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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 | ||
88cb7938 | 16 | /* $Id$ */ |
4c039060 | 17 | |
fe4da5cc | 18 | /////////////////////////////////////////////////////////////////////////////// |
19 | // // | |
769257f4 | 20 | // Transition Radiation Detector version 1 -- slow simulator // |
fe4da5cc | 21 | // // |
22 | //Begin_Html | |
23 | /* | |
5c7f4665 | 24 | <img src="picts/AliTRDfullClass.gif"> |
fe4da5cc | 25 | */ |
26 | //End_Html | |
27 | // // | |
28 | // // | |
29 | /////////////////////////////////////////////////////////////////////////////// | |
30 | ||
769257f4 | 31 | #include <stdlib.h> |
32 | ||
793ff80c | 33 | #include <TF1.h> |
1819f4bb | 34 | #include <TLorentzVector.h> |
88cb7938 | 35 | #include <TMath.h> |
36 | #include <TRandom.h> | |
37 | #include <TVector.h> | |
38 | #include <TVirtualMC.h> | |
fe4da5cc | 39 | |
d3f347ff | 40 | #include "AliConst.h" |
88cb7938 | 41 | #include "AliRun.h" |
42 | #include "AliTRDgeometry.h" | |
793ff80c | 43 | #include "AliTRDhit.h" |
793ff80c | 44 | #include "AliTRDsim.h" |
88cb7938 | 45 | #include "AliTRDv1.h" |
5d12ce38 | 46 | #include "AliMC.h" |
851d3db9 | 47 | |
fe4da5cc | 48 | ClassImp(AliTRDv1) |
8230f242 | 49 | |
50 | //_____________________________________________________________________________ | |
51 | AliTRDv1::AliTRDv1():AliTRD() | |
52 | { | |
53 | // | |
54 | // Default constructor | |
55 | // | |
56 | ||
a328fff9 | 57 | fSensSelect = 0; |
58 | fSensPlane = -1; | |
59 | fSensChamber = -1; | |
60 | fSensSector = -1; | |
61 | fSensSectorRange = 0; | |
8230f242 | 62 | |
a328fff9 | 63 | fDeltaE = NULL; |
64 | fDeltaG = NULL; | |
65 | fTR = NULL; | |
66 | ||
67 | fStepSize = 0.1; | |
68 | fTypeOfStepManager = 2; | |
8230f242 | 69 | |
70 | } | |
71 | ||
fe4da5cc | 72 | //_____________________________________________________________________________ |
73 | AliTRDv1::AliTRDv1(const char *name, const char *title) | |
74 | :AliTRD(name, title) | |
75 | { | |
76 | // | |
851d3db9 | 77 | // Standard constructor for Transition Radiation Detector version 1 |
fe4da5cc | 78 | // |
82bbf98a | 79 | |
a328fff9 | 80 | fSensSelect = 0; |
81 | fSensPlane = -1; | |
82 | fSensChamber = -1; | |
83 | fSensSector = -1; | |
84 | fSensSectorRange = 0; | |
5c7f4665 | 85 | |
a328fff9 | 86 | fDeltaE = NULL; |
87 | fDeltaG = NULL; | |
88 | fTR = NULL; | |
89 | fStepSize = 0.1; | |
90 | fTypeOfStepManager = 2; | |
5c7f4665 | 91 | |
92 | SetBufferSize(128000); | |
93 | ||
94 | } | |
95 | ||
8230f242 | 96 | //_____________________________________________________________________________ |
73ae7b59 | 97 | AliTRDv1::AliTRDv1(const AliTRDv1 &trd):AliTRD(trd) |
8230f242 | 98 | { |
99 | // | |
100 | // Copy constructor | |
101 | // | |
102 | ||
dd9a6ee3 | 103 | ((AliTRDv1 &) trd).Copy(*this); |
8230f242 | 104 | |
105 | } | |
106 | ||
5c7f4665 | 107 | //_____________________________________________________________________________ |
108 | AliTRDv1::~AliTRDv1() | |
109 | { | |
dd9a6ee3 | 110 | // |
111 | // AliTRDv1 destructor | |
112 | // | |
82bbf98a | 113 | |
5c7f4665 | 114 | if (fDeltaE) delete fDeltaE; |
a328fff9 | 115 | if (fDeltaG) delete fDeltaG; |
793ff80c | 116 | if (fTR) delete fTR; |
82bbf98a | 117 | |
fe4da5cc | 118 | } |
119 | ||
dd9a6ee3 | 120 | //_____________________________________________________________________________ |
121 | AliTRDv1 &AliTRDv1::operator=(const AliTRDv1 &trd) | |
122 | { | |
123 | // | |
124 | // Assignment operator | |
125 | // | |
126 | ||
127 | if (this != &trd) ((AliTRDv1 &) trd).Copy(*this); | |
128 | return *this; | |
129 | ||
130 | } | |
8230f242 | 131 | |
132 | //_____________________________________________________________________________ | |
43da34c0 | 133 | void AliTRDv1::Copy(TObject &trd) |
8230f242 | 134 | { |
135 | // | |
136 | // Copy function | |
137 | // | |
138 | ||
a328fff9 | 139 | ((AliTRDv1 &) trd).fSensSelect = fSensSelect; |
140 | ((AliTRDv1 &) trd).fSensPlane = fSensPlane; | |
141 | ((AliTRDv1 &) trd).fSensChamber = fSensChamber; | |
142 | ((AliTRDv1 &) trd).fSensSector = fSensSector; | |
143 | ((AliTRDv1 &) trd).fSensSectorRange = fSensSectorRange; | |
144 | ||
145 | ((AliTRDv1 &) trd).fTypeOfStepManager = fTypeOfStepManager; | |
146 | ((AliTRDv1 &) trd).fStepSize = fStepSize; | |
8230f242 | 147 | |
793ff80c | 148 | fDeltaE->Copy(*((AliTRDv1 &) trd).fDeltaE); |
a328fff9 | 149 | fDeltaG->Copy(*((AliTRDv1 &) trd).fDeltaG); |
793ff80c | 150 | fTR->Copy(*((AliTRDv1 &) trd).fTR); |
8230f242 | 151 | |
152 | } | |
153 | ||
fe4da5cc | 154 | //_____________________________________________________________________________ |
