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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> |
fe4da5cc | 33 | |
d3f347ff | 34 | #include "AliConst.h" |
45160b1f | 35 | #include "AliLog.h" |
36 | #include "AliMC.h" | |
88cb7938 | 37 | #include "AliRun.h" |
030b4415 | 38 | |
88cb7938 | 39 | #include "AliTRDgeometry.h" |
793ff80c | 40 | #include "AliTRDhit.h" |
793ff80c | 41 | #include "AliTRDsim.h" |
88cb7938 | 42 | #include "AliTRDv1.h" |
851d3db9 | 43 | |
fe4da5cc | 44 | ClassImp(AliTRDv1) |
8230f242 | 45 | |
46 | //_____________________________________________________________________________ | |
030b4415 | 47 | AliTRDv1::AliTRDv1() |
48 | :AliTRD() | |
49 | ,fTRon(kFALSE) | |
50 | ,fTR(NULL) | |
51 | ,fTypeOfStepManager(0) | |
52 | ,fStepSize(0) | |
53 | ,fDeltaE(NULL) | |
54 | ,fDeltaG(NULL) | |
55 | ,fTrackLength0(0) | |
56 | ,fPrimaryTrackPid(0) | |
8230f242 | 57 | { |
58 | // | |
59 | // Default constructor | |
60 | // | |
61 | ||
8230f242 | 62 | } |
63 | ||
fe4da5cc | 64 | //_____________________________________________________________________________ |
65 | AliTRDv1::AliTRDv1(const char *name, const char *title) | |
030b4415 | 66 | :AliTRD(name,title) |
67 | ,fTRon(kTRUE) | |
68 | ,fTR(NULL) | |
67c47633 | 69 | ,fTypeOfStepManager(2) |
030b4415 | 70 | ,fStepSize(0.1) |
71 | ,fDeltaE(NULL) | |
72 | ,fDeltaG(NULL) | |
73 | ,fTrackLength0(0) | |
74 | ,fPrimaryTrackPid(0) | |
fe4da5cc | 75 | { |
76 | // | |
851d3db9 | 77 | // Standard constructor for Transition Radiation Detector version 1 |
fe4da5cc | 78 | // |
82bbf98a | 79 | |
5c7f4665 | 80 | SetBufferSize(128000); |
81 | ||
82 | } | |
83 | ||
84 | //_____________________________________________________________________________ | |
85 | AliTRDv1::~AliTRDv1() | |
86 | { | |
dd9a6ee3 | 87 | // |
88 | // AliTRDv1 destructor | |
89 | // | |
82bbf98a | 90 | |
030b4415 | 91 | if (fDeltaE) { |
92 | delete fDeltaE; | |
93 | fDeltaE = 0; | |
94 | } | |
95 | ||
96 | if (fDeltaG) { | |
97 | delete fDeltaG; | |
98 | fDeltaG = 0; | |
99 | } | |
100 | ||
101 | if (fTR) { | |
102 | delete fTR; | |
103 | fTR = 0; | |
104 | } | |
82bbf98a | 105 | |
fe4da5cc | 106 | } |
107 | ||
f57bb418 | 108 | //_____________________________________________________________________________ |
109 | void AliTRDv1::AddAlignableVolumes() const | |
110 | { | |
111 | // | |
112 | // Create entries for alignable volumes associating the symbolic volume | |
113 | // name with the corresponding volume path. Needs to be syncronized with | |
114 | // eventual changes in the geometry. | |
115 | // | |
116 | ||
117 | TString volPath; | |
118 | TString symName; | |
119 | ||
120 | TString vpStr = "ALIC_1/B077_1/BSEGMO"; | |
121 | TString vpApp1 = "_1/BTRD"; | |
122 | TString vpApp2 = "_1"; | |
123 | TString vpApp3 = "/UTR1_1/UTS1_1/UTI1_1/UT"; | |
124 | ||
125 | TString snStr = "TRD/sm"; | |
126 | TString snApp1 = "/st"; | |
127 | TString snApp2 = "/pl"; | |
128 | ||
129 | // | |
130 | // The super modules | |
131 | // The symbolic names are: TRD/sm00 | |
132 | // ... | |
133 | // TRD/sm17 | |
134 | // | |
135 | for (Int_t isect = 0; isect < AliTRDgeometry::Nsect(); isect++) { | |
136 | ||
137 | volPath = vpStr; | |
138 | volPath += isect; | |
139 | volPath += vpApp1; | |
140 | volPath += isect; | |
141 | volPath += vpApp2; | |
142 | ||
143 | symName = snStr; | |
144 | symName += Form("%02d",isect); | |
145 | ||
146 | gGeoManager->SetAlignableEntry(symName.Data(),volPath.Data()); | |
147 | ||
148 | } | |
149 | ||
150 | // | |
151 | // The readout chambers | |
152 | // The symbolic names are: TRD/sm00/st0/pl0 | |
153 | // ... | |
154 | // TRD/sm17/st4/pl5 | |
155 | // | |
156 | for (Int_t isect = 0; isect < AliTRDgeometry::Nsect(); isect++) { | |
157 | for (Int_t icham = 0; icham < AliTRDgeometry::Ncham(); icham++) { | |
158 | for (Int_t iplan = 0; iplan < AliTRDgeometry::Nplan(); iplan++) { | |
159 | ||
160 | Int_t idet = AliTRDgeometry::GetDetectorSec(iplan,icham); | |
161 | ||
162 | volPath = vpStr; | |
163 | volPath += isect; | |
164 | volPath += vpApp1; | |
165 | volPath += isect; | |
166 | volPath += vpApp2; | |
167 | volPath += vpApp3; | |
168 | volPath += Form("%02d",idet); | |
169 | volPath += vpApp2; | |
170 | ||
171 | symName = snStr; | |
172 | symName += Form("%02d",isect); | |
173 | symName += snApp1; | |
174 | symName += icham; | |
175 | symName += snApp2; | |
176 | symName += iplan; | |
177 | ||
f57bb418 | 178 | gGeoManager->SetAlignableEntry(symName.Data(),volPath.Data()); |
179 | ||
180 | } | |
181 | } | |
182 | } | |
183 | ||
184 | } | |
185 | ||
fe4da5cc | 186 | //_____________________________________________________________________________ |
187 | void AliTRDv1::CreateGeometry() | |
188 | { | |
189 | // | |
851d3db9 | 190 | // Create the GEANT geometry for the Transition Radiation Detector - Version 1 |
5c7f4665 | 191 | // This version covers the full azimuth. |
d3f347ff | 192 | // |
193 | ||
82bbf98a | 194 | // Check that FRAME is there otherwise we have no place where to put the TRD |
8230f242 | 195 | AliModule* frame = gAlice->GetModule("FRAME"); |
030b4415 | 196 | if (!frame) { |
197 | AliError("TRD needs FRAME to be present\n"); | |
198 | return; | |
199 | } | |
d3f347ff | 200 | |
