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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 | $Log$ | |
6f1e466d | 18 | Revision 1.17.2.1 2000/05/08 14:59:16 cblume |
19 | Made inline function non-virtual. Bug fix in setting sensitive chamber | |
20 | ||
21 | Revision 1.17 2000/02/28 19:10:26 cblume | |
22 | Include the new TRD classes | |
23 | ||
851d3db9 | 24 | Revision 1.16.4.1 2000/02/28 18:04:35 cblume |
25 | Change to new hit version, introduce geometry class, and move digitization and clustering to AliTRDdigitizer/AliTRDclusterizerV1 | |
26 | ||
27 | Revision 1.16 1999/11/05 22:50:28 fca | |
28 | Do not use Atan, removed from ROOT too | |
29 | ||
90f8d287 | 30 | Revision 1.15 1999/11/02 17:20:19 fca |
31 | initialise nbytes before using it | |
32 | ||
036da493 | 33 | Revision 1.14 1999/11/02 17:15:54 fca |
34 | Correct ansi scoping not accepted by HP compilers | |
35 | ||
0549c011 | 36 | Revision 1.13 1999/11/02 17:14:51 fca |
37 | Correct ansi scoping not accepted by HP compilers | |
38 | ||
9c767df4 | 39 | Revision 1.12 1999/11/02 16:35:56 fca |
40 | New version of TRD introduced | |
41 | ||
5c7f4665 | 42 | Revision 1.11 1999/11/01 20:41:51 fca |
43 | Added protections against using the wrong version of FRAME | |
44 | ||
ab76897d | 45 | Revision 1.10 1999/09/29 09:24:35 fca |
46 | Introduction of the Copyright and cvs Log | |
47 | ||
4c039060 | 48 | */ |
49 | ||
fe4da5cc | 50 | /////////////////////////////////////////////////////////////////////////////// |
51 | // // | |
5c7f4665 | 52 | // Transition Radiation Detector version 2 -- slow simulator // |
fe4da5cc | 53 | // // |
54 | //Begin_Html | |
55 | /* | |
5c7f4665 | 56 | <img src="picts/AliTRDfullClass.gif"> |
fe4da5cc | 57 | */ |
58 | //End_Html | |
59 | // // | |
60 | // // | |
61 | /////////////////////////////////////////////////////////////////////////////// | |
62 | ||
63 | #include <TMath.h> | |
fe4da5cc | 64 | #include <TVector.h> |
5c7f4665 | 65 | #include <TRandom.h> |
fe4da5cc | 66 | |
fe4da5cc | 67 | #include "AliRun.h" |
fe4da5cc | 68 | #include "AliMC.h" |
d3f347ff | 69 | #include "AliConst.h" |
5c7f4665 | 70 | |
851d3db9 | 71 | #include "AliTRDv1.h" |
72 | #include "AliTRDmatrix.h" | |
73 | #include "AliTRDgeometry.h" | |
74 | ||
fe4da5cc | 75 | ClassImp(AliTRDv1) |
76 | ||
77 | //_____________________________________________________________________________ | |
78 | AliTRDv1::AliTRDv1(const char *name, const char *title) | |
79 | :AliTRD(name, title) | |
80 | { | |
81 | // | |
851d3db9 | 82 | // Standard constructor for Transition Radiation Detector version 1 |
fe4da5cc | 83 | // |
82bbf98a | 84 | |
851d3db9 | 85 | fIdSens = 0; |
82bbf98a | 86 | |
851d3db9 | 87 | fIdChamber1 = 0; |
88 | fIdChamber2 = 0; | |
89 | fIdChamber3 = 0; | |
5c7f4665 | 90 | |
851d3db9 | 91 | fSensSelect = 0; |
92 | fSensPlane = -1; | |
93 | fSensChamber = -1; | |
94 | fSensSector = -1; | |
5c7f4665 | 95 | |
96 | fDeltaE = NULL; | |
97 | ||
98 | SetBufferSize(128000); | |
99 | ||
100 | } | |
101 | ||
102 | //_____________________________________________________________________________ | |
103 | AliTRDv1::~AliTRDv1() | |
104 | { | |
82bbf98a | 105 | |
5c7f4665 | 106 | if (fDeltaE) delete fDeltaE; |
82bbf98a | 107 | |
fe4da5cc | 108 | } |
109 | ||
110 | //_____________________________________________________________________________ | |
