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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 | $Log$ | |
a3c76cdc | 18 | Revision 1.26 2000/11/30 17:38:08 cblume |
19 | Changes to get in line with new STEER and EVGEN | |
20 | ||
1819f4bb | 21 | Revision 1.25 2000/11/15 14:30:16 cblume |
22 | Fixed bug in calculating detector no. of extra hit | |
23 | ||
990e4068 | 24 | Revision 1.24 2000/11/10 14:58:36 cblume |
25 | Introduce additional hit with amplitude 0 at the chamber borders | |
26 | ||
769257f4 | 27 | Revision 1.23 2000/11/01 14:53:21 cblume |
28 | Merge with TRD-develop | |
29 | ||
793ff80c | 30 | Revision 1.17.2.5 2000/10/15 23:40:01 cblume |
31 | Remove AliTRDconst | |
32 | ||
33 | Revision 1.17.2.4 2000/10/06 16:49:46 cblume | |
34 | Made Getters const | |
35 | ||
36 | Revision 1.17.2.3 2000/10/04 16:34:58 cblume | |
37 | Replace include files by forward declarations | |
38 | ||
39 | Revision 1.17.2.2 2000/09/18 13:50:17 cblume | |
40 | Include TR photon generation and adapt to new AliTRDhit | |
41 | ||
42 | Revision 1.22 2000/06/27 13:08:50 cblume | |
43 | Changed to Copy(TObject &A) to appease the HP-compiler | |
44 | ||
43da34c0 | 45 | Revision 1.21 2000/06/09 11:10:07 cblume |
46 | Compiler warnings and coding conventions, next round | |
47 | ||
dd9a6ee3 | 48 | Revision 1.20 2000/06/08 18:32:58 cblume |
49 | Make code compliant to coding conventions | |
50 | ||
8230f242 | 51 | Revision 1.19 2000/06/07 16:27:32 cblume |
52 | Try to remove compiler warnings on Sun and HP | |
53 | ||
9d0b222b | 54 | Revision 1.18 2000/05/08 16:17:27 cblume |
55 | Merge TRD-develop | |
56 | ||
6f1e466d | 57 | Revision 1.17.2.1 2000/05/08 14:59:16 cblume |
58 | Made inline function non-virtual. Bug fix in setting sensitive chamber | |
59 | ||
60 | Revision 1.17 2000/02/28 19:10:26 cblume | |
61 | Include the new TRD classes | |
62 | ||
851d3db9 | 63 | Revision 1.16.4.1 2000/02/28 18:04:35 cblume |
64 | Change to new hit version, introduce geometry class, and move digitization and clustering to AliTRDdigitizer/AliTRDclusterizerV1 | |
65 | ||
66 | Revision 1.16 1999/11/05 22:50:28 fca | |
67 | Do not use Atan, removed from ROOT too | |
68 | ||
90f8d287 | 69 | Revision 1.15 1999/11/02 17:20:19 fca |
70 | initialise nbytes before using it | |
71 | ||
036da493 | 72 | Revision 1.14 1999/11/02 17:15:54 fca |
73 | Correct ansi scoping not accepted by HP compilers | |
74 | ||
0549c011 | 75 | Revision 1.13 1999/11/02 17:14:51 fca |
76 | Correct ansi scoping not accepted by HP compilers | |
77 | ||
9c767df4 | 78 | Revision 1.12 1999/11/02 16:35:56 fca |
79 | New version of TRD introduced | |
80 | ||
5c7f4665 | 81 | Revision 1.11 1999/11/01 20:41:51 fca |
82 | Added protections against using the wrong version of FRAME | |
83 | ||
ab76897d | 84 | Revision 1.10 1999/09/29 09:24:35 fca |
85 | Introduction of the Copyright and cvs Log | |
86 | ||
4c039060 | 87 | */ |
88 | ||
fe4da5cc | 89 | /////////////////////////////////////////////////////////////////////////////// |
90 | // // | |
769257f4 | 91 | // Transition Radiation Detector version 1 -- slow simulator // |
fe4da5cc | 92 | // // |
93 | //Begin_Html | |
94 | /* | |
5c7f4665 | 95 | <img src="picts/AliTRDfullClass.gif"> |
fe4da5cc | 96 | */ |
97 | //End_Html | |
98 | // // | |
99 | // // | |
100 | /////////////////////////////////////////////////////////////////////////////// | |
101 | ||
769257f4 | 102 | #include <stdlib.h> |
103 | ||
fe4da5cc | 104 | #include <TMath.h> |
fe4da5cc | 105 | #include <TVector.h> |
