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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 | $Log$ | |
f73816f5 | 18 | Revision 1.27 2001/03/30 14:40:15 cblume |
19 | Update of the digitization parameter | |
20 | ||
a3c76cdc | 21 | Revision 1.26 2000/11/30 17:38:08 cblume |
22 | Changes to get in line with new STEER and EVGEN | |
23 | ||
1819f4bb | 24 | Revision 1.25 2000/11/15 14:30:16 cblume |
25 | Fixed bug in calculating detector no. of extra hit | |
26 | ||
990e4068 | 27 | Revision 1.24 2000/11/10 14:58:36 cblume |
28 | Introduce additional hit with amplitude 0 at the chamber borders | |
29 | ||
769257f4 | 30 | Revision 1.23 2000/11/01 14:53:21 cblume |
31 | Merge with TRD-develop | |
32 | ||
793ff80c | 33 | Revision 1.17.2.5 2000/10/15 23:40:01 cblume |
34 | Remove AliTRDconst | |
35 | ||
36 | Revision 1.17.2.4 2000/10/06 16:49:46 cblume | |
37 | Made Getters const | |
38 | ||
39 | Revision 1.17.2.3 2000/10/04 16:34:58 cblume | |
40 | Replace include files by forward declarations | |
41 | ||
42 | Revision 1.17.2.2 2000/09/18 13:50:17 cblume | |
43 | Include TR photon generation and adapt to new AliTRDhit | |
44 | ||
45 | Revision 1.22 2000/06/27 13:08:50 cblume | |
46 | Changed to Copy(TObject &A) to appease the HP-compiler | |
47 | ||
43da34c0 | 48 | Revision 1.21 2000/06/09 11:10:07 cblume |
49 | Compiler warnings and coding conventions, next round | |
50 | ||
dd9a6ee3 | 51 | Revision 1.20 2000/06/08 18:32:58 cblume |
52 | Make code compliant to coding conventions | |
53 | ||
8230f242 | 54 | Revision 1.19 2000/06/07 16:27:32 cblume |
55 | Try to remove compiler warnings on Sun and HP | |
56 | ||
9d0b222b | 57 | Revision 1.18 2000/05/08 16:17:27 cblume |
58 | Merge TRD-develop | |
59 | ||
6f1e466d | 60 | Revision 1.17.2.1 2000/05/08 14:59:16 cblume |
61 | Made inline function non-virtual. Bug fix in setting sensitive chamber | |
62 | ||
63 | Revision 1.17 2000/02/28 19:10:26 cblume | |
64 | Include the new TRD classes | |
65 | ||
851d3db9 | 66 | Revision 1.16.4.1 2000/02/28 18:04:35 cblume |
67 | Change to new hit version, introduce geometry class, and move digitization and clustering to AliTRDdigitizer/AliTRDclusterizerV1 | |
68 | ||
69 | Revision 1.16 1999/11/05 22:50:28 fca | |
70 | Do not use Atan, removed from ROOT too | |
71 | ||
90f8d287 | 72 | Revision 1.15 1999/11/02 17:20:19 fca |
73 | initialise nbytes before using it | |
74 | ||
036da493 | 75 | Revision 1.14 1999/11/02 17:15:54 fca |
76 | Correct ansi scoping not accepted by HP compilers | |
77 | ||
0549c011 | 78 | Revision 1.13 1999/11/02 17:14:51 fca |
79 | Correct ansi scoping not accepted by HP compilers | |
80 | ||
9c767df4 | 81 | Revision 1.12 1999/11/02 16:35:56 fca |
82 | New version of TRD introduced | |
83 | ||
5c7f4665 | 84 | Revision 1.11 1999/11/01 20:41:51 fca |
85 | Added protections against using the wrong version of FRAME | |
86 | ||
ab76897d | 87 | Revision 1.10 1999/09/29 09:24:35 fca |
88 | Introduction of the Copyright and cvs Log | |
89 | ||
4c039060 | 90 | */ |
91 | ||
fe4da5cc | 92 | /////////////////////////////////////////////////////////////////////////////// |
93 | // // | |
769257f4 | 94 | // Transition Radiation Detector version 1 -- slow simulator // |
fe4da5cc | 95 | // // |
96 | //Begin_Html | |
97 | /* | |
5c7f4665 | 98 | <img src="picts/AliTRDfullClass.gif"> |
fe4da5cc | 99 | */ |
100 | //End_Html | |
101 | // // | |
102 | // // | |
103 | /////////////////////////////////////////////////////////////////////////////// | |
104 | ||
769257f4 | 105 | #include <stdlib.h> |
106 | ||
fe4da5cc | 107 | #include <TMath.h> |
