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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 | |
030b4415 | 18 | //////////////////////////////////////////////////////////////////////////// |
19 | // // | |
20 | // Transition Radiation Detector version 1 -- slow simulator // | |
21 | // // | |
22 | //////////////////////////////////////////////////////////////////////////// | |
fe4da5cc | 23 | |
769257f4 | 24 | #include <stdlib.h> |
25 | ||
793ff80c | 26 | #include <TF1.h> |
1819f4bb | 27 | #include <TLorentzVector.h> |
88cb7938 | 28 | #include <TMath.h> |
29 | #include <TRandom.h> | |
30 | #include <TVector.h> | |
31 | #include <TVirtualMC.h> | |
f57bb418 | 32 | #include <TGeoManager.h> |
170c35f1 | 33 | #include <TGeoPhysicalNode.h> |
fe4da5cc | 34 | |
d3f347ff | 35 | #include "AliConst.h" |
45160b1f | 36 | #include "AliLog.h" |
37 | #include "AliMC.h" | |
88cb7938 | 38 | #include "AliRun.h" |
030b4415 | 39 | |
88cb7938 | 40 | #include "AliTRDgeometry.h" |
793ff80c | 41 | #include "AliTRDhit.h" |
cb2f9e9b | 42 | #include "AliTRDsimTR.h" |
88cb7938 | 43 | #include "AliTRDv1.h" |
851d3db9 | 44 | |
fe4da5cc | 45 | ClassImp(AliTRDv1) |
8230f242 | 46 | |
47 | //_____________________________________________________________________________ | |
030b4415 | 48 | AliTRDv1::AliTRDv1() |
49 | :AliTRD() | |
50 | ,fTRon(kFALSE) | |
51 | ,fTR(NULL) | |
52 | ,fTypeOfStepManager(0) | |
53 | ,fStepSize(0) | |
54 | ,fDeltaE(NULL) | |
55 | ,fDeltaG(NULL) | |
56 | ,fTrackLength0(0) | |
57 | ,fPrimaryTrackPid(0) | |
8230f242 | 58 | { |
59 | // | |
60 | // Default constructor | |
61 | // | |
62 | ||
8230f242 | 63 | } |
64 | ||
fe4da5cc | 65 | //_____________________________________________________________________________ |
66 | AliTRDv1::AliTRDv1(const char *name, const char *title) | |
030b4415 | 67 | :AliTRD(name,title) |
68 | ,fTRon(kTRUE) | |
69 | ,fTR(NULL) | |
67c47633 | 70 | ,fTypeOfStepManager(2) |
030b4415 | 71 | ,fStepSize(0.1) |
72 | ,fDeltaE(NULL) | |
73 | ,fDeltaG(NULL) | |
74 | ,fTrackLength0(0) | |
75 | ,fPrimaryTrackPid(0) | |
fe4da5cc | 76 | { |
77 | // | |
851d3db9 | 78 | // Standard constructor for Transition Radiation Detector version 1 |
fe4da5cc | 79 | // |
82bbf98a | 80 | |
5c7f4665 | 81 | SetBufferSize(128000); |
82 | ||
83 | } | |
84 | ||
85 | //_____________________________________________________________________________ | |
86 | AliTRDv1::~AliTRDv1() | |
87 | { | |
dd9a6ee3 | 88 | // |
89 | // AliTRDv1 destructor | |
90 | // | |
82bbf98a | 91 | |
030b4415 | 92 | if (fDeltaE) { |
93 | delete fDeltaE; | |
94 | fDeltaE = 0; | |
95 | } | |
96 | ||
97 | if (fDeltaG) { | |
98 | delete fDeltaG; | |
99 | fDeltaG = 0; | |
100 | } | |
101 | ||
102 | if (fTR) { | |
103 | delete fTR; | |
104 | fTR = 0; | |
105 | } | |
82bbf98a | 106 | |
fe4da5cc | 107 | } |
108 | ||
f57bb418 | 109 | //_____________________________________________________________________________ |
110 | void AliTRDv1::AddAlignableVolumes() const | |
111 | { | |
112 | // | |
113 | // Create entries for alignable volumes associating the symbolic volume | |
114 | // name with the corresponding volume path. Needs to be syncronized with | |
115 | // eventual changes in the geometry. | |
116 | // | |
117 | ||
118 | TString volPath; | |
119 | TString symName; | |
120 | ||
121 | TString vpStr = "ALIC_1/B077_1/BSEGMO"; | |
122 | TString vpApp1 = "_1/BTRD"; | |
123 | TString vpApp2 = "_1"; | |
124 | TString vpApp3 = "/UTR1_1/UTS1_1/UTI1_1/UT"; | |
125 | ||
126 | TString snStr = "TRD/sm"; | |
127 | TString snApp1 = "/st"; | |
128 | TString snApp2 = "/pl"; | |
129 | ||
130 | // | |
131 | // The super modules | |
132 | // The symbolic names are: TRD/sm00 | |
133 | // ... | |
134 | // TRD/sm17 | |
135 | // | |
136 | for (Int_t isect = 0; isect < AliTRDgeometry::Nsect(); isect++) { | |
137 | ||
138 | volPath = vpStr; | |
139 | volPath += isect; | |
140 | volPath += vpApp1; | |
141 | volPath += isect; | |
142 | volPath += vpApp2; | |
143 | ||
144 | symName = snStr; | |
145 | symName += Form("%02d",isect); | |
146 | ||
147 | gGeoManager->SetAlignableEntry(symName.Data(),volPath.Data()); | |
148 | ||
149 | } | |
150 | ||
151 | // | |
152 | // The readout chambers | |
153 | // The symbolic names are: TRD/sm00/st0/pl0 | |
154 | // ... | |
155 | // TRD/sm17/st4/pl5 | |
156 | // | |
157 | for (Int_t isect = 0; isect < AliTRDgeometry::Nsect(); isect++) { | |
158 | for (Int_t icham = 0; icham < AliTRDgeometry::Ncham(); icham++) { | |
159 | for (Int_t iplan = 0; iplan < AliTRDgeometry::Nplan(); iplan++) { | |
160 | ||
161 | Int_t idet = AliTRDgeometry::GetDetectorSec(iplan,icham); | |
162 | ||
163 | volPath = vpStr; | |
164 | volPath += isect; | |
165 | volPath += vpApp1; | |
166 | volPath += isect; | |
167 | volPath += vpApp2; | |
168 | volPath += vpApp3; | |
169 | volPath += Form("%02d",idet); | |
170 | volPath += vpApp2; | |
171 | ||
172 | symName = snStr; | |
173 | symName += Form("%02d",isect); | |
174 | symName += snApp1; | |
175 | symName += icham; | |
176 | symName += snApp2; | |
177 | symName += iplan; | |
178 | ||
51a5f1d0 | 179 | TGeoPNEntry *alignableEntry = |
180 | gGeoManager->SetAlignableEntry(symName.Data(),volPath.Data()); | |
f57bb418 | 181 | |
170c35f1 | 182 | // Add the tracking to local matrix following the TPC example |
170c35f1 | 183 | |
51a5f1d0 | 184 | if (alignableEntry) { |
185 | const char *path = alignableEntry->GetTitle(); | |
186 | if (!gGeoManager->cd(path)) { | |