5c7f4665 | 106 | #include <TRandom.h> |
793ff80c | 107 | #include <TF1.h> |
1819f4bb | 108 | #include <TLorentzVector.h> |
fe4da5cc | 109 | |
fe4da5cc | 110 | #include "AliRun.h" |
fe4da5cc | 111 | #include "AliMC.h" |
d3f347ff | 112 | #include "AliConst.h" |
5c7f4665 | 113 | |
851d3db9 | 114 | #include "AliTRDv1.h" |
793ff80c | 115 | #include "AliTRDhit.h" |
851d3db9 | 116 | #include "AliTRDmatrix.h" |
117 | #include "AliTRDgeometry.h" | |
793ff80c | 118 | #include "AliTRDsim.h" |
851d3db9 | 119 | |
fe4da5cc | 120 | ClassImp(AliTRDv1) |
8230f242 | 121 | |
122 | //_____________________________________________________________________________ | |
123 | AliTRDv1::AliTRDv1():AliTRD() | |
124 | { | |
125 | // | |
126 | // Default constructor | |
127 | // | |
128 | ||
129 | fIdSens = 0; | |
130 | ||
131 | fIdChamber1 = 0; | |
132 | fIdChamber2 = 0; | |
133 | fIdChamber3 = 0; | |
134 | ||
135 | fSensSelect = 0; | |
136 | fSensPlane = -1; | |
137 | fSensChamber = -1; | |
138 | fSensSector = -1; | |
139 | fSensSectorRange = 0; | |
140 | ||
141 | fDeltaE = NULL; | |
793ff80c | 142 | fTR = NULL; |
8230f242 | 143 | |
144 | } | |
145 | ||
fe4da5cc | 146 | //_____________________________________________________________________________ |
147 | AliTRDv1::AliTRDv1(const char *name, const char *title) | |
148 | :AliTRD(name, title) | |
149 | { | |
150 | // | |
851d3db9 | 151 | // Standard constructor for Transition Radiation Detector version 1 |
fe4da5cc | 152 | // |
82bbf98a | 153 | |
9d0b222b | 154 | fIdSens = 0; |
82bbf98a | 155 | |
9d0b222b | 156 | fIdChamber1 = 0; |
157 | fIdChamber2 = 0; | |
158 | fIdChamber3 = 0; | |
5c7f4665 | 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).fIdSens = fIdSens; |
8230f242 | 216 | |
43da34c0 | 217 | ((AliTRDv1 &) trd).fIdChamber1 = fIdChamber1; |
218 | ((AliTRDv1 &) trd).fIdChamber2 = fIdChamber2; | |
219 | ((AliTRDv1 &) trd).fIdChamber3 = fIdChamber3; | |
8230f242 | 220 | |
43da34c0 | 221 | ((AliTRDv1 &) trd).fSensSelect = fSensSelect; |
222 | ((AliTRDv1 &) trd).fSensPlane = fSensPlane; | |
223 | ((AliTRDv1 &) trd).fSensChamber = fSensChamber; | |
224 | ((AliTRDv1 &) trd).fSensSector = fSensSector; | |
225 | ((AliTRDv1 &) trd).fSensSectorRange = fSensSectorRange; | |
8230f242 | 226 | |
793ff80c | 227 | fDeltaE->Copy(*((AliTRDv1 &) trd).fDeltaE); |
228 | fTR->Copy(*((AliTRDv1 &) trd).fTR); | |
8230f242 | 229 | |
230 | } | |
231 | ||
fe4da5cc | 232 | //_____________________________________________________________________________ |
233 | void AliTRDv1::CreateGeometry() | |
234 | { | |
235 | // | |
851d3db9 | 236 | // Create the GEANT geometry for the Transition Radiation Detector - Version 1 |
5c7f4665 | 237 | // This version covers the full azimuth. |
d3f347ff | 238 | // |
239 | ||
82bbf98a | 240 | // Check that FRAME is there otherwise we have no place where to put the TRD |
8230f242 | 241 | AliModule* frame = gAlice->GetModule("FRAME"); |
242 | if (!frame) return; | |
d3f347ff | 243 | |
82bbf98a | 244 | // Define the chambers |
245 | AliTRD::CreateGeometry(); | |
d3f347ff | 246 | |
fe4da5cc | 247 | } |
248 | ||
249 | //_____________________________________________________________________________ | |
250 | void AliTRDv1::CreateMaterials() | |
251 | { | |
252 | // | |
851d3db9 | 253 | // Create materials for the Transition Radiation Detector version 1 |
fe4da5cc | 254 | // |
82bbf98a | 255 | |
d3f347ff | 256 | AliTRD::CreateMaterials(); |
82bbf98a | 257 | |
fe4da5cc | 258 | } |
259 | ||
