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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> | |
fe4da5cc | 32 | |
d3f347ff | 33 | #include "AliConst.h" |
45160b1f | 34 | #include "AliLog.h" |
35 | #include "AliMC.h" | |
88cb7938 | 36 | #include "AliRun.h" |
030b4415 | 37 | |
88cb7938 | 38 | #include "AliTRDgeometry.h" |
793ff80c | 39 | #include "AliTRDhit.h" |
793ff80c | 40 | #include "AliTRDsim.h" |
88cb7938 | 41 | #include "AliTRDv1.h" |
851d3db9 | 42 | |
fe4da5cc | 43 | ClassImp(AliTRDv1) |
8230f242 | 44 | |
45 | //_____________________________________________________________________________ | |
030b4415 | 46 | AliTRDv1::AliTRDv1() |
47 | :AliTRD() | |
48 | ,fTRon(kFALSE) | |
49 | ,fTR(NULL) | |
50 | ,fTypeOfStepManager(0) | |
51 | ,fStepSize(0) | |
52 | ,fDeltaE(NULL) | |
53 | ,fDeltaG(NULL) | |
54 | ,fTrackLength0(0) | |
55 | ,fPrimaryTrackPid(0) | |
8230f242 | 56 | { |
57 | // | |
58 | // Default constructor | |
59 | // | |
60 | ||
8230f242 | 61 | } |
62 | ||
fe4da5cc | 63 | //_____________________________________________________________________________ |
64 | AliTRDv1::AliTRDv1(const char *name, const char *title) | |
030b4415 | 65 | :AliTRD(name,title) |
66 | ,fTRon(kTRUE) | |
67 | ,fTR(NULL) | |
68 | ,fTypeOfStepManager(1) | |
69 | ,fStepSize(0.1) | |
70 | ,fDeltaE(NULL) | |
71 | ,fDeltaG(NULL) | |
72 | ,fTrackLength0(0) | |
73 | ,fPrimaryTrackPid(0) | |
fe4da5cc | 74 | { |
75 | // | |
851d3db9 | 76 | // Standard constructor for Transition Radiation Detector version 1 |
fe4da5cc | 77 | // |
82bbf98a | 78 | |
5c7f4665 | 79 | SetBufferSize(128000); |
80 | ||
81 | } | |
82 | ||
8230f242 | 83 | //_____________________________________________________________________________ |
030b4415 | 84 | AliTRDv1::AliTRDv1(const AliTRDv1 &trd) |
85 | :AliTRD(trd) | |
86 | ,fTRon(trd.fTRon) | |
87 | ,fTR(NULL) | |
88 | ,fTypeOfStepManager(trd.fTypeOfStepManager) | |
89 | ,fStepSize(trd.fStepSize) | |
90 | ,fDeltaE(NULL) | |
91 | ,fDeltaG(NULL) | |
92 | ,fTrackLength0(trd.fTrackLength0) | |
93 | ,fPrimaryTrackPid(trd.fPrimaryTrackPid) | |
8230f242 | 94 | { |
95 | // | |
96 | // Copy constructor | |
97 | // | |
98 | ||
030b4415 | 99 | fDeltaE->Copy(*((AliTRDv1 &) trd).fDeltaE); |
100 | fDeltaG->Copy(*((AliTRDv1 &) trd).fDeltaG); | |
101 | fTR->Copy(*((AliTRDv1 &) trd).fTR); | |
8230f242 | 102 | |
103 | } | |
104 | ||
5c7f4665 | 105 | //_____________________________________________________________________________ |
106 | AliTRDv1::~AliTRDv1() | |
107 | { | |
dd9a6ee3 | 108 | // |
109 | // AliTRDv1 destructor | |
110 | // | |
82bbf98a | 111 | |
030b4415 | 112 | if (fDeltaE) { |
113 | delete fDeltaE; | |
114 | fDeltaE = 0; | |
115 | } | |
116 | ||
117 | if (fDeltaG) { | |
118 | delete fDeltaG; | |
119 | fDeltaG = 0; | |
120 | } | |
121 | ||
122 | if (fTR) { | |
123 | delete fTR; | |
124 | fTR = 0; | |
125 | } | |
82bbf98a | 126 | |
fe4da5cc | 127 | } |
128 | ||
dd9a6ee3 | 129 | //_____________________________________________________________________________ |
130 | AliTRDv1 &AliTRDv1::operator=(const AliTRDv1 &trd) | |
131 | { | |
132 | // | |
133 | // Assignment operator | |
134 | // | |
135 | ||
136 | if (this != &trd) ((AliTRDv1 &) trd).Copy(*this); | |
030b4415 | 137 | |
dd9a6ee3 | 138 | return *this; |
139 | ||
140 | } | |
8230f242 | 141 | |
142 | //_____________________________________________________________________________ | |
e0d47c25 | 143 | void AliTRDv1::Copy(TObject &trd) const |
8230f242 | 144 | { |
145 | // | |
146 | // Copy function | |
147 | // | |
148 | ||
a328fff9 | 149 | ((AliTRDv1 &) trd).fTypeOfStepManager = fTypeOfStepManager; |
150 | ((AliTRDv1 &) trd).fStepSize = fStepSize; | |
bd0f8685 | 151 | ((AliTRDv1 &) trd).fTRon = fTRon; |
030b4415 | 152 | ((AliTRDv1 &) trd).fTrackLength0 = fTrackLength0; |
153 | ((AliTRDv1 &) trd).fPrimaryTrackPid = fPrimaryTrackPid; | |
bd0f8685 | 154 | |
793ff80c | 155 | fDeltaE->Copy(*((AliTRDv1 &) trd).fDeltaE); |
a328fff9 | 156 | fDeltaG->Copy(*((AliTRDv1 &) trd).fDeltaG); |
793ff80c | 157 | fTR->Copy(*((AliTRDv1 &) trd).fTR); |
8230f242 | 158 | |
159 | } | |
160 | ||
fe4da5cc | 161 | //_____________________________________________________________________________ |
162 | void AliTRDv1::CreateGeometry() | |
163 | { | |
164 | // | |
851d3db9 | 165 | // Create the GEANT geometry for the Transition Radiation Detector - Version 1 |
5c7f4665 | 166 | // This version covers the full azimuth. |
d3f347ff | 167 | // |
168 | ||
82bbf98a | 169 | // Check that FRAME is there otherwise we have no place where to put the TRD |
8230f242 | 170 | AliModule* frame = gAlice->GetModule("FRAME"); |
030b4415 | 171 | if (!frame) { |
172 | AliError("TRD needs FRAME to be present\n"); | |
173 | return; | |
174 | } | |
d3f347ff | 175 | |
82bbf98a | 176 | // Define the chambers |
177 | AliTRD::CreateGeometry(); | |
d3f347ff | 178 | |
fe4da5cc | 179 | } |
180 | ||
181 | //_____________________________________________________________________________ | |
182 | void AliTRDv1::CreateMaterials() | |
183 | { | |
184 | // | |