187 | AliFatal(Form("Volume path %s not valid!",path)); | |
188 | } | |
189 | TGeoHMatrix *globMatrix = gGeoManager->GetCurrentMatrix(); | |
190 | Double_t sectorAngle = 20.0 * (isect % 18) + 10.0; | |
191 | TGeoHMatrix *t2lMatrix = new TGeoHMatrix(); | |
192 | t2lMatrix->RotateZ(sectorAngle); | |
193 | t2lMatrix->MultiplyLeft(&(globMatrix->Inverse())); | |
194 | alignableEntry->SetMatrix(t2lMatrix); | |
195 | } | |
196 | else { | |
197 | AliError(Form("Alignable entry %s is not valid!",symName.Data())); | |
198 | } | |
f57bb418 | 199 | } |
200 | } | |
201 | } | |
202 | ||
203 | } | |
204 | ||
fe4da5cc | 205 | //_____________________________________________________________________________ |
206 | void AliTRDv1::CreateGeometry() | |
207 | { | |
208 | // | |
851d3db9 | 209 | // Create the GEANT geometry for the Transition Radiation Detector - Version 1 |
5c7f4665 | 210 | // This version covers the full azimuth. |
d3f347ff | 211 | // |
212 | ||
82bbf98a | 213 | // Check that FRAME is there otherwise we have no place where to put the TRD |
8230f242 | 214 | AliModule* frame = gAlice->GetModule("FRAME"); |
030b4415 | 215 | if (!frame) { |
216 | AliError("TRD needs FRAME to be present\n"); | |
217 | return; | |
218 | } | |
d3f347ff | 219 | |
82bbf98a | 220 | // Define the chambers |
221 | AliTRD::CreateGeometry(); | |
d3f347ff | 222 | |
fe4da5cc | 223 | } |
224 | ||
225 | //_____________________________________________________________________________ | |
226 | void AliTRDv1::CreateMaterials() | |
227 | { | |
228 | // | |
851d3db9 | 229 | // Create materials for the Transition Radiation Detector version 1 |
fe4da5cc | 230 | // |
82bbf98a | 231 | |
d3f347ff | 232 | AliTRD::CreateMaterials(); |
82bbf98a | 233 | |
fe4da5cc | 234 | } |
235 | ||
793ff80c | 236 | //_____________________________________________________________________________ |
237 | void AliTRDv1::CreateTRhit(Int_t det) | |
238 | { | |
239 | // | |
240 | // Creates an electron cluster from a TR photon. | |
241 | // The photon is assumed to be created a the end of the radiator. The | |
242 | // distance after which it deposits its energy takes into account the | |
243 | // absorbtion of the entrance window and of the gas mixture in drift | |
244 | // volume. | |
245 | // | |
246 | ||
793ff80c | 247 | // Ionization energy |
bc327ce2 | 248 | const Float_t kWion = 23.53; |
793ff80c | 249 | |
250 | // Maximum number of TR photons per track | |
251 | const Int_t kNTR = 50; | |
252 | ||
030b4415 | 253 | TLorentzVector mom; |
254 | TLorentzVector pos; | |
793ff80c | 255 | |
ce0d6231 | 256 | Float_t eTR[kNTR]; |
257 | Int_t nTR; | |
793ff80c | 258 | |
ce0d6231 | 259 | // Create TR photons |
260 | gMC->TrackMomentum(mom); | |
261 | Float_t pTot = mom.Rho(); | |
262 | fTR->CreatePhotons(11,pTot,nTR,eTR); | |
263 | if (nTR > kNTR) { | |
264 | AliFatal(Form("Boundary error: nTR = %d, kNTR = %d",nTR,kNTR)); | |
265 | } | |
f73816f5 | 266 | |
ce0d6231 | 267 | // Loop through the TR photons |
268 | for (Int_t iTR = 0; iTR < nTR; iTR++) { | |
793ff80c | 269 | |
ce0d6231 | 270 | Float_t energyMeV = eTR[iTR] * 0.001; |
271 | Float_t energyeV = eTR[iTR] * 1000.0; | |
272 | Float_t absLength = 0.0; | |
273 | Float_t sigma = 0.0; | |
793ff80c | 274 | |
ce0d6231 | 275 | // Take the absorbtion in the entrance window into account |
276 | Double_t muMy = fTR->GetMuMy(energyMeV); | |
277 | sigma = muMy * fFoilDensity; | |
278 | if (sigma > 0.0) { | |
279 | absLength = gRandom->Exp(1.0/sigma); | |
280 | if (absLength < AliTRDgeometry::MyThick()) { | |
842287f2 | 281 | continue; |
282 | } | |
ce0d6231 | 283 | } |
284 | else { | |
285 | continue; | |
286 | } | |
793ff80c | 287 | |
ce0d6231 | 288 | // The absorbtion cross sections in the drift gas |
289 | // Gas-mixture (Xe/CO2) | |
290 | Double_t muXe = fTR->GetMuXe(energyMeV); | |
291 | Double_t muCO = fTR->GetMuCO(energyMeV); | |
292 | sigma = (0.85 * muXe + 0.15 * muCO) * fGasDensity * fTR->GetTemp(); | |
293 | ||
294 | // The distance after which the energy of the TR photon | |
295 | // is deposited. | |
296 | if (sigma > 0.0) { | |
297 | absLength = gRandom->Exp(1.0/sigma); | |
298 | if (absLength > (AliTRDgeometry::DrThick() | |
299 | + AliTRDgeometry::AmThick())) { | |
842287f2 | 300 | continue; |
301 | } | |
ce0d6231 | 302 | } |
303 | else { | |
304 | continue; | |
305 | } | |
793ff80c | 306 | |
ce0d6231 | 307 | // The position of the absorbtion |
308 | Float_t posHit[3]; | |
309 | gMC->TrackPosition(pos); | |
310 | posHit[0] = pos[0] + mom[0] / pTot * absLength; | |
311 | posHit[1] = pos[1] + mom[1] / pTot * absLength; | |
312 | posHit[2] = pos[2] + mom[2] / pTot * absLength; | |
793ff80c | 313 | |
ce0d6231 | 314 | // Create the charge |
315 | Int_t q = ((Int_t) (energyeV / kWion)); | |
793ff80c | 316 | |
ce0d6231 | 317 | // Add the hit to the array. TR photon hits are marked |
318 | // by negative charge | |
319 | AddHit(gAlice->GetMCApp()->GetCurrentTrackNumber() | |
320 | ,det | |
321 | ,posHit | |
322 | ,-q | |
25ca55ce | 323 | ,gMC->TrackTime()*1.0e06 |
d4c6453d | 324 | ,kTRUE); |
793ff80c | 325 | |
326 | } | |
327 | ||
328 | } | |
329 | ||
5c7f4665 | 330 | //_____________________________________________________________________________ |
331 | void AliTRDv1::Init() | |
332 | { | |
333 | // | |
334 | // Initialise Transition Radiation Detector after geometry has been built. | |
5c7f4665 | 335 | // |
336 | ||
337 | AliTRD::Init(); | |
338 | ||
45160b1f | 339 | AliDebug(1,"Slow simulator\n"); |