82bbf98a | 201 | // Define the chambers |
202 | AliTRD::CreateGeometry(); | |
d3f347ff | 203 | |
fe4da5cc | 204 | } |
205 | ||
206 | //_____________________________________________________________________________ | |
207 | void AliTRDv1::CreateMaterials() | |
208 | { | |
209 | // | |
851d3db9 | 210 | // Create materials for the Transition Radiation Detector version 1 |
fe4da5cc | 211 | // |
82bbf98a | 212 | |
d3f347ff | 213 | AliTRD::CreateMaterials(); |
82bbf98a | 214 | |
fe4da5cc | 215 | } |
216 | ||
793ff80c | 217 | //_____________________________________________________________________________ |
218 | void AliTRDv1::CreateTRhit(Int_t det) | |
219 | { | |
220 | // | |
221 | // Creates an electron cluster from a TR photon. | |
222 | // The photon is assumed to be created a the end of the radiator. The | |
223 | // distance after which it deposits its energy takes into account the | |
224 | // absorbtion of the entrance window and of the gas mixture in drift | |
225 | // volume. | |
226 | // | |
227 | ||
793ff80c | 228 | // Ionization energy |
bc327ce2 | 229 | const Float_t kWion = 23.53; |
793ff80c | 230 | |
231 | // Maximum number of TR photons per track | |
232 | const Int_t kNTR = 50; | |
233 | ||
030b4415 | 234 | TLorentzVector mom; |
235 | TLorentzVector pos; | |
793ff80c | 236 | |
ce0d6231 | 237 | Float_t eTR[kNTR]; |
238 | Int_t nTR; | |
793ff80c | 239 | |
ce0d6231 | 240 | // Create TR photons |
241 | gMC->TrackMomentum(mom); | |
242 | Float_t pTot = mom.Rho(); | |
243 | fTR->CreatePhotons(11,pTot,nTR,eTR); | |
244 | if (nTR > kNTR) { | |
245 | AliFatal(Form("Boundary error: nTR = %d, kNTR = %d",nTR,kNTR)); | |
246 | } | |
f73816f5 | 247 | |
ce0d6231 | 248 | // Loop through the TR photons |
249 | for (Int_t iTR = 0; iTR < nTR; iTR++) { | |
793ff80c | 250 | |
ce0d6231 | 251 | Float_t energyMeV = eTR[iTR] * 0.001; |
252 | Float_t energyeV = eTR[iTR] * 1000.0; | |
253 | Float_t absLength = 0.0; | |
254 | Float_t sigma = 0.0; | |
793ff80c | 255 | |
ce0d6231 | 256 | // Take the absorbtion in the entrance window into account |
257 | Double_t muMy = fTR->GetMuMy(energyMeV); | |
258 | sigma = muMy * fFoilDensity; | |
259 | if (sigma > 0.0) { | |
260 | absLength = gRandom->Exp(1.0/sigma); | |
261 | if (absLength < AliTRDgeometry::MyThick()) { | |
842287f2 | 262 | continue; |
263 | } | |
ce0d6231 | 264 | } |
265 | else { | |
266 | continue; | |
267 | } | |
793ff80c | 268 | |
ce0d6231 | 269 | // The absorbtion cross sections in the drift gas |
270 | // Gas-mixture (Xe/CO2) | |
271 | Double_t muXe = fTR->GetMuXe(energyMeV); | |
272 | Double_t muCO = fTR->GetMuCO(energyMeV); | |
273 | sigma = (0.85 * muXe + 0.15 * muCO) * fGasDensity * fTR->GetTemp(); | |
274 | ||
275 | // The distance after which the energy of the TR photon | |
276 | // is deposited. | |
277 | if (sigma > 0.0) { | |
278 | absLength = gRandom->Exp(1.0/sigma); | |
279 | if (absLength > (AliTRDgeometry::DrThick() | |
280 | + AliTRDgeometry::AmThick())) { | |
842287f2 | 281 | continue; |
282 | } | |
ce0d6231 | 283 | } |
284 | else { | |
285 | continue; | |
286 | } | |
793ff80c | 287 | |
ce0d6231 | 288 | // The position of the absorbtion |
289 | Float_t posHit[3]; | |
290 | gMC->TrackPosition(pos); | |
291 | posHit[0] = pos[0] + mom[0] / pTot * absLength; | |
292 | posHit[1] = pos[1] + mom[1] / pTot * absLength; | |
293 | posHit[2] = pos[2] + mom[2] / pTot * absLength; | |
793ff80c | 294 | |
ce0d6231 | 295 | // Create the charge |
296 | Int_t q = ((Int_t) (energyeV / kWion)); | |
793ff80c | 297 | |
ce0d6231 | 298 | // Add the hit to the array. TR photon hits are marked |
299 | // by negative charge | |
300 | AddHit(gAlice->GetMCApp()->GetCurrentTrackNumber() | |
301 | ,det | |
302 | ,posHit | |
303 | ,-q | |
304 | ,kTRUE); | |
793ff80c | 305 | |
306 | } | |
307 | ||
308 | } | |
309 | ||
5c7f4665 | 310 | //_____________________________________________________________________________ |
311 | void AliTRDv1::Init() | |
312 | { | |
313 | // | |
314 | // Initialise Transition Radiation Detector after geometry has been built. | |
5c7f4665 | 315 | // |
316 | ||
317 | AliTRD::Init(); | |
318 | ||
45160b1f | 319 | AliDebug(1,"Slow simulator\n"); |
bd0f8685 | 320 | |
321 | // Switch on TR simulation as default | |
322 | if (!fTRon) { | |
45160b1f | 323 | AliInfo("TR simulation off"); |
bd0f8685 | 324 | } |
325 | else { | |
326 | fTR = new AliTRDsim(); | |
327 | } | |
5c7f4665 | 328 | |
329 | // First ionization potential (eV) for the gas mixture (90% Xe + 10% CO2) | |
330 | const Float_t kPoti = 12.1; | |
331 | // Maximum energy (50 keV); | |
332 | const Float_t kEend = 50000.0; | |
333 | // Ermilova distribution for the delta-ray spectrum | |
030b4415 | 334 | Float_t poti = TMath::Log(kPoti); |
335 | Float_t eEnd = TMath::Log(kEend); | |
a328fff9 | 336 | |
337 | // Ermilova distribution for the delta-ray spectrum | |
c4214bc0 | 338 | fDeltaE = new TF1("deltae" ,Ermilova ,poti,eEnd,0); |
a328fff9 | 339 | |
340 | // Geant3 distribution for the delta-ray spectrum | |
c4214bc0 | 341 | fDeltaG = new TF1("deltag",IntSpecGeant,2.421257,28.536469,0); |
5c7f4665 | 342 | |
45160b1f | 343 | AliDebug(1,"+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++"); |
5c7f4665 | 344 | |
fe4da5cc | 345 | } |