793ff80c | 260 | //_____________________________________________________________________________ |
261 | void AliTRDv1::CreateTRhit(Int_t det) | |
262 | { | |
263 | // | |
264 | // Creates an electron cluster from a TR photon. | |
265 | // The photon is assumed to be created a the end of the radiator. The | |
266 | // distance after which it deposits its energy takes into account the | |
267 | // absorbtion of the entrance window and of the gas mixture in drift | |
268 | // volume. | |
269 | // | |
270 | ||
271 | // PDG code electron | |
272 | const Int_t kPdgElectron = 11; | |
273 | ||
274 | // Ionization energy | |
275 | const Float_t kWion = 22.04; | |
276 | ||
277 | // Maximum number of TR photons per track | |
278 | const Int_t kNTR = 50; | |
279 | ||
280 | TLorentzVector mom, pos; | |
281 | TClonesArray &lhits = *fHits; | |
282 | ||
283 | // Create TR only for electrons | |
284 | Int_t iPdg = gMC->TrackPid(); | |
285 | if (TMath::Abs(iPdg) != kPdgElectron) return; | |
286 | ||
287 | // Create TR at the entrance of the chamber | |
288 | if (gMC->IsTrackEntering()) { | |
289 | ||
290 | Float_t eTR[kNTR]; | |
291 | Int_t nTR; | |
292 | ||
293 | // Create TR photons | |
294 | gMC->TrackMomentum(mom); | |
295 | Float_t pTot = mom.Rho(); | |
296 | fTR->CreatePhotons(iPdg,pTot,nTR,eTR); | |
297 | if (nTR > kNTR) { | |
298 | printf("AliTRDv1::CreateTRhit -- "); | |
299 | printf("Boundary error: nTR = %d, kNTR = %d\n",nTR,kNTR); | |
300 | exit(1); | |
301 | } | |
302 | ||
303 | // Loop through the TR photons | |
304 | for (Int_t iTR = 0; iTR < nTR; iTR++) { | |
305 | ||
306 | Float_t energyMeV = eTR[iTR] * 0.001; | |
307 | Float_t energyeV = eTR[iTR] * 1000.0; | |
308 | Float_t absLength = 0; | |
309 | Float_t sigma = 0; | |
310 | ||
311 | // Take the absorbtion in the entrance window into account | |
312 | Double_t muMy = fTR->GetMuMy(energyMeV); | |
313 | sigma = muMy * fFoilDensity; | |
314 | absLength = gRandom->Exp(sigma); | |
315 | if (absLength < AliTRDgeometry::MyThick()) continue; | |
316 | ||
317 | // The absorbtion cross sections in the drift gas | |
318 | if (fGasMix == 1) { | |
319 | // Gas-mixture (Xe/CO2) | |
320 | Double_t muXe = fTR->GetMuXe(energyMeV); | |
321 | Double_t muCO = fTR->GetMuCO(energyMeV); | |
322 | sigma = (0.90 * muXe + 0.10 * muCO) * fGasDensity; | |
323 | } | |
324 | else { | |
325 | // Gas-mixture (Xe/Isobutane) | |
326 | Double_t muXe = fTR->GetMuXe(energyMeV); | |
327 | Double_t muBu = fTR->GetMuBu(energyMeV); | |
328 | sigma = (0.97 * muXe + 0.03 * muBu) * fGasDensity; | |
329 | } | |
330 | ||
331 | // The distance after which the energy of the TR photon | |
332 | // is deposited. | |
333 | absLength = gRandom->Exp(sigma); | |
334 | if (absLength > AliTRDgeometry::DrThick()) continue; | |
335 | ||
336 | // The position of the absorbtion | |
337 | Float_t posHit[3]; | |
338 | gMC->TrackPosition(pos); | |
339 | posHit[0] = pos[0] + mom[0] / pTot * absLength; | |
340 | posHit[1] = pos[1] + mom[1] / pTot * absLength; | |
341 | posHit[2] = pos[2] + mom[2] / pTot * absLength; | |
342 | ||
343 | // Create the charge | |
344 | Int_t q = ((Int_t) (energyeV / kWion)); | |
345 | ||
346 | // Add the hit to the array. TR photon hits are marked | |
347 | // by negative charge | |
348 | new(lhits[fNhits++]) AliTRDhit(fIshunt,gAlice->CurrentTrack() | |
349 | ,det,posHit,-q); | |
350 | ||
351 | } | |
352 | ||
353 | } | |
354 | ||
355 | } | |
356 | ||
5c7f4665 | 357 | //_____________________________________________________________________________ |
358 | void AliTRDv1::Init() | |
359 | { | |