bd0f8685 | 340 | |
341 | // Switch on TR simulation as default | |
342 | if (!fTRon) { | |
45160b1f | 343 | AliInfo("TR simulation off"); |
bd0f8685 | 344 | } |
345 | else { | |
cb2f9e9b | 346 | fTR = new AliTRDsimTR(); |
bd0f8685 | 347 | } |
5c7f4665 | 348 | |
349 | // First ionization potential (eV) for the gas mixture (90% Xe + 10% CO2) | |
350 | const Float_t kPoti = 12.1; | |
351 | // Maximum energy (50 keV); | |
352 | const Float_t kEend = 50000.0; | |
353 | // Ermilova distribution for the delta-ray spectrum | |
030b4415 | 354 | Float_t poti = TMath::Log(kPoti); |
355 | Float_t eEnd = TMath::Log(kEend); | |
a328fff9 | 356 | |
357 | // Ermilova distribution for the delta-ray spectrum | |
c4214bc0 | 358 | fDeltaE = new TF1("deltae" ,Ermilova ,poti,eEnd,0); |
a328fff9 | 359 | |
360 | // Geant3 distribution for the delta-ray spectrum | |
c4214bc0 | 361 | fDeltaG = new TF1("deltag",IntSpecGeant,2.421257,28.536469,0); |
5c7f4665 | 362 | |
45160b1f | 363 | AliDebug(1,"+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++"); |
5c7f4665 | 364 | |
fe4da5cc | 365 | } |
366 | ||
5c7f4665 | 367 | //_____________________________________________________________________________ |
368 | void AliTRDv1::StepManager() | |
a328fff9 | 369 | { |
370 | // | |
c4214bc0 | 371 | // Slow simulator. Every charged track produces electron cluster as hits |
a328fff9 | 372 | // along its path across the drift volume. |
373 | // | |
374 | ||
375 | switch (fTypeOfStepManager) { | |
a6dd11e9 | 376 | case 0: |
377 | StepManagerErmilova(); | |
378 | break; | |
379 | case 1: | |
380 | StepManagerGeant(); | |
381 | break; | |
382 | case 2: | |
383 | StepManagerFixedStep(); | |
384 | break; | |
385 | default: | |
386 | AliWarning("Not a valid Step Manager."); | |
a328fff9 | 387 | } |
388 | ||
389 | } | |
390 | ||
391 | //_____________________________________________________________________________ | |
392 | void AliTRDv1::SelectStepManager(Int_t t) | |
393 | { | |
394 | // | |
395 | // Selects a step manager type: | |
396 | // 0 - Ermilova | |
397 | // 1 - Geant3 | |
398 | // 2 - Fixed step size | |
399 | // | |
400 | ||
a328fff9 | 401 | fTypeOfStepManager = t; |
45160b1f | 402 | AliInfo(Form("Step Manager type %d was selected",fTypeOfStepManager)); |
a328fff9 | 403 | |
404 | } | |
405 | ||
406 | //_____________________________________________________________________________ | |
407 | void AliTRDv1::StepManagerGeant() | |
408 | { | |
409 | // | |
c4214bc0 | 410 | // Slow simulator. Every charged track produces electron cluster as hits |
a328fff9 | 411 | // along its path across the drift volume. The step size is set acording |
412 | // to Bethe-Bloch. The energy distribution of the delta electrons follows | |
413 | // a spectrum taken from Geant3. | |
414 | // | |
f2e3a0b5 | 415 | // Version by A. Bercuci |
416 | // | |
417 | ||
c4214bc0 | 418 | Int_t pla = 0; |
419 | Int_t cha = 0; | |
420 | Int_t sec = 0; | |
421 | Int_t det = 0; | |
422 | Int_t iPdg; | |
423 | Int_t qTot; | |
424 | ||
425 | Float_t hits[3]; | |
426 | Float_t charge; | |
427 | Float_t aMass; | |
428 | ||
030b4415 | 429 | Double_t pTot = 0; |
c4214bc0 | 430 | Double_t eDelta; |
030b4415 | 431 | Double_t betaGamma; |
432 | Double_t pp; | |
f2e3a0b5 | 433 | Double_t stepSize = 0; |
c4214bc0 | 434 | |
435 | Bool_t drRegion = kFALSE; | |
436 | Bool_t amRegion = kFALSE; | |
437 | ||
2c8bf4aa | 438 | TString cIdPath; |
439 | Char_t cIdSector[3]; | |
440 | cIdSector[2] = 0; | |
441 | ||
c4214bc0 | 442 | TString cIdCurrent; |
443 | TString cIdSensDr = "J"; | |
444 | TString cIdSensAm = "K"; | |
445 | Char_t cIdChamber[3]; | |
446 | cIdChamber[2] = 0; | |
447 | ||
030b4415 | 448 | TLorentzVector pos; |
449 | TLorentzVector mom; | |
c4214bc0 | 450 | |
030b4415 | 451 | TArrayI processes; |
f2e3a0b5 | 452 | |
c4214bc0 | 453 | const Int_t kNplan = AliTRDgeometry::Nplan(); |
454 | const Int_t kNcham = AliTRDgeometry::Ncham(); | |
455 | const Int_t kNdetsec = kNplan * kNcham; | |
456 | ||
030b4415 | 457 | const Double_t kBig = 1.0e+12; // Infinitely big |
bc327ce2 | 458 | const Float_t kWion = 23.53; // Ionization energy |
c4214bc0 | 459 | const Float_t kPTotMaxEl = 0.002; // Maximum momentum for e+ e- g |
460 | ||
461 | // Minimum energy for the step size adjustment | |
462 | const Float_t kEkinMinStep = 1.0e-5; | |
463 | // energy threshold for production of delta electrons | |
f2e3a0b5 | 464 | const Float_t kECut = 1.0e4; |
465 | // Parameters entering the parametrized range for delta electrons | |
030b4415 | 466 | const Float_t kRa = 5.37e-4; |
f2e3a0b5 | 467 | const Float_t kRb = 0.9815; |
030b4415 | 468 | const Float_t kRc = 3.123e-3; |
f2e3a0b5 | 469 | // Gas density -> To be made user adjustable ! |
030b4415 | 470 | // [0.85*0.00549+0.15*0.00186 (Xe-CO2 85-15)] |
471 | const Float_t kRho = 0.004945 ; | |
a328fff9 | 472 | |
c4214bc0 | 473 | // Plateau value of the energy-loss for electron in xenon |
030b4415 | 474 | // The averaged value (26/3/99) |
c4214bc0 | 475 | const Float_t kPlateau = 1.55; |
030b4415 | 476 | // dN1/dx|min for the gas mixture (90% Xe + 10% CO2) |
477 | const Float_t kPrim = 19.34; | |
c4214bc0 | 478 | // First ionization potential (eV) for the gas mixture (90% Xe + 10% CO2) |
479 | const Float_t kPoti = 12.1; | |
030b4415 | 480 | // PDG code electron |
481 | const Int_t kPdgElectron = 11; | |
c4214bc0 | 482 | |
483 | // Set the maximum step size to a very large number for all | |