346 | ||
5c7f4665 | 347 | //_____________________________________________________________________________ |
348 | void AliTRDv1::StepManager() | |
a328fff9 | 349 | { |
350 | // | |
c4214bc0 | 351 | // Slow simulator. Every charged track produces electron cluster as hits |
a328fff9 | 352 | // along its path across the drift volume. |
353 | // | |
354 | ||
355 | switch (fTypeOfStepManager) { | |
a6dd11e9 | 356 | case 0: |
357 | StepManagerErmilova(); | |
358 | break; | |
359 | case 1: | |
360 | StepManagerGeant(); | |
361 | break; | |
362 | case 2: | |
363 | StepManagerFixedStep(); | |
364 | break; | |
365 | default: | |
366 | AliWarning("Not a valid Step Manager."); | |
a328fff9 | 367 | } |
368 | ||
369 | } | |
370 | ||
371 | //_____________________________________________________________________________ | |
372 | void AliTRDv1::SelectStepManager(Int_t t) | |
373 | { | |
374 | // | |
375 | // Selects a step manager type: | |
376 | // 0 - Ermilova | |
377 | // 1 - Geant3 | |
378 | // 2 - Fixed step size | |
379 | // | |
380 | ||
a328fff9 | 381 | fTypeOfStepManager = t; |
45160b1f | 382 | AliInfo(Form("Step Manager type %d was selected",fTypeOfStepManager)); |
a328fff9 | 383 | |
384 | } | |
385 | ||
386 | //_____________________________________________________________________________ | |
387 | void AliTRDv1::StepManagerGeant() | |
388 | { | |
389 | // | |
c4214bc0 | 390 | // Slow simulator. Every charged track produces electron cluster as hits |
a328fff9 | 391 | // along its path across the drift volume. The step size is set acording |
392 | // to Bethe-Bloch. The energy distribution of the delta electrons follows | |
393 | // a spectrum taken from Geant3. | |
394 | // | |
f2e3a0b5 | 395 | // Version by A. Bercuci |
396 | // | |
397 | ||
c4214bc0 | 398 | Int_t pla = 0; |
399 | Int_t cha = 0; | |
400 | Int_t sec = 0; | |
401 | Int_t det = 0; | |
402 | Int_t iPdg; | |
403 | Int_t qTot; | |
404 | ||
405 | Float_t hits[3]; | |
406 | Float_t charge; | |
407 | Float_t aMass; | |
408 | ||
030b4415 | 409 | Double_t pTot = 0; |
c4214bc0 | 410 | Double_t eDelta; |
030b4415 | 411 | Double_t betaGamma; |
412 | Double_t pp; | |
f2e3a0b5 | 413 | Double_t stepSize = 0; |
c4214bc0 | 414 | |
415 | Bool_t drRegion = kFALSE; | |
416 | Bool_t amRegion = kFALSE; | |
417 | ||
418 | TString cIdCurrent; | |
419 | TString cIdSensDr = "J"; | |
420 | TString cIdSensAm = "K"; | |
421 | Char_t cIdChamber[3]; | |
422 | cIdChamber[2] = 0; | |
423 | ||
030b4415 | 424 | TLorentzVector pos; |
425 | TLorentzVector mom; | |
c4214bc0 | 426 | |
030b4415 | 427 | TArrayI processes; |
f2e3a0b5 | 428 | |
c4214bc0 | 429 | const Int_t kNplan = AliTRDgeometry::Nplan(); |
430 | const Int_t kNcham = AliTRDgeometry::Ncham(); | |
431 | const Int_t kNdetsec = kNplan * kNcham; | |
432 | ||
030b4415 | 433 | const Double_t kBig = 1.0e+12; // Infinitely big |
bc327ce2 | 434 | const Float_t kWion = 23.53; // Ionization energy |
c4214bc0 | 435 | const Float_t kPTotMaxEl = 0.002; // Maximum momentum for e+ e- g |
436 | ||
437 | // Minimum energy for the step size adjustment | |
438 | const Float_t kEkinMinStep = 1.0e-5; | |
439 | // energy threshold for production of delta electrons | |
f2e3a0b5 | 440 | const Float_t kECut = 1.0e4; |
441 | // Parameters entering the parametrized range for delta electrons | |
030b4415 | 442 | const Float_t kRa = 5.37e-4; |
f2e3a0b5 | 443 | const Float_t kRb = 0.9815; |
030b4415 | 444 | const Float_t kRc = 3.123e-3; |
f2e3a0b5 | 445 | // Gas density -> To be made user adjustable ! |
030b4415 | 446 | // [0.85*0.00549+0.15*0.00186 (Xe-CO2 85-15)] |
447 | const Float_t kRho = 0.004945 ; | |
a328fff9 | 448 | |
c4214bc0 | 449 | // Plateau value of the energy-loss for electron in xenon |
030b4415 | 450 | // The averaged value (26/3/99) |
c4214bc0 | 451 | const Float_t kPlateau = 1.55; |
030b4415 | 452 | // dN1/dx|min for the gas mixture (90% Xe + 10% CO2) |
453 | const Float_t kPrim = 19.34; | |
c4214bc0 | 454 | // First ionization potential (eV) for the gas mixture (90% Xe + 10% CO2) |
455 | const Float_t kPoti = 12.1; | |
030b4415 | 456 | // PDG code electron |
457 | const Int_t kPdgElectron = 11; | |
c4214bc0 | 458 | |
459 | // Set the maximum step size to a very large number for all | |
460 | // neutral particles and those outside the driftvolume | |
461 | gMC->SetMaxStep(kBig); | |
462 | ||
463 | // Use only charged tracks | |
464 | if (( gMC->TrackCharge() ) && | |
c4214bc0 | 465 | (!gMC->IsTrackDisappeared())) { |
466 | ||
467 | // Inside a sensitive volume? | |
468 | drRegion = kFALSE; | |
469 | amRegion = kFALSE; | |
470 | cIdCurrent = gMC->CurrentVolName(); | |
471 | if (cIdSensDr == cIdCurrent[1]) { | |
472 | drRegion = kTRUE; | |
473 | } | |
474 | if (cIdSensAm == cIdCurrent[1]) { | |
475 | amRegion = kTRUE; | |
476 | } | |
477 | if (drRegion || amRegion) { | |
a328fff9 | 478 | |
c4214bc0 | 479 | // The hit coordinates and charge |
480 | gMC->TrackPosition(pos); | |
481 | hits[0] = pos[0]; | |
482 | hits[1] = pos[1]; | |
483 | hits[2] = pos[2]; | |
484 | ||
485 | // The sector number (0 - 17) | |
486 | // The numbering goes clockwise and starts at y = 0 | |
487 | Float_t phi = kRaddeg*TMath::ATan2(pos[0],pos[1]); | |
030b4415 | 488 | if (phi < 90.0) { |
