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