851d3db9 | 185 | // Create materials for the Transition Radiation Detector version 1 |
fe4da5cc | 186 | // |
82bbf98a | 187 | |
d3f347ff | 188 | AliTRD::CreateMaterials(); |
82bbf98a | 189 | |
fe4da5cc | 190 | } |
191 | ||
793ff80c | 192 | //_____________________________________________________________________________ |
193 | void AliTRDv1::CreateTRhit(Int_t det) | |
194 | { | |
195 | // | |
196 | // Creates an electron cluster from a TR photon. | |
197 | // The photon is assumed to be created a the end of the radiator. The | |
198 | // distance after which it deposits its energy takes into account the | |
199 | // absorbtion of the entrance window and of the gas mixture in drift | |
200 | // volume. | |
201 | // | |
202 | ||
203 | // PDG code electron | |
204 | const Int_t kPdgElectron = 11; | |
205 | ||
206 | // Ionization energy | |
bc327ce2 | 207 | const Float_t kWion = 23.53; |
793ff80c | 208 | |
209 | // Maximum number of TR photons per track | |
210 | const Int_t kNTR = 50; | |
211 | ||
030b4415 | 212 | TLorentzVector mom; |
213 | TLorentzVector pos; | |
793ff80c | 214 | |
793ff80c | 215 | // Create TR at the entrance of the chamber |
216 | if (gMC->IsTrackEntering()) { | |
217 | ||
f73816f5 | 218 | // Create TR only for electrons |
219 | Int_t iPdg = gMC->TrackPid(); | |
030b4415 | 220 | if (TMath::Abs(iPdg) != kPdgElectron) { |
221 | return; | |
222 | } | |
f73816f5 | 223 | |
793ff80c | 224 | Float_t eTR[kNTR]; |
225 | Int_t nTR; | |
226 | ||
227 | // Create TR photons | |
228 | gMC->TrackMomentum(mom); | |
229 | Float_t pTot = mom.Rho(); | |
230 | fTR->CreatePhotons(iPdg,pTot,nTR,eTR); | |
231 | if (nTR > kNTR) { | |
45160b1f | 232 | AliFatal(Form("Boundary error: nTR = %d, kNTR = %d",nTR,kNTR)); |
793ff80c | 233 | } |
234 | ||
235 | // Loop through the TR photons | |
236 | for (Int_t iTR = 0; iTR < nTR; iTR++) { | |
237 | ||
238 | Float_t energyMeV = eTR[iTR] * 0.001; | |
239 | Float_t energyeV = eTR[iTR] * 1000.0; | |
030b4415 | 240 | Float_t absLength = 0.0; |
241 | Float_t sigma = 0.0; | |
793ff80c | 242 | |
243 | // Take the absorbtion in the entrance window into account | |
244 | Double_t muMy = fTR->GetMuMy(energyMeV); | |
030b4415 | 245 | sigma = muMy * fFoilDensity; |
842287f2 | 246 | if (sigma > 0.0) { |
247 | absLength = gRandom->Exp(1.0/sigma); | |
030b4415 | 248 | if (absLength < AliTRDgeometry::MyThick()) { |
249 | continue; | |
250 | } | |
842287f2 | 251 | } |
252 | else { | |
253 | continue; | |
254 | } | |
793ff80c | 255 | |
256 | // The absorbtion cross sections in the drift gas | |
3dac2b2d | 257 | // Gas-mixture (Xe/CO2) |
258 | Double_t muXe = fTR->GetMuXe(energyMeV); | |
259 | Double_t muCO = fTR->GetMuCO(energyMeV); | |
260 | sigma = (0.85 * muXe + 0.15 * muCO) * fGasDensity * fTR->GetTemp(); | |
793ff80c | 261 | |
262 | // The distance after which the energy of the TR photon | |
263 | // is deposited. | |
842287f2 | 264 | if (sigma > 0.0) { |
265 | absLength = gRandom->Exp(1.0/sigma); | |
a328fff9 | 266 | if (absLength > (AliTRDgeometry::DrThick() |
267 | + AliTRDgeometry::AmThick())) { | |
268 | continue; | |
269 | } | |
842287f2 | 270 | } |
271 | else { | |
272 | continue; | |
273 | } | |
793ff80c | 274 | |
275 | // The position of the absorbtion | |
276 | Float_t posHit[3]; | |
277 | gMC->TrackPosition(pos); | |
278 | posHit[0] = pos[0] + mom[0] / pTot * absLength; | |
279 | posHit[1] = pos[1] + mom[1] / pTot * absLength; | |
c4214bc0 | 280 | posHit[2] = pos[2] + mom[2] / pTot * absLength; |
793ff80c | 281 | |
282 | // Create the charge | |
283 | Int_t q = ((Int_t) (energyeV / kWion)); | |
284 | ||
285 | // Add the hit to the array. TR photon hits are marked | |
286 | // by negative charge | |
030b4415 | 287 | AddHit(gAlice->GetMCApp()->GetCurrentTrackNumber() |
288 | ,det | |
289 | ,posHit | |
290 | ,-q | |
291 | ,kTRUE); | |
793ff80c | 292 | |
293 | } | |
294 | ||
295 | } | |
296 | ||
297 | } | |
298 | ||
5c7f4665 | 299 | //_____________________________________________________________________________ |
300 | void AliTRDv1::Init() | |
301 | { | |
302 | // | |
303 | // Initialise Transition Radiation Detector after geometry has been built. | |
5c7f4665 | 304 | // |
305 | ||
306 | AliTRD::Init(); | |
307 | ||
45160b1f | 308 | AliDebug(1,"Slow simulator\n"); |
bd0f8685 | 309 | |
310 | // Switch on TR simulation as default | |
311 | if (!fTRon) { | |
45160b1f | 312 | AliInfo("TR simulation off"); |
bd0f8685 | 313 | } |
314 | else { | |
315 | fTR = new AliTRDsim(); | |
316 | } | |
5c7f4665 | 317 | |
318 | // First ionization potential (eV) for the gas mixture (90% Xe + 10% CO2) | |
319 | const Float_t kPoti = 12.1; | |
320 | // Maximum energy (50 keV); | |
321 | const Float_t kEend = 50000.0; | |
322 | // Ermilova distribution for the delta-ray spectrum | |
030b4415 | 323 | Float_t poti = TMath::Log(kPoti); |
324 | Float_t eEnd = TMath::Log(kEend); | |
a328fff9 | 325 | |
326 | // Ermilova distribution for the delta-ray spectrum | |
c4214bc0 | 327 | fDeltaE = new TF1("deltae" ,Ermilova ,poti,eEnd,0); |