155 | void AliTRDv1::CreateGeometry() | |
156 | { | |
157 | // | |
851d3db9 | 158 | // Create the GEANT geometry for the Transition Radiation Detector - Version 1 |
5c7f4665 | 159 | // This version covers the full azimuth. |
d3f347ff | 160 | // |
161 | ||
82bbf98a | 162 | // Check that FRAME is there otherwise we have no place where to put the TRD |
8230f242 | 163 | AliModule* frame = gAlice->GetModule("FRAME"); |
164 | if (!frame) return; | |
d3f347ff | 165 | |
82bbf98a | 166 | // Define the chambers |
167 | AliTRD::CreateGeometry(); | |
d3f347ff | 168 | |
fe4da5cc | 169 | } |
170 | ||
171 | //_____________________________________________________________________________ | |
172 | void AliTRDv1::CreateMaterials() | |
173 | { | |
174 | // | |
851d3db9 | 175 | // Create materials for the Transition Radiation Detector version 1 |
fe4da5cc | 176 | // |
82bbf98a | 177 | |
d3f347ff | 178 | AliTRD::CreateMaterials(); |
82bbf98a | 179 | |
fe4da5cc | 180 | } |
181 | ||
793ff80c | 182 | //_____________________________________________________________________________ |
183 | void AliTRDv1::CreateTRhit(Int_t det) | |
184 | { | |
185 | // | |
186 | // Creates an electron cluster from a TR photon. | |
187 | // The photon is assumed to be created a the end of the radiator. The | |
188 | // distance after which it deposits its energy takes into account the | |
189 | // absorbtion of the entrance window and of the gas mixture in drift | |
190 | // volume. | |
191 | // | |
192 | ||
193 | // PDG code electron | |
194 | const Int_t kPdgElectron = 11; | |
195 | ||
196 | // Ionization energy | |
197 | const Float_t kWion = 22.04; | |
198 | ||
199 | // Maximum number of TR photons per track | |
200 | const Int_t kNTR = 50; | |
201 | ||
202 | TLorentzVector mom, pos; | |
793ff80c | 203 | |
793ff80c | 204 | // Create TR at the entrance of the chamber |
205 | if (gMC->IsTrackEntering()) { | |
206 | ||
f73816f5 | 207 | // Create TR only for electrons |
208 | Int_t iPdg = gMC->TrackPid(); | |
209 | if (TMath::Abs(iPdg) != kPdgElectron) return; | |
210 | ||
793ff80c | 211 | Float_t eTR[kNTR]; |
212 | Int_t nTR; | |
213 | ||
214 | // Create TR photons | |
215 | gMC->TrackMomentum(mom); | |
216 | Float_t pTot = mom.Rho(); | |
217 | fTR->CreatePhotons(iPdg,pTot,nTR,eTR); | |
218 | if (nTR > kNTR) { | |
219 | printf("AliTRDv1::CreateTRhit -- "); | |
220 | printf("Boundary error: nTR = %d, kNTR = %d\n",nTR,kNTR); | |
221 | exit(1); | |
222 | } | |
223 | ||
224 | // Loop through the TR photons | |
225 | for (Int_t iTR = 0; iTR < nTR; iTR++) { | |
226 | ||
227 | Float_t energyMeV = eTR[iTR] * 0.001; | |
228 | Float_t energyeV = eTR[iTR] * 1000.0; | |
229 | Float_t absLength = 0; | |
230 | Float_t sigma = 0; | |
231 | ||
232 | // Take the absorbtion in the entrance window into account | |
233 | Double_t muMy = fTR->GetMuMy(energyMeV); | |
234 | sigma = muMy * fFoilDensity; | |
842287f2 | 235 | if (sigma > 0.0) { |
236 | absLength = gRandom->Exp(1.0/sigma); | |
237 | if (absLength < AliTRDgeometry::MyThick()) continue; | |
238 | } | |
239 | else { | |
240 | continue; | |
241 | } | |
793ff80c | 242 | |
243 | // The absorbtion cross sections in the drift gas | |
244 | if (fGasMix == 1) { | |
245 | // Gas-mixture (Xe/CO2) | |
246 | Double_t muXe = fTR->GetMuXe(energyMeV); | |
247 | Double_t muCO = fTR->GetMuCO(energyMeV); | |
842287f2 | 248 | sigma = (0.85 * muXe + 0.15 * muCO) * fGasDensity * fTR->GetTemp(); |
793ff80c | 249 | } |
250 | else { | |
251 | // Gas-mixture (Xe/Isobutane) | |
252 | Double_t muXe = fTR->GetMuXe(energyMeV); | |
253 | Double_t muBu = fTR->GetMuBu(energyMeV); | |
842287f2 | 254 | sigma = (0.97 * muXe + 0.03 * muBu) * fGasDensity * fTR->GetTemp(); |
793ff80c | 255 | } |
256 | ||
257 | // The distance after which the energy of the TR photon | |
258 | // is deposited. | |
842287f2 | 259 | if (sigma > 0.0) { |
260 | absLength = gRandom->Exp(1.0/sigma); | |
a328fff9 | 261 | if (absLength > (AliTRDgeometry::DrThick() |
262 | + AliTRDgeometry::AmThick())) { | |
263 | continue; | |
264 | } | |
842287f2 | 265 | } |
266 | else { | |
267 | continue; | |
268 | } | |
793ff80c | 269 | |
270 | // The position of the absorbtion | |
271 | Float_t posHit[3]; | |
272 | gMC->TrackPosition(pos); | |
273 | posHit[0] = pos[0] + mom[0] / pTot * absLength; | |
274 | posHit[1] = pos[1] + mom[1] / pTot * absLength; | |
275 | posHit[2] = pos[2] + mom[2] / pTot * absLength; | |
276 | ||
277 | // Create the charge | |
278 | Int_t q = ((Int_t) (energyeV / kWion)); | |
279 | ||
280 | // Add the hit to the array. TR photon hits are marked | |