fe4da5cc | 108 | #include <TVector.h> |
5c7f4665 | 109 | #include <TRandom.h> |
793ff80c | 110 | #include <TF1.h> |
1819f4bb | 111 | #include <TLorentzVector.h> |
fe4da5cc | 112 | |
fe4da5cc | 113 | #include "AliRun.h" |
fe4da5cc | 114 | #include "AliMC.h" |
d3f347ff | 115 | #include "AliConst.h" |
5c7f4665 | 116 | |
851d3db9 | 117 | #include "AliTRDv1.h" |
793ff80c | 118 | #include "AliTRDhit.h" |
851d3db9 | 119 | #include "AliTRDmatrix.h" |
120 | #include "AliTRDgeometry.h" | |
793ff80c | 121 | #include "AliTRDsim.h" |
851d3db9 | 122 | |
fe4da5cc | 123 | ClassImp(AliTRDv1) |
8230f242 | 124 | |
125 | //_____________________________________________________________________________ | |
126 | AliTRDv1::AliTRDv1():AliTRD() | |
127 | { | |
128 | // | |
129 | // Default constructor | |
130 | // | |
131 | ||
f73816f5 | 132 | fIdSensDr = 0; |
133 | fIdSensAm = 0; | |
8230f242 | 134 | |
135 | fIdChamber1 = 0; | |
136 | fIdChamber2 = 0; | |
137 | fIdChamber3 = 0; | |
138 | ||
139 | fSensSelect = 0; | |
140 | fSensPlane = -1; | |
141 | fSensChamber = -1; | |
142 | fSensSector = -1; | |
143 | fSensSectorRange = 0; | |
144 | ||
145 | fDeltaE = NULL; | |
793ff80c | 146 | fTR = NULL; |
8230f242 | 147 | |
148 | } | |
149 | ||
fe4da5cc | 150 | //_____________________________________________________________________________ |
151 | AliTRDv1::AliTRDv1(const char *name, const char *title) | |
152 | :AliTRD(name, title) | |
153 | { | |
154 | // | |
851d3db9 | 155 | // Standard constructor for Transition Radiation Detector version 1 |
fe4da5cc | 156 | // |
82bbf98a | 157 | |
f73816f5 | 158 | fIdSensDr = 0; |
159 | fIdSensAm = 0; | |
82bbf98a | 160 | |
9d0b222b | 161 | fIdChamber1 = 0; |
162 | fIdChamber2 = 0; | |
163 | fIdChamber3 = 0; | |
5c7f4665 | 164 | |
9d0b222b | 165 | fSensSelect = 0; |
166 | fSensPlane = -1; | |
167 | fSensChamber = -1; | |
168 | fSensSector = -1; | |
8230f242 | 169 | fSensSectorRange = 0; |
5c7f4665 | 170 | |
9d0b222b | 171 | fDeltaE = NULL; |
793ff80c | 172 | fTR = NULL; |
5c7f4665 | 173 | |
174 | SetBufferSize(128000); | |
175 | ||
176 | } | |
177 | ||
8230f242 | 178 | //_____________________________________________________________________________ |
dd9a6ee3 | 179 | AliTRDv1::AliTRDv1(const AliTRDv1 &trd) |
8230f242 | 180 | { |
181 | // | |
182 | // Copy constructor | |
183 | // | |
184 | ||
dd9a6ee3 | 185 | ((AliTRDv1 &) trd).Copy(*this); |
8230f242 | 186 | |
187 | } | |
188 | ||
5c7f4665 | 189 | //_____________________________________________________________________________ |
190 | AliTRDv1::~AliTRDv1() | |
191 | { | |
dd9a6ee3 | 192 | // |
193 | // AliTRDv1 destructor | |
194 | // | |
82bbf98a | 195 | |
5c7f4665 | 196 | if (fDeltaE) delete fDeltaE; |
793ff80c | 197 | if (fTR) delete fTR; |
82bbf98a | 198 | |
fe4da5cc | 199 | } |
200 | ||
dd9a6ee3 | 201 | //_____________________________________________________________________________ |
202 | AliTRDv1 &AliTRDv1::operator=(const AliTRDv1 &trd) | |
203 | { | |
204 | // | |
205 | // Assignment operator | |
206 | // | |
207 | ||
208 | if (this != &trd) ((AliTRDv1 &) trd).Copy(*this); | |
209 | return *this; | |
210 | ||
211 | } | |
8230f242 | 212 | |
213 | //_____________________________________________________________________________ | |
43da34c0 | 214 | void AliTRDv1::Copy(TObject &trd) |
8230f242 | 215 | { |
216 | // | |
217 | // Copy function | |
218 | // | |
219 | ||
f73816f5 | 220 | ((AliTRDv1 &) trd).fIdSensDr = fIdSensDr; |
221 | ((AliTRDv1 &) trd).fIdSensAm = fIdSensAm; | |
8230f242 | 222 | |
43da34c0 | 223 | ((AliTRDv1 &) trd).fIdChamber1 = fIdChamber1; |
