TrackPid()); | |
672 | if ( (iPdg != kPdgElectron) || | |
673 | ((iPdg == kPdgElectron) && (pTot < kPTotMaxEl))) { | |
674 | gMC->TrackMomentum(mom); | |
675 | pTot = mom.Rho(); | |
676 | betaGamma = pTot / aMass; | |
677 | pp = kPrim * BetheBloch(betaGamma); | |
678 | // Take charge > 1 into account | |
679 | charge = gMC->TrackCharge(); | |
680 | if (TMath::Abs(charge) > 1) pp = pp * charge*charge; | |
681 | } | |
682 | // Electrons above 20 Mev/c are at the plateau | |
683 | else { | |
684 | pp = kPrim * kPlateau; | |
685 | } | |
686 | ||
687 | if (pp > 0) { | |
688 | do | |
b9d0a01d | 689 | gMC->GetRandom()->RndmArray(1, random); |
f73816f5 | 690 | while ((random[0] == 1.) || (random[0] == 0.)); |
691 | stepSize = - TMath::Log(random[0]) / pp; | |
692 | gMC->SetMaxStep(stepSize); | |
693 | } | |
694 | ||
5c7f4665 | 695 | } |
696 | ||
697 | } | |
d3f347ff | 698 | |
699 | } | |
700 | ||
5c7f4665 | 701 | } |
702 | ||
703 | } | |
704 | ||
705 | //_____________________________________________________________________________ | |
706 | Double_t AliTRDv1::BetheBloch(Double_t bg) | |
707 | { | |
708 | // | |
709 | // Parametrization of the Bethe-Bloch-curve | |
710 | // The parametrization is the same as for the TPC and is taken from Lehrhaus. | |
711 | // | |
712 | ||
713 | // This parameters have been adjusted to averaged values from GEANT | |
714 | const Double_t kP1 = 7.17960e-02; | |
715 | const Double_t kP2 = 8.54196; | |
716 | const Double_t kP3 = 1.38065e-06; | |
717 | const Double_t kP4 = 5.30972; | |
718 | const Double_t kP5 = 2.83798; | |
719 | ||
720 | // This parameters have been adjusted to Xe-data found in: | |
721 | // Allison & Cobb, Ann. Rev. Nucl. Sci. (1980), 30, 253 | |
722 | //const Double_t kP1 = 0.76176E-1; | |
723 | //const Double_t kP2 = 10.632; | |
724 | //const Double_t kP3 = 3.17983E-6; | |
725 | //const Double_t kP4 = 1.8631; | |
726 | //const Double_t kP5 = 1.9479; | |
727 | ||
f73816f5 | 728 | // Lower cutoff of the Bethe-Bloch-curve to limit step sizes |
729 | const Double_t kBgMin = 0.8; | |
730 | const Double_t kBBMax = 6.83298; | |
731 | //const Double_t kBgMin = 0.6; | |
732 | //const Double_t kBBMax = 17.2809; | |
733 | //const Double_t kBgMin = 0.4; | |
734 | //const Double_t kBBMax = 82.0; | |
735 | ||
736 | if (bg > kBgMin) { | |
5c7f4665 | 737 | Double_t yy = bg / TMath::Sqrt(1. + bg*bg); |
738 | Double_t aa = TMath::Power(yy,kP4); | |
739 | Double_t bb = TMath::Power((1./bg),kP5); | |
740 | bb = TMath::Log(kP3 + bb); | |
741 | return ((kP2 - aa - bb)*kP1 / aa); | |
742 | } | |
f73816f5 | 743 | else { |
744 | return kBBMax; | |
745 | } | |
d3f347ff | 746 | |
fe4da5cc | 747 | } |
5c7f4665 | 748 | |
749 | //_____________________________________________________________________________ | |
750 | Double_t Ermilova(Double_t *x, Double_t *) | |
751 | { | |
752 | // | |
753 | // Calculates the delta-ray energy distribution according to Ermilova. | |
754 | // Logarithmic scale ! | |
755 | // | |
756 | ||
757 | Double_t energy; | |
758 | Double_t dpos; | |
759 | Double_t dnde; | |
760 | ||
761 | Int_t pos1, pos2; | |
762 | ||
8230f242 | 763 | const Int_t kNv = 31; |
5c7f4665 | 764 | |
8230f242 | 765 | Float_t vxe[kNv] = { 2.3026, 2.9957, 3.4012, 3.6889, 3.9120 |
766 | , 4.0943, 4.2485, 4.3820, 4.4998, 4.6052 | |
767 | , 4.7005, 5.0752, 5.2983, 5.7038, 5.9915 | |
768 | , 6.2146, 6.5221, 6.9078, 7.3132, 7.6009 | |
769 | , 8.0064, 8.5172, 8.6995, 8.9872, 9.2103 | |
770 | , 9.4727, 9.9035,10.3735,10.5966,10.8198 | |
771 | ,11.5129 }; | |
5c7f4665 | 772 | |
8230f242 | 773 | Float_t vye[kNv] = { 80.0 , 31.0 , 23.3 , 21.1 , 21.0 |
774 | , 20.9 , 20.8 , 20.0 , 16.0 , 11.0 | |
775 | , 8.0 , 6.0 , 5.2 , 4.6 , 4.0 | |
776 | , 3.5 , 3.0 , 1.4 , 0.67 , 0.44 | |
777 | , 0.3 , 0.18 , 0.12 , 0.08 , 0.056 | |
778 | , 0.04 , 0.023, 0.015, 0.011, 0.01 | |
779 | , 0.004 }; | |
5c7f4665 | 780 | |
781 | energy = x[0]; | |
782 | ||
783 | // Find the position | |
784 | pos1 = pos2 = 0; | |
785 | dpos = 0; | |
786 | do { | |
787 | dpos = energy - vxe[pos2++]; | |
788 | } | |
789 | while (dpos > 0); | |
790 | pos2--; | |
f73816f5 | 791 | if (pos2 > kNv) pos2 = kNv - 1; |
5c7f4665 | 792 | pos1 = pos2 - 1; |
793 | ||
794 | // Differentiate between the sampling points | |
795 | dnde = (vye[pos1] - vye[pos2]) / (vxe[pos2] - vxe[pos1]); | |
796 | ||
797 | return dnde; | |
798 | ||
799 | } |