489 | phi = phi + 270.0; | |
490 | } | |
491 | else { | |
492 | phi = phi - 90.0; | |
493 | } | |
494 | sec = ((Int_t) (phi / 20.0)); | |
c4214bc0 | 495 | |
496 | // The plane and chamber number | |
030b4415 | 497 | cIdChamber[0] = cIdCurrent[2]; |
498 | cIdChamber[1] = cIdCurrent[3]; | |
c4214bc0 | 499 | Int_t idChamber = (atoi(cIdChamber) % kNdetsec); |
500 | cha = kNcham - ((Int_t) idChamber / kNplan) - 1; | |
501 | pla = ((Int_t) idChamber % kNplan); | |
502 | ||
ce0d6231 | 503 | // The detector number |
504 | det = fGeometry->GetDetector(pla,cha,sec); | |
c4214bc0 | 505 | |
ce0d6231 | 506 | // Special hits only in the drift region |
507 | if ((drRegion) && | |
508 | (gMC->IsTrackEntering())) { | |
c4214bc0 | 509 | |
ce0d6231 | 510 | // Create a track reference at the entrance of each |
511 | // chamber that contains the momentum components of the particle | |
512 | gMC->TrackMomentum(mom); | |
513 | AddTrackReference(gAlice->GetMCApp()->GetCurrentTrackNumber()); | |
c4214bc0 | 514 | |
ce0d6231 | 515 | // Create the hits from TR photons if electron/positron is |
516 | // entering the drift volume | |
517 | if ((fTR) && | |
518 | (TMath::Abs(gMC->TrackPid()) == kPdgElectron)) { | |
519 | CreateTRhit(det); | |
520 | } | |
f2e3a0b5 | 521 | |
ce0d6231 | 522 | } |
523 | else if ((amRegion) && | |
524 | (gMC->IsTrackExiting())) { | |
f2e3a0b5 | 525 | |
ce0d6231 | 526 | // Create a track reference at the exit of each |
527 | // chamber that contains the momentum components of the particle | |
528 | gMC->TrackMomentum(mom); | |
529 | AddTrackReference(gAlice->GetMCApp()->GetCurrentTrackNumber()); | |
c4214bc0 | 530 | |
ce0d6231 | 531 | } |
c4214bc0 | 532 | |
ce0d6231 | 533 | // Calculate the energy of the delta-electrons |
534 | // modified by Alex Bercuci (A.Bercuci@gsi.de) on 26.01.06 | |
535 | // take into account correlation with the underlying GEANT tracking | |
536 | // mechanism. see | |
537 | // http://www-linux.gsi.de/~abercuci/Contributions/TRD/index.html | |
538 | // | |
539 | // determine the most significant process (last on the processes list) | |
540 | // which caused this hit | |
541 | gMC->StepProcesses(processes); | |
542 | Int_t nofprocesses = processes.GetSize(); | |
543 | Int_t pid; | |
544 | if (!nofprocesses) { | |
545 | pid = 0; | |
546 | } | |
547 | else { | |
548 | pid = processes[nofprocesses-1]; | |
549 | } | |
f2e3a0b5 | 550 | |
ce0d6231 | 551 | // Generate Edep according to GEANT parametrisation |
552 | eDelta = TMath::Exp(fDeltaG->GetRandom()) - kPoti; | |
553 | eDelta = TMath::Max(eDelta,0.0); | |
554 | Float_t prRange = 0.0; | |
555 | Float_t range = gMC->TrackLength() - fTrackLength0; | |
556 | // merge GEANT tracker information with locally cooked one | |
557 | if (gAlice->GetMCApp()->GetCurrentTrackNumber() == fPrimaryTrackPid) { | |
558 | if (pid == 27) { | |
559 | if (eDelta >= kECut) { | |
560 | prRange = kRa * eDelta * 0.001 | |
561 | * (1.0 - kRb / (1.0 + kRc * eDelta * 0.001)) / kRho; | |
562 | if (prRange >= (3.7 - range)) { | |
563 | eDelta *= 0.1; | |
564 | } | |
565 | } | |
566 | } | |
567 | else if (pid == 1) { | |
568 | if (eDelta < kECut) { | |
569 | eDelta *= 0.5; | |
570 | } | |
571 | else { | |
572 | prRange = kRa * eDelta * 0.001 | |
573 | * (1.0 - kRb / (1.0 + kRc * eDelta * 0.001)) / kRho; | |
574 | if (prRange >= ((AliTRDgeometry::DrThick() | |
575 | + AliTRDgeometry::AmThick()) - range)) { | |
576 | eDelta *= 0.05; | |
577 | } | |
578 | else { | |
f2e3a0b5 | 579 | eDelta *= 0.5; |
ce0d6231 | 580 | } |
581 | } | |
582 | } | |
f2e3a0b5 | 583 | else { |
584 | eDelta = 0.0; | |
ce0d6231 | 585 | } |
586 | } | |
587 | else { | |
588 | eDelta = 0.0; | |
589 | } | |
c4214bc0 | 590 | |
ce0d6231 | 591 | // Generate the electron cluster size |
592 | if (eDelta > 0.0) { | |
f2e3a0b5 | 593 | |
ce0d6231 | 594 | qTot = ((Int_t) (eDelta / kWion) + 1); |
595 | ||
596 | // Create a new dEdx hit | |
030b4415 | 597 | AddHit(gAlice->GetMCApp()->GetCurrentTrackNumber() |
598 | ,det | |
599 | ,hits | |
600 | ,qTot | |
601 | ,drRegion); | |
c4214bc0 | 602 | |
ce0d6231 | 603 | } |
604 | ||
605 | // Calculate the maximum step size for the next tracking step | |
606 | // Produce only one hit if Ekin is below cutoff | |
607 | aMass = gMC->TrackMass(); | |
608 | if ((gMC->Etot() - aMass) > kEkinMinStep) { | |
609 | ||
610 | // The energy loss according to Bethe Bloch | |
611 | iPdg = TMath::Abs(gMC->TrackPid()); | |
612 | if ((iPdg != kPdgElectron) || | |
613 | ((iPdg == kPdgElectron) && | |
614 | (pTot < kPTotMaxEl))) { | |
615 | gMC->TrackMomentum(mom); | |
616 | pTot = mom.Rho(); | |
617 | betaGamma = pTot / aMass; | |
618 | pp = BetheBlochGeant(betaGamma); | |
619 | // Take charge > 1 into account | |
620 | charge = gMC->TrackCharge(); | |
621 | if (TMath::Abs(charge) > 1) { | |
622 | pp = pp * charge*charge; | |
623 | } | |
624 | } | |
625 | else { | |
626 | // Electrons above 20 Mev/c are at the plateau | |
627 | pp = kPrim * kPlateau; | |
628 | } | |
f2e3a0b5 | 629 | |
ce0d6231 | 630 | Int_t nsteps = 0; |
631 | do { | |
632 | nsteps = gRandom->Poisson(pp); | |
633 | } while(!nsteps); | |
634 | stepSize = 1.0 / nsteps; | |
635 | gMC->SetMaxStep(stepSize); | |
f2e3a0b5 | 636 | |
c4214bc0 | 637 | } |