360 | // | |
361 | // Initialise Transition Radiation Detector after geometry has been built. | |
5c7f4665 | 362 | // |
363 | ||
364 | AliTRD::Init(); | |
365 | ||
851d3db9 | 366 | printf(" Slow simulator\n\n"); |
367 | if (fSensSelect) { | |
368 | if (fSensPlane >= 0) | |
369 | printf(" Only plane %d is sensitive\n",fSensPlane); | |
370 | if (fSensChamber >= 0) | |
371 | printf(" Only chamber %d is sensitive\n",fSensChamber); | |
9d0b222b | 372 | if (fSensSector >= 0) { |
373 | Int_t sens1 = fSensSector; | |
374 | Int_t sens2 = fSensSector + fSensSectorRange; | |
793ff80c | 375 | sens2 -= ((Int_t) (sens2 / AliTRDgeometry::Nsect())) |
376 | * AliTRDgeometry::Nsect(); | |
9d0b222b | 377 | printf(" Only sectors %d - %d are sensitive\n",sens1,sens2-1); |
378 | } | |
851d3db9 | 379 | } |
793ff80c | 380 | if (fTR) |
381 | printf(" TR simulation on\n"); | |
382 | else | |
383 | printf(" TR simulation off\n"); | |
851d3db9 | 384 | printf("\n"); |
5c7f4665 | 385 | |
386 | // First ionization potential (eV) for the gas mixture (90% Xe + 10% CO2) | |
387 | const Float_t kPoti = 12.1; | |
388 | // Maximum energy (50 keV); | |
389 | const Float_t kEend = 50000.0; | |
390 | // Ermilova distribution for the delta-ray spectrum | |
8230f242 | 391 | Float_t poti = TMath::Log(kPoti); |
392 | Float_t eEnd = TMath::Log(kEend); | |
793ff80c | 393 | fDeltaE = new TF1("deltae",Ermilova,poti,eEnd,0); |
5c7f4665 | 394 | |
395 | // Identifier of the sensitive volume (drift region) | |
396 | fIdSens = gMC->VolId("UL05"); | |
82bbf98a | 397 | |
398 | // Identifier of the TRD-driftchambers | |
399 | fIdChamber1 = gMC->VolId("UCIO"); | |
400 | fIdChamber2 = gMC->VolId("UCIM"); | |
401 | fIdChamber3 = gMC->VolId("UCII"); | |
402 | ||
5c7f4665 | 403 | for (Int_t i = 0; i < 80; i++) printf("*"); |
404 | printf("\n"); | |
405 | ||
fe4da5cc | 406 | } |
407 | ||
793ff80c | 408 | //_____________________________________________________________________________ |
409 | AliTRDsim *AliTRDv1::CreateTR() | |
410 | { | |
411 | // | |
412 | // Enables the simulation of TR | |
413 | // | |
414 | ||
415 | fTR = new AliTRDsim(); | |
416 | return fTR; | |
417 | ||
418 | } | |
419 | ||
5c7f4665 | 420 | //_____________________________________________________________________________ |
421 | void AliTRDv1::SetSensPlane(Int_t iplane) | |
422 | { | |
423 | // | |
851d3db9 | 424 | // Defines the hit-sensitive plane (0-5) |
5c7f4665 | 425 | // |
82bbf98a | 426 | |
851d3db9 | 427 | if ((iplane < 0) || (iplane > 5)) { |
5c7f4665 | 428 | printf("Wrong input value: %d\n",iplane); |
429 | printf("Use standard setting\n"); | |
851d3db9 | 430 | fSensPlane = -1; |
431 | fSensSelect = 0; | |
5c7f4665 | 432 | return; |
433 | } | |
82bbf98a | 434 | |
5c7f4665 | 435 | fSensSelect = 1; |
436 | fSensPlane = iplane; | |
82bbf98a | 437 | |
5c7f4665 | 438 | } |
439 | ||
440 | //_____________________________________________________________________________ | |
441 | void AliTRDv1::SetSensChamber(Int_t ichamber) | |
442 | { | |
443 | // | |
851d3db9 | 444 | // Defines the hit-sensitive chamber (0-4) |
5c7f4665 | 445 | // |
446 | ||
851d3db9 | 447 | if ((ichamber < 0) || (ichamber > 4)) { |
5c7f4665 | 448 | printf("Wrong input value: %d\n",ichamber); |
449 | printf("Use standard setting\n"); | |
851d3db9 | 450 | fSensChamber = -1; |
451 | fSensSelect = 0; | |
5c7f4665 | 452 | return; |
453 | } | |
454 | ||
455 | fSensSelect = 1; | |
456 | fSensChamber = ichamber; | |
457 | ||
458 | } | |
459 | ||