484 | // neutral particles and those outside the driftvolume | |
485 | gMC->SetMaxStep(kBig); | |
486 | ||
487 | // Use only charged tracks | |
488 | if (( gMC->TrackCharge() ) && | |
c4214bc0 | 489 | (!gMC->IsTrackDisappeared())) { |
490 | ||
491 | // Inside a sensitive volume? | |
492 | drRegion = kFALSE; | |
493 | amRegion = kFALSE; | |
494 | cIdCurrent = gMC->CurrentVolName(); | |
495 | if (cIdSensDr == cIdCurrent[1]) { | |
496 | drRegion = kTRUE; | |
497 | } | |
498 | if (cIdSensAm == cIdCurrent[1]) { | |
499 | amRegion = kTRUE; | |
500 | } | |
501 | if (drRegion || amRegion) { | |
a328fff9 | 502 | |
c4214bc0 | 503 | // The hit coordinates and charge |
504 | gMC->TrackPosition(pos); | |
505 | hits[0] = pos[0]; | |
506 | hits[1] = pos[1]; | |
507 | hits[2] = pos[2]; | |
508 | ||
2c8bf4aa | 509 | // The sector number (0 - 17), according to standard coordinate system |
510 | cIdPath = gGeoManager->GetPath(); | |
511 | cIdSector[0] = cIdPath[21]; | |
512 | cIdSector[1] = cIdPath[22]; | |
513 | sec = atoi(cIdSector); | |
c4214bc0 | 514 | |
515 | // The plane and chamber number | |
030b4415 | 516 | cIdChamber[0] = cIdCurrent[2]; |
517 | cIdChamber[1] = cIdCurrent[3]; | |
c4214bc0 | 518 | Int_t idChamber = (atoi(cIdChamber) % kNdetsec); |
8a497c18 | 519 | cha = ((Int_t) idChamber / kNplan); |
c4214bc0 | 520 | pla = ((Int_t) idChamber % kNplan); |
521 | ||
ce0d6231 | 522 | // The detector number |
523 | det = fGeometry->GetDetector(pla,cha,sec); | |
c4214bc0 | 524 | |
ce0d6231 | 525 | // Special hits only in the drift region |
526 | if ((drRegion) && | |
527 | (gMC->IsTrackEntering())) { | |
c4214bc0 | 528 | |
ce0d6231 | 529 | // Create a track reference at the entrance of each |
530 | // chamber that contains the momentum components of the particle | |
531 | gMC->TrackMomentum(mom); | |
532 | AddTrackReference(gAlice->GetMCApp()->GetCurrentTrackNumber()); | |
c4214bc0 | 533 | |
ce0d6231 | 534 | // Create the hits from TR photons if electron/positron is |
535 | // entering the drift volume | |
536 | if ((fTR) && | |
537 | (TMath::Abs(gMC->TrackPid()) == kPdgElectron)) { | |
538 | CreateTRhit(det); | |
539 | } | |
f2e3a0b5 | 540 | |
ce0d6231 | 541 | } |
542 | else if ((amRegion) && | |
543 | (gMC->IsTrackExiting())) { | |
f2e3a0b5 | 544 | |
ce0d6231 | 545 | // Create a track reference at the exit of each |
546 | // chamber that contains the momentum components of the particle | |
547 | gMC->TrackMomentum(mom); | |
548 | AddTrackReference(gAlice->GetMCApp()->GetCurrentTrackNumber()); | |
c4214bc0 | 549 | |
ce0d6231 | 550 | } |
c4214bc0 | 551 | |
ce0d6231 | 552 | // Calculate the energy of the delta-electrons |
553 | // modified by Alex Bercuci (A.Bercuci@gsi.de) on 26.01.06 | |
554 | // take into account correlation with the underlying GEANT tracking | |
555 | // mechanism. see | |
556 | // http://www-linux.gsi.de/~abercuci/Contributions/TRD/index.html | |
557 | // | |
558 | // determine the most significant process (last on the processes list) | |
559 | // which caused this hit | |
560 | gMC->StepProcesses(processes); | |
561 | Int_t nofprocesses = processes.GetSize(); | |
562 | Int_t pid; | |
563 | if (!nofprocesses) { | |
564 | pid = 0; | |
565 | } | |
566 | else { | |
567 | pid = processes[nofprocesses-1]; | |
568 | } | |
f2e3a0b5 | 569 | |
ce0d6231 | 570 | // Generate Edep according to GEANT parametrisation |
571 | eDelta = TMath::Exp(fDeltaG->GetRandom()) - kPoti; | |
572 | eDelta = TMath::Max(eDelta,0.0); | |
573 | Float_t prRange = 0.0; | |
574 | Float_t range = gMC->TrackLength() - fTrackLength0; | |
575 | // merge GEANT tracker information with locally cooked one | |
576 | if (gAlice->GetMCApp()->GetCurrentTrackNumber() == fPrimaryTrackPid) { | |
577 | if (pid == 27) { | |
578 | if (eDelta >= kECut) { | |
579 | prRange = kRa * eDelta * 0.001 | |
580 | * (1.0 - kRb / (1.0 + kRc * eDelta * 0.001)) / kRho; | |
581 | if (prRange >= (3.7 - range)) { | |
582 | eDelta *= 0.1; | |
583 | } | |
584 | } | |
585 | } | |
586 | else if (pid == 1) { | |
587 | if (eDelta < kECut) { | |
588 | eDelta *= 0.5; | |
589 | } | |
590 | else { | |
591 | prRange = kRa * eDelta * 0.001 | |
592 | * (1.0 - kRb / (1.0 + kRc * eDelta * 0.001)) / kRho; | |
593 | if (prRange >= ((AliTRDgeometry::DrThick() | |
594 | + AliTRDgeometry::AmThick()) - range)) { | |
595 | eDelta *= 0.05; | |
596 | } | |
597 | else { | |
f2e3a0b5 | 598 | eDelta *= 0.5; |
ce0d6231 | 599 | } |
600 | } | |
601 | } | |
f2e3a0b5 | 602 | else { |
603 | eDelta = 0.0; | |
ce0d6231 | 604 | } |
605 | } | |
606 | else { | |
607 | eDelta = 0.0; | |
608 | } | |
c4214bc0 | 609 | |
ce0d6231 | 610 | // Generate the electron cluster size |
611 | if (eDelta > 0.0) { | |
f2e3a0b5 | 612 | |
ce0d6231 | 613 | qTot = ((Int_t) (eDelta / kWion) + 1); |
614 | ||
615 | // Create a new dEdx hit | |
030b4415 | 616 | AddHit(gAlice->GetMCApp()->GetCurrentTrackNumber() |
617 | ,det | |
618 | ,hits | |
619 | ,qTot | |
25ca55ce | 620 | ,gMC->TrackTime()*1.0e06 |
030b4415 | 621 | ,drRegion); |
c4214bc0 | 622 | |
ce0d6231 | 623 | } |
624 | ||
625 | // Calculate the maximum step size for the next tracking step | |
626 | // Produce only one hit if Ekin is below cutoff | |
627 | aMass = gMC->TrackMass(); | |
628 | if ((gMC->Etot() - aMass) > kEkinMinStep) { | |
629 | ||
630 | // The energy loss according to Bethe Bloch | |
631 | iPdg = TMath::Abs(gMC->TrackPid()); | |
632 | if ((iPdg != kPdgElectron) || | |
633 | ((iPdg == kPdgElectron) && | |