a328fff9 | 328 | |
329 | // Geant3 distribution for the delta-ray spectrum | |
c4214bc0 | 330 | fDeltaG = new TF1("deltag",IntSpecGeant,2.421257,28.536469,0); |
5c7f4665 | 331 | |
45160b1f | 332 | AliDebug(1,"+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++"); |
5c7f4665 | 333 | |
fe4da5cc | 334 | } |
335 | ||
5c7f4665 | 336 | //_____________________________________________________________________________ |
337 | void AliTRDv1::StepManager() | |
a328fff9 | 338 | { |
339 | // | |
c4214bc0 | 340 | // Slow simulator. Every charged track produces electron cluster as hits |
a328fff9 | 341 | // along its path across the drift volume. |
342 | // | |
343 | ||
344 | switch (fTypeOfStepManager) { | |
345 | case 0 : StepManagerErmilova(); break; // 0 is Ermilova | |
346 | case 1 : StepManagerGeant(); break; // 1 is Geant | |
347 | case 2 : StepManagerFixedStep(); break; // 2 is fixed step | |
45160b1f | 348 | default : AliWarning("Not a valid Step Manager."); |
a328fff9 | 349 | } |
350 | ||
351 | } | |
352 | ||
353 | //_____________________________________________________________________________ | |
354 | void AliTRDv1::SelectStepManager(Int_t t) | |
355 | { | |
356 | // | |
357 | // Selects a step manager type: | |
358 | // 0 - Ermilova | |
359 | // 1 - Geant3 | |
360 | // 2 - Fixed step size | |
361 | // | |
362 | ||
a328fff9 | 363 | fTypeOfStepManager = t; |
45160b1f | 364 | AliInfo(Form("Step Manager type %d was selected",fTypeOfStepManager)); |
a328fff9 | 365 | |
366 | } | |
367 | ||
368 | //_____________________________________________________________________________ | |
369 | void AliTRDv1::StepManagerGeant() | |
370 | { | |
371 | // | |
c4214bc0 | 372 | // Slow simulator. Every charged track produces electron cluster as hits |
a328fff9 | 373 | // along its path across the drift volume. The step size is set acording |
374 | // to Bethe-Bloch. The energy distribution of the delta electrons follows | |
375 | // a spectrum taken from Geant3. | |
376 | // | |
f2e3a0b5 | 377 | // Version by A. Bercuci |
378 | // | |
379 | ||
c4214bc0 | 380 | Int_t pla = 0; |
381 | Int_t cha = 0; | |
382 | Int_t sec = 0; | |
383 | Int_t det = 0; | |
384 | Int_t iPdg; | |
385 | Int_t qTot; | |
386 | ||
387 | Float_t hits[3]; | |
388 | Float_t charge; | |
389 | Float_t aMass; | |
390 | ||
030b4415 | 391 | Double_t pTot = 0; |
c4214bc0 | 392 | Double_t eDelta; |
030b4415 | 393 | Double_t betaGamma; |
394 | Double_t pp; | |
f2e3a0b5 | 395 | Double_t stepSize = 0; |
c4214bc0 | 396 | |
397 | Bool_t drRegion = kFALSE; | |
398 | Bool_t amRegion = kFALSE; | |
399 | ||
400 | TString cIdCurrent; | |
401 | TString cIdSensDr = "J"; | |
402 | TString cIdSensAm = "K"; | |
403 | Char_t cIdChamber[3]; | |
404 | cIdChamber[2] = 0; | |
405 | ||
030b4415 | 406 | TLorentzVector pos; |
407 | TLorentzVector mom; | |
c4214bc0 | 408 | |
030b4415 | 409 | TArrayI processes; |
f2e3a0b5 | 410 | |
c4214bc0 | 411 | const Int_t kNplan = AliTRDgeometry::Nplan(); |
412 | const Int_t kNcham = AliTRDgeometry::Ncham(); | |
413 | const Int_t kNdetsec = kNplan * kNcham; | |
414 | ||
030b4415 | 415 | const Double_t kBig = 1.0e+12; // Infinitely big |
bc327ce2 | 416 | const Float_t kWion = 23.53; // Ionization energy |
c4214bc0 | 417 | const Float_t kPTotMaxEl = 0.002; // Maximum momentum for e+ e- g |
418 | ||
419 | // Minimum energy for the step size adjustment | |
420 | const Float_t kEkinMinStep = 1.0e-5; | |
421 | // energy threshold for production of delta electrons | |
f2e3a0b5 | 422 | const Float_t kECut = 1.0e4; |
423 | // Parameters entering the parametrized range for delta electrons | |
030b4415 | 424 | const Float_t kRa = 5.37e-4; |
f2e3a0b5 | 425 | const Float_t kRb = 0.9815; |
030b4415 | 426 | const Float_t kRc = 3.123e-3; |
f2e3a0b5 | 427 | // Gas density -> To be made user adjustable ! |
030b4415 | 428 | // [0.85*0.00549+0.15*0.00186 (Xe-CO2 85-15)] |
429 | const Float_t kRho = 0.004945 ; | |
a328fff9 | 430 | |
c4214bc0 | 431 | // Plateau value of the energy-loss for electron in xenon |
030b4415 | 432 | // The averaged value (26/3/99) |
c4214bc0 | 433 | const Float_t kPlateau = 1.55; |
030b4415 | 434 | // dN1/dx|min for the gas mixture (90% Xe + 10% CO2) |
435 | const Float_t kPrim = 19.34; | |
c4214bc0 | 436 | // First ionization potential (eV) for the gas mixture (90% Xe + 10% CO2) |
437 | const Float_t kPoti = 12.1; | |
030b4415 | 438 | // PDG code electron |
439 | const Int_t kPdgElectron = 11; | |
c4214bc0 | 440 | |
441 | // Set the maximum step size to a very large number for all | |
442 | // neutral particles and those outside the driftvolume | |
443 | gMC->SetMaxStep(kBig); | |
444 | ||
445 | // Use only charged tracks | |
446 | if (( gMC->TrackCharge() ) && | |
c4214bc0 | 447 | (!gMC->IsTrackDisappeared())) { |
448 | ||
449 | // Inside a sensitive volume? | |
450 | drRegion = kFALSE; | |
451 | amRegion = kFALSE; | |
452 | cIdCurrent = gMC->CurrentVolName(); | |
453 | if (cIdSensDr == cIdCurrent[1]) { | |
454 | drRegion = kTRUE; | |
455 | } | |
456 | if (cIdSensAm == cIdCurrent[1]) { | |