460 | //_____________________________________________________________________________ | |
461 | void AliTRDv1::SetSensSector(Int_t isector) | |
462 | { | |
463 | // | |
851d3db9 | 464 | // Defines the hit-sensitive sector (0-17) |
5c7f4665 | 465 | // |
466 | ||
9d0b222b | 467 | SetSensSector(isector,1); |
468 | ||
469 | } | |
470 | ||
471 | //_____________________________________________________________________________ | |
472 | void AliTRDv1::SetSensSector(Int_t isector, Int_t nsector) | |
473 | { | |
474 | // | |
475 | // Defines a range of hit-sensitive sectors. The range is defined by | |
476 | // <isector> (0-17) as the starting point and <nsector> as the number | |
477 | // of sectors to be included. | |
478 | // | |
479 | ||
851d3db9 | 480 | if ((isector < 0) || (isector > 17)) { |
9d0b222b | 481 | printf("Wrong input value <isector>: %d\n",isector); |
5c7f4665 | 482 | printf("Use standard setting\n"); |
9d0b222b | 483 | fSensSector = -1; |
484 | fSensSectorRange = 0; | |
485 | fSensSelect = 0; | |
5c7f4665 | 486 | return; |
487 | } | |
488 | ||
9d0b222b | 489 | if ((nsector < 1) || (nsector > 18)) { |
490 | printf("Wrong input value <nsector>: %d\n",nsector); | |
491 | printf("Use standard setting\n"); | |
492 | fSensSector = -1; | |
493 | fSensSectorRange = 0; | |
494 | fSensSelect = 0; | |
495 | return; | |
496 | } | |
497 | ||
498 | fSensSelect = 1; | |
499 | fSensSector = isector; | |
500 | fSensSectorRange = nsector; | |
5c7f4665 | 501 | |
502 | } | |
503 | ||
504 | //_____________________________________________________________________________ | |
505 | void AliTRDv1::StepManager() | |
506 | { | |
507 | // | |
5c7f4665 | 508 | // Slow simulator. Every charged track produces electron cluster as hits |
509 | // along its path across the drift volume. The step size is set acording | |
510 | // to Bethe-Bloch. The energy distribution of the delta electrons follows | |
511 | // a spectrum taken from Ermilova et al. | |
512 | // | |
513 | ||
514 | Int_t iIdSens, icSens; | |
515 | Int_t iIdSpace, icSpace; | |
516 | Int_t iIdChamber, icChamber; | |
851d3db9 | 517 | Int_t pla = 0; |
518 | Int_t cha = 0; | |
519 | Int_t sec = 0; | |
793ff80c | 520 | Int_t det = 0; |
851d3db9 | 521 | Int_t iPdg; |
793ff80c | 522 | Int_t qTot; |
5c7f4665 | 523 | |
793ff80c | 524 | Float_t hits[3]; |
990e4068 | 525 | Float_t moms[3]; |
5c7f4665 | 526 | Float_t random[1]; |
527 | Float_t charge; | |
528 | Float_t aMass; | |
529 | ||
530 | Double_t pTot; | |
5c7f4665 | 531 | Double_t eDelta; |
532 | Double_t betaGamma, pp; | |
533 | ||
534 | TLorentzVector pos, mom; | |
82bbf98a | 535 | TClonesArray &lhits = *fHits; |
536 | ||
851d3db9 | 537 | const Double_t kBig = 1.0E+12; |
5c7f4665 | 538 | |
539 | // Ionization energy | |
a3c76cdc | 540 | const Float_t kWion = 22.04; |
541 | // Maximum momentum for e+ e- g | |
542 | const Float_t kPTotMaxEl = 0.002; | |
543 | // Minimum momentum for the step size adjustment | |
544 | const Float_t kPTotMinStep = 1.0e-5; | |
5c7f4665 | 545 | // Plateau value of the energy-loss for electron in xenon |
546 | // taken from: Allison + Comb, Ann. Rev. Nucl. Sci. (1980), 30, 253 | |
547 | //const Double_t kPlateau = 1.70; | |
548 | // the averaged value (26/3/99) | |
a3c76cdc | 549 | const Float_t kPlateau = 1.55; |
5c7f4665 | 550 | // dN1/dx|min for the gas mixture (90% Xe + 10% CO2) |
a3c76cdc | 551 | const Float_t kPrim = 48.0; |
5c7f4665 | 552 | // First ionization potential (eV) for the gas mixture (90% Xe + 10% CO2) |
a3c76cdc | 553 | const Float_t kPoti = 12.1; |
851d3db9 | 554 | |