111 | void AliTRDv1::CreateGeometry() | |
112 | { | |
113 | // | |
851d3db9 | 114 | // Create the GEANT geometry for the Transition Radiation Detector - Version 1 |
5c7f4665 | 115 | // This version covers the full azimuth. |
d3f347ff | 116 | // |
117 | ||
82bbf98a | 118 | // Check that FRAME is there otherwise we have no place where to put the TRD |
119 | AliModule* FRAME = gAlice->GetModule("FRAME"); | |
120 | if (!FRAME) return; | |
d3f347ff | 121 | |
82bbf98a | 122 | // Define the chambers |
123 | AliTRD::CreateGeometry(); | |
d3f347ff | 124 | |
fe4da5cc | 125 | } |
126 | ||
127 | //_____________________________________________________________________________ | |
128 | void AliTRDv1::CreateMaterials() | |
129 | { | |
130 | // | |
851d3db9 | 131 | // Create materials for the Transition Radiation Detector version 1 |
fe4da5cc | 132 | // |
82bbf98a | 133 | |
d3f347ff | 134 | AliTRD::CreateMaterials(); |
82bbf98a | 135 | |
fe4da5cc | 136 | } |
137 | ||
5c7f4665 | 138 | //_____________________________________________________________________________ |
139 | void AliTRDv1::Init() | |
140 | { | |
141 | // | |
142 | // Initialise Transition Radiation Detector after geometry has been built. | |
5c7f4665 | 143 | // |
144 | ||
145 | AliTRD::Init(); | |
146 | ||
851d3db9 | 147 | printf(" Slow simulator\n\n"); |
148 | if (fSensSelect) { | |
149 | if (fSensPlane >= 0) | |
150 | printf(" Only plane %d is sensitive\n",fSensPlane); | |
151 | if (fSensChamber >= 0) | |
152 | printf(" Only chamber %d is sensitive\n",fSensChamber); | |
153 | if (fSensSector >= 0) | |
154 | printf(" Only sector %d is sensitive\n",fSensSector); | |
155 | } | |
156 | printf("\n"); | |
5c7f4665 | 157 | |
158 | // First ionization potential (eV) for the gas mixture (90% Xe + 10% CO2) | |
159 | const Float_t kPoti = 12.1; | |
160 | // Maximum energy (50 keV); | |
161 | const Float_t kEend = 50000.0; | |
162 | // Ermilova distribution for the delta-ray spectrum | |
163 | Float_t Poti = TMath::Log(kPoti); | |
164 | Float_t Eend = TMath::Log(kEend); | |
165 | fDeltaE = new TF1("deltae",Ermilova,Poti,Eend,0); | |
166 | ||
167 | // Identifier of the sensitive volume (drift region) | |
168 | fIdSens = gMC->VolId("UL05"); | |
82bbf98a | 169 | |
170 | // Identifier of the TRD-driftchambers | |
171 | fIdChamber1 = gMC->VolId("UCIO"); | |
172 | fIdChamber2 = gMC->VolId("UCIM"); | |
173 | fIdChamber3 = gMC->VolId("UCII"); | |
174 | ||
5c7f4665 | 175 | for (Int_t i = 0; i < 80; i++) printf("*"); |
176 | printf("\n"); | |
177 | ||
fe4da5cc | 178 | } |
179 | ||
5c7f4665 | 180 | //_____________________________________________________________________________ |
181 | void AliTRDv1::SetSensPlane(Int_t iplane) | |
182 | { | |
183 | // | |
851d3db9 | 184 | // Defines the hit-sensitive plane (0-5) |
5c7f4665 | 185 | // |
82bbf98a | 186 | |
851d3db9 | 187 | if ((iplane < 0) || (iplane > 5)) { |
5c7f4665 | 188 | printf("Wrong input value: %d\n",iplane); |
189 | printf("Use standard setting\n"); | |
851d3db9 | 190 | fSensPlane = -1; |
191 | fSensSelect = 0; | |
5c7f4665 | 192 | return; |
193 | } | |
82bbf98a | 194 | |
5c7f4665 | 195 | fSensSelect = 1; |
196 | fSensPlane = iplane; | |
82bbf98a | 197 | |
5c7f4665 | 198 | } |
199 | ||
200 | //_____________________________________________________________________________ | |