457 | amRegion = kTRUE; | |
458 | } | |
459 | if (drRegion || amRegion) { | |
a328fff9 | 460 | |
c4214bc0 | 461 | // The hit coordinates and charge |
462 | gMC->TrackPosition(pos); | |
463 | hits[0] = pos[0]; | |
464 | hits[1] = pos[1]; | |
465 | hits[2] = pos[2]; | |
466 | ||
467 | // The sector number (0 - 17) | |
468 | // The numbering goes clockwise and starts at y = 0 | |
469 | Float_t phi = kRaddeg*TMath::ATan2(pos[0],pos[1]); | |
030b4415 | 470 | if (phi < 90.0) { |
471 | phi = phi + 270.0; | |
472 | } | |
473 | else { | |
474 | phi = phi - 90.0; | |
475 | } | |
476 | sec = ((Int_t) (phi / 20.0)); | |
c4214bc0 | 477 | |
478 | // The plane and chamber number | |
030b4415 | 479 | cIdChamber[0] = cIdCurrent[2]; |
480 | cIdChamber[1] = cIdCurrent[3]; | |
c4214bc0 | 481 | Int_t idChamber = (atoi(cIdChamber) % kNdetsec); |
482 | cha = kNcham - ((Int_t) idChamber / kNplan) - 1; | |
483 | pla = ((Int_t) idChamber % kNplan); | |
484 | ||
485 | // Check on selected volumes | |
486 | Int_t addthishit = 1; | |
c4214bc0 | 487 | |
488 | // Add this hit | |
489 | if (addthishit) { | |
490 | ||
491 | // The detector number | |
492 | det = fGeometry->GetDetector(pla,cha,sec); | |
493 | ||
494 | // Special hits only in the drift region | |
495 | if (drRegion) { | |
f2e3a0b5 | 496 | |
c4214bc0 | 497 | // Create a track reference at the entrance and |
498 | // exit of each chamber that contain the | |
f2e3a0b5 | 499 | // momentum components of the particle |
030b4415 | 500 | if (gMC->IsTrackEntering() || |
501 | gMC->IsTrackExiting()) { | |
c4214bc0 | 502 | gMC->TrackMomentum(mom); |
503 | AddTrackReference(gAlice->GetMCApp()->GetCurrentTrackNumber()); | |
504 | } | |
f2e3a0b5 | 505 | |
030b4415 | 506 | if (gMC->IsTrackEntering() && |
507 | !gMC->IsNewTrack()) { | |
f2e3a0b5 | 508 | // determine if hit belong to primary track |
509 | fPrimaryTrackPid = gAlice->GetMCApp()->GetCurrentTrackNumber(); | |
510 | // determine track length when entering the detector | |
511 | fTrackLength0 = gMC->TrackLength(); | |
512 | } | |
c4214bc0 | 513 | |
f2e3a0b5 | 514 | // Create the hits from TR photons |
c4214bc0 | 515 | if (fTR) CreateTRhit(det); |
c4214bc0 | 516 | |
f2e3a0b5 | 517 | } |
c4214bc0 | 518 | |
f2e3a0b5 | 519 | // Calculate the energy of the delta-electrons |
520 | // modified by Alex Bercuci (A.Bercuci@gsi.de) on 26.01.06 | |
521 | // take into account correlation with the underlying GEANT tracking | |
522 | // mechanism. see | |
523 | // http://www-linux.gsi.de/~abercuci/Contributions/TRD/index.html | |
524 | // | |
525 | // determine the most significant process (last on the processes list) | |
526 | // which caused this hit | |
c4214bc0 | 527 | gMC->StepProcesses(processes); |
f2e3a0b5 | 528 | Int_t nofprocesses = processes.GetSize(); |
529 | Int_t pid; | |
530 | if (!nofprocesses) { | |
531 | pid = 0; | |
532 | } | |
533 | else { | |
534 | pid = processes[nofprocesses-1]; | |
535 | } | |
536 | ||
537 | // generate Edep according to GEANT parametrisation | |
538 | eDelta = TMath::Exp(fDeltaG->GetRandom()) - kPoti; | |
539 | eDelta = TMath::Max(eDelta,0.0); | |
030b4415 | 540 | Float_t prRange = 0.0; |
541 | Float_t range = gMC->TrackLength() - fTrackLength0; | |
f2e3a0b5 | 542 | // merge GEANT tracker information with locally cooked one |
543 | if (gAlice->GetMCApp()->GetCurrentTrackNumber() == fPrimaryTrackPid) { | |
f2e3a0b5 | 544 | if (pid == 27) { |
545 | if (eDelta >= kECut) { | |
030b4415 | 546 | prRange = kRa * eDelta * 0.001 |
547 | * (1.0 - kRb / (1.0 + kRc * eDelta * 0.001)) / kRho; | |
548 | if (prRange >= (3.7 - range)) { | |
549 | eDelta *= 0.1; | |
550 | } | |
f2e3a0b5 | 551 | } |
552 | } | |
553 | else if (pid == 1) { | |
554 | if (eDelta < kECut) { | |
555 | eDelta *= 0.5; | |
556 | } | |
557 | else { | |
030b4415 | 558 | prRange = kRa * eDelta * 0.001 |
559 | * (1.0 - kRb / (1.0 + kRc * eDelta * 0.001)) / kRho; | |
560 | if (prRange >= ((AliTRDgeometry::DrThick() | |
561 | + AliTRDgeometry::AmThick()) - range)) { | |
f2e3a0b5 | 562 | eDelta *= 0.05; |
563 | } | |
564 | else { | |
565 | eDelta *= 0.5; | |
566 | } | |
567 | } | |
568 | } | |
569 | else { | |
570 | eDelta = 0.0; | |
571 | } | |
572 | } | |
573 | else { | |
574 | eDelta = 0.0; | |
575 | } | |
c4214bc0 | 576 | |
577 | // Generate the electron cluster size | |
f2e3a0b5 | 578 | if (eDelta == 0.0) { |
579 | qTot = 0; | |
580 | } | |
581 | else { | |
582 | qTot = ((Int_t) (eDelta / kWion) + 1); | |
583 | } | |
584 | ||
585 | // Create a new dEdx hit | |
030b4415 | 586 | AddHit(gAlice->GetMCApp()->GetCurrentTrackNumber() |
587 | ,det | |
588 | ,hits | |
589 | ,qTot | |
590 | ,drRegion); | |
c4214bc0 | 591 | |
592 | // Calculate the maximum step size for the next tracking step | |
593 | // Produce only one hit if Ekin is below cutoff | |
594 | aMass = gMC->TrackMass(); | |
595 | if ((gMC->Etot() - aMass) > kEkinMinStep) { | |
596 | ||
597 | // The energy loss according to Bethe Bloch | |
f2e3a0b5 | 598 | iPdg = TMath::Abs(gMC->TrackPid()); |
599 | if ((iPdg != kPdgElectron) || | |