555 | // PDG code electron | |
8230f242 | 556 | const Int_t kPdgElectron = 11; |
5c7f4665 | 557 | |
558 | // Set the maximum step size to a very large number for all | |
559 | // neutral particles and those outside the driftvolume | |
560 | gMC->SetMaxStep(kBig); | |
561 | ||
769257f4 | 562 | // Create some special hits with amplitude 0 at the entrance and |
563 | // exit of each chamber that contain the momentum components of the particle | |
564 | if (gMC->TrackCharge() && | |
565 | (gMC->IsTrackEntering() || gMC->IsTrackExiting())) { | |
566 | ||
567 | // Inside a sensitive volume? | |
568 | iIdSens = gMC->CurrentVolID(icSens); | |
569 | if (iIdSens == fIdSens) { | |
570 | ||
571 | iIdSpace = gMC->CurrentVolOffID(4,icSpace ); | |
572 | iIdChamber = gMC->CurrentVolOffID(1,icChamber); | |
573 | ||
574 | // The hit coordinates | |
575 | gMC->TrackPosition(pos); | |
990e4068 | 576 | hits[0] = pos[0]; |
577 | hits[1] = pos[1]; | |
578 | hits[2] = pos[2]; | |
769257f4 | 579 | |
580 | // The track momentum | |
581 | gMC->TrackMomentum(mom); | |
990e4068 | 582 | moms[0] = mom[0]; |
583 | moms[1] = mom[1]; | |
584 | moms[2] = mom[2]; | |
769257f4 | 585 | |
586 | // The sector number (0 - 17) | |
587 | // The numbering goes clockwise and starts at y = 0 | |
588 | Float_t phi = kRaddeg*TMath::ATan2(pos[0],pos[1]); | |
589 | if (phi < 90.) | |
590 | phi = phi + 270.; | |
591 | else | |
592 | phi = phi - 90.; | |
593 | sec = ((Int_t) (phi / 20)); | |
594 | ||
595 | // The chamber number | |
596 | // 0: outer left | |
597 | // 1: middle left | |
598 | // 2: inner | |
599 | // 3: middle right | |
600 | // 4: outer right | |
601 | if (iIdChamber == fIdChamber1) | |
602 | cha = (hits[2] < 0 ? 0 : 4); | |
603 | else if (iIdChamber == fIdChamber2) | |
604 | cha = (hits[2] < 0 ? 1 : 3); | |
605 | else if (iIdChamber == fIdChamber3) | |
606 | cha = 2; | |
607 | ||
608 | // The plane number | |
609 | // The numbering starts at the innermost plane | |
610 | pla = icChamber - TMath::Nint((Float_t) (icChamber / 7)) * 6 - 1; | |
611 | ||
612 | // Check on selected volumes | |
613 | Int_t addthishit = 1; | |
614 | if (fSensSelect) { | |
615 | if ((fSensPlane >= 0) && (pla != fSensPlane )) addthishit = 0; | |
616 | if ((fSensChamber >= 0) && (cha != fSensChamber)) addthishit = 0; | |
617 | if (fSensSector >= 0) { | |
618 | Int_t sens1 = fSensSector; | |
619 | Int_t sens2 = fSensSector + fSensSectorRange; | |
620 | sens2 -= ((Int_t) (sens2 / AliTRDgeometry::Nsect())) | |
621 | * AliTRDgeometry::Nsect(); | |
622 | if (sens1 < sens2) { | |
623 | if ((sec < sens1) || (sec >= sens2)) addthishit = 0; | |
624 | } | |
625 | else { | |
626 | if ((sec < sens1) && (sec >= sens2)) addthishit = 0; | |
627 | } | |
628 | } | |
629 | } | |
630 | ||
631 | // Add this hit | |
632 | if (addthishit) { | |
633 | det = fGeometry->GetDetector(pla,cha,sec); | |
634 | new(lhits[fNhits++]) AliTRDhit(fIshunt | |
635 | ,gAlice->CurrentTrack() | |
636 | ,det | |
990e4068 | 637 | ,moms |
769257f4 | 638 | ,0); |
639 | } | |
640 | ||
641 | } | |
642 | ||
643 | } | |
644 | ||
5c7f4665 | 645 | // Use only charged tracks |
646 | if (( gMC->TrackCharge() ) && | |
647 | (!gMC->IsTrackStop() ) && | |
648 | (!gMC->IsTrackDisappeared())) { | |
fe4da5cc | 649 | |
5c7f4665 | 650 | // Inside a sensitive volume? |
82bbf98a | 651 | iIdSens = gMC->CurrentVolID(icSens); |
652 | if (iIdSens == fIdSens) { | |
653 | ||
82bbf98a | 654 | iIdSpace = gMC->CurrentVolOffID(4,icSpace ); |
655 | iIdChamber = gMC->CurrentVolOffID(1,icChamber); | |