281 | // by negative charge | |
5d12ce38 | 282 | AddHit(gAlice->GetMCApp()->GetCurrentTrackNumber(),det,posHit,-q,kTRUE); |
793ff80c | 283 | |
284 | } | |
285 | ||
286 | } | |
287 | ||
288 | } | |
289 | ||
5c7f4665 | 290 | //_____________________________________________________________________________ |
291 | void AliTRDv1::Init() | |
292 | { | |
293 | // | |
294 | // Initialise Transition Radiation Detector after geometry has been built. | |
5c7f4665 | 295 | // |
296 | ||
297 | AliTRD::Init(); | |
298 | ||
9e1a0ddb | 299 | if(fDebug) printf("%s: Slow simulator\n",ClassName()); |
851d3db9 | 300 | if (fSensSelect) { |
301 | if (fSensPlane >= 0) | |
302 | printf(" Only plane %d is sensitive\n",fSensPlane); | |
303 | if (fSensChamber >= 0) | |
304 | printf(" Only chamber %d is sensitive\n",fSensChamber); | |
9d0b222b | 305 | if (fSensSector >= 0) { |
306 | Int_t sens1 = fSensSector; | |
307 | Int_t sens2 = fSensSector + fSensSectorRange; | |
793ff80c | 308 | sens2 -= ((Int_t) (sens2 / AliTRDgeometry::Nsect())) |
309 | * AliTRDgeometry::Nsect(); | |
9d0b222b | 310 | printf(" Only sectors %d - %d are sensitive\n",sens1,sens2-1); |
311 | } | |
851d3db9 | 312 | } |
793ff80c | 313 | if (fTR) |
9e1a0ddb | 314 | printf("%s: TR simulation on\n",ClassName()); |
793ff80c | 315 | else |
9e1a0ddb | 316 | printf("%s: TR simulation off\n",ClassName()); |
851d3db9 | 317 | printf("\n"); |
5c7f4665 | 318 | |
319 | // First ionization potential (eV) for the gas mixture (90% Xe + 10% CO2) | |
320 | const Float_t kPoti = 12.1; | |
321 | // Maximum energy (50 keV); | |
322 | const Float_t kEend = 50000.0; | |
323 | // Ermilova distribution for the delta-ray spectrum | |
8230f242 | 324 | Float_t poti = TMath::Log(kPoti); |
325 | Float_t eEnd = TMath::Log(kEend); | |
a328fff9 | 326 | |
327 | // Ermilova distribution for the delta-ray spectrum | |
328 | fDeltaE = new TF1("deltae" ,Ermilova ,poti,eEnd,0); | |
329 | ||
330 | // Geant3 distribution for the delta-ray spectrum | |
331 | fDeltaG = new TF1("deltaeg",IntSpecGeant,poti,eEnd,0); | |
5c7f4665 | 332 | |
9e1a0ddb | 333 | if(fDebug) { |
334 | printf("%s: ",ClassName()); | |
335 | for (Int_t i = 0; i < 80; i++) printf("*"); | |
336 | printf("\n"); | |
337 | } | |
5c7f4665 | 338 | |
fe4da5cc | 339 | } |
340 | ||
793ff80c | 341 | //_____________________________________________________________________________ |
342 | AliTRDsim *AliTRDv1::CreateTR() | |
343 | { | |
344 | // | |
345 | // Enables the simulation of TR | |
346 | // | |
347 | ||
348 | fTR = new AliTRDsim(); | |
349 | return fTR; | |
350 | ||
351 | } | |
352 | ||
5c7f4665 | 353 | //_____________________________________________________________________________ |
354 | void AliTRDv1::SetSensPlane(Int_t iplane) | |
355 | { | |
356 | // | |
851d3db9 | 357 | // Defines the hit-sensitive plane (0-5) |
5c7f4665 | 358 | // |
82bbf98a | 359 | |
851d3db9 | 360 | if ((iplane < 0) || (iplane > 5)) { |
5c7f4665 | 361 | printf("Wrong input value: %d\n",iplane); |
362 | printf("Use standard setting\n"); | |
851d3db9 | 363 | fSensPlane = -1; |
364 | fSensSelect = 0; | |
5c7f4665 | 365 | return; |
366 | } | |
82bbf98a | 367 | |
5c7f4665 | 368 | fSensSelect = 1; |
369 | fSensPlane = iplane; | |
82bbf98a | 370 | |
5c7f4665 | 371 | } |
372 | ||
373 | //_____________________________________________________________________________ | |
374 | void AliTRDv1::SetSensChamber(Int_t ichamber) | |
375 | { | |
376 | // | |
851d3db9 | 377 | // Defines the hit-sensitive chamber (0-4) |
5c7f4665 | 378 | // |
379 | ||
851d3db9 | 380 | if ((ichamber < 0) || (ichamber > 4)) { |
5c7f4665 | 381 | printf("Wrong input value: %d\n",ichamber); |
382 | printf("Use standard setting\n"); | |
851d3db9 | 383 | fSensChamber = -1; |
384 | fSensSelect = 0; | |
5c7f4665 | 385 | return; |
386 | } | |
387 | ||
388 | fSensSelect = 1; | |
389 | fSensChamber = ichamber; | |
390 | ||
391 | } | |
392 | ||
393 | //_____________________________________________________________________________ | |
394 | void AliTRDv1::SetSensSector(Int_t isector) | |
395 | { | |
396 | // | |
851d3db9 | 397 | // Defines the hit-sensitive sector (0-17) |
5c7f4665 | 398 | // |
399 | ||
9d0b222b | 400 | SetSensSector(isector,1); |
401 | ||
402 | } | |
403 | ||
404 | //_____________________________________________________________________________ | |
405 | void AliTRDv1::SetSensSector(Int_t isector, Int_t nsector) | |
406 | { | |
407 | // | |
408 | // Defines a range of hit-sensitive sectors. The range is defined by | |
409 | // <isector> (0-17) as the starting point and <nsector> as the number | |
410 | // of sectors to be included. | |