f2e3a0b5 | 638 | |
c4214bc0 | 639 | } |
f2e3a0b5 | 640 | |
c4214bc0 | 641 | } |
f2e3a0b5 | 642 | |
a328fff9 | 643 | } |
644 | ||
645 | //_____________________________________________________________________________ | |
646 | void AliTRDv1::StepManagerErmilova() | |
5c7f4665 | 647 | { |
648 | // | |
5c7f4665 | 649 | // Slow simulator. Every charged track produces electron cluster as hits |
650 | // along its path across the drift volume. The step size is set acording | |
651 | // to Bethe-Bloch. The energy distribution of the delta electrons follows | |
652 | // a spectrum taken from Ermilova et al. | |
653 | // | |
654 | ||
851d3db9 | 655 | Int_t pla = 0; |
656 | Int_t cha = 0; | |
657 | Int_t sec = 0; | |
793ff80c | 658 | Int_t det = 0; |
851d3db9 | 659 | Int_t iPdg; |
793ff80c | 660 | Int_t qTot; |
5c7f4665 | 661 | |
793ff80c | 662 | Float_t hits[3]; |
a5cadd36 | 663 | Double_t random[1]; |
5c7f4665 | 664 | Float_t charge; |
665 | Float_t aMass; | |
666 | ||
030b4415 | 667 | Double_t pTot = 0.0; |
5c7f4665 | 668 | Double_t eDelta; |
030b4415 | 669 | Double_t betaGamma; |
670 | Double_t pp; | |
f73816f5 | 671 | Double_t stepSize; |
5c7f4665 | 672 | |
332e9569 | 673 | Bool_t drRegion = kFALSE; |
674 | Bool_t amRegion = kFALSE; | |
675 | ||
676 | TString cIdCurrent; | |
677 | TString cIdSensDr = "J"; | |
678 | TString cIdSensAm = "K"; | |
593a9fc3 | 679 | Char_t cIdChamber[3]; |
680 | cIdChamber[2] = 0; | |
332e9569 | 681 | |
030b4415 | 682 | TLorentzVector pos; |
683 | TLorentzVector mom; | |
82bbf98a | 684 | |
332e9569 | 685 | const Int_t kNplan = AliTRDgeometry::Nplan(); |
e644678a | 686 | const Int_t kNcham = AliTRDgeometry::Ncham(); |
687 | const Int_t kNdetsec = kNplan * kNcham; | |
688 | ||
030b4415 | 689 | const Double_t kBig = 1.0e+12; // Infinitely big |
bc327ce2 | 690 | const Float_t kWion = 23.53; // Ionization energy |
a328fff9 | 691 | const Float_t kPTotMaxEl = 0.002; // Maximum momentum for e+ e- g |
5c7f4665 | 692 | |
f73816f5 | 693 | // Minimum energy for the step size adjustment |
694 | const Float_t kEkinMinStep = 1.0e-5; | |
a328fff9 | 695 | |
5c7f4665 | 696 | // Plateau value of the energy-loss for electron in xenon |
030b4415 | 697 | // The averaged value (26/3/99) |
a3c76cdc | 698 | const Float_t kPlateau = 1.55; |
030b4415 | 699 | // dN1/dx|min for the gas mixture (90% Xe + 10% CO2) |
700 | const Float_t kPrim = 48.0; | |
5c7f4665 | 701 | // First ionization potential (eV) for the gas mixture (90% Xe + 10% CO2) |
a3c76cdc | 702 | const Float_t kPoti = 12.1; |
030b4415 | 703 | // PDG code electron |
704 | const Int_t kPdgElectron = 11; | |
5c7f4665 | 705 | |
706 | // Set the maximum step size to a very large number for all | |
707 | // neutral particles and those outside the driftvolume | |
708 | gMC->SetMaxStep(kBig); | |
709 | ||
710 | // Use only charged tracks | |
711 | if (( gMC->TrackCharge() ) && | |
5c7f4665 | 712 | (!gMC->IsTrackDisappeared())) { |
fe4da5cc | 713 | |
5c7f4665 | 714 | // Inside a sensitive volume? |
332e9569 | 715 | drRegion = kFALSE; |
716 | amRegion = kFALSE; | |
717 | cIdCurrent = gMC->CurrentVolName(); | |
e6674585 | 718 | if (cIdSensDr == cIdCurrent[1]) { |
332e9569 | 719 | drRegion = kTRUE; |
720 | } | |
e6674585 | 721 | if (cIdSensAm == cIdCurrent[1]) { |
332e9569 | 722 | amRegion = kTRUE; |
723 | } | |
724 | if (drRegion || amRegion) { | |
fe4da5cc | 725 | |
5c7f4665 | 726 | // The hit coordinates and charge |
727 | gMC->TrackPosition(pos); | |
728 | hits[0] = pos[0]; | |
729 | hits[1] = pos[1]; | |
730 | hits[2] = pos[2]; | |
5c7f4665 | 731 | |
851d3db9 | 732 | // The sector number (0 - 17) |
733 | // The numbering goes clockwise and starts at y = 0 | |
e15eb584 | 734 | Float_t phi = kRaddeg*TMath::ATan2(pos[0],pos[1]); |
030b4415 | 735 | if (phi < 90.0) { |
736 | phi = phi + 270.0; | |
737 | } | |
738 | else { | |
739 | phi = phi - 90.0; | |
740 | } | |
741 | sec = ((Int_t) (phi / 20.0)); | |
82bbf98a | 742 | |
332e9569 | 743 | // The plane and chamber number |
744 | cIdChamber[0] = cIdCurrent[2]; | |
745 | cIdChamber[1] = cIdCurrent[3]; | |
e644678a | 746 | Int_t idChamber = (atoi(cIdChamber) % kNdetsec); |
a5cadd36 | 747 | cha = kNcham - ((Int_t) idChamber / kNplan) - 1; |
332e9569 | 748 | pla = ((Int_t) idChamber % kNplan); |
82bbf98a | 749 | |
ce0d6231 | 750 | // The detector number |
751 | det = fGeometry->GetDetector(pla,cha,sec); | |
5c7f4665 | 752 | |
ce0d6231 | 753 | // Special hits only in the drift region |
754 | if ((drRegion) && | |
755 | (gMC->IsTrackEntering())) { | |
5c7f4665 | 756 | |
ce0d6231 | 757 | // Create a track reference at the entrance of each |
758 | // chamber that contains the momentum components of the particle | |
759 | gMC->TrackMomentum(mom); | |
760 | AddTrackReference(gAlice->GetMCApp()->GetCurrentTrackNumber()); | |
793ff80c | 761 | |
ce0d6231 | 762 | // Create the hits from TR photons if electron/positron is |
763 | // entering the drift volume | |
764 | if ((fTR) && | |
765 | (TMath::Abs(gMC->TrackPid()) == kPdgElectron)) { | |
766 | CreateTRhit(det); | |
767 | } | |
f73816f5 | 768 | |
ce0d6231 | 769 | } |
770 | else if ((amRegion) && | |
771 | (gMC->IsTrackExiting())) { | |
f73816f5 | 772 | |
ce0d6231 | 773 | // Create a track reference at the exit of each |