224 | ((AliTRDv1 &) trd).fIdChamber2 = fIdChamber2; | |
225 | ((AliTRDv1 &) trd).fIdChamber3 = fIdChamber3; | |
8230f242 | 226 | |
43da34c0 | 227 | ((AliTRDv1 &) trd).fSensSelect = fSensSelect; |
228 | ((AliTRDv1 &) trd).fSensPlane = fSensPlane; | |
229 | ((AliTRDv1 &) trd).fSensChamber = fSensChamber; | |
230 | ((AliTRDv1 &) trd).fSensSector = fSensSector; | |
231 | ((AliTRDv1 &) trd).fSensSectorRange = fSensSectorRange; | |
8230f242 | 232 | |
793ff80c | 233 | fDeltaE->Copy(*((AliTRDv1 &) trd).fDeltaE); |
234 | fTR->Copy(*((AliTRDv1 &) trd).fTR); | |
8230f242 | 235 | |
236 | } | |
237 | ||
fe4da5cc | 238 | //_____________________________________________________________________________ |
239 | void AliTRDv1::CreateGeometry() | |
240 | { | |
241 | // | |
851d3db9 | 242 | // Create the GEANT geometry for the Transition Radiation Detector - Version 1 |
5c7f4665 | 243 | // This version covers the full azimuth. |
d3f347ff | 244 | // |
245 | ||
82bbf98a | 246 | // Check that FRAME is there otherwise we have no place where to put the TRD |
8230f242 | 247 | AliModule* frame = gAlice->GetModule("FRAME"); |
248 | if (!frame) return; | |
d3f347ff | 249 | |
82bbf98a | 250 | // Define the chambers |
251 | AliTRD::CreateGeometry(); | |
d3f347ff | 252 | |
fe4da5cc | 253 | } |
254 | ||
255 | //_____________________________________________________________________________ | |
256 | void AliTRDv1::CreateMaterials() | |
257 | { | |
258 | // | |
851d3db9 | 259 | // Create materials for the Transition Radiation Detector version 1 |
fe4da5cc | 260 | // |
82bbf98a | 261 | |
d3f347ff | 262 | AliTRD::CreateMaterials(); |
82bbf98a | 263 | |
fe4da5cc | 264 | } |
265 | ||
793ff80c | 266 | //_____________________________________________________________________________ |
267 | void AliTRDv1::CreateTRhit(Int_t det) | |
268 | { | |
269 | // | |
270 | // Creates an electron cluster from a TR photon. | |
271 | // The photon is assumed to be created a the end of the radiator. The | |
272 | // distance after which it deposits its energy takes into account the | |
273 | // absorbtion of the entrance window and of the gas mixture in drift | |
274 | // volume. | |
275 | // | |
276 | ||
277 | // PDG code electron | |
278 | const Int_t kPdgElectron = 11; | |
279 | ||
280 | // Ionization energy | |
281 | const Float_t kWion = 22.04; | |
282 | ||
283 | // Maximum number of TR photons per track | |
284 | const Int_t kNTR = 50; | |
285 | ||
286 | TLorentzVector mom, pos; | |
287 | TClonesArray &lhits = *fHits; | |
288 | ||
793ff80c | 289 | // Create TR at the entrance of the chamber |
290 | if (gMC->IsTrackEntering()) { | |
291 | ||
f73816f5 | 292 | // Create TR only for electrons |
293 | Int_t iPdg = gMC->TrackPid(); | |
294 | if (TMath::Abs(iPdg) != kPdgElectron) return; | |
295 | ||
793ff80c | 296 | Float_t eTR[kNTR]; |
297 | Int_t nTR; | |
298 | ||
299 | // Create TR photons | |
300 | gMC->TrackMomentum(mom); | |
301 | Float_t pTot = mom.Rho(); | |
302 | fTR->CreatePhotons(iPdg,pTot,nTR,eTR); | |
303 | if (nTR > kNTR) { | |
304 | printf("AliTRDv1::CreateTRhit -- "); | |
305 | printf("Boundary error: nTR = %d, kNTR = %d\n",nTR,kNTR); | |
306 | exit(1); | |
307 | } | |
308 | ||
309 | // Loop through the TR photons | |
310 | for (Int_t iTR = 0; iTR < nTR; iTR++) { | |
311 | ||
312 | Float_t energyMeV = eTR[iTR] * 0.001; | |
313 | Float_t energyeV = eTR[iTR] * 1000.0; | |
314 | Float_t absLength = 0; | |
315 | Float_t sigma = 0; | |
316 | ||
317 | // Take the absorbtion in the entrance window into account | |
318 | Double_t muMy = fTR->GetMuMy(energyMeV); | |