030b4415 | 600 | ((iPdg == kPdgElectron) && |
601 | (pTot < kPTotMaxEl))) { | |
c4214bc0 | 602 | gMC->TrackMomentum(mom); |
603 | pTot = mom.Rho(); | |
604 | betaGamma = pTot / aMass; | |
605 | pp = BetheBlochGeant(betaGamma); | |
f2e3a0b5 | 606 | // Take charge > 1 into account |
030b4415 | 607 | charge = gMC->TrackCharge(); |
f2e3a0b5 | 608 | if (TMath::Abs(charge) > 1) { |
609 | pp = pp * charge*charge; | |
610 | } | |
611 | } | |
612 | else { | |
613 | // Electrons above 20 Mev/c are at the plateau | |
614 | pp = kPrim * kPlateau; | |
c4214bc0 | 615 | } |
616 | ||
1b775a44 | 617 | Int_t nsteps = 0; |
030b4415 | 618 | do { |
619 | nsteps = gRandom->Poisson(pp); | |
620 | } while(!nsteps); | |
621 | stepSize = 1.0 / nsteps; | |
1b775a44 | 622 | gMC->SetMaxStep(stepSize); |
f2e3a0b5 | 623 | |
1b775a44 | 624 | } |
f2e3a0b5 | 625 | |
c4214bc0 | 626 | } |
f2e3a0b5 | 627 | |
c4214bc0 | 628 | } |
f2e3a0b5 | 629 | |
c4214bc0 | 630 | } |
f2e3a0b5 | 631 | |
a328fff9 | 632 | } |
633 | ||
634 | //_____________________________________________________________________________ | |
635 | void AliTRDv1::StepManagerErmilova() | |
5c7f4665 | 636 | { |
637 | // | |
5c7f4665 | 638 | // Slow simulator. Every charged track produces electron cluster as hits |
639 | // along its path across the drift volume. The step size is set acording | |
640 | // to Bethe-Bloch. The energy distribution of the delta electrons follows | |
641 | // a spectrum taken from Ermilova et al. | |
642 | // | |
643 | ||
851d3db9 | 644 | Int_t pla = 0; |
645 | Int_t cha = 0; | |
646 | Int_t sec = 0; | |
793ff80c | 647 | Int_t det = 0; |
851d3db9 | 648 | Int_t iPdg; |
793ff80c | 649 | Int_t qTot; |
5c7f4665 | 650 | |
793ff80c | 651 | Float_t hits[3]; |
a5cadd36 | 652 | Double_t random[1]; |
5c7f4665 | 653 | Float_t charge; |
654 | Float_t aMass; | |
655 | ||
030b4415 | 656 | Double_t pTot = 0.0; |
5c7f4665 | 657 | Double_t eDelta; |
030b4415 | 658 | Double_t betaGamma; |
659 | Double_t pp; | |
f73816f5 | 660 | Double_t stepSize; |
5c7f4665 | 661 | |
332e9569 | 662 | Bool_t drRegion = kFALSE; |
663 | Bool_t amRegion = kFALSE; | |
664 | ||
665 | TString cIdCurrent; | |
666 | TString cIdSensDr = "J"; | |
667 | TString cIdSensAm = "K"; | |
593a9fc3 | 668 | Char_t cIdChamber[3]; |
669 | cIdChamber[2] = 0; | |
332e9569 | 670 | |
030b4415 | 671 | TLorentzVector pos; |
672 | TLorentzVector mom; | |
82bbf98a | 673 | |
332e9569 | 674 | const Int_t kNplan = AliTRDgeometry::Nplan(); |
e644678a | 675 | const Int_t kNcham = AliTRDgeometry::Ncham(); |
676 | const Int_t kNdetsec = kNplan * kNcham; | |
677 | ||
030b4415 | 678 | const Double_t kBig = 1.0e+12; // Infinitely big |
bc327ce2 | 679 | const Float_t kWion = 23.53; // Ionization energy |
a328fff9 | 680 | const Float_t kPTotMaxEl = 0.002; // Maximum momentum for e+ e- g |
5c7f4665 | 681 | |
f73816f5 | 682 | // Minimum energy for the step size adjustment |
683 | const Float_t kEkinMinStep = 1.0e-5; | |
a328fff9 | 684 | |
5c7f4665 | 685 | // Plateau value of the energy-loss for electron in xenon |
030b4415 | 686 | // The averaged value (26/3/99) |
a3c76cdc | 687 | const Float_t kPlateau = 1.55; |
030b4415 | 688 | // dN1/dx|min for the gas mixture (90% Xe + 10% CO2) |
689 | const Float_t kPrim = 48.0; | |
5c7f4665 | 690 | // First ionization potential (eV) for the gas mixture (90% Xe + 10% CO2) |
a3c76cdc | 691 | const Float_t kPoti = 12.1; |
030b4415 | 692 | // PDG code electron |
693 | const Int_t kPdgElectron = 11; | |
5c7f4665 | 694 | |
695 | // Set the maximum step size to a very large number for all | |
696 | // neutral particles and those outside the driftvolume | |
697 | gMC->SetMaxStep(kBig); | |
698 | ||
699 | // Use only charged tracks | |
700 | if (( gMC->TrackCharge() ) && | |
5c7f4665 | 701 | (!gMC->IsTrackDisappeared())) { |
fe4da5cc | 702 | |
5c7f4665 | 703 | // Inside a sensitive volume? |
332e9569 | 704 | drRegion = kFALSE; |
705 | amRegion = kFALSE; | |
706 | cIdCurrent = gMC->CurrentVolName(); | |
e6674585 | 707 | if (cIdSensDr == cIdCurrent[1]) { |
332e9569 | 708 | drRegion = kTRUE; |
709 | } | |
e6674585 | 710 | if (cIdSensAm == cIdCurrent[1]) { |
332e9569 | 711 | amRegion = kTRUE; |
712 | } | |
713 | if (drRegion || amRegion) { | |
fe4da5cc | 714 | |
5c7f4665 | 715 | // The hit coordinates and charge |
716 | gMC->TrackPosition(pos); | |
717 | hits[0] = pos[0]; | |
718 | hits[1] = pos[1]; | |
719 | hits[2] = pos[2]; | |
5c7f4665 | 720 | |
851d3db9 | 721 | // The sector number (0 - 17) |
722 | // The numbering goes clockwise and starts at y = 0 | |
e15eb584 | 723 | Float_t phi = kRaddeg*TMath::ATan2(pos[0],pos[1]); |
030b4415 | 724 | if (phi < 90.0) { |
725 | phi = phi + 270.0; | |
726 | } | |
727 | else { | |
728 | phi = phi - 90.0; | |
729 | } | |
730 | sec = ((Int_t) (phi / 20.0)); | |
82bbf98a | 731 | |
332e9569 | 732 | // The plane and chamber number |
733 | cIdChamber[0] = cIdCurrent[2]; | |
734 | cIdChamber[1] = cIdCurrent[3]; | |
e644678a | 735 | Int_t idChamber = (atoi(cIdChamber) % kNdetsec); |