411 | // | |
412 | ||
851d3db9 | 413 | if ((isector < 0) || (isector > 17)) { |
9d0b222b | 414 | printf("Wrong input value <isector>: %d\n",isector); |
5c7f4665 | 415 | printf("Use standard setting\n"); |
9d0b222b | 416 | fSensSector = -1; |
417 | fSensSectorRange = 0; | |
418 | fSensSelect = 0; | |
5c7f4665 | 419 | return; |
420 | } | |
421 | ||
9d0b222b | 422 | if ((nsector < 1) || (nsector > 18)) { |
423 | printf("Wrong input value <nsector>: %d\n",nsector); | |
424 | printf("Use standard setting\n"); | |
425 | fSensSector = -1; | |
426 | fSensSectorRange = 0; | |
427 | fSensSelect = 0; | |
428 | return; | |
429 | } | |
430 | ||
431 | fSensSelect = 1; | |
432 | fSensSector = isector; | |
433 | fSensSectorRange = nsector; | |
5c7f4665 | 434 | |
435 | } | |
436 | ||
437 | //_____________________________________________________________________________ | |
438 | void AliTRDv1::StepManager() | |
a328fff9 | 439 | { |
440 | // | |
441 | // Slow simulator. Every charged track produces electron cluster as hits | |
442 | // along its path across the drift volume. | |
443 | // | |
444 | ||
445 | switch (fTypeOfStepManager) { | |
446 | case 0 : StepManagerErmilova(); break; // 0 is Ermilova | |
447 | case 1 : StepManagerGeant(); break; // 1 is Geant | |
448 | case 2 : StepManagerFixedStep(); break; // 2 is fixed step | |
449 | default : printf("<AliTRDv1::StepManager>: Not a valid Step Manager.\n"); | |
450 | } | |
451 | ||
452 | } | |
453 | ||
454 | //_____________________________________________________________________________ | |
455 | void AliTRDv1::SelectStepManager(Int_t t) | |
456 | { | |
457 | // | |
458 | // Selects a step manager type: | |
459 | // 0 - Ermilova | |
460 | // 1 - Geant3 | |
461 | // 2 - Fixed step size | |
462 | // | |
463 | ||
464 | if (t == 1) { | |
465 | printf("<AliTRDv1::SelectStepManager>: Sorry, Geant parametrization step" | |
466 | "manager is not implemented yet. Please ask K.Oyama for detail.\n"); | |
467 | } | |
468 | ||
469 | fTypeOfStepManager = t; | |
470 | printf("<AliTRDv1::SelectStepManager>: Step Manager type %d was selected.\n" | |
471 | , fTypeOfStepManager); | |
472 | ||
473 | } | |
474 | ||
475 | //_____________________________________________________________________________ | |
476 | void AliTRDv1::StepManagerGeant() | |
477 | { | |
478 | // | |
479 | // Slow simulator. Every charged track produces electron cluster as hits | |
480 | // along its path across the drift volume. The step size is set acording | |
481 | // to Bethe-Bloch. The energy distribution of the delta electrons follows | |
482 | // a spectrum taken from Geant3. | |
483 | // | |
484 | ||
485 | printf("AliTRDv1::StepManagerGeant: Not implemented yet.\n"); | |
486 | ||
487 | } | |
488 | ||
489 | //_____________________________________________________________________________ | |
490 | void AliTRDv1::StepManagerErmilova() | |
5c7f4665 | 491 | { |
492 | // | |
5c7f4665 | 493 | // Slow simulator. Every charged track produces electron cluster as hits |
494 | // along its path across the drift volume. The step size is set acording | |
495 | // to Bethe-Bloch. The energy distribution of the delta electrons follows | |
496 | // a spectrum taken from Ermilova et al. | |
497 | // | |
498 | ||
851d3db9 | 499 | Int_t pla = 0; |
500 | Int_t cha = 0; | |
501 | Int_t sec = 0; | |
793ff80c | 502 | Int_t det = 0; |
851d3db9 | 503 | Int_t iPdg; |
793ff80c | 504 | Int_t qTot; |
5c7f4665 | 505 | |
793ff80c | 506 | Float_t hits[3]; |
b9d0a01d | 507 | Double_t random[1]; |
5c7f4665 | 508 | Float_t charge; |
509 | Float_t aMass; | |
510 | ||
f73816f5 | 511 | Double_t pTot = 0; |
5c7f4665 | 512 | Double_t eDelta; |
513 | Double_t betaGamma, pp; | |
f73816f5 | 514 | Double_t stepSize; |
5c7f4665 | 515 | |
332e9569 | 516 | Bool_t drRegion = kFALSE; |
517 | Bool_t amRegion = kFALSE; | |
518 | ||
519 | TString cIdCurrent; | |
520 | TString cIdSensDr = "J"; | |
521 | TString cIdSensAm = "K"; | |
593a9fc3 | 522 | Char_t cIdChamber[3]; |
523 | cIdChamber[2] = 0; | |
332e9569 | 524 | |
5c7f4665 | 525 | TLorentzVector pos, mom; |
82bbf98a | 526 | |
332e9569 | 527 | const Int_t kNplan = AliTRDgeometry::Nplan(); |
e644678a | 528 | const Int_t kNcham = AliTRDgeometry::Ncham(); |
529 | const Int_t kNdetsec = kNplan * kNcham; | |
530 | ||
a328fff9 | 531 | const Double_t kBig = 1.0E+12; // Infinitely big |
532 | const Float_t kWion = 22.04; // Ionization energy | |
533 | const Float_t kPTotMaxEl = 0.002; // Maximum momentum for e+ e- g | |
5c7f4665 | 534 | |
f73816f5 | 535 | // Minimum energy for the step size adjustment |
536 | const Float_t kEkinMinStep = 1.0e-5; | |