319 | sigma = muMy * fFoilDensity; | |
320 | absLength = gRandom->Exp(sigma); | |
321 | if (absLength < AliTRDgeometry::MyThick()) continue; | |
322 | ||
323 | // The absorbtion cross sections in the drift gas | |
324 | if (fGasMix == 1) { | |
325 | // Gas-mixture (Xe/CO2) | |
326 | Double_t muXe = fTR->GetMuXe(energyMeV); | |
327 | Double_t muCO = fTR->GetMuCO(energyMeV); | |
328 | sigma = (0.90 * muXe + 0.10 * muCO) * fGasDensity; | |
329 | } | |
330 | else { | |
331 | // Gas-mixture (Xe/Isobutane) | |
332 | Double_t muXe = fTR->GetMuXe(energyMeV); | |
333 | Double_t muBu = fTR->GetMuBu(energyMeV); | |
334 | sigma = (0.97 * muXe + 0.03 * muBu) * fGasDensity; | |
335 | } | |
336 | ||
337 | // The distance after which the energy of the TR photon | |
338 | // is deposited. | |
339 | absLength = gRandom->Exp(sigma); | |
340 | if (absLength > AliTRDgeometry::DrThick()) continue; | |
341 | ||
342 | // The position of the absorbtion | |
343 | Float_t posHit[3]; | |
344 | gMC->TrackPosition(pos); | |
345 | posHit[0] = pos[0] + mom[0] / pTot * absLength; | |
346 | posHit[1] = pos[1] + mom[1] / pTot * absLength; | |
347 | posHit[2] = pos[2] + mom[2] / pTot * absLength; | |
348 | ||
349 | // Create the charge | |
350 | Int_t q = ((Int_t) (energyeV / kWion)); | |
351 | ||
352 | // Add the hit to the array. TR photon hits are marked | |
353 | // by negative charge | |
f73816f5 | 354 | AliTRDhit *hit = new(lhits[fNhits++]) AliTRDhit(fIshunt |
355 | ,gAlice->CurrentTrack() | |
356 | ,det,posHit,-q); | |
357 | hit->SetTRphoton(); | |
793ff80c | 358 | |
359 | } | |
360 | ||
361 | } | |
362 | ||
363 | } | |
364 | ||
5c7f4665 | 365 | //_____________________________________________________________________________ |
366 | void AliTRDv1::Init() | |
367 | { | |
368 | // | |
369 | // Initialise Transition Radiation Detector after geometry has been built. | |
5c7f4665 | 370 | // |
371 | ||
372 | AliTRD::Init(); | |
373 | ||
851d3db9 | 374 | printf(" Slow simulator\n\n"); |
375 | if (fSensSelect) { | |
376 | if (fSensPlane >= 0) | |
377 | printf(" Only plane %d is sensitive\n",fSensPlane); | |
378 | if (fSensChamber >= 0) | |
379 | printf(" Only chamber %d is sensitive\n",fSensChamber); | |
9d0b222b | 380 | if (fSensSector >= 0) { |
381 | Int_t sens1 = fSensSector; | |
382 | Int_t sens2 = fSensSector + fSensSectorRange; | |
793ff80c | 383 | sens2 -= ((Int_t) (sens2 / AliTRDgeometry::Nsect())) |
384 | * AliTRDgeometry::Nsect(); | |
9d0b222b | 385 | printf(" Only sectors %d - %d are sensitive\n",sens1,sens2-1); |
386 | } | |
851d3db9 | 387 | } |
793ff80c | 388 | if (fTR) |
389 | printf(" TR simulation on\n"); | |
390 | else | |
391 | printf(" TR simulation off\n"); | |
851d3db9 | 392 | printf("\n"); |
5c7f4665 | 393 | |
394 | // First ionization potential (eV) for the gas mixture (90% Xe + 10% CO2) | |
395 | const Float_t kPoti = 12.1; | |
396 | // Maximum energy (50 keV); | |
397 | const Float_t kEend = 50000.0; | |
398 | // Ermilova distribution for the delta-ray spectrum | |
8230f242 | 399 | Float_t poti = TMath::Log(kPoti); |
400 | Float_t eEnd = TMath::Log(kEend); | |
793ff80c | 401 | fDeltaE = new TF1("deltae",Ermilova,poti,eEnd,0); |
5c7f4665 | 402 | |
403 | // Identifier of the sensitive volume (drift region) | |
f73816f5 | 404 | fIdSensDr = gMC->VolId("UL05"); |
405 | // Identifier of the sensitive volume (amplification region) | |
406 | fIdSensAm = gMC->VolId("UL06"); | |
82bbf98a | 407 | |
408 | // Identifier of the TRD-driftchambers | |
409 | fIdChamber1 = gMC->VolId("UCIO"); | |
410 | fIdChamber2 = gMC->VolId("UCIM"); | |