634 | (pTot < kPTotMaxEl))) { | |
635 | gMC->TrackMomentum(mom); | |
636 | pTot = mom.Rho(); | |
637 | betaGamma = pTot / aMass; | |
638 | pp = BetheBlochGeant(betaGamma); | |
639 | // Take charge > 1 into account | |
640 | charge = gMC->TrackCharge(); | |
641 | if (TMath::Abs(charge) > 1) { | |
642 | pp = pp * charge*charge; | |
643 | } | |
644 | } | |
645 | else { | |
646 | // Electrons above 20 Mev/c are at the plateau | |
647 | pp = kPrim * kPlateau; | |
648 | } | |
f2e3a0b5 | 649 | |
ce0d6231 | 650 | Int_t nsteps = 0; |
651 | do { | |
652 | nsteps = gRandom->Poisson(pp); | |
653 | } while(!nsteps); | |
654 | stepSize = 1.0 / nsteps; | |
655 | gMC->SetMaxStep(stepSize); | |
f2e3a0b5 | 656 | |
c4214bc0 | 657 | } |
f2e3a0b5 | 658 | |
c4214bc0 | 659 | } |
f2e3a0b5 | 660 | |
c4214bc0 | 661 | } |
f2e3a0b5 | 662 | |
a328fff9 | 663 | } |
664 | ||
665 | //_____________________________________________________________________________ | |
666 | void AliTRDv1::StepManagerErmilova() | |
5c7f4665 | 667 | { |
668 | // | |
5c7f4665 | 669 | // Slow simulator. Every charged track produces electron cluster as hits |
670 | // along its path across the drift volume. The step size is set acording | |
671 | // to Bethe-Bloch. The energy distribution of the delta electrons follows | |
672 | // a spectrum taken from Ermilova et al. | |
673 | // | |
674 | ||
851d3db9 | 675 | Int_t pla = 0; |
676 | Int_t cha = 0; | |
677 | Int_t sec = 0; | |
793ff80c | 678 | Int_t det = 0; |
851d3db9 | 679 | Int_t iPdg; |
793ff80c | 680 | Int_t qTot; |
5c7f4665 | 681 | |
793ff80c | 682 | Float_t hits[3]; |
a5cadd36 | 683 | Double_t random[1]; |
5c7f4665 | 684 | Float_t charge; |
685 | Float_t aMass; | |
686 | ||
030b4415 | 687 | Double_t pTot = 0.0; |
5c7f4665 | 688 | Double_t eDelta; |
030b4415 | 689 | Double_t betaGamma; |
690 | Double_t pp; | |
f73816f5 | 691 | Double_t stepSize; |
5c7f4665 | 692 | |
332e9569 | 693 | Bool_t drRegion = kFALSE; |
694 | Bool_t amRegion = kFALSE; | |
695 | ||
2c8bf4aa | 696 | TString cIdPath; |
697 | Char_t cIdSector[3]; | |
698 | cIdSector[2] = 0; | |
699 | ||
332e9569 | 700 | TString cIdCurrent; |
701 | TString cIdSensDr = "J"; | |
702 | TString cIdSensAm = "K"; | |
593a9fc3 | 703 | Char_t cIdChamber[3]; |
704 | cIdChamber[2] = 0; | |
332e9569 | 705 | |
030b4415 | 706 | TLorentzVector pos; |
707 | TLorentzVector mom; | |
82bbf98a | 708 | |
332e9569 | 709 | const Int_t kNplan = AliTRDgeometry::Nplan(); |
e644678a | 710 | const Int_t kNcham = AliTRDgeometry::Ncham(); |
711 | const Int_t kNdetsec = kNplan * kNcham; | |
712 | ||
030b4415 | 713 | const Double_t kBig = 1.0e+12; // Infinitely big |
bc327ce2 | 714 | const Float_t kWion = 23.53; // Ionization energy |
a328fff9 | 715 | const Float_t kPTotMaxEl = 0.002; // Maximum momentum for e+ e- g |
5c7f4665 | 716 | |
f73816f5 | 717 | // Minimum energy for the step size adjustment |
718 | const Float_t kEkinMinStep = 1.0e-5; | |
a328fff9 | 719 | |
5c7f4665 | 720 | // Plateau value of the energy-loss for electron in xenon |
030b4415 | 721 | // The averaged value (26/3/99) |
a3c76cdc | 722 | const Float_t kPlateau = 1.55; |
030b4415 | 723 | // dN1/dx|min for the gas mixture (90% Xe + 10% CO2) |
724 | const Float_t kPrim = 48.0; | |
5c7f4665 | 725 | // First ionization potential (eV) for the gas mixture (90% Xe + 10% CO2) |
a3c76cdc | 726 | const Float_t kPoti = 12.1; |
030b4415 | 727 | // PDG code electron |
728 | const Int_t kPdgElectron = 11; | |
5c7f4665 | 729 | |
730 | // Set the maximum step size to a very large number for all | |
731 | // neutral particles and those outside the driftvolume | |
732 | gMC->SetMaxStep(kBig); | |
733 | ||
734 | // Use only charged tracks | |
735 | if (( gMC->TrackCharge() ) && | |
5c7f4665 | 736 | (!gMC->IsTrackDisappeared())) { |
fe4da5cc | 737 | |
5c7f4665 | 738 | // Inside a sensitive volume? |
332e9569 | 739 | drRegion = kFALSE; |
740 | amRegion = kFALSE; | |
741 | cIdCurrent = gMC->CurrentVolName(); | |
e6674585 | 742 | if (cIdSensDr == cIdCurrent[1]) { |
332e9569 | 743 | drRegion = kTRUE; |
744 | } | |
e6674585 | 745 | if (cIdSensAm == cIdCurrent[1]) { |
332e9569 | 746 | amRegion = kTRUE; |
747 | } | |
748 | if (drRegion || amRegion) { | |
fe4da5cc | 749 | |
5c7f4665 | 750 | // The hit coordinates and charge |
751 | gMC->TrackPosition(pos); | |
752 | hits[0] = pos[0]; | |
753 | hits[1] = pos[1]; | |
754 | hits[2] = pos[2]; | |
5c7f4665 | 755 | |
2c8bf4aa | 756 | // The sector number (0 - 17), according to standard coordinate system |
757 | cIdPath = gGeoManager->GetPath(); | |
758 | cIdSector[0] = cIdPath[21]; | |
759 | cIdSector[1] = cIdPath[22]; | |
760 | sec = atoi(cIdSector); | |
82bbf98a | 761 | |
332e9569 | 762 | // The plane and chamber number |
763 | cIdChamber[0] = cIdCurrent[2]; | |
764 | cIdChamber[1] = cIdCurrent[3]; | |
e644678a | 765 | Int_t idChamber = (atoi(cIdChamber) % kNdetsec); |
8a497c18 | 766 | cha = ((Int_t) idChamber / kNplan); |
332e9569 | 767 | pla = ((Int_t) idChamber % kNplan); |
82bbf98a | 768 | |
ce0d6231 | 769 | // The detector number |
770 | det = fGeometry->GetDetector(pla,cha,sec); | |
5c7f4665 | 771 | |
ce0d6231 | 772 | // Special hits only in the drift region |
773 | if ((drRegion) && | |
774 | (gMC->IsTrackEntering())) { | |
5c7f4665 | 775 | |
ce0d6231 | 776 | // Create a track reference at the entrance of each |
777 | // chamber that contains the momentum components of the particle | |
778 | gMC->TrackMomentum(mom); | |