774 | // chamber that contains the momentum components of the particle | |
775 | gMC->TrackMomentum(mom); | |
776 | AddTrackReference(gAlice->GetMCApp()->GetCurrentTrackNumber()); | |
f73816f5 | 777 | |
ce0d6231 | 778 | } |
779 | ||
780 | // Calculate the energy of the delta-electrons | |
781 | eDelta = TMath::Exp(fDeltaE->GetRandom()) - kPoti; | |
782 | eDelta = TMath::Max(eDelta,0.0); | |
783 | ||
784 | // Generate the electron cluster size | |
785 | if (eDelta > 0.0) { | |
786 | ||
787 | qTot = ((Int_t) (eDelta / kWion) + 1); | |
f73816f5 | 788 | |
030b4415 | 789 | // Create a new dEdx hit |
332e9569 | 790 | if (drRegion) { |
a328fff9 | 791 | AddHit(gAlice->GetMCApp()->GetCurrentTrackNumber() |
030b4415 | 792 | ,det |
793 | ,hits | |
794 | ,qTot | |
795 | ,kTRUE); | |
796 | } | |
5c7f4665 | 797 | else { |
a328fff9 | 798 | AddHit(gAlice->GetMCApp()->GetCurrentTrackNumber() |
030b4415 | 799 | ,det |
800 | ,hits | |
801 | ,qTot | |
802 | ,kFALSE); | |
803 | } | |
f73816f5 | 804 | |
ce0d6231 | 805 | } |
806 | ||
807 | // Calculate the maximum step size for the next tracking step | |
808 | // Produce only one hit if Ekin is below cutoff | |
809 | aMass = gMC->TrackMass(); | |
810 | if ((gMC->Etot() - aMass) > kEkinMinStep) { | |
811 | ||
812 | // The energy loss according to Bethe Bloch | |
813 | iPdg = TMath::Abs(gMC->TrackPid()); | |
814 | if ((iPdg != kPdgElectron) || | |
815 | ((iPdg == kPdgElectron) && | |
816 | (pTot < kPTotMaxEl))) { | |
817 | gMC->TrackMomentum(mom); | |
818 | pTot = mom.Rho(); | |
819 | betaGamma = pTot / aMass; | |
820 | pp = kPrim * BetheBloch(betaGamma); | |
821 | // Take charge > 1 into account | |
822 | charge = gMC->TrackCharge(); | |
823 | if (TMath::Abs(charge) > 1) { | |
824 | pp = pp * charge*charge; | |
f73816f5 | 825 | } |
ce0d6231 | 826 | } |
827 | else { | |
828 | // Electrons above 20 Mev/c are at the plateau | |
829 | pp = kPrim * kPlateau; | |
830 | } | |
f73816f5 | 831 | |
ce0d6231 | 832 | if (pp > 0.0) { |
833 | do { | |
834 | gMC->GetRandom()->RndmArray(1,random); | |
030b4415 | 835 | } |
ce0d6231 | 836 | while ((random[0] == 1.0) || |
837 | (random[0] == 0.0)); | |
838 | stepSize = - TMath::Log(random[0]) / pp; | |
839 | gMC->SetMaxStep(stepSize); | |
840 | } | |
030b4415 | 841 | |
5c7f4665 | 842 | } |
030b4415 | 843 | |
d3f347ff | 844 | } |
030b4415 | 845 | |
5c7f4665 | 846 | } |
030b4415 | 847 | |
5c7f4665 | 848 | } |
849 | ||
a328fff9 | 850 | //_____________________________________________________________________________ |
851 | void AliTRDv1::StepManagerFixedStep() | |
852 | { | |
853 | // | |
854 | // Slow simulator. Every charged track produces electron cluster as hits | |
855 | // along its path across the drift volume. The step size is fixed in | |
856 | // this version of the step manager. | |
857 | // | |
858 | ||
ce0d6231 | 859 | // PDG code electron |
860 | const Int_t kPdgElectron = 11; | |
861 | ||
a328fff9 | 862 | Int_t pla = 0; |
863 | Int_t cha = 0; | |
864 | Int_t sec = 0; | |
865 | Int_t det = 0; | |
866 | Int_t qTot; | |
867 | ||
868 | Float_t hits[3]; | |
869 | Double_t eDep; | |
870 | ||
871 | Bool_t drRegion = kFALSE; | |
872 | Bool_t amRegion = kFALSE; | |
873 | ||
874 | TString cIdCurrent; | |
875 | TString cIdSensDr = "J"; | |
876 | TString cIdSensAm = "K"; | |
877 | Char_t cIdChamber[3]; | |
878 | cIdChamber[2] = 0; | |
879 | ||
030b4415 | 880 | TLorentzVector pos; |
881 | TLorentzVector mom; | |
a328fff9 | 882 | |
883 | const Int_t kNplan = AliTRDgeometry::Nplan(); | |
884 | const Int_t kNcham = AliTRDgeometry::Ncham(); | |
885 | const Int_t kNdetsec = kNplan * kNcham; | |
886 | ||
030b4415 | 887 | const Double_t kBig = 1.0e+12; |
a328fff9 | 888 | |
bc327ce2 | 889 | const Float_t kWion = 23.53; // Ionization energy |
a328fff9 | 890 | const Float_t kEkinMinStep = 1.0e-5; // Minimum energy for the step size adjustment |
891 | ||
892 | // Set the maximum step size to a very large number for all | |
893 | // neutral particles and those outside the driftvolume | |
894 | gMC->SetMaxStep(kBig); | |
895 | ||
896 | // If not charged track or already stopped or disappeared, just return. | |
897 | if ((!gMC->TrackCharge()) || | |
ce0d6231 | 898 | gMC->IsTrackDisappeared()) { |
899 | return; | |
900 | } | |
a328fff9 | 901 | |
902 | // Inside a sensitive volume? | |
903 | cIdCurrent = gMC->CurrentVolName(); | |
904 | ||
ce0d6231 | 905 | if (cIdSensDr == cIdCurrent[1]) { |
906 | drRegion = kTRUE; | |
907 | } | |
908 | if (cIdSensAm == cIdCurrent[1]) { | |
909 | amRegion = kTRUE; | |
910 | } | |
a328fff9 | 911 | |
030b4415 | 912 | if ((!drRegion) && |
913 | (!amRegion)) { | |
914 | return; | |
915 | } | |
a328fff9 | 916 | |
917 | // The hit coordinates and charge | |
918 | gMC->TrackPosition(pos); | |
919 | hits[0] = pos[0]; | |
920 | hits[1] = pos[1]; | |
921 | hits[2] = pos[2]; | |
922 | ||
923 | // The sector number (0 - 17) | |
924 | // The numbering goes clockwise and starts at y = 0 | |
ce0d6231 | 925 | Float_t phi = kRaddeg * TMath::ATan2(pos[0],pos[1]); |
030b4415 | 926 | if (phi < 90.0) { |
927 | phi = phi + 270.0; | |
928 | } | |
929 | else { | |
930 | phi = phi - 90.0; | |
931 | } | |
932 | sec = ((Int_t) (phi / 20.0)); | |
a328fff9 | 933 | |