411 | fIdChamber3 = gMC->VolId("UCII"); | |
412 | ||
5c7f4665 | 413 | for (Int_t i = 0; i < 80; i++) printf("*"); |
414 | printf("\n"); | |
415 | ||
fe4da5cc | 416 | } |
417 | ||
793ff80c | 418 | //_____________________________________________________________________________ |
419 | AliTRDsim *AliTRDv1::CreateTR() | |
420 | { | |
421 | // | |
422 | // Enables the simulation of TR | |
423 | // | |
424 | ||
425 | fTR = new AliTRDsim(); | |
426 | return fTR; | |
427 | ||
428 | } | |
429 | ||
5c7f4665 | 430 | //_____________________________________________________________________________ |
431 | void AliTRDv1::SetSensPlane(Int_t iplane) | |
432 | { | |
433 | // | |
851d3db9 | 434 | // Defines the hit-sensitive plane (0-5) |
5c7f4665 | 435 | // |
82bbf98a | 436 | |
851d3db9 | 437 | if ((iplane < 0) || (iplane > 5)) { |
5c7f4665 | 438 | printf("Wrong input value: %d\n",iplane); |
439 | printf("Use standard setting\n"); | |
851d3db9 | 440 | fSensPlane = -1; |
441 | fSensSelect = 0; | |
5c7f4665 | 442 | return; |
443 | } | |
82bbf98a | 444 | |
5c7f4665 | 445 | fSensSelect = 1; |
446 | fSensPlane = iplane; | |
82bbf98a | 447 | |
5c7f4665 | 448 | } |
449 | ||
450 | //_____________________________________________________________________________ | |
451 | void AliTRDv1::SetSensChamber(Int_t ichamber) | |
452 | { | |
453 | // | |
851d3db9 | 454 | // Defines the hit-sensitive chamber (0-4) |
5c7f4665 | 455 | // |
456 | ||
851d3db9 | 457 | if ((ichamber < 0) || (ichamber > 4)) { |
5c7f4665 | 458 | printf("Wrong input value: %d\n",ichamber); |
459 | printf("Use standard setting\n"); | |
851d3db9 | 460 | fSensChamber = -1; |
461 | fSensSelect = 0; | |
5c7f4665 | 462 | return; |
463 | } | |
464 | ||
465 | fSensSelect = 1; | |
466 | fSensChamber = ichamber; | |
467 | ||
468 | } | |
469 | ||
470 | //_____________________________________________________________________________ | |
471 | void AliTRDv1::SetSensSector(Int_t isector) | |
472 | { | |
473 | // | |
851d3db9 | 474 | // Defines the hit-sensitive sector (0-17) |
5c7f4665 | 475 | // |
476 | ||
9d0b222b | 477 | SetSensSector(isector,1); |
478 | ||
479 | } | |
480 | ||
481 | //_____________________________________________________________________________ | |
482 | void AliTRDv1::SetSensSector(Int_t isector, Int_t nsector) | |
483 | { | |
484 | // | |
485 | // Defines a range of hit-sensitive sectors. The range is defined by | |
486 | // <isector> (0-17) as the starting point and <nsector> as the number | |
487 | // of sectors to be included. | |
488 | // | |
489 | ||
851d3db9 | 490 | if ((isector < 0) || (isector > 17)) { |
9d0b222b | 491 | printf("Wrong input value <isector>: %d\n",isector); |
5c7f4665 | 492 | printf("Use standard setting\n"); |
9d0b222b | 493 | fSensSector = -1; |
494 | fSensSectorRange = 0; | |
495 | fSensSelect = 0; | |
5c7f4665 | 496 | return; |
497 | } | |
498 | ||
9d0b222b | 499 | if ((nsector < 1) || (nsector > 18)) { |
500 | printf("Wrong input value <nsector>: %d\n",nsector); | |
501 | printf("Use standard setting\n"); | |
502 | fSensSector = -1; | |
503 | fSensSectorRange = 0; | |
504 | fSensSelect = 0; | |
505 | return; | |
506 | } | |
507 | ||
508 | fSensSelect = 1; | |
509 | fSensSector = isector; | |
510 | fSensSectorRange = nsector; | |
5c7f4665 | 511 | |
512 | } | |
513 | ||
514 | //_____________________________________________________________________________ | |
515 | void AliTRDv1::StepManager() | |
516 | { | |
517 | // | |
5c7f4665 | 518 | // Slow simulator. Every charged track produces electron cluster as hits |