a5cadd36 | 736 | cha = kNcham - ((Int_t) idChamber / kNplan) - 1; |
332e9569 | 737 | pla = ((Int_t) idChamber % kNplan); |
82bbf98a | 738 | |
5c7f4665 | 739 | // Check on selected volumes |
740 | Int_t addthishit = 1; | |
5c7f4665 | 741 | |
742 | // Add this hit | |
743 | if (addthishit) { | |
744 | ||
f73816f5 | 745 | // The detector number |
793ff80c | 746 | det = fGeometry->GetDetector(pla,cha,sec); |
747 | ||
a328fff9 | 748 | // Special hits only in the drift region |
332e9569 | 749 | if (drRegion) { |
f73816f5 | 750 | |
c61f1a66 | 751 | // Create a track reference at the entrance and |
752 | // exit of each chamber that contain the | |
753 | // momentum components of the particle | |
030b4415 | 754 | if (gMC->IsTrackEntering() || |
755 | gMC->IsTrackExiting()) { | |
f73816f5 | 756 | gMC->TrackMomentum(mom); |
5d12ce38 | 757 | AddTrackReference(gAlice->GetMCApp()->GetCurrentTrackNumber()); |
f73816f5 | 758 | } |
f73816f5 | 759 | // Create the hits from TR photons |
030b4415 | 760 | if (fTR) { |
761 | CreateTRhit(det); | |
762 | } | |
f73816f5 | 763 | |
030b4415 | 764 | } |
f73816f5 | 765 | |
766 | // Calculate the energy of the delta-electrons | |
767 | eDelta = TMath::Exp(fDeltaE->GetRandom()) - kPoti; | |
768 | eDelta = TMath::Max(eDelta,0.0); | |
c4214bc0 | 769 | // Generate the electron cluster size |
030b4415 | 770 | if (eDelta == 0.0) { |
771 | qTot = 0; | |
772 | } | |
773 | else { | |
774 | qTot = ((Int_t) (eDelta / kWion) + 1); | |
775 | } | |
f73816f5 | 776 | |
030b4415 | 777 | // Create a new dEdx hit |
332e9569 | 778 | if (drRegion) { |
a328fff9 | 779 | AddHit(gAlice->GetMCApp()->GetCurrentTrackNumber() |
030b4415 | 780 | ,det |
781 | ,hits | |
782 | ,qTot | |
783 | ,kTRUE); | |
784 | } | |
5c7f4665 | 785 | else { |
a328fff9 | 786 | AddHit(gAlice->GetMCApp()->GetCurrentTrackNumber() |
030b4415 | 787 | ,det |
788 | ,hits | |
789 | ,qTot | |
790 | ,kFALSE); | |
791 | } | |
f73816f5 | 792 | |
5c7f4665 | 793 | // Calculate the maximum step size for the next tracking step |
f73816f5 | 794 | // Produce only one hit if Ekin is below cutoff |
795 | aMass = gMC->TrackMass(); | |
796 | if ((gMC->Etot() - aMass) > kEkinMinStep) { | |
797 | ||
798 | // The energy loss according to Bethe Bloch | |
799 | iPdg = TMath::Abs(gMC->TrackPid()); | |
030b4415 | 800 | if ((iPdg != kPdgElectron) || |
801 | ((iPdg == kPdgElectron) && | |
802 | (pTot < kPTotMaxEl))) { | |
f73816f5 | 803 | gMC->TrackMomentum(mom); |
804 | pTot = mom.Rho(); | |
805 | betaGamma = pTot / aMass; | |
806 | pp = kPrim * BetheBloch(betaGamma); | |
807 | // Take charge > 1 into account | |
808 | charge = gMC->TrackCharge(); | |
030b4415 | 809 | if (TMath::Abs(charge) > 1) { |
810 | pp = pp * charge*charge; | |
811 | } | |
812 | } | |
813 | else { | |
814 | // Electrons above 20 Mev/c are at the plateau | |
815 | pp = kPrim * kPlateau; | |
f73816f5 | 816 | } |
817 | ||
030b4415 | 818 | if (pp > 0.0) { |
819 | do { | |
820 | gMC->GetRandom()->RndmArray(1,random); | |
821 | } | |
822 | while ((random[0] == 1.0) || | |
823 | (random[0] == 0.0)); | |
f73816f5 | 824 | stepSize = - TMath::Log(random[0]) / pp; |
825 | gMC->SetMaxStep(stepSize); | |
030b4415 | 826 | } |
827 | ||
828 | } | |
829 | ||
5c7f4665 | 830 | } |
030b4415 | 831 | |
d3f347ff | 832 | } |
030b4415 | 833 | |
5c7f4665 | 834 | } |
030b4415 | 835 | |
5c7f4665 | 836 | } |
837 | ||
a328fff9 | 838 | //_____________________________________________________________________________ |
839 | void AliTRDv1::StepManagerFixedStep() | |
840 | { | |
841 | // | |
842 | // Slow simulator. Every charged track produces electron cluster as hits | |
843 | // along its path across the drift volume. The step size is fixed in | |
844 | // this version of the step manager. | |
845 | // | |
846 | ||
847 | Int_t pla = 0; | |
848 | Int_t cha = 0; | |
849 | Int_t sec = 0; | |
850 | Int_t det = 0; | |
851 | Int_t qTot; | |
852 | ||
853 | Float_t hits[3]; | |
854 | Double_t eDep; | |
855 | ||
856 | Bool_t drRegion = kFALSE; | |
857 | Bool_t amRegion = kFALSE; | |
858 | ||
859 | TString cIdCurrent; | |
860 | TString cIdSensDr = "J"; | |
861 | TString cIdSensAm = "K"; | |
862 | Char_t cIdChamber[3]; | |
863 | cIdChamber[2] = 0; | |
864 | ||
030b4415 | 865 | TLorentzVector pos; |
866 | TLorentzVector mom; | |
a328fff9 | 867 | |
868 | const Int_t kNplan = AliTRDgeometry::Nplan(); | |
869 | const Int_t kNcham = AliTRDgeometry::Ncham(); | |
870 | const Int_t kNdetsec = kNplan * kNcham; | |
871 | ||
030b4415 | 872 | const Double_t kBig = 1.0e+12; |
a328fff9 | 873 | |
bc327ce2 | 874 | const Float_t kWion = 23.53; // Ionization energy |
a328fff9 | 875 | const Float_t kEkinMinStep = 1.0e-5; // Minimum energy for the step size adjustment |
876 | ||
877 | // Set the maximum step size to a very large number for all | |
878 | // neutral particles and those outside the driftvolume | |
879 | gMC->SetMaxStep(kBig); | |
880 | ||
881 | // If not charged track or already stopped or disappeared, just return. | |
882 | if ((!gMC->TrackCharge()) || | |
a328fff9 | 883 | gMC->IsTrackDisappeared()) return; |