779 | AddTrackReference(gAlice->GetMCApp()->GetCurrentTrackNumber()); | |
793ff80c | 780 | |
ce0d6231 | 781 | // Create the hits from TR photons if electron/positron is |
782 | // entering the drift volume | |
783 | if ((fTR) && | |
784 | (TMath::Abs(gMC->TrackPid()) == kPdgElectron)) { | |
785 | CreateTRhit(det); | |
786 | } | |
f73816f5 | 787 | |
ce0d6231 | 788 | } |
789 | else if ((amRegion) && | |
790 | (gMC->IsTrackExiting())) { | |
f73816f5 | 791 | |
ce0d6231 | 792 | // Create a track reference at the exit of each |
793 | // chamber that contains the momentum components of the particle | |
794 | gMC->TrackMomentum(mom); | |
795 | AddTrackReference(gAlice->GetMCApp()->GetCurrentTrackNumber()); | |
f73816f5 | 796 | |
ce0d6231 | 797 | } |
798 | ||
799 | // Calculate the energy of the delta-electrons | |
800 | eDelta = TMath::Exp(fDeltaE->GetRandom()) - kPoti; | |
801 | eDelta = TMath::Max(eDelta,0.0); | |
802 | ||
803 | // Generate the electron cluster size | |
804 | if (eDelta > 0.0) { | |
805 | ||
806 | qTot = ((Int_t) (eDelta / kWion) + 1); | |
f73816f5 | 807 | |
030b4415 | 808 | // Create a new dEdx hit |
332e9569 | 809 | if (drRegion) { |
a328fff9 | 810 | AddHit(gAlice->GetMCApp()->GetCurrentTrackNumber() |
030b4415 | 811 | ,det |
812 | ,hits | |
813 | ,qTot | |
25ca55ce | 814 | ,gMC->TrackTime()*1.0e06 |
030b4415 | 815 | ,kTRUE); |
816 | } | |
5c7f4665 | 817 | else { |
a328fff9 | 818 | AddHit(gAlice->GetMCApp()->GetCurrentTrackNumber() |
030b4415 | 819 | ,det |
820 | ,hits | |
821 | ,qTot | |
25ca55ce | 822 | ,gMC->TrackTime()*1.0e06 |
030b4415 | 823 | ,kFALSE); |
824 | } | |
f73816f5 | 825 | |
ce0d6231 | 826 | } |
827 | ||
828 | // Calculate the maximum step size for the next tracking step | |
829 | // Produce only one hit if Ekin is below cutoff | |
830 | aMass = gMC->TrackMass(); | |
831 | if ((gMC->Etot() - aMass) > kEkinMinStep) { | |
832 | ||
833 | // The energy loss according to Bethe Bloch | |
834 | iPdg = TMath::Abs(gMC->TrackPid()); | |
835 | if ((iPdg != kPdgElectron) || | |
836 | ((iPdg == kPdgElectron) && | |
837 | (pTot < kPTotMaxEl))) { | |
838 | gMC->TrackMomentum(mom); | |
839 | pTot = mom.Rho(); | |
840 | betaGamma = pTot / aMass; | |
841 | pp = kPrim * BetheBloch(betaGamma); | |
842 | // Take charge > 1 into account | |
843 | charge = gMC->TrackCharge(); | |
844 | if (TMath::Abs(charge) > 1) { | |
845 | pp = pp * charge*charge; | |
f73816f5 | 846 | } |
ce0d6231 | 847 | } |
848 | else { | |
849 | // Electrons above 20 Mev/c are at the plateau | |
850 | pp = kPrim * kPlateau; | |
851 | } | |
f73816f5 | 852 | |
ce0d6231 | 853 | if (pp > 0.0) { |
854 | do { | |
855 | gMC->GetRandom()->RndmArray(1,random); | |
030b4415 | 856 | } |
ce0d6231 | 857 | while ((random[0] == 1.0) || |
858 | (random[0] == 0.0)); | |
859 | stepSize = - TMath::Log(random[0]) / pp; | |
860 | gMC->SetMaxStep(stepSize); | |
861 | } | |
030b4415 | 862 | |
5c7f4665 | 863 | } |
030b4415 | 864 | |
d3f347ff | 865 | } |
030b4415 | 866 | |
5c7f4665 | 867 | } |
030b4415 | 868 | |
5c7f4665 | 869 | } |
870 | ||
a328fff9 | 871 | //_____________________________________________________________________________ |
872 | void AliTRDv1::StepManagerFixedStep() | |
873 | { | |
874 | // | |
875 | // Slow simulator. Every charged track produces electron cluster as hits | |
876 | // along its path across the drift volume. The step size is fixed in | |
877 | // this version of the step manager. | |
878 | // | |
879 | ||
ce0d6231 | 880 | // PDG code electron |
881 | const Int_t kPdgElectron = 11; | |
882 | ||
a328fff9 | 883 | Int_t pla = 0; |
884 | Int_t cha = 0; | |
885 | Int_t sec = 0; | |
886 | Int_t det = 0; | |
887 | Int_t qTot; | |
888 | ||
889 | Float_t hits[3]; | |
890 | Double_t eDep; | |
891 | ||
892 | Bool_t drRegion = kFALSE; | |
893 | Bool_t amRegion = kFALSE; | |
894 | ||
2c8bf4aa | 895 | TString cIdPath; |
896 | Char_t cIdSector[3]; | |
897 | cIdSector[2] = 0; | |
898 | ||
a328fff9 | 899 | TString cIdCurrent; |
900 | TString cIdSensDr = "J"; | |
901 | TString cIdSensAm = "K"; | |
902 | Char_t cIdChamber[3]; | |
2c8bf4aa | 903 | cIdChamber[2] = 0; |
a328fff9 | 904 | |
030b4415 | 905 | TLorentzVector pos; |
906 | TLorentzVector mom; | |
a328fff9 | 907 | |
908 | const Int_t kNplan = AliTRDgeometry::Nplan(); | |
909 | const Int_t kNcham = AliTRDgeometry::Ncham(); | |
910 | const Int_t kNdetsec = kNplan * kNcham; | |
911 | ||
030b4415 | 912 | const Double_t kBig = 1.0e+12; |
a328fff9 | 913 | |
bc327ce2 | 914 | const Float_t kWion = 23.53; // Ionization energy |
a328fff9 | 915 | const Float_t kEkinMinStep = 1.0e-5; // Minimum energy for the step size adjustment |
916 | ||
917 | // Set the maximum step size to a very large number for all | |
918 | // neutral particles and those outside the driftvolume | |
919 | gMC->SetMaxStep(kBig); | |
920 | ||
921 | // If not charged track or already stopped or disappeared, just return. | |
922 | if ((!gMC->TrackCharge()) || | |
ce0d6231 | 923 | gMC->IsTrackDisappeared()) { |
924 | return; | |
925 | } | |
a328fff9 | 926 | |
927 | // Inside a sensitive volume? | |
928 | cIdCurrent = gMC->CurrentVolName(); | |
929 | ||
ce0d6231 | 930 | if (cIdSensDr == cIdCurrent[1]) { |
931 | drRegion = kTRUE; | |
932 | } | |
933 | if (cIdSensAm == cIdCurrent[1]) { | |
934 | amRegion = kTRUE; | |
935 | } | |
a328fff9 | 936 | |
030b4415 | 937 | if ((!drRegion) && |
938 | (!amRegion)) { | |
939 | return; | |
940 | } | |
a328fff9 | 941 | |
942 | // The hit coordinates and charge | |