519 | // along its path across the drift volume. The step size is set acording | |
520 | // to Bethe-Bloch. The energy distribution of the delta electrons follows | |
521 | // a spectrum taken from Ermilova et al. | |
522 | // | |
523 | ||
524 | Int_t iIdSens, icSens; | |
5c7f4665 | 525 | Int_t iIdChamber, icChamber; |
851d3db9 | 526 | Int_t pla = 0; |
527 | Int_t cha = 0; | |
528 | Int_t sec = 0; | |
793ff80c | 529 | Int_t det = 0; |
851d3db9 | 530 | Int_t iPdg; |
793ff80c | 531 | Int_t qTot; |
5c7f4665 | 532 | |
793ff80c | 533 | Float_t hits[3]; |
990e4068 | 534 | Float_t moms[3]; |
5c7f4665 | 535 | Float_t random[1]; |
536 | Float_t charge; | |
537 | Float_t aMass; | |
538 | ||
f73816f5 | 539 | Double_t pTot = 0; |
5c7f4665 | 540 | Double_t eDelta; |
541 | Double_t betaGamma, pp; | |
f73816f5 | 542 | Double_t stepSize; |
5c7f4665 | 543 | |
544 | TLorentzVector pos, mom; | |
82bbf98a | 545 | TClonesArray &lhits = *fHits; |
546 | ||
851d3db9 | 547 | const Double_t kBig = 1.0E+12; |
5c7f4665 | 548 | |
549 | // Ionization energy | |
a3c76cdc | 550 | const Float_t kWion = 22.04; |
551 | // Maximum momentum for e+ e- g | |
552 | const Float_t kPTotMaxEl = 0.002; | |
f73816f5 | 553 | // Minimum energy for the step size adjustment |
554 | const Float_t kEkinMinStep = 1.0e-5; | |
5c7f4665 | 555 | // Plateau value of the energy-loss for electron in xenon |
556 | // taken from: Allison + Comb, Ann. Rev. Nucl. Sci. (1980), 30, 253 | |
557 | //const Double_t kPlateau = 1.70; | |
558 | // the averaged value (26/3/99) | |
a3c76cdc | 559 | const Float_t kPlateau = 1.55; |
5c7f4665 | 560 | // dN1/dx|min for the gas mixture (90% Xe + 10% CO2) |
a3c76cdc | 561 | const Float_t kPrim = 48.0; |
5c7f4665 | 562 | // First ionization potential (eV) for the gas mixture (90% Xe + 10% CO2) |
a3c76cdc | 563 | const Float_t kPoti = 12.1; |
851d3db9 | 564 | |
565 | // PDG code electron | |
8230f242 | 566 | const Int_t kPdgElectron = 11; |
5c7f4665 | 567 | |
568 | // Set the maximum step size to a very large number for all | |
569 | // neutral particles and those outside the driftvolume | |
570 | gMC->SetMaxStep(kBig); | |
571 | ||
572 | // Use only charged tracks | |
573 | if (( gMC->TrackCharge() ) && | |
574 | (!gMC->IsTrackStop() ) && | |
575 | (!gMC->IsTrackDisappeared())) { | |
fe4da5cc | 576 | |
5c7f4665 | 577 | // Inside a sensitive volume? |
82bbf98a | 578 | iIdSens = gMC->CurrentVolID(icSens); |
f73816f5 | 579 | if ((iIdSens == fIdSensDr) || |
580 | (iIdSens == fIdSensAm)) { | |
82bbf98a | 581 | |
82bbf98a | 582 | iIdChamber = gMC->CurrentVolOffID(1,icChamber); |
fe4da5cc | 583 | |
5c7f4665 | 584 | // The hit coordinates and charge |
585 | gMC->TrackPosition(pos); | |
586 | hits[0] = pos[0]; | |
587 | hits[1] = pos[1]; | |
588 | hits[2] = pos[2]; | |
5c7f4665 | 589 | |
851d3db9 | 590 | // The sector number (0 - 17) |
591 | // The numbering goes clockwise and starts at y = 0 | |
592 | Float_t phi = kRaddeg*TMath::ATan2(pos[0],pos[1]); | |
593 | if (phi < 90.) | |
594 | phi = phi + 270.; | |
595 | else | |
596 | phi = phi - 90.; | |
597 | sec = ((Int_t) (phi / 20)); | |
82bbf98a | 598 | |
d3f347ff | 599 | // The chamber number |
851d3db9 | 600 | // 0: outer left |
601 | // 1: middle left | |
602 | // 2: inner | |
603 | // 3: middle right | |
604 | // 4: outer right | |
82bbf98a | 605 | if (iIdChamber == fIdChamber1) |
851d3db9 | 606 | cha = (hits[2] < 0 ? 0 : 4); |
82bbf98a | 607 | else if (iIdChamber == fIdChamber2) |
851d3db9 | 608 | cha = (hits[2] < 0 ? 1 : 3); |
82bbf98a | 609 | else if (iIdChamber == fIdChamber3) |
851d3db9 | 610 | cha = 2; |
82bbf98a | 611 | |