201 | void AliTRDv1::SetSensChamber(Int_t ichamber) | |
202 | { | |
203 | // | |
851d3db9 | 204 | // Defines the hit-sensitive chamber (0-4) |
5c7f4665 | 205 | // |
206 | ||
851d3db9 | 207 | if ((ichamber < 0) || (ichamber > 4)) { |
5c7f4665 | 208 | printf("Wrong input value: %d\n",ichamber); |
209 | printf("Use standard setting\n"); | |
851d3db9 | 210 | fSensChamber = -1; |
211 | fSensSelect = 0; | |
5c7f4665 | 212 | return; |
213 | } | |
214 | ||
215 | fSensSelect = 1; | |
216 | fSensChamber = ichamber; | |
217 | ||
218 | } | |
219 | ||
220 | //_____________________________________________________________________________ | |
221 | void AliTRDv1::SetSensSector(Int_t isector) | |
222 | { | |
223 | // | |
851d3db9 | 224 | // Defines the hit-sensitive sector (0-17) |
5c7f4665 | 225 | // |
226 | ||
851d3db9 | 227 | if ((isector < 0) || (isector > 17)) { |
5c7f4665 | 228 | printf("Wrong input value: %d\n",isector); |
229 | printf("Use standard setting\n"); | |
851d3db9 | 230 | fSensSector = -1; |
231 | fSensSelect = 0; | |
5c7f4665 | 232 | return; |
233 | } | |
234 | ||
235 | fSensSelect = 1; | |
236 | fSensSector = isector; | |
237 | ||
238 | } | |
239 | ||
240 | //_____________________________________________________________________________ | |
241 | void AliTRDv1::StepManager() | |
242 | { | |
243 | // | |
5c7f4665 | 244 | // Slow simulator. Every charged track produces electron cluster as hits |
245 | // along its path across the drift volume. The step size is set acording | |
246 | // to Bethe-Bloch. The energy distribution of the delta electrons follows | |
247 | // a spectrum taken from Ermilova et al. | |
248 | // | |
249 | ||
250 | Int_t iIdSens, icSens; | |
251 | Int_t iIdSpace, icSpace; | |
252 | Int_t iIdChamber, icChamber; | |
851d3db9 | 253 | Int_t pla = 0; |
254 | Int_t cha = 0; | |
255 | Int_t sec = 0; | |
256 | Int_t iPdg; | |
5c7f4665 | 257 | |
258 | Float_t hits[4]; | |
259 | Float_t random[1]; | |
260 | Float_t charge; | |
261 | Float_t aMass; | |
262 | ||
263 | Double_t pTot; | |
264 | Double_t qTot; | |
265 | Double_t eDelta; | |
266 | Double_t betaGamma, pp; | |
267 | ||
268 | TLorentzVector pos, mom; | |
82bbf98a | 269 | TClonesArray &lhits = *fHits; |
270 | ||
851d3db9 | 271 | const Double_t kBig = 1.0E+12; |
5c7f4665 | 272 | |
273 | // Ionization energy | |
851d3db9 | 274 | const Float_t kWion = 22.04; |
5c7f4665 | 275 | // Maximum energy for e+ e- g for the step-size calculation |
851d3db9 | 276 | const Float_t kPTotMax = 0.002; |
5c7f4665 | 277 | // Plateau value of the energy-loss for electron in xenon |
278 | // taken from: Allison + Comb, Ann. Rev. Nucl. Sci. (1980), 30, 253 | |
279 | //const Double_t kPlateau = 1.70; | |
280 | // the averaged value (26/3/99) | |
851d3db9 | 281 | const Float_t kPlateau = 1.55; |
5c7f4665 | 282 | // dN1/dx|min for the gas mixture (90% Xe + 10% CO2) |
851d3db9 | 283 | const Float_t kPrim = 48.0; |
5c7f4665 | 284 | // First ionization potential (eV) for the gas mixture (90% Xe + 10% CO2) |
851d3db9 | 285 | const Float_t kPoti = 12.1; |
286 | ||
287 | // PDG code electron | |
288 | const Int_t pdgElectron = 11; | |
5c7f4665 | 289 | |
290 | // Set the maximum step size to a very large number for all | |
291 | // neutral particles and those outside the driftvolume | |
292 | gMC->SetMaxStep(kBig); | |
293 | ||
294 | // Use only charged tracks | |
