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