a328fff9 | 537 | |
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; |
a328fff9 | 543 | |
544 | const Float_t kPrim = 48.0; // dN1/dx|min for the gas mixture (90% Xe + 10% CO2) | |
5c7f4665 | 545 | // First ionization potential (eV) for the gas mixture (90% Xe + 10% CO2) |
a3c76cdc | 546 | const Float_t kPoti = 12.1; |
851d3db9 | 547 | |
a328fff9 | 548 | const Int_t kPdgElectron = 11; // PDG code electron |
5c7f4665 | 549 | |
550 | // Set the maximum step size to a very large number for all | |
551 | // neutral particles and those outside the driftvolume | |
552 | gMC->SetMaxStep(kBig); | |
553 | ||
554 | // Use only charged tracks | |
555 | if (( gMC->TrackCharge() ) && | |
556 | (!gMC->IsTrackStop() ) && | |
557 | (!gMC->IsTrackDisappeared())) { | |
fe4da5cc | 558 | |
5c7f4665 | 559 | // Inside a sensitive volume? |
332e9569 | 560 | drRegion = kFALSE; |
561 | amRegion = kFALSE; | |
562 | cIdCurrent = gMC->CurrentVolName(); | |
e6674585 | 563 | if (cIdSensDr == cIdCurrent[1]) { |
332e9569 | 564 | drRegion = kTRUE; |
565 | } | |
e6674585 | 566 | if (cIdSensAm == cIdCurrent[1]) { |
332e9569 | 567 | amRegion = kTRUE; |
568 | } | |
569 | if (drRegion || amRegion) { | |
fe4da5cc | 570 | |
5c7f4665 | 571 | // The hit coordinates and charge |
572 | gMC->TrackPosition(pos); | |
573 | hits[0] = pos[0]; | |
574 | hits[1] = pos[1]; | |
575 | hits[2] = pos[2]; | |
5c7f4665 | 576 | |
851d3db9 | 577 | // The sector number (0 - 17) |
578 | // The numbering goes clockwise and starts at y = 0 | |
e15eb584 | 579 | Float_t phi = kRaddeg*TMath::ATan2(pos[0],pos[1]); |
851d3db9 | 580 | if (phi < 90.) |
581 | phi = phi + 270.; | |
582 | else | |
583 | phi = phi - 90.; | |
584 | sec = ((Int_t) (phi / 20)); | |
82bbf98a | 585 | |
332e9569 | 586 | // The plane and chamber number |
587 | cIdChamber[0] = cIdCurrent[2]; | |
588 | cIdChamber[1] = cIdCurrent[3]; | |
e644678a | 589 | Int_t idChamber = (atoi(cIdChamber) % kNdetsec); |
332e9569 | 590 | cha = ((Int_t) idChamber / kNplan); |
591 | pla = ((Int_t) idChamber % kNplan); | |
82bbf98a | 592 | |
5c7f4665 | 593 | // Check on selected volumes |
594 | Int_t addthishit = 1; | |
595 | if (fSensSelect) { | |
6f1e466d | 596 | if ((fSensPlane >= 0) && (pla != fSensPlane )) addthishit = 0; |
597 | if ((fSensChamber >= 0) && (cha != fSensChamber)) addthishit = 0; | |
9d0b222b | 598 | if (fSensSector >= 0) { |
599 | Int_t sens1 = fSensSector; | |
600 | Int_t sens2 = fSensSector + fSensSectorRange; | |
793ff80c | 601 | sens2 -= ((Int_t) (sens2 / AliTRDgeometry::Nsect())) |
602 | * AliTRDgeometry::Nsect(); | |
9d0b222b | 603 | if (sens1 < sens2) { |
604 | if ((sec < sens1) || (sec >= sens2)) addthishit = 0; | |
605 | } | |
606 | else { | |
607 | if ((sec < sens1) && (sec >= sens2)) addthishit = 0; | |
608 | } | |
609 | } | |
5c7f4665 | 610 | } |
611 | ||
612 | // Add this hit | |
613 | if (addthishit) { | |
614 | ||
f73816f5 | 615 | // The detector number |
793ff80c | 616 | det = fGeometry->GetDetector(pla,cha,sec); |
617 | ||
a328fff9 | 618 | // Special hits only in the drift region |
332e9569 | 619 | if (drRegion) { |
f73816f5 | 620 | |
c61f1a66 | 621 | // Create a track reference at the entrance and |
622 | // exit of each chamber that contain the | |
623 | // momentum components of the particle | |
f73816f5 | 624 | if (gMC->IsTrackEntering() || gMC->IsTrackExiting()) { |
625 | gMC->TrackMomentum(mom); | |
5d12ce38 | 626 | AddTrackReference(gAlice->GetMCApp()->GetCurrentTrackNumber()); |
f73816f5 | 627 | } |
628 | ||
629 | // Create the hits from TR photons | |
630 | if (fTR) CreateTRhit(det); | |
631 | ||
632 | } | |
633 | ||
634 | // Calculate the energy of the delta-electrons | |
635 | eDelta = TMath::Exp(fDeltaE->GetRandom()) - kPoti; | |
636 | eDelta = TMath::Max(eDelta,0.0); | |
637 | ||
638 | // The number of secondary electrons created | |
639 | qTot = ((Int_t) (eDelta / kWion) + 1); | |
640 | ||
641 | // Create a new dEdx hit | |
332e9569 | 642 | if (drRegion) { |
a328fff9 | 643 | AddHit(gAlice->GetMCApp()->GetCurrentTrackNumber() |
644 | ,det,hits,qTot,kTRUE); | |
f73816f5 | 645 | } |
5c7f4665 | 646 | else { |
a328fff9 | 647 | AddHit(gAlice->GetMCApp()->GetCurrentTrackNumber() |
648 | ,det,hits,qTot,kFALSE); | |
f73816f5 | 649 | } |
650 | ||
5c7f4665 | 651 | // Calculate the maximum step size for the next tracking step |
f73816f5 | 652 | // Produce only one hit if Ekin is below cutoff |
653 | aMass = gMC->TrackMass(); | |
654 | if ((gMC->Etot() - aMass) > kEkinMinStep) { | |
655 | ||
656 | // The energy loss according to Bethe Bloch | |
657 | iPdg = TMath::Abs(gMC->TrackPid()); | |