fe4da5cc | 612 | // The plane number |
851d3db9 | 613 | // The numbering starts at the innermost plane |
614 | pla = icChamber - TMath::Nint((Float_t) (icChamber / 7)) * 6 - 1; | |
82bbf98a | 615 | |
5c7f4665 | 616 | // Check on selected volumes |
617 | Int_t addthishit = 1; | |
618 | if (fSensSelect) { | |
6f1e466d | 619 | if ((fSensPlane >= 0) && (pla != fSensPlane )) addthishit = 0; |
620 | if ((fSensChamber >= 0) && (cha != fSensChamber)) addthishit = 0; | |
9d0b222b | 621 | if (fSensSector >= 0) { |
622 | Int_t sens1 = fSensSector; | |
623 | Int_t sens2 = fSensSector + fSensSectorRange; | |
793ff80c | 624 | sens2 -= ((Int_t) (sens2 / AliTRDgeometry::Nsect())) |
625 | * AliTRDgeometry::Nsect(); | |
9d0b222b | 626 | if (sens1 < sens2) { |
627 | if ((sec < sens1) || (sec >= sens2)) addthishit = 0; | |
628 | } | |
629 | else { | |
630 | if ((sec < sens1) && (sec >= sens2)) addthishit = 0; | |
631 | } | |
632 | } | |
5c7f4665 | 633 | } |
634 | ||
635 | // Add this hit | |
636 | if (addthishit) { | |
637 | ||
f73816f5 | 638 | // The detector number |
793ff80c | 639 | det = fGeometry->GetDetector(pla,cha,sec); |
640 | ||
f73816f5 | 641 | // Special hits and TR photons only in the drift region |
642 | if (iIdSens == fIdSensDr) { | |
643 | ||
644 | // Create some special hits with amplitude 0 at the entrance and | |
645 | // exit of each chamber that contain the momentum components of the particle | |
646 | if (gMC->IsTrackEntering() || gMC->IsTrackExiting()) { | |
647 | gMC->TrackMomentum(mom); | |
648 | moms[0] = mom[0]; | |
649 | moms[1] = mom[1]; | |
650 | moms[2] = mom[2]; | |
651 | AliTRDhit *hitTest = new(lhits[fNhits++]) AliTRDhit(fIshunt | |
652 | ,gAlice->CurrentTrack() | |
653 | ,det,moms,0); | |
654 | hitTest->SetTest(); | |
655 | } | |
656 | ||
657 | // Create the hits from TR photons | |
658 | if (fTR) CreateTRhit(det); | |
659 | ||
660 | } | |
661 | ||
662 | // Calculate the energy of the delta-electrons | |
663 | eDelta = TMath::Exp(fDeltaE->GetRandom()) - kPoti; | |
664 | eDelta = TMath::Max(eDelta,0.0); | |
665 | ||
666 | // The number of secondary electrons created | |
667 | qTot = ((Int_t) (eDelta / kWion) + 1); | |
668 | ||
669 | // Create a new dEdx hit | |
670 | AliTRDhit *hit = new(lhits[fNhits++]) AliTRDhit(fIshunt | |
671 | ,gAlice->CurrentTrack() | |
672 | ,det,hits,qTot); | |
673 | if (iIdSens == fIdSensDr) { | |
674 | hit->SetDrift(); | |
675 | } | |
5c7f4665 | 676 | else { |
f73816f5 | 677 | hit->SetAmplification(); |
678 | } | |
679 | ||
5c7f4665 | 680 | // Calculate the maximum step size for the next tracking step |
f73816f5 | 681 | // Produce only one hit if Ekin is below cutoff |
682 | aMass = gMC->TrackMass(); | |
683 | if ((gMC->Etot() - aMass) > kEkinMinStep) { | |
684 | ||
685 | // The energy loss according to Bethe Bloch | |
686 | iPdg = TMath::Abs(gMC->TrackPid()); | |
687 | if ( (iPdg != kPdgElectron) || | |
688 | ((iPdg == kPdgElectron) && (pTot < kPTotMaxEl))) { | |
689 | gMC->TrackMomentum(mom); | |
690 | pTot = mom.Rho(); | |
691 | betaGamma = pTot / aMass; | |
692 | pp = kPrim * BetheBloch(betaGamma); | |
693 | // Take charge > 1 into account | |
694 | charge = gMC->TrackCharge(); | |
695 | if (TMath::Abs(charge) > 1) pp = pp * charge*charge; | |
696 | } | |
697 | // Electrons above 20 Mev/c are at the plateau | |
698 | else { | |
699 | pp = kPrim * kPlateau; | |
700 | } | |
701 | ||
702 | if (pp > 0) { | |
703 | do | |
704 | gMC->Rndm(random,1); | |
705 | while ((random[0] == 1.) || (random[0] == 0.)); | |
706 | stepSize = - TMath::Log(random[0]) / pp; | |
707 | gMC->SetMaxStep(stepSize); | |