943 | gMC->TrackPosition(pos); | |
944 | hits[0] = pos[0]; | |
945 | hits[1] = pos[1]; | |
946 | hits[2] = pos[2]; | |
947 | ||
2c8bf4aa | 948 | // The sector number (0 - 17), according to standard coordinate system |
949 | cIdPath = gGeoManager->GetPath(); | |
950 | cIdSector[0] = cIdPath[21]; | |
951 | cIdSector[1] = cIdPath[22]; | |
952 | sec = atoi(cIdSector); | |
a328fff9 | 953 | |
954 | // The plane and chamber number | |
030b4415 | 955 | cIdChamber[0] = cIdCurrent[2]; |
956 | cIdChamber[1] = cIdCurrent[3]; | |
a328fff9 | 957 | Int_t idChamber = (atoi(cIdChamber) % kNdetsec); |
8a497c18 | 958 | cha = ((Int_t) idChamber / kNplan); |
a328fff9 | 959 | pla = ((Int_t) idChamber % kNplan); |
e0d47c25 | 960 | |
030b4415 | 961 | // The detector number |
962 | det = fGeometry->GetDetector(pla,cha,sec); | |
963 | ||
25ca55ce | 964 | // 0: InFlight 1:Entering 2:Exiting |
030b4415 | 965 | Int_t trkStat = 0; |
a328fff9 | 966 | |
967 | // Special hits only in the drift region | |
ce0d6231 | 968 | if ((drRegion) && |
969 | (gMC->IsTrackEntering())) { | |
a328fff9 | 970 | |
ce0d6231 | 971 | // Create a track reference at the entrance of each |
972 | // chamber that contains the momentum components of the particle | |
973 | gMC->TrackMomentum(mom); | |
974 | AddTrackReference(gAlice->GetMCApp()->GetCurrentTrackNumber()); | |
975 | trkStat = 1; | |
a328fff9 | 976 | |
ce0d6231 | 977 | // Create the hits from TR photons if electron/positron is |
978 | // entering the drift volume | |
979 | if ((fTR) && | |
980 | (TMath::Abs(gMC->TrackPid()) == kPdgElectron)) { | |
030b4415 | 981 | CreateTRhit(det); |
982 | } | |
a328fff9 | 983 | |
ce0d6231 | 984 | } |
985 | else if ((amRegion) && | |
986 | (gMC->IsTrackExiting())) { | |
987 | ||
988 | // Create a track reference at the exit of each | |
989 | // chamber that contains the momentum components of the particle | |
990 | gMC->TrackMomentum(mom); | |
991 | AddTrackReference(gAlice->GetMCApp()->GetCurrentTrackNumber()); | |
992 | trkStat = 2; | |
993 | ||
a328fff9 | 994 | } |
995 | ||
996 | // Calculate the charge according to GEANT Edep | |
997 | // Create a new dEdx hit | |
998 | eDep = TMath::Max(gMC->Edep(),0.0) * 1.0e+09; | |
999 | qTot = (Int_t) (eDep / kWion); | |
ce0d6231 | 1000 | if ((qTot) || |
1001 | (trkStat)) { | |
1002 | AddHit(gAlice->GetMCApp()->GetCurrentTrackNumber() | |
1003 | ,det | |
1004 | ,hits | |
1005 | ,qTot | |
25ca55ce | 1006 | ,gMC->TrackTime()*1.0e06 |
ce0d6231 | 1007 | ,drRegion); |
1008 | } | |
a328fff9 | 1009 | |
1010 | // Set Maximum Step Size | |
1011 | // Produce only one hit if Ekin is below cutoff | |
030b4415 | 1012 | if ((gMC->Etot() - gMC->TrackMass()) < kEkinMinStep) { |
1013 | return; | |
1014 | } | |
a328fff9 | 1015 | gMC->SetMaxStep(fStepSize); |
1016 | ||
1017 | } | |
1018 | ||
5c7f4665 | 1019 | //_____________________________________________________________________________ |
1020 | Double_t AliTRDv1::BetheBloch(Double_t bg) | |
1021 | { | |
1022 | // | |
1023 | // Parametrization of the Bethe-Bloch-curve | |
1024 | // The parametrization is the same as for the TPC and is taken from Lehrhaus. | |
1025 | // | |
1026 | ||
1027 | // This parameters have been adjusted to averaged values from GEANT | |
f57bb418 | 1028 | const Double_t kP1 = 7.17960e-02; |
1029 | const Double_t kP2 = 8.54196; | |
1030 | const Double_t kP3 = 1.38065e-06; | |
1031 | const Double_t kP4 = 5.30972; | |
1032 | const Double_t kP5 = 2.83798; | |
5c7f4665 | 1033 | |
f73816f5 | 1034 | // Lower cutoff of the Bethe-Bloch-curve to limit step sizes |
1035 | const Double_t kBgMin = 0.8; | |
1036 | const Double_t kBBMax = 6.83298; | |
f73816f5 | 1037 | |
1038 | if (bg > kBgMin) { | |
030b4415 | 1039 | Double_t yy = bg / TMath::Sqrt(1.0 + bg*bg); |
5c7f4665 | 1040 | Double_t aa = TMath::Power(yy,kP4); |
030b4415 | 1041 | Double_t bb = TMath::Power((1.0/bg),kP5); |
5c7f4665 | 1042 | bb = TMath::Log(kP3 + bb); |
030b4415 | 1043 | return ((kP2 - aa - bb) * kP1 / aa); |
5c7f4665 | 1044 | } |
f73816f5 | 1045 | else { |
1046 | return kBBMax; | |
1047 | } | |
d3f347ff | 1048 | |
fe4da5cc | 1049 | } |
5c7f4665 | 1050 | |
a328fff9 | 1051 | //_____________________________________________________________________________ |
c4214bc0 | 1052 | Double_t AliTRDv1::BetheBlochGeant(Double_t bg) |
a328fff9 | 1053 | { |
1054 | // | |
1055 | // Return dN/dx (number of primary collisions per centimeter) | |
1056 | // for given beta*gamma factor. | |
1057 | // | |
1058 | // Implemented by K.Oyama according to GEANT 3 parametrization shown in | |
1059 | // A.Andronic's webpage: http://www-alice.gsi.de/trd/papers/dedx/dedx.html | |
1060 | // This must be used as a set with IntSpecGeant. | |
1061 | // | |
1062 | ||
030b4415 | 1063 | Int_t i = 0; |
a328fff9 | 1064 | |
030b4415 | 1065 | Double_t arrG[20] = { 1.100000, 1.200000, 1.300000, 1.500000 |
1066 | , 1.800000, 2.000000, 2.500000, 3.000000 | |
1067 | , 4.000000, 7.000000, 10.000000, 20.000000 | |
1068 | , 40.000000, 70.000000, 100.000000, 300.000000 | |
1069 | , 600.000000, 1000.000000, 3000.000000, 10000.000000 }; | |
a328fff9 | 1070 | |
030b4415 | 1071 | Double_t arrNC[20] = { 75.009056, 45.508083, 35.299252, 27.116327 |
1072 | , 22.734999, 21.411915, 19.934095, 19.449375 | |
1073 | , 19.344431, 20.185553, 21.027925, 22.912676 | |
1074 | , 24.933352, 26.504053, 27.387468, 29.566597 | |
1075 | , 30.353779, 30.787134, 31.129285, 31.157350 }; | |
1076 | ||
1077 | // Betagamma to gamma | |