934 | // The plane and chamber number | |
030b4415 | 935 | cIdChamber[0] = cIdCurrent[2]; |
936 | cIdChamber[1] = cIdCurrent[3]; | |
a328fff9 | 937 | Int_t idChamber = (atoi(cIdChamber) % kNdetsec); |
a5cadd36 | 938 | cha = kNcham - ((Int_t) idChamber / kNplan) - 1; |
a328fff9 | 939 | pla = ((Int_t) idChamber % kNplan); |
e0d47c25 | 940 | |
030b4415 | 941 | // The detector number |
942 | det = fGeometry->GetDetector(pla,cha,sec); | |
943 | ||
944 | // 0: InFlight 1:Entering 2:Exiting | |
945 | Int_t trkStat = 0; | |
a328fff9 | 946 | |
947 | // Special hits only in the drift region | |
ce0d6231 | 948 | if ((drRegion) && |
949 | (gMC->IsTrackEntering())) { | |
a328fff9 | 950 | |
ce0d6231 | 951 | // Create a track reference at the entrance of each |
952 | // chamber that contains the momentum components of the particle | |
953 | gMC->TrackMomentum(mom); | |
954 | AddTrackReference(gAlice->GetMCApp()->GetCurrentTrackNumber()); | |
955 | trkStat = 1; | |
a328fff9 | 956 | |
ce0d6231 | 957 | // Create the hits from TR photons if electron/positron is |
958 | // entering the drift volume | |
959 | if ((fTR) && | |
960 | (TMath::Abs(gMC->TrackPid()) == kPdgElectron)) { | |
030b4415 | 961 | CreateTRhit(det); |
962 | } | |
a328fff9 | 963 | |
ce0d6231 | 964 | } |
965 | else if ((amRegion) && | |
966 | (gMC->IsTrackExiting())) { | |
967 | ||
968 | // Create a track reference at the exit of each | |
969 | // chamber that contains the momentum components of the particle | |
970 | gMC->TrackMomentum(mom); | |
971 | AddTrackReference(gAlice->GetMCApp()->GetCurrentTrackNumber()); | |
972 | trkStat = 2; | |
973 | ||
a328fff9 | 974 | } |
975 | ||
976 | // Calculate the charge according to GEANT Edep | |
977 | // Create a new dEdx hit | |
978 | eDep = TMath::Max(gMC->Edep(),0.0) * 1.0e+09; | |
979 | qTot = (Int_t) (eDep / kWion); | |
ce0d6231 | 980 | if ((qTot) || |
981 | (trkStat)) { | |
982 | AddHit(gAlice->GetMCApp()->GetCurrentTrackNumber() | |
983 | ,det | |
984 | ,hits | |
985 | ,qTot | |
986 | ,drRegion); | |
987 | } | |
a328fff9 | 988 | |
989 | // Set Maximum Step Size | |
990 | // Produce only one hit if Ekin is below cutoff | |
030b4415 | 991 | if ((gMC->Etot() - gMC->TrackMass()) < kEkinMinStep) { |
992 | return; | |
993 | } | |
a328fff9 | 994 | gMC->SetMaxStep(fStepSize); |
995 | ||
996 | } | |
997 | ||
5c7f4665 | 998 | //_____________________________________________________________________________ |
999 | Double_t AliTRDv1::BetheBloch(Double_t bg) | |
1000 | { | |
1001 | // | |
1002 | // Parametrization of the Bethe-Bloch-curve | |
1003 | // The parametrization is the same as for the TPC and is taken from Lehrhaus. | |
1004 | // | |
1005 | ||
1006 | // This parameters have been adjusted to averaged values from GEANT | |
f57bb418 | 1007 | const Double_t kP1 = 7.17960e-02; |
1008 | const Double_t kP2 = 8.54196; | |
1009 | const Double_t kP3 = 1.38065e-06; | |
1010 | const Double_t kP4 = 5.30972; | |
1011 | const Double_t kP5 = 2.83798; | |
5c7f4665 | 1012 | |
f73816f5 | 1013 | // Lower cutoff of the Bethe-Bloch-curve to limit step sizes |
1014 | const Double_t kBgMin = 0.8; | |
1015 | const Double_t kBBMax = 6.83298; | |
f73816f5 | 1016 | |
1017 | if (bg > kBgMin) { | |
030b4415 | 1018 | Double_t yy = bg / TMath::Sqrt(1.0 + bg*bg); |
5c7f4665 | 1019 | Double_t aa = TMath::Power(yy,kP4); |
030b4415 | 1020 | Double_t bb = TMath::Power((1.0/bg),kP5); |
5c7f4665 | 1021 | bb = TMath::Log(kP3 + bb); |
030b4415 | 1022 | return ((kP2 - aa - bb) * kP1 / aa); |
5c7f4665 | 1023 | } |
f73816f5 | 1024 | else { |
1025 | return kBBMax; | |
1026 | } | |
d3f347ff | 1027 | |
fe4da5cc | 1028 | } |
5c7f4665 | 1029 | |
a328fff9 | 1030 | //_____________________________________________________________________________ |
c4214bc0 | 1031 | Double_t AliTRDv1::BetheBlochGeant(Double_t bg) |
a328fff9 | 1032 | { |
1033 | // | |
1034 | // Return dN/dx (number of primary collisions per centimeter) | |
1035 | // for given beta*gamma factor. | |
1036 | // | |
1037 | // Implemented by K.Oyama according to GEANT 3 parametrization shown in | |
1038 | // A.Andronic's webpage: http://www-alice.gsi.de/trd/papers/dedx/dedx.html | |
1039 | // This must be used as a set with IntSpecGeant. | |
1040 | // | |
1041 | ||
030b4415 | 1042 | Int_t i = 0; |
a328fff9 | 1043 | |
030b4415 | 1044 | Double_t arrG[20] = { 1.100000, 1.200000, 1.300000, 1.500000 |
1045 | , 1.800000, 2.000000, 2.500000, 3.000000 | |
1046 | , 4.000000, 7.000000, 10.000000, 20.000000 | |
1047 | , 40.000000, 70.000000, 100.000000, 300.000000 | |
1048 | , 600.000000, 1000.000000, 3000.000000, 10000.000000 }; | |
a328fff9 | 1049 | |
030b4415 | 1050 | Double_t arrNC[20] = { 75.009056, 45.508083, 35.299252, 27.116327 |
1051 | , 22.734999, 21.411915, 19.934095, 19.449375 | |
1052 | , 19.344431, 20.185553, 21.027925, 22.912676 | |
1053 | , 24.933352, 26.504053, 27.387468, 29.566597 | |
1054 | , 30.353779, 30.787134, 31.129285, 31.157350 }; | |
1055 | ||
1056 | // Betagamma to gamma | |
1057 | Double_t g = TMath::Sqrt(1.0 + bg*bg); | |
a328fff9 | 1058 | |
1059 | // Find the index just before the point we need. | |
030b4415 | 1060 | for (i = 0; i < 18; i++) { |
1061 | if ((arrG[i] < g) && | |
1062 | (arrG[i+1] > g)) { | |