658 | if ( (iPdg != kPdgElectron) || | |
659 | ((iPdg == kPdgElectron) && (pTot < kPTotMaxEl))) { | |
660 | gMC->TrackMomentum(mom); | |
661 | pTot = mom.Rho(); | |
662 | betaGamma = pTot / aMass; | |
663 | pp = kPrim * BetheBloch(betaGamma); | |
664 | // Take charge > 1 into account | |
665 | charge = gMC->TrackCharge(); | |
666 | if (TMath::Abs(charge) > 1) pp = pp * charge*charge; | |
667 | } | |
668 | // Electrons above 20 Mev/c are at the plateau | |
669 | else { | |
670 | pp = kPrim * kPlateau; | |
671 | } | |
672 | ||
673 | if (pp > 0) { | |
674 | do | |
b9d0a01d | 675 | gMC->GetRandom()->RndmArray(1, random); |
f73816f5 | 676 | while ((random[0] == 1.) || (random[0] == 0.)); |
677 | stepSize = - TMath::Log(random[0]) / pp; | |
678 | gMC->SetMaxStep(stepSize); | |
679 | } | |
680 | ||
5c7f4665 | 681 | } |
682 | ||
683 | } | |
d3f347ff | 684 | |
685 | } | |
686 | ||
5c7f4665 | 687 | } |
688 | ||
689 | } | |
690 | ||
a328fff9 | 691 | //_____________________________________________________________________________ |
692 | void AliTRDv1::StepManagerFixedStep() | |
693 | { | |
694 | // | |
695 | // Slow simulator. Every charged track produces electron cluster as hits | |
696 | // along its path across the drift volume. The step size is fixed in | |
697 | // this version of the step manager. | |
698 | // | |
699 | ||
700 | Int_t pla = 0; | |
701 | Int_t cha = 0; | |
702 | Int_t sec = 0; | |
703 | Int_t det = 0; | |
704 | Int_t qTot; | |
705 | ||
706 | Float_t hits[3]; | |
707 | Double_t eDep; | |
708 | ||
709 | Bool_t drRegion = kFALSE; | |
710 | Bool_t amRegion = kFALSE; | |
711 | ||
712 | TString cIdCurrent; | |
713 | TString cIdSensDr = "J"; | |
714 | TString cIdSensAm = "K"; | |
715 | Char_t cIdChamber[3]; | |
716 | cIdChamber[2] = 0; | |
717 | ||
718 | TLorentzVector pos, mom; | |
719 | ||
720 | const Int_t kNplan = AliTRDgeometry::Nplan(); | |
721 | const Int_t kNcham = AliTRDgeometry::Ncham(); | |
722 | const Int_t kNdetsec = kNplan * kNcham; | |
723 | ||
724 | const Double_t kBig = 1.0E+12; | |
725 | ||
726 | const Float_t kWion = 22.04; // Ionization energy | |
727 | const Float_t kEkinMinStep = 1.0e-5; // Minimum energy for the step size adjustment | |
728 | ||
729 | // Set the maximum step size to a very large number for all | |
730 | // neutral particles and those outside the driftvolume | |
731 | gMC->SetMaxStep(kBig); | |
732 | ||
733 | // If not charged track or already stopped or disappeared, just return. | |
734 | if ((!gMC->TrackCharge()) || | |
735 | gMC->IsTrackStop() || | |
736 | gMC->IsTrackDisappeared()) return; | |
737 | ||
738 | // Inside a sensitive volume? | |
739 | cIdCurrent = gMC->CurrentVolName(); | |
740 | ||
741 | if (cIdSensDr == cIdCurrent[1]) drRegion = kTRUE; | |
742 | if (cIdSensAm == cIdCurrent[1]) amRegion = kTRUE; | |
743 | ||
744 | if ((!drRegion) && (!amRegion)) return; | |
745 | ||
746 | // The hit coordinates and charge | |
747 | gMC->TrackPosition(pos); | |
748 | hits[0] = pos[0]; | |
749 | hits[1] = pos[1]; | |
750 | hits[2] = pos[2]; | |
751 | ||
752 | // The sector number (0 - 17) | |
753 | // The numbering goes clockwise and starts at y = 0 | |
754 | Float_t phi = kRaddeg*TMath::ATan2(pos[0],pos[1]); | |
755 | if (phi < 90.) phi += 270.; | |
756 | else phi -= 90.; | |
757 | sec = ((Int_t) (phi / 20.)); | |
758 | ||
759 | // The plane and chamber number | |
760 | cIdChamber[0] = cIdCurrent[2]; | |
761 | cIdChamber[1] = cIdCurrent[3]; | |
762 | Int_t idChamber = (atoi(cIdChamber) % kNdetsec); | |
763 | cha = ((Int_t) idChamber / kNplan); | |
764 | pla = ((Int_t) idChamber % kNplan); | |
765 | ||
766 | // Check on selected volumes | |
767 | Int_t addthishit = 1; | |
768 | if(fSensSelect) { | |
769 | if ((fSensPlane >= 0) && (pla != fSensPlane )) addthishit = 0; | |
770 | if ((fSensChamber >= 0) && (cha != fSensChamber)) addthishit = 0; | |
771 | if (fSensSector >= 0) { | |
772 | Int_t sens1 = fSensSector; | |
773 | Int_t sens2 = fSensSector + fSensSectorRange; | |
774 | sens2 -= ((Int_t) (sens2 / AliTRDgeometry::Nsect())) * AliTRDgeometry::Nsect(); | |
775 | if (sens1 < sens2) { | |
776 | if ((sec < sens1) || (sec >= sens2)) addthishit = 0; | |
777 | } | |
778 | else { | |
779 | if ((sec < sens1) && (sec >= sens2)) addthishit = 0; | |
780 | } | |
781 | } | |
782 | } | |
783 | ||
784 | if (!addthishit) return; | |
785 | ||
786 | det = fGeometry->GetDetector(pla,cha,sec); // The detector number | |
787 | ||
788 | Int_t trkStat = 0; // 0: InFlight 1:Entering 2:Exiting | |
789 | ||
790 | // Special hits only in the drift region | |
791 | if (drRegion) { | |
792 | ||
793 | // Create a track reference at the entrance and exit of each | |