295 | if (( gMC->TrackCharge() ) && | |
296 | (!gMC->IsTrackStop() ) && | |
297 | (!gMC->IsTrackDisappeared())) { | |
fe4da5cc | 298 | |
5c7f4665 | 299 | // Inside a sensitive volume? |
82bbf98a | 300 | iIdSens = gMC->CurrentVolID(icSens); |
301 | if (iIdSens == fIdSens) { | |
302 | ||
82bbf98a | 303 | iIdSpace = gMC->CurrentVolOffID(4,icSpace ); |
304 | iIdChamber = gMC->CurrentVolOffID(1,icChamber); | |
fe4da5cc | 305 | |
5c7f4665 | 306 | // Calculate the energy of the delta-electrons |
307 | eDelta = TMath::Exp(fDeltaE->GetRandom()) - kPoti; | |
308 | eDelta = TMath::Max(eDelta,0.0); | |
309 | ||
310 | // The number of secondary electrons created | |
311 | qTot = (Double_t) ((Int_t) (eDelta / kWion) + 1); | |
312 | ||
313 | // The hit coordinates and charge | |
314 | gMC->TrackPosition(pos); | |
315 | hits[0] = pos[0]; | |
316 | hits[1] = pos[1]; | |
317 | hits[2] = pos[2]; | |
318 | hits[3] = qTot; | |
319 | ||
851d3db9 | 320 | // The sector number (0 - 17) |
321 | // The numbering goes clockwise and starts at y = 0 | |
322 | Float_t phi = kRaddeg*TMath::ATan2(pos[0],pos[1]); | |
323 | if (phi < 90.) | |
324 | phi = phi + 270.; | |
325 | else | |
326 | phi = phi - 90.; | |
327 | sec = ((Int_t) (phi / 20)); | |
82bbf98a | 328 | |
d3f347ff | 329 | // The chamber number |
851d3db9 | 330 | // 0: outer left |
331 | // 1: middle left | |
332 | // 2: inner | |
333 | // 3: middle right | |
334 | // 4: outer right | |
82bbf98a | 335 | if (iIdChamber == fIdChamber1) |
851d3db9 | 336 | cha = (hits[2] < 0 ? 0 : 4); |
82bbf98a | 337 | else if (iIdChamber == fIdChamber2) |
851d3db9 | 338 | cha = (hits[2] < 0 ? 1 : 3); |
82bbf98a | 339 | else if (iIdChamber == fIdChamber3) |
851d3db9 | 340 | cha = 2; |
82bbf98a | 341 | |
fe4da5cc | 342 | // The plane number |
851d3db9 | 343 | // The numbering starts at the innermost plane |
344 | pla = icChamber - TMath::Nint((Float_t) (icChamber / 7)) * 6 - 1; | |
82bbf98a | 345 | |
5c7f4665 | 346 | // Check on selected volumes |
347 | Int_t addthishit = 1; | |
348 | if (fSensSelect) { | |
6f1e466d | 349 | if ((fSensPlane >= 0) && (pla != fSensPlane )) addthishit = 0; |
350 | if ((fSensChamber >= 0) && (cha != fSensChamber)) addthishit = 0; | |
351 | if ((fSensSector >= 0) && (sec != fSensSector )) addthishit = 0; | |
5c7f4665 | 352 | } |
353 | ||
354 | // Add this hit | |
355 | if (addthishit) { | |
356 | ||
851d3db9 | 357 | new(lhits[fNhits++]) AliTRDhit(fIshunt |
358 | ,gAlice->CurrentTrack() | |
359 | ,fGeometry->GetDetector(pla,cha,sec) | |
360 | ,hits); | |
5c7f4665 | 361 | |
362 | // The energy loss according to Bethe Bloch | |
363 | gMC->TrackMomentum(mom); | |
364 | pTot = mom.Rho(); | |
851d3db9 | 365 | iPdg = TMath::Abs(gMC->TrackPid()); |
366 | if ( (iPdg != pdgElectron) || | |
367 | ((iPdg == pdgElectron) && (pTot < kPTotMax))) { | |
5c7f4665 | 368 | aMass = gMC->TrackMass(); |
369 | betaGamma = pTot / aMass; | |
370 | pp = kPrim * BetheBloch(betaGamma); | |
371 | // Take charge > 1 into account | |
372 | charge = gMC->TrackCharge(); | |
373 | if (TMath::Abs(charge) > 1) pp = pp * charge*charge; | |
374 | } | |
375 | // Electrons above 20 Mev/c are at the plateau | |
376 | else { | |
377 | pp = kPrim * kPlateau; | |
378 | } | |
379 | ||
380 | // Calculate the maximum step size for the next tracking step | |
381 | if (pp > 0) { | |