a328fff9 | 1063 | break; |
030b4415 | 1064 | } |
1065 | } | |
a328fff9 | 1066 | |
1067 | // Simple interpolation. | |
030b4415 | 1068 | Double_t pp = ((arrNC[i+1] - arrNC[i]) / (arrG[i+1] - arrG[i])) |
1069 | * (g - arrG[i]) + arrNC[i]; | |
a328fff9 | 1070 | |
030b4415 | 1071 | return pp; |
a328fff9 | 1072 | |
1073 | } | |
1074 | ||
5c7f4665 | 1075 | //_____________________________________________________________________________ |
1076 | Double_t Ermilova(Double_t *x, Double_t *) | |
1077 | { | |
1078 | // | |
1079 | // Calculates the delta-ray energy distribution according to Ermilova. | |
1080 | // Logarithmic scale ! | |
1081 | // | |
1082 | ||
1083 | Double_t energy; | |
1084 | Double_t dpos; | |
1085 | Double_t dnde; | |
1086 | ||
030b4415 | 1087 | Int_t pos1; |
1088 | Int_t pos2; | |
5c7f4665 | 1089 | |
8230f242 | 1090 | const Int_t kNv = 31; |
5c7f4665 | 1091 | |
030b4415 | 1092 | Float_t vxe[kNv] = { 2.3026, 2.9957, 3.4012, 3.6889, 3.9120 |
1093 | , 4.0943, 4.2485, 4.3820, 4.4998, 4.6052 | |
1094 | , 4.7005, 5.0752, 5.2983, 5.7038, 5.9915 | |
1095 | , 6.2146, 6.5221, 6.9078, 7.3132, 7.6009 | |
1096 | , 8.0064, 8.5172, 8.6995, 8.9872, 9.2103 | |
1097 | , 9.4727, 9.9035, 10.3735, 10.5966, 10.8198 | |
1098 | , 11.5129 }; | |
1099 | ||
1100 | Float_t vye[kNv] = { 80.0, 31.0, 23.3, 21.1, 21.0 | |
1101 | , 20.9, 20.8, 20.0, 16.0, 11.0 | |
1102 | , 8.0, 6.0, 5.2, 4.6, 4.0 | |
1103 | , 3.5, 3.0, 1.4, 0.67, 0.44 | |
1104 | , 0.3, 0.18, 0.12, 0.08, 0.056 | |
1105 | , 0.04, 0.023, 0.015, 0.011, 0.01 | |
1106 | , 0.004 }; | |
5c7f4665 | 1107 | |
1108 | energy = x[0]; | |
1109 | ||
1110 | // Find the position | |
030b4415 | 1111 | pos1 = 0; |
1112 | pos2 = 0; | |
5c7f4665 | 1113 | dpos = 0; |
1114 | do { | |
1115 | dpos = energy - vxe[pos2++]; | |
1116 | } | |
1117 | while (dpos > 0); | |
1118 | pos2--; | |
030b4415 | 1119 | if (pos2 > kNv) { |
1120 | pos2 = kNv - 1; | |
1121 | } | |
5c7f4665 | 1122 | pos1 = pos2 - 1; |
1123 | ||
1124 | // Differentiate between the sampling points | |
1125 | dnde = (vye[pos1] - vye[pos2]) / (vxe[pos2] - vxe[pos1]); | |
1126 | ||
1127 | return dnde; | |
1128 | ||
1129 | } | |
a328fff9 | 1130 | |
1131 | //_____________________________________________________________________________ | |
1132 | Double_t IntSpecGeant(Double_t *x, Double_t *) | |
1133 | { | |
1134 | // | |
1135 | // Integrated spectrum from Geant3 | |
1136 | // | |
1137 | ||
96efaf83 | 1138 | const Int_t npts = 83; |
030b4415 | 1139 | Double_t arre[npts] = { 2.421257, 2.483278, 2.534301, 2.592230 |
1140 | , 2.672067, 2.813299, 3.015059, 3.216819 | |
1141 | , 3.418579, 3.620338, 3.868209, 3.920198 | |
1142 | , 3.978284, 4.063923, 4.186264, 4.308605 | |
1143 | , 4.430946, 4.553288, 4.724261, 4.837736 | |
1144 | , 4.999842, 5.161949, 5.324056, 5.486163 | |
1145 | , 5.679688, 5.752998, 5.857728, 5.962457 | |
1146 | , 6.067185, 6.171914, 6.315653, 6.393674 | |
1147 | , 6.471694, 6.539689, 6.597658, 6.655627 | |
1148 | , 6.710957, 6.763648, 6.816338, 6.876198 | |
1149 | , 6.943227, 7.010257, 7.106285, 7.252151 | |
1150 | , 7.460531, 7.668911, 7.877290, 8.085670 | |
1151 | , 8.302979, 8.353585, 8.413120, 8.483500 | |
1152 | , 8.541030, 8.592857, 8.668865, 8.820485 | |
1153 | , 9.037086, 9.253686, 9.470286, 9.686887 | |
1154 | , 9.930838, 9.994655, 10.085822, 10.176990 | |
1155 | , 10.268158, 10.359325, 10.503614, 10.627565 | |
1156 | , 10.804637, 10.981709, 11.158781, 11.335854 | |
1157 | , 11.593397, 11.781165, 12.049404, 12.317644 | |
1158 | , 12.585884, 12.854123, 14.278421, 16.975889 | |
1159 | , 20.829416, 24.682943, 28.536469 }; | |
1160 | ||
1161 | Double_t arrdnde[npts] = { 10.960000, 10.960000, 10.359500, 9.811340 | |
1162 | , 9.1601500, 8.206670, 6.919630, 5.655430 | |
1163 | , 4.6221300, 3.777610, 3.019560, 2.591950 | |
1164 | , 2.5414600, 2.712920, 3.327460, 4.928240 | |
1165 | , 7.6185300, 10.966700, 12.225800, 8.094750 | |
1166 | , 3.3586900, 1.553650, 1.209600, 1.263840 | |
1167 | , 1.3241100, 1.312140, 1.255130, 1.165770 | |
1168 | , 1.0594500, 0.945450, 0.813231, 0.699837 | |
1169 | , 0.6235580, 2.260990, 2.968350, 2.240320 | |
1170 | , 1.7988300, 1.553300, 1.432070, 1.535520 | |
1171 | , 1.4429900, 1.247990, 1.050750, 0.829549 | |
1172 | , 0.5900280, 0.395897, 0.268741, 0.185320 | |
1173 | , 0.1292120, 0.103545, 0.0949525, 0.101535 | |
1174 | , 0.1276380, 0.134216, 0.123816, 0.104557 | |
1175 | , 0.0751843, 0.0521745, 0.0373546, 0.0275391 | |
1176 | , 0.0204713, 0.0169234, 0.0154552, 0.0139194 | |
1177 | , 0.0125592, 0.0113638, 0.0107354, 0.0102137 | |
1178 | , 0.00845984, 0.00683338, 0.00556836, 0.00456874 | |
1179 | , 0.0036227, 0.00285991, 0.00226664, 0.00172234 | |
1180 | , 0.00131226, 0.00100284, 0.000465492, 7.26607e-05 | |
1181 | , 3.63304e-06, 0.0000000, 0.0000000 }; | |
1182 | ||
1183 | Int_t i; | |
a328fff9 | 1184 | Double_t energy = x[0]; |
a328fff9 | 1185 | |
030b4415 | 1186 | for (i = 0; i < npts; i++) { |
1187 | if (energy < arre[i]) { | |
1188 | break; | |
1189 | } | |
1190 | } | |
a328fff9 | 1191 | |
030b4415 | 1192 | if (i == 0) { |
1193 | AliErrorGeneral("AliTRDv1::IntSpecGeant","Given energy value is too small or zero"); | |
1194 | } | |
a328fff9 | 1195 | |
f57bb418 | 1196 | return arrdnde[i]; |
a328fff9 | 1197 | |
1198 | } |