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