382 | do | |
383 | gMC->Rndm(random,1); | |
384 | while ((random[0] == 1.) || (random[0] == 0.)); | |
385 | gMC->SetMaxStep( - TMath::Log(random[0]) / pp); | |
386 | } | |
387 | ||
388 | } | |
389 | else { | |
390 | // set step size to maximal value | |
391 | gMC->SetMaxStep(kBig); | |
392 | } | |
d3f347ff | 393 | |
394 | } | |
395 | ||
5c7f4665 | 396 | } |
397 | ||
398 | } | |
399 | ||
400 | //_____________________________________________________________________________ | |
401 | Double_t AliTRDv1::BetheBloch(Double_t bg) | |
402 | { | |
403 | // | |
404 | // Parametrization of the Bethe-Bloch-curve | |
405 | // The parametrization is the same as for the TPC and is taken from Lehrhaus. | |
406 | // | |
407 | ||
408 | // This parameters have been adjusted to averaged values from GEANT | |
409 | const Double_t kP1 = 7.17960e-02; | |
410 | const Double_t kP2 = 8.54196; | |
411 | const Double_t kP3 = 1.38065e-06; | |
412 | const Double_t kP4 = 5.30972; | |
413 | const Double_t kP5 = 2.83798; | |
414 | ||
415 | // This parameters have been adjusted to Xe-data found in: | |
416 | // Allison & Cobb, Ann. Rev. Nucl. Sci. (1980), 30, 253 | |
417 | //const Double_t kP1 = 0.76176E-1; | |
418 | //const Double_t kP2 = 10.632; | |
419 | //const Double_t kP3 = 3.17983E-6; | |
420 | //const Double_t kP4 = 1.8631; | |
421 | //const Double_t kP5 = 1.9479; | |
422 | ||
423 | if (bg > 0) { | |
424 | Double_t yy = bg / TMath::Sqrt(1. + bg*bg); | |
425 | Double_t aa = TMath::Power(yy,kP4); | |
426 | Double_t bb = TMath::Power((1./bg),kP5); | |
427 | bb = TMath::Log(kP3 + bb); | |
428 | return ((kP2 - aa - bb)*kP1 / aa); | |
429 | } | |
430 | else | |
431 | return 0; | |
d3f347ff | 432 | |
fe4da5cc | 433 | } |
5c7f4665 | 434 | |
435 | //_____________________________________________________________________________ | |
436 | Double_t Ermilova(Double_t *x, Double_t *) | |
437 | { | |
438 | // | |
439 | // Calculates the delta-ray energy distribution according to Ermilova. | |
440 | // Logarithmic scale ! | |
441 | // | |
442 | ||
443 | Double_t energy; | |
444 | Double_t dpos; | |
445 | Double_t dnde; | |
446 | ||
447 | Int_t pos1, pos2; | |
448 | ||
449 | const Int_t nV = 31; | |
450 | ||
451 | Float_t vxe[nV] = { 2.3026, 2.9957, 3.4012, 3.6889, 3.9120 | |
452 | , 4.0943, 4.2485, 4.3820, 4.4998, 4.6052 | |
453 | , 4.7005, 5.0752, 5.2983, 5.7038, 5.9915 | |
454 | , 6.2146, 6.5221, 6.9078, 7.3132, 7.6009 | |
455 | , 8.0064, 8.5172, 8.6995, 8.9872, 9.2103 | |
456 | , 9.4727, 9.9035,10.3735,10.5966,10.8198 | |
457 | ,11.5129 }; | |
458 | ||
459 | Float_t vye[nV] = { 80.0 , 31.0 , 23.3 , 21.1 , 21.0 | |
460 | , 20.9 , 20.8 , 20.0 , 16.0 , 11.0 | |
461 | , 8.0 , 6.0 , 5.2 , 4.6 , 4.0 | |
462 | , 3.5 , 3.0 , 1.4 , 0.67 , 0.44 | |
463 | , 0.3 , 0.18 , 0.12 , 0.08 , 0.056 | |
464 | , 0.04 , 0.023, 0.015, 0.011, 0.01 | |
465 | , 0.004 }; | |
466 | ||
467 | energy = x[0]; | |
468 | ||
469 | // Find the position | |
470 | pos1 = pos2 = 0; | |
471 | dpos = 0; | |
472 | do { | |
473 | dpos = energy - vxe[pos2++]; | |
474 | } | |
475 | while (dpos > 0); | |
476 | pos2--; | |
477 | if (pos2 > nV) pos2 = nV; | |
478 | pos1 = pos2 - 1; | |
479 | ||
480 | // Differentiate between the sampling points | |
481 | dnde = (vye[pos1] - vye[pos2]) / (vxe[pos2] - vxe[pos1]); | |
482 | ||
483 | return dnde; | |
484 | ||
485 | } |