794 | // chamber that contain the momentum components of the particle | |
795 | ||
796 | if (gMC->IsTrackEntering()) { | |
797 | gMC->TrackMomentum(mom); | |
798 | AddTrackReference(gAlice->GetMCApp()->GetCurrentTrackNumber()); | |
799 | trkStat = 1; | |
800 | } | |
801 | if (gMC->IsTrackExiting()) { | |
802 | gMC->TrackMomentum(mom); | |
803 | AddTrackReference(gAlice->GetMCApp()->GetCurrentTrackNumber()); | |
804 | trkStat = 2; | |
805 | } | |
806 | ||
807 | // Create the hits from TR photons | |
808 | if (fTR) CreateTRhit(det); | |
809 | ||
810 | } | |
811 | ||
812 | // Calculate the charge according to GEANT Edep | |
813 | // Create a new dEdx hit | |
814 | eDep = TMath::Max(gMC->Edep(),0.0) * 1.0e+09; | |
815 | qTot = (Int_t) (eDep / kWion); | |
816 | AddHit(gAlice->GetMCApp()->GetCurrentTrackNumber(),det,hits,qTot,drRegion); | |
817 | ||
818 | // Set Maximum Step Size | |
819 | // Produce only one hit if Ekin is below cutoff | |
820 | if ((gMC->Etot() - gMC->TrackMass()) < kEkinMinStep) return; | |
821 | gMC->SetMaxStep(fStepSize); | |
822 | ||
823 | } | |
824 | ||
5c7f4665 | 825 | //_____________________________________________________________________________ |
826 | Double_t AliTRDv1::BetheBloch(Double_t bg) | |
827 | { | |
828 | // | |
829 | // Parametrization of the Bethe-Bloch-curve | |
830 | // The parametrization is the same as for the TPC and is taken from Lehrhaus. | |
831 | // | |
832 | ||
833 | // This parameters have been adjusted to averaged values from GEANT | |
834 | const Double_t kP1 = 7.17960e-02; | |
835 | const Double_t kP2 = 8.54196; | |
836 | const Double_t kP3 = 1.38065e-06; | |
837 | const Double_t kP4 = 5.30972; | |
838 | const Double_t kP5 = 2.83798; | |
839 | ||
840 | // This parameters have been adjusted to Xe-data found in: | |
841 | // Allison & Cobb, Ann. Rev. Nucl. Sci. (1980), 30, 253 | |
842 | //const Double_t kP1 = 0.76176E-1; | |
843 | //const Double_t kP2 = 10.632; | |
844 | //const Double_t kP3 = 3.17983E-6; | |
845 | //const Double_t kP4 = 1.8631; | |
846 | //const Double_t kP5 = 1.9479; | |
847 | ||
f73816f5 | 848 | // Lower cutoff of the Bethe-Bloch-curve to limit step sizes |
849 | const Double_t kBgMin = 0.8; | |
850 | const Double_t kBBMax = 6.83298; | |
851 | //const Double_t kBgMin = 0.6; | |
852 | //const Double_t kBBMax = 17.2809; | |
853 | //const Double_t kBgMin = 0.4; | |
854 | //const Double_t kBBMax = 82.0; | |
855 | ||
856 | if (bg > kBgMin) { | |
5c7f4665 | 857 | Double_t yy = bg / TMath::Sqrt(1. + bg*bg); |
858 | Double_t aa = TMath::Power(yy,kP4); | |
859 | Double_t bb = TMath::Power((1./bg),kP5); | |
860 | bb = TMath::Log(kP3 + bb); | |
861 | return ((kP2 - aa - bb)*kP1 / aa); | |
862 | } | |
f73816f5 | 863 | else { |
864 | return kBBMax; | |
865 | } | |
d3f347ff | 866 | |
fe4da5cc | 867 | } |
5c7f4665 | 868 | |
a328fff9 | 869 | //_____________________________________________________________________________ |
870 | Double_t BetheBlochGeant(Double_t bg) | |
871 | { | |
872 | // | |
873 | // Return dN/dx (number of primary collisions per centimeter) | |
874 | // for given beta*gamma factor. | |
875 | // | |
876 | // Implemented by K.Oyama according to GEANT 3 parametrization shown in | |
877 | // A.Andronic's webpage: http://www-alice.gsi.de/trd/papers/dedx/dedx.html | |
878 | // This must be used as a set with IntSpecGeant. | |
879 | // | |
880 | ||
881 | Double_t arr_g[20] = { | |
882 | 1.100000, 1.200000, 1.300000, 1.500000, | |
883 | 1.800000, 2.000000, 2.500000, 3.000000, | |
884 | 4.000000, 7.000000, 10.000000, 20.000000, | |
885 | 40.000000, 70.000000, 100.000000, 300.000000, | |
886 | 600.000000, 1000.000000, 3000.000000, 10000.000000 }; | |
887 | ||
888 | Double_t arr_nc[20] = { | |
889 | 75.009056, 45.508083, 35.299252, 27.116327, | |
890 | 22.734999, 21.411915, 19.934095, 19.449375, | |
891 | 19.344431, 20.185553, 21.027925, 22.912676, | |
892 | 24.933352, 26.504053, 27.387468, 29.566597, | |
893 | 30.353779, 30.787134, 31.129285, 31.157350 }; | |
894 | ||
895 | // betagamma to gamma | |
896 | Double_t g = TMath::Sqrt( 1. + bg*bg ); | |
897 | ||
898 | // Find the index just before the point we need. | |
899 | int i; | |
900 | for( i = 0 ; i < 18 ; i++ ) | |
901 | if( arr_g[i] < g && arr_g[i+1] > g ) | |
902 | break; | |
903 | ||
904 | // Simple interpolation. | |
905 | Double_t pp = ((arr_nc[i+1] - arr_nc[i]) / | |
906 | (arr_g[i+1]-arr_g[i])) * (g-arr_g[i]) + arr_nc[i]; | |
907 | ||
908 | return pp; | |
909 | ||
910 | } | |
911 | ||
5c7f4665 | 912 | //_____________________________________________________________________________ |