fe4da5cc | 656 | |
5c7f4665 | 657 | // Calculate the energy of the delta-electrons |
658 | eDelta = TMath::Exp(fDeltaE->GetRandom()) - kPoti; | |
659 | eDelta = TMath::Max(eDelta,0.0); | |
660 | ||
661 | // The number of secondary electrons created | |
793ff80c | 662 | qTot = ((Int_t) (eDelta / kWion) + 1); |
5c7f4665 | 663 | |
664 | // The hit coordinates and charge | |
665 | gMC->TrackPosition(pos); | |
666 | hits[0] = pos[0]; | |
667 | hits[1] = pos[1]; | |
668 | hits[2] = pos[2]; | |
5c7f4665 | 669 | |
851d3db9 | 670 | // The sector number (0 - 17) |
671 | // The numbering goes clockwise and starts at y = 0 | |
672 | Float_t phi = kRaddeg*TMath::ATan2(pos[0],pos[1]); | |
673 | if (phi < 90.) | |
674 | phi = phi + 270.; | |
675 | else | |
676 | phi = phi - 90.; | |
677 | sec = ((Int_t) (phi / 20)); | |
82bbf98a | 678 | |
d3f347ff | 679 | // The chamber number |
851d3db9 | 680 | // 0: outer left |
681 | // 1: middle left | |
682 | // 2: inner | |
683 | // 3: middle right | |
684 | // 4: outer right | |
82bbf98a | 685 | if (iIdChamber == fIdChamber1) |
851d3db9 | 686 | cha = (hits[2] < 0 ? 0 : 4); |
82bbf98a | 687 | else if (iIdChamber == fIdChamber2) |
851d3db9 | 688 | cha = (hits[2] < 0 ? 1 : 3); |
82bbf98a | 689 | else if (iIdChamber == fIdChamber3) |
851d3db9 | 690 | cha = 2; |
82bbf98a | 691 | |
fe4da5cc | 692 | // The plane number |
851d3db9 | 693 | // The numbering starts at the innermost plane |
694 | pla = icChamber - TMath::Nint((Float_t) (icChamber / 7)) * 6 - 1; | |
82bbf98a | 695 | |
5c7f4665 | 696 | // Check on selected volumes |
697 | Int_t addthishit = 1; | |
698 | if (fSensSelect) { | |
6f1e466d | 699 | if ((fSensPlane >= 0) && (pla != fSensPlane )) addthishit = 0; |
700 | if ((fSensChamber >= 0) && (cha != fSensChamber)) addthishit = 0; | |
9d0b222b | 701 | if (fSensSector >= 0) { |
702 | Int_t sens1 = fSensSector; | |
703 | Int_t sens2 = fSensSector + fSensSectorRange; | |
793ff80c | 704 | sens2 -= ((Int_t) (sens2 / AliTRDgeometry::Nsect())) |
705 | * AliTRDgeometry::Nsect(); | |
9d0b222b | 706 | if (sens1 < sens2) { |
707 | if ((sec < sens1) || (sec >= sens2)) addthishit = 0; | |
708 | } | |
709 | else { | |
710 | if ((sec < sens1) && (sec >= sens2)) addthishit = 0; | |
711 | } | |
712 | } | |
5c7f4665 | 713 | } |
714 | ||
715 | // Add this hit | |
716 | if (addthishit) { | |
717 | ||
793ff80c | 718 | det = fGeometry->GetDetector(pla,cha,sec); |
719 | ||
720 | // Create the electron cluster from TR photons | |
721 | if (fTR) CreateTRhit(det); | |
722 | ||
851d3db9 | 723 | new(lhits[fNhits++]) AliTRDhit(fIshunt |
724 | ,gAlice->CurrentTrack() | |
9d0b222b | 725 | ,det |
793ff80c | 726 | ,hits |
727 | ,qTot); | |
5c7f4665 | 728 | |
729 | // The energy loss according to Bethe Bloch | |
730 | gMC->TrackMomentum(mom); | |
731 | pTot = mom.Rho(); | |
851d3db9 | 732 | iPdg = TMath::Abs(gMC->TrackPid()); |
8230f242 | 733 | if ( (iPdg != kPdgElectron) || |
a3c76cdc | 734 | ((iPdg == kPdgElectron) && (pTot < kPTotMaxEl))) { |
5c7f4665 | 735 | aMass = gMC->TrackMass(); |
736 | betaGamma = pTot / aMass; | |
737 | pp = kPrim * BetheBloch(betaGamma); | |
738 | // Take charge > 1 into account | |
739 | charge = gMC->TrackCharge(); | |
740 | if (TMath::Abs(charge) > 1) pp = pp * charge*charge; | |
741 | } | |
742 | // Electrons above 20 Mev/c are at the plateau | |
743 | else { | |
744 | pp = kPrim * kPlateau; | |
745 | } | |
746 | ||
747 | // Calculate the maximum step size for the next tracking step | |
a3c76cdc | 748 | // introduce a lower momentum cut |