1078 | Double_t g = TMath::Sqrt(1.0 + bg*bg); | |
a328fff9 | 1079 | |
1080 | // Find the index just before the point we need. | |
030b4415 | 1081 | for (i = 0; i < 18; i++) { |
1082 | if ((arrG[i] < g) && | |
1083 | (arrG[i+1] > g)) { | |
a328fff9 | 1084 | break; |
030b4415 | 1085 | } |
1086 | } | |
a328fff9 | 1087 | |
1088 | // Simple interpolation. | |
030b4415 | 1089 | Double_t pp = ((arrNC[i+1] - arrNC[i]) / (arrG[i+1] - arrG[i])) |
1090 | * (g - arrG[i]) + arrNC[i]; | |
a328fff9 | 1091 | |
030b4415 | 1092 | return pp; |
a328fff9 | 1093 | |
1094 | } | |
1095 | ||
5c7f4665 | 1096 | //_____________________________________________________________________________ |
1097 | Double_t Ermilova(Double_t *x, Double_t *) | |
1098 | { | |
1099 | // | |
1100 | // Calculates the delta-ray energy distribution according to Ermilova. | |
1101 | // Logarithmic scale ! | |
1102 | // | |
1103 | ||
1104 | Double_t energy; | |
1105 | Double_t dpos; | |
1106 | Double_t dnde; | |
1107 | ||
030b4415 | 1108 | Int_t pos1; |
1109 | Int_t pos2; | |
5c7f4665 | 1110 | |
8230f242 | 1111 | const Int_t kNv = 31; |
5c7f4665 | 1112 | |
030b4415 | 1113 | Float_t vxe[kNv] = { 2.3026, 2.9957, 3.4012, 3.6889, 3.9120 |
1114 | , 4.0943, 4.2485, 4.3820, 4.4998, 4.6052 | |
1115 | , 4.7005, 5.0752, 5.2983, 5.7038, 5.9915 | |
1116 | , 6.2146, 6.5221, 6.9078, 7.3132, 7.6009 | |
1117 | , 8.0064, 8.5172, 8.6995, 8.9872, 9.2103 | |
1118 | , 9.4727, 9.9035, 10.3735, 10.5966, 10.8198 | |
1119 | , 11.5129 }; | |
1120 | ||
1121 | Float_t vye[kNv] = { 80.0, 31.0, 23.3, 21.1, 21.0 | |
1122 | , 20.9, 20.8, 20.0, 16.0, 11.0 | |
1123 | , 8.0, 6.0, 5.2, 4.6, 4.0 | |
1124 | , 3.5, 3.0, 1.4, 0.67, 0.44 | |
1125 | , 0.3, 0.18, 0.12, 0.08, 0.056 | |
1126 | , 0.04, 0.023, 0.015, 0.011, 0.01 | |
1127 | , 0.004 }; | |
5c7f4665 | 1128 | |
1129 | energy = x[0]; | |
1130 | ||
1131 | // Find the position | |
030b4415 | 1132 | pos1 = 0; |
1133 | pos2 = 0; | |
5c7f4665 | 1134 | dpos = 0; |
1135 | do { | |
1136 | dpos = energy - vxe[pos2++]; | |
1137 | } | |
1138 | while (dpos > 0); | |
1139 | pos2--; | |
030b4415 | 1140 | if (pos2 > kNv) { |
1141 | pos2 = kNv - 1; | |
1142 | } | |
5c7f4665 | 1143 | pos1 = pos2 - 1; |
1144 | ||
1145 | // Differentiate between the sampling points | |
1146 | dnde = (vye[pos1] - vye[pos2]) / (vxe[pos2] - vxe[pos1]); | |
1147 | ||
1148 | return dnde; | |
1149 | ||
1150 | } | |
a328fff9 | 1151 | |
1152 | //_____________________________________________________________________________ | |
1153 | Double_t IntSpecGeant(Double_t *x, Double_t *) | |
1154 | { | |
1155 | // | |
1156 | // Integrated spectrum from Geant3 | |
1157 | // | |
1158 | ||
96efaf83 | 1159 | const Int_t npts = 83; |
030b4415 | 1160 | Double_t arre[npts] = { 2.421257, 2.483278, 2.534301, 2.592230 |
1161 | , 2.672067, 2.813299, 3.015059, 3.216819 | |
1162 | , 3.418579, 3.620338, 3.868209, 3.920198 | |
1163 | , 3.978284, 4.063923, 4.186264, 4.308605 | |
1164 | , 4.430946, 4.553288, 4.724261, 4.837736 | |
1165 | , 4.999842, 5.161949, 5.324056, 5.486163 | |
1166 | , 5.679688, 5.752998, 5.857728, 5.962457 | |
1167 | , 6.067185, 6.171914, 6.315653, 6.393674 | |
1168 | , 6.471694, 6.539689, 6.597658, 6.655627 | |
1169 | , 6.710957, 6.763648, 6.816338, 6.876198 | |
1170 | , 6.943227, 7.010257, 7.106285, 7.252151 | |
1171 | , 7.460531, 7.668911, 7.877290, 8.085670 | |
1172 | , 8.302979, 8.353585, 8.413120, 8.483500 | |
1173 | , 8.541030, 8.592857, 8.668865, 8.820485 | |
1174 | , 9.037086, 9.253686, 9.470286, 9.686887 | |
1175 | , 9.930838, 9.994655, 10.085822, 10.176990 | |
1176 | , 10.268158, 10.359325, 10.503614, 10.627565 | |
1177 | , 10.804637, 10.981709, 11.158781, 11.335854 | |
1178 | , 11.593397, 11.781165, 12.049404, 12.317644 | |
1179 | , 12.585884, 12.854123, 14.278421, 16.975889 | |
1180 | , 20.829416, 24.682943, 28.536469 }; | |
1181 | ||
1182 | Double_t arrdnde[npts] = { 10.960000, 10.960000, 10.359500, 9.811340 | |
1183 | , 9.1601500, 8.206670, 6.919630, 5.655430 | |
1184 | , 4.6221300, 3.777610, 3.019560, 2.591950 | |
1185 | , 2.5414600, 2.712920, 3.327460, 4.928240 | |
1186 | , 7.6185300, 10.966700, 12.225800, 8.094750 | |
1187 | , 3.3586900, 1.553650, 1.209600, 1.263840 | |
1188 | , 1.3241100, 1.312140, 1.255130, 1.165770 | |
1189 | , 1.0594500, 0.945450, 0.813231, 0.699837 | |
1190 | , 0.6235580, 2.260990, 2.968350, 2.240320 | |
1191 | , 1.7988300, 1.553300, 1.432070, 1.535520 | |
1192 | , 1.4429900, 1.247990, 1.050750, 0.829549 | |
1193 | , 0.5900280, 0.395897, 0.268741, 0.185320 | |
1194 | , 0.1292120, 0.103545, 0.0949525, 0.101535 | |
1195 | , 0.1276380, 0.134216, 0.123816, 0.104557 | |
1196 | , 0.0751843, 0.0521745, 0.0373546, 0.0275391 | |
1197 | , 0.0204713, 0.0169234, 0.0154552, 0.0139194 | |
1198 | , 0.0125592, 0.0113638, 0.0107354, 0.0102137 | |
1199 | , 0.00845984, 0.00683338, 0.00556836, 0.00456874 | |
1200 | , 0.0036227, 0.00285991, 0.00226664, 0.00172234 | |
1201 | , 0.00131226, 0.00100284, 0.000465492, 7.26607e-05 | |
1202 | , 3.63304e-06, 0.0000000, 0.0000000 }; | |
1203 | ||
1204 | Int_t i; | |
a328fff9 | 1205 | Double_t energy = x[0]; |
a328fff9 | 1206 | |
030b4415 | 1207 | for (i = 0; i < npts; i++) { |
1208 | if (energy < arre[i]) { | |
1209 | break; | |
1210 | } | |
1211 | } | |
a328fff9 | 1212 | |
030b4415 | 1213 | if (i == 0) { |
1214 | AliErrorGeneral("AliTRDv1::IntSpecGeant","Given energy value is too small or zero"); | |
1215 | } | |
a328fff9 | 1216 | |
f57bb418 | 1217 | return arrdnde[i]; |
a328fff9 | 1218 | |
1219 | } |