708 | } | |
709 | ||
5c7f4665 | 710 | } |
711 | ||
712 | } | |
d3f347ff | 713 | |
714 | } | |
715 | ||
5c7f4665 | 716 | } |
717 | ||
718 | } | |
719 | ||
720 | //_____________________________________________________________________________ | |
721 | Double_t AliTRDv1::BetheBloch(Double_t bg) | |
722 | { | |
723 | // | |
724 | // Parametrization of the Bethe-Bloch-curve | |
725 | // The parametrization is the same as for the TPC and is taken from Lehrhaus. | |
726 | // | |
727 | ||
728 | // This parameters have been adjusted to averaged values from GEANT | |
729 | const Double_t kP1 = 7.17960e-02; | |
730 | const Double_t kP2 = 8.54196; | |
731 | const Double_t kP3 = 1.38065e-06; | |
732 | const Double_t kP4 = 5.30972; | |
733 | const Double_t kP5 = 2.83798; | |
734 | ||
735 | // This parameters have been adjusted to Xe-data found in: | |
736 | // Allison & Cobb, Ann. Rev. Nucl. Sci. (1980), 30, 253 | |
737 | //const Double_t kP1 = 0.76176E-1; | |
738 | //const Double_t kP2 = 10.632; | |
739 | //const Double_t kP3 = 3.17983E-6; | |
740 | //const Double_t kP4 = 1.8631; | |
741 | //const Double_t kP5 = 1.9479; | |
742 | ||
f73816f5 | 743 | // Lower cutoff of the Bethe-Bloch-curve to limit step sizes |
744 | const Double_t kBgMin = 0.8; | |
745 | const Double_t kBBMax = 6.83298; | |
746 | //const Double_t kBgMin = 0.6; | |
747 | //const Double_t kBBMax = 17.2809; | |
748 | //const Double_t kBgMin = 0.4; | |
749 | //const Double_t kBBMax = 82.0; | |
750 | ||
751 | if (bg > kBgMin) { | |
5c7f4665 | 752 | Double_t yy = bg / TMath::Sqrt(1. + bg*bg); |
753 | Double_t aa = TMath::Power(yy,kP4); | |
754 | Double_t bb = TMath::Power((1./bg),kP5); | |
755 | bb = TMath::Log(kP3 + bb); | |
756 | return ((kP2 - aa - bb)*kP1 / aa); | |
757 | } | |
f73816f5 | 758 | else { |
759 | return kBBMax; | |
760 | } | |
d3f347ff | 761 | |
fe4da5cc | 762 | } |
5c7f4665 | 763 | |
764 | //_____________________________________________________________________________ | |
765 | Double_t Ermilova(Double_t *x, Double_t *) | |
766 | { | |
767 | // | |
768 | // Calculates the delta-ray energy distribution according to Ermilova. | |
769 | // Logarithmic scale ! | |
770 | // | |
771 | ||
772 | Double_t energy; | |
773 | Double_t dpos; | |
774 | Double_t dnde; | |
775 | ||
776 | Int_t pos1, pos2; | |
777 | ||
8230f242 | 778 | const Int_t kNv = 31; |
5c7f4665 | 779 | |
8230f242 | 780 | Float_t vxe[kNv] = { 2.3026, 2.9957, 3.4012, 3.6889, 3.9120 |
781 | , 4.0943, 4.2485, 4.3820, 4.4998, 4.6052 | |
782 | , 4.7005, 5.0752, 5.2983, 5.7038, 5.9915 | |
783 | , 6.2146, 6.5221, 6.9078, 7.3132, 7.6009 | |
784 | , 8.0064, 8.5172, 8.6995, 8.9872, 9.2103 | |
785 | , 9.4727, 9.9035,10.3735,10.5966,10.8198 | |
786 | ,11.5129 }; | |
5c7f4665 | 787 | |
8230f242 | 788 | Float_t vye[kNv] = { 80.0 , 31.0 , 23.3 , 21.1 , 21.0 |
789 | , 20.9 , 20.8 , 20.0 , 16.0 , 11.0 | |
790 | , 8.0 , 6.0 , 5.2 , 4.6 , 4.0 | |
791 | , 3.5 , 3.0 , 1.4 , 0.67 , 0.44 | |
792 | , 0.3 , 0.18 , 0.12 , 0.08 , 0.056 | |
793 | , 0.04 , 0.023, 0.015, 0.011, 0.01 | |
794 | , 0.004 }; | |
5c7f4665 | 795 | |
796 | energy = x[0]; | |
797 | ||
798 | // Find the position | |
799 | pos1 = pos2 = 0; | |
800 | dpos = 0; | |
801 | do { | |
802 | dpos = energy - vxe[pos2++]; | |
803 | } | |
804 | while (dpos > 0); | |
805 | pos2--; | |
f73816f5 | 806 | if (pos2 > kNv) pos2 = kNv - 1; |
5c7f4665 | 807 | pos1 = pos2 - 1; |
808 | ||
809 | // Differentiate between the sampling points | |
810 | dnde = (vye[pos1] - vye[pos2]) / (vxe[pos2] - vxe[pos1]); | |
811 | ||
812 | return dnde; | |
813 | ||
814 | } |