913 | Double_t Ermilova(Double_t *x, Double_t *) | |
914 | { | |
915 | // | |
916 | // Calculates the delta-ray energy distribution according to Ermilova. | |
917 | // Logarithmic scale ! | |
918 | // | |
919 | ||
920 | Double_t energy; | |
921 | Double_t dpos; | |
922 | Double_t dnde; | |
923 | ||
924 | Int_t pos1, pos2; | |
925 | ||
8230f242 | 926 | const Int_t kNv = 31; |
5c7f4665 | 927 | |
8230f242 | 928 | Float_t vxe[kNv] = { 2.3026, 2.9957, 3.4012, 3.6889, 3.9120 |
929 | , 4.0943, 4.2485, 4.3820, 4.4998, 4.6052 | |
930 | , 4.7005, 5.0752, 5.2983, 5.7038, 5.9915 | |
931 | , 6.2146, 6.5221, 6.9078, 7.3132, 7.6009 | |
932 | , 8.0064, 8.5172, 8.6995, 8.9872, 9.2103 | |
933 | , 9.4727, 9.9035,10.3735,10.5966,10.8198 | |
934 | ,11.5129 }; | |
5c7f4665 | 935 | |
8230f242 | 936 | Float_t vye[kNv] = { 80.0 , 31.0 , 23.3 , 21.1 , 21.0 |
937 | , 20.9 , 20.8 , 20.0 , 16.0 , 11.0 | |
938 | , 8.0 , 6.0 , 5.2 , 4.6 , 4.0 | |
939 | , 3.5 , 3.0 , 1.4 , 0.67 , 0.44 | |
940 | , 0.3 , 0.18 , 0.12 , 0.08 , 0.056 | |
941 | , 0.04 , 0.023, 0.015, 0.011, 0.01 | |
942 | , 0.004 }; | |
5c7f4665 | 943 | |
944 | energy = x[0]; | |
945 | ||
946 | // Find the position | |
947 | pos1 = pos2 = 0; | |
948 | dpos = 0; | |
949 | do { | |
950 | dpos = energy - vxe[pos2++]; | |
951 | } | |
952 | while (dpos > 0); | |
953 | pos2--; | |
f73816f5 | 954 | if (pos2 > kNv) pos2 = kNv - 1; |
5c7f4665 | 955 | pos1 = pos2 - 1; |
956 | ||
957 | // Differentiate between the sampling points | |
958 | dnde = (vye[pos1] - vye[pos2]) / (vxe[pos2] - vxe[pos1]); | |
959 | ||
960 | return dnde; | |
961 | ||
962 | } | |
a328fff9 | 963 | |
964 | //_____________________________________________________________________________ | |
965 | Double_t IntSpecGeant(Double_t *x, Double_t *) | |
966 | { | |
967 | // | |
968 | // Integrated spectrum from Geant3 | |
969 | // | |
970 | ||
971 | const Int_t n_pts = 83; | |
972 | Double_t arr_e[n_pts] = { | |
973 | 2.421257, 2.483278, 2.534301, 2.592230, | |
974 | 2.672067, 2.813299, 3.015059, 3.216819, | |
975 | 3.418579, 3.620338, 3.868209, 3.920198, | |
976 | 3.978284, 4.063923, 4.186264, 4.308605, | |
977 | 4.430946, 4.553288, 4.724261, 4.837736, | |
978 | 4.999842, 5.161949, 5.324056, 5.486163, | |
979 | 5.679688, 5.752998, 5.857728, 5.962457, | |
980 | 6.067185, 6.171914, 6.315653, 6.393674, | |
981 | 6.471694, 6.539689, 6.597658, 6.655627, | |
982 | 6.710957, 6.763648, 6.816338, 6.876198, | |
983 | 6.943227, 7.010257, 7.106285, 7.252151, | |
984 | 7.460531, 7.668911, 7.877290, 8.085670, | |
985 | 8.302979, 8.353585, 8.413120, 8.483500, | |
986 | 8.541030, 8.592857, 8.668865, 8.820485, | |
987 | 9.037086, 9.253686, 9.470286, 9.686887, | |
988 | 9.930838, 9.994655, 10.085822, 10.176990, | |
989 | 10.268158, 10.359325, 10.503614, 10.627565, | |
990 | 10.804637, 10.981709, 11.158781, 11.335854, | |
991 | 11.593397, 11.781165, 12.049404, 12.317644, | |
992 | 12.585884, 12.854123, 14.278421, 16.975889, | |
993 | 20.829416, 24.682943, 28.536469 | |
994 | }; | |
995 | Double_t arr_dndx[n_pts] = { | |
996 | 19.344431, 18.664679, 18.136106, 17.567745, | |
997 | 16.836426, 15.677382, 14.281277, 13.140237, | |
998 | 12.207677, 11.445510, 10.697049, 10.562296, | |
999 | 10.414673, 10.182341, 9.775256, 9.172330, | |
1000 | 8.240271, 6.898587, 4.808303, 3.889751, | |
1001 | 3.345288, 3.093431, 2.897347, 2.692470, | |
1002 | 2.436222, 2.340029, 2.208579, 2.086489, | |
1003 | 1.975535, 1.876519, 1.759626, 1.705024, | |
1004 | 1.656374, 1.502638, 1.330566, 1.200697, | |
1005 | 1.101168, 1.019323, 0.943867, 0.851951, | |
1006 | 0.755229, 0.671576, 0.570675, 0.449672, | |
1007 | 0.326722, 0.244225, 0.188225, 0.149608, | |
1008 | 0.121529, 0.116289, 0.110636, 0.103490, | |
1009 | 0.096147, 0.089191, 0.079780, 0.063927, | |
1010 | 0.047642, 0.036341, 0.028250, 0.022285, | |
1011 | 0.017291, 0.016211, 0.014802, 0.013533, | |
1012 | 0.012388, 0.011352, 0.009803, 0.008537, | |
1013 | 0.007039, 0.005829, 0.004843, 0.004034, | |
1014 | 0.003101, 0.002564, 0.001956, 0.001494, | |
1015 | 0.001142, 0.000873, 0.000210, 0.000014, | |
1016 | 0.000000, 0.000000, 0.000000 | |
1017 | }; | |
1018 | ||
1019 | Int_t i; | |
1020 | Double_t energy = x[0]; | |
1021 | Double_t dnde; | |
1022 | ||
1023 | for( i = 0 ; i < n_pts ; i++ ) | |
1024 | if( energy < arr_e[i] ) break; | |
1025 | ||
1026 | if( i == 0 ) | |
1027 | printf("Error in AliTRDv1::IntSpecGeant: " | |
1028 | "given energy value is too small or zero.\n"); | |
1029 | ||
1030 | // Interpolate | |
1031 | dnde = (arr_dndx[i-1] - arr_dndx[i]) / (arr_e[i] - arr_e[i-1]); | |
1032 | ||
1033 | return dnde; | |
1034 | ||
1035 | } |