884 | ||
885 | // Inside a sensitive volume? | |
886 | cIdCurrent = gMC->CurrentVolName(); | |
887 | ||
888 | if (cIdSensDr == cIdCurrent[1]) drRegion = kTRUE; | |
889 | if (cIdSensAm == cIdCurrent[1]) amRegion = kTRUE; | |
890 | ||
030b4415 | 891 | if ((!drRegion) && |
892 | (!amRegion)) { | |
893 | return; | |
894 | } | |
a328fff9 | 895 | |
896 | // The hit coordinates and charge | |
897 | gMC->TrackPosition(pos); | |
898 | hits[0] = pos[0]; | |
899 | hits[1] = pos[1]; | |
900 | hits[2] = pos[2]; | |
901 | ||
902 | // The sector number (0 - 17) | |
903 | // The numbering goes clockwise and starts at y = 0 | |
904 | Float_t phi = kRaddeg*TMath::ATan2(pos[0],pos[1]); | |
030b4415 | 905 | if (phi < 90.0) { |
906 | phi = phi + 270.0; | |
907 | } | |
908 | else { | |
909 | phi = phi - 90.0; | |
910 | } | |
911 | sec = ((Int_t) (phi / 20.0)); | |
a328fff9 | 912 | |
913 | // The plane and chamber number | |
030b4415 | 914 | cIdChamber[0] = cIdCurrent[2]; |
915 | cIdChamber[1] = cIdCurrent[3]; | |
a328fff9 | 916 | Int_t idChamber = (atoi(cIdChamber) % kNdetsec); |
a5cadd36 | 917 | cha = kNcham - ((Int_t) idChamber / kNplan) - 1; |
a328fff9 | 918 | pla = ((Int_t) idChamber % kNplan); |
e0d47c25 | 919 | |
a328fff9 | 920 | // Check on selected volumes |
921 | Int_t addthishit = 1; | |
a328fff9 | 922 | |
030b4415 | 923 | if (!addthishit) { |
924 | return; | |
925 | } | |
a328fff9 | 926 | |
030b4415 | 927 | // The detector number |
928 | det = fGeometry->GetDetector(pla,cha,sec); | |
929 | ||
930 | // 0: InFlight 1:Entering 2:Exiting | |
931 | Int_t trkStat = 0; | |
a328fff9 | 932 | |
933 | // Special hits only in the drift region | |
934 | if (drRegion) { | |
935 | ||
936 | // Create a track reference at the entrance and exit of each | |
937 | // chamber that contain the momentum components of the particle | |
938 | ||
939 | if (gMC->IsTrackEntering()) { | |
940 | gMC->TrackMomentum(mom); | |
941 | AddTrackReference(gAlice->GetMCApp()->GetCurrentTrackNumber()); | |
942 | trkStat = 1; | |
943 | } | |
944 | if (gMC->IsTrackExiting()) { | |
945 | gMC->TrackMomentum(mom); | |
946 | AddTrackReference(gAlice->GetMCApp()->GetCurrentTrackNumber()); | |
947 | trkStat = 2; | |
948 | } | |
949 | ||
950 | // Create the hits from TR photons | |
030b4415 | 951 | if (fTR) { |
952 | CreateTRhit(det); | |
953 | } | |
a328fff9 | 954 | |
955 | } | |
956 | ||
957 | // Calculate the charge according to GEANT Edep | |
958 | // Create a new dEdx hit | |
959 | eDep = TMath::Max(gMC->Edep(),0.0) * 1.0e+09; | |
960 | qTot = (Int_t) (eDep / kWion); | |
c4214bc0 | 961 | AddHit(gAlice->GetMCApp()->GetCurrentTrackNumber() |
030b4415 | 962 | ,det |
963 | ,hits | |
964 | ,qTot | |
965 | ,drRegion); | |
a328fff9 | 966 | |
967 | // Set Maximum Step Size | |
968 | // Produce only one hit if Ekin is below cutoff | |
030b4415 | 969 | if ((gMC->Etot() - gMC->TrackMass()) < kEkinMinStep) { |
970 | return; | |
971 | } | |
a328fff9 | 972 | gMC->SetMaxStep(fStepSize); |
973 | ||
974 | } | |
975 | ||
5c7f4665 | 976 | //_____________________________________________________________________________ |
977 | Double_t AliTRDv1::BetheBloch(Double_t bg) | |
978 | { | |
979 | // | |
980 | // Parametrization of the Bethe-Bloch-curve | |
981 | // The parametrization is the same as for the TPC and is taken from Lehrhaus. | |
982 | // | |
983 | ||
984 | // This parameters have been adjusted to averaged values from GEANT | |
985 | const Double_t kP1 = 7.17960e-02; | |
986 | const Double_t kP2 = 8.54196; | |
987 | const Double_t kP3 = 1.38065e-06; | |
988 | const Double_t kP4 = 5.30972; | |
989 | const Double_t kP5 = 2.83798; | |
990 | ||
f73816f5 | 991 | // Lower cutoff of the Bethe-Bloch-curve to limit step sizes |
992 | const Double_t kBgMin = 0.8; | |
993 | const Double_t kBBMax = 6.83298; | |
f73816f5 | 994 | |
995 | if (bg > kBgMin) { | |
030b4415 | 996 | Double_t yy = bg / TMath::Sqrt(1.0 + bg*bg); |
5c7f4665 | 997 | Double_t aa = TMath::Power(yy,kP4); |
030b4415 | 998 | Double_t bb = TMath::Power((1.0/bg),kP5); |
5c7f4665 | 999 | bb = TMath::Log(kP3 + bb); |
030b4415 | 1000 | return ((kP2 - aa - bb) * kP1 / aa); |
5c7f4665 | 1001 | } |
f73816f5 | 1002 | else { |
1003 | return kBBMax; | |
1004 | } | |
d3f347ff | 1005 | |
fe4da5cc | 1006 | } |
5c7f4665 | 1007 | |
a328fff9 | 1008 | //_____________________________________________________________________________ |
c4214bc0 | 1009 | Double_t AliTRDv1::BetheBlochGeant(Double_t bg) |
a328fff9 | 1010 | { |
1011 | // | |
1012 | // Return dN/dx (number of primary collisions per centimeter) | |
1013 | // for given beta*gamma factor. | |
1014 | // | |
1015 | // Implemented by K.Oyama according to GEANT 3 parametrization shown in | |
1016 | // A.Andronic's webpage: http://www-alice.gsi.de/trd/papers/dedx/dedx.html | |
1017 | // This must be used as a set with IntSpecGeant. | |
1018 | // | |
1019 | ||
030b4415 | 1020 | Int_t i = 0; |
a328fff9 | 1021 | |
030b4415 | 1022 | Double_t arrG[20] = { 1.100000, 1.200000, 1.300000, 1.500000 |