749 | //if ((pp > 0) && (pTot > kPTotMinStep)) { | |
5c7f4665 | 750 | if (pp > 0) { |
751 | do | |
752 | gMC->Rndm(random,1); | |
753 | while ((random[0] == 1.) || (random[0] == 0.)); | |
754 | gMC->SetMaxStep( - TMath::Log(random[0]) / pp); | |
755 | } | |
756 | ||
757 | } | |
758 | else { | |
759 | // set step size to maximal value | |
760 | gMC->SetMaxStep(kBig); | |
761 | } | |
d3f347ff | 762 | |
763 | } | |
764 | ||
5c7f4665 | 765 | } |
766 | ||
767 | } | |
768 | ||
769 | //_____________________________________________________________________________ | |
770 | Double_t AliTRDv1::BetheBloch(Double_t bg) | |
771 | { | |
772 | // | |
773 | // Parametrization of the Bethe-Bloch-curve | |
774 | // The parametrization is the same as for the TPC and is taken from Lehrhaus. | |
775 | // | |
776 | ||
777 | // This parameters have been adjusted to averaged values from GEANT | |
778 | const Double_t kP1 = 7.17960e-02; | |
779 | const Double_t kP2 = 8.54196; | |
780 | const Double_t kP3 = 1.38065e-06; | |
781 | const Double_t kP4 = 5.30972; | |
782 | const Double_t kP5 = 2.83798; | |
783 | ||
784 | // This parameters have been adjusted to Xe-data found in: | |
785 | // Allison & Cobb, Ann. Rev. Nucl. Sci. (1980), 30, 253 | |
786 | //const Double_t kP1 = 0.76176E-1; | |
787 | //const Double_t kP2 = 10.632; | |
788 | //const Double_t kP3 = 3.17983E-6; | |
789 | //const Double_t kP4 = 1.8631; | |
790 | //const Double_t kP5 = 1.9479; | |
791 | ||
792 | if (bg > 0) { | |
793 | Double_t yy = bg / TMath::Sqrt(1. + bg*bg); | |
794 | Double_t aa = TMath::Power(yy,kP4); | |
795 | Double_t bb = TMath::Power((1./bg),kP5); | |
796 | bb = TMath::Log(kP3 + bb); | |
797 | return ((kP2 - aa - bb)*kP1 / aa); | |
798 | } | |
799 | else | |
800 | return 0; | |
d3f347ff | 801 | |
fe4da5cc | 802 | } |
5c7f4665 | 803 | |
804 | //_____________________________________________________________________________ | |
805 | Double_t Ermilova(Double_t *x, Double_t *) | |
806 | { | |
807 | // | |
808 | // Calculates the delta-ray energy distribution according to Ermilova. | |
809 | // Logarithmic scale ! | |
810 | // | |
811 | ||
812 | Double_t energy; | |
813 | Double_t dpos; | |
814 | Double_t dnde; | |
815 | ||
816 | Int_t pos1, pos2; | |
817 | ||
8230f242 | 818 | const Int_t kNv = 31; |
5c7f4665 | 819 | |
8230f242 | 820 | Float_t vxe[kNv] = { 2.3026, 2.9957, 3.4012, 3.6889, 3.9120 |
821 | , 4.0943, 4.2485, 4.3820, 4.4998, 4.6052 | |
822 | , 4.7005, 5.0752, 5.2983, 5.7038, 5.9915 | |
823 | , 6.2146, 6.5221, 6.9078, 7.3132, 7.6009 | |
824 | , 8.0064, 8.5172, 8.6995, 8.9872, 9.2103 | |
825 | , 9.4727, 9.9035,10.3735,10.5966,10.8198 | |
826 | ,11.5129 }; | |
5c7f4665 | 827 | |
8230f242 | 828 | Float_t vye[kNv] = { 80.0 , 31.0 , 23.3 , 21.1 , 21.0 |
829 | , 20.9 , 20.8 , 20.0 , 16.0 , 11.0 | |
830 | , 8.0 , 6.0 , 5.2 , 4.6 , 4.0 | |
831 | , 3.5 , 3.0 , 1.4 , 0.67 , 0.44 | |
832 | , 0.3 , 0.18 , 0.12 , 0.08 , 0.056 | |
833 | , 0.04 , 0.023, 0.015, 0.011, 0.01 | |
834 | , 0.004 }; | |
5c7f4665 | 835 | |
836 | energy = x[0]; | |
837 | ||
838 | // Find the position | |
839 | pos1 = pos2 = 0; | |
840 | dpos = 0; | |
841 | do { | |
842 | dpos = energy - vxe[pos2++]; | |
843 | } | |
844 | while (dpos > 0); | |
845 | pos2--; | |
8230f242 | 846 | if (pos2 > kNv) pos2 = kNv; |
5c7f4665 | 847 | pos1 = pos2 - 1; |
848 | ||
849 | // Differentiate between the sampling points | |
850 | dnde = (vye[pos1] - vye[pos2]) / (vxe[pos2] - vxe[pos1]); | |
851 | ||
852 | return dnde; | |
853 | ||
854 | } |