1023 | , 1.800000, 2.000000, 2.500000, 3.000000 | |
1024 | , 4.000000, 7.000000, 10.000000, 20.000000 | |
1025 | , 40.000000, 70.000000, 100.000000, 300.000000 | |
1026 | , 600.000000, 1000.000000, 3000.000000, 10000.000000 }; | |
a328fff9 | 1027 | |
030b4415 | 1028 | Double_t arrNC[20] = { 75.009056, 45.508083, 35.299252, 27.116327 |
1029 | , 22.734999, 21.411915, 19.934095, 19.449375 | |
1030 | , 19.344431, 20.185553, 21.027925, 22.912676 | |
1031 | , 24.933352, 26.504053, 27.387468, 29.566597 | |
1032 | , 30.353779, 30.787134, 31.129285, 31.157350 }; | |
1033 | ||
1034 | // Betagamma to gamma | |
1035 | Double_t g = TMath::Sqrt(1.0 + bg*bg); | |
a328fff9 | 1036 | |
1037 | // Find the index just before the point we need. | |
030b4415 | 1038 | for (i = 0; i < 18; i++) { |
1039 | if ((arrG[i] < g) && | |
1040 | (arrG[i+1] > g)) { | |
a328fff9 | 1041 | break; |
030b4415 | 1042 | } |
1043 | } | |
a328fff9 | 1044 | |
1045 | // Simple interpolation. | |
030b4415 | 1046 | Double_t pp = ((arrNC[i+1] - arrNC[i]) / (arrG[i+1] - arrG[i])) |
1047 | * (g - arrG[i]) + arrNC[i]; | |
a328fff9 | 1048 | |
030b4415 | 1049 | return pp; |
a328fff9 | 1050 | |
1051 | } | |
1052 | ||
5c7f4665 | 1053 | //_____________________________________________________________________________ |
1054 | Double_t Ermilova(Double_t *x, Double_t *) | |
1055 | { | |
1056 | // | |
1057 | // Calculates the delta-ray energy distribution according to Ermilova. | |
1058 | // Logarithmic scale ! | |
1059 | // | |
1060 | ||
1061 | Double_t energy; | |
1062 | Double_t dpos; | |
1063 | Double_t dnde; | |
1064 | ||
030b4415 | 1065 | Int_t pos1; |
1066 | Int_t pos2; | |
5c7f4665 | 1067 | |
8230f242 | 1068 | const Int_t kNv = 31; |
5c7f4665 | 1069 | |
030b4415 | 1070 | Float_t vxe[kNv] = { 2.3026, 2.9957, 3.4012, 3.6889, 3.9120 |
1071 | , 4.0943, 4.2485, 4.3820, 4.4998, 4.6052 | |
1072 | , 4.7005, 5.0752, 5.2983, 5.7038, 5.9915 | |
1073 | , 6.2146, 6.5221, 6.9078, 7.3132, 7.6009 | |
1074 | , 8.0064, 8.5172, 8.6995, 8.9872, 9.2103 | |
1075 | , 9.4727, 9.9035, 10.3735, 10.5966, 10.8198 | |
1076 | , 11.5129 }; | |
1077 | ||
1078 | Float_t vye[kNv] = { 80.0, 31.0, 23.3, 21.1, 21.0 | |
1079 | , 20.9, 20.8, 20.0, 16.0, 11.0 | |
1080 | , 8.0, 6.0, 5.2, 4.6, 4.0 | |
1081 | , 3.5, 3.0, 1.4, 0.67, 0.44 | |
1082 | , 0.3, 0.18, 0.12, 0.08, 0.056 | |
1083 | , 0.04, 0.023, 0.015, 0.011, 0.01 | |
1084 | , 0.004 }; | |
5c7f4665 | 1085 | |
1086 | energy = x[0]; | |
1087 | ||
1088 | // Find the position | |
030b4415 | 1089 | pos1 = 0; |
1090 | pos2 = 0; | |
5c7f4665 | 1091 | dpos = 0; |
1092 | do { | |
1093 | dpos = energy - vxe[pos2++]; | |
1094 | } | |
1095 | while (dpos > 0); | |
1096 | pos2--; | |
030b4415 | 1097 | if (pos2 > kNv) { |
1098 | pos2 = kNv - 1; | |
1099 | } | |
5c7f4665 | 1100 | pos1 = pos2 - 1; |
1101 | ||
1102 | // Differentiate between the sampling points | |
1103 | dnde = (vye[pos1] - vye[pos2]) / (vxe[pos2] - vxe[pos1]); | |
1104 | ||
1105 | return dnde; | |
1106 | ||
1107 | } | |
a328fff9 | 1108 | |
1109 | //_____________________________________________________________________________ | |
1110 | Double_t IntSpecGeant(Double_t *x, Double_t *) | |
1111 | { | |
1112 | // | |
1113 | // Integrated spectrum from Geant3 | |
1114 | // | |
1115 | ||
96efaf83 | 1116 | const Int_t npts = 83; |
030b4415 | 1117 | Double_t arre[npts] = { 2.421257, 2.483278, 2.534301, 2.592230 |
1118 | , 2.672067, 2.813299, 3.015059, 3.216819 | |
1119 | , 3.418579, 3.620338, 3.868209, 3.920198 | |
1120 | , 3.978284, 4.063923, 4.186264, 4.308605 | |
1121 | , 4.430946, 4.553288, 4.724261, 4.837736 | |
1122 | , 4.999842, 5.161949, 5.324056, 5.486163 | |
1123 | , 5.679688, 5.752998, 5.857728, 5.962457 | |
1124 | , 6.067185, 6.171914, 6.315653, 6.393674 | |
1125 | , 6.471694, 6.539689, 6.597658, 6.655627 | |
1126 | , 6.710957, 6.763648, 6.816338, 6.876198 | |
1127 | , 6.943227, 7.010257, 7.106285, 7.252151 | |
1128 | , 7.460531, 7.668911, 7.877290, 8.085670 | |
1129 | , 8.302979, 8.353585, 8.413120, 8.483500 | |
1130 | , 8.541030, 8.592857, 8.668865, 8.820485 | |
1131 | , 9.037086, 9.253686, 9.470286, 9.686887 | |
1132 | , 9.930838, 9.994655, 10.085822, 10.176990 | |
1133 | , 10.268158, 10.359325, 10.503614, 10.627565 | |
1134 | , 10.804637, 10.981709, 11.158781, 11.335854 | |
1135 | , 11.593397, 11.781165, 12.049404, 12.317644 | |
1136 | , 12.585884, 12.854123, 14.278421, 16.975889 | |
1137 | , 20.829416, 24.682943, 28.536469 }; | |
1138 | ||
1139 | Double_t arrdnde[npts] = { 10.960000, 10.960000, 10.359500, 9.811340 | |
1140 | , 9.1601500, 8.206670, 6.919630, 5.655430 | |
1141 | , 4.6221300, 3.777610, 3.019560, 2.591950 | |
1142 | , 2.5414600, 2.712920, 3.327460, 4.928240 | |
1143 | , 7.6185300, 10.966700, 12.225800, 8.094750 | |
1144 | , 3.3586900, 1.553650, 1.209600, 1.263840 | |
1145 | , 1.3241100, 1.312140, 1.255130, 1.165770 | |
1146 | , 1.0594500, 0.945450, 0.813231, 0.699837 | |
1147 | , 0.6235580, 2.260990, 2.968350, 2.240320 | |
1148 | , 1.7988300, 1.553300, 1.432070, 1.535520 | |
1149 | , 1.4429900, 1.247990, 1.050750, 0.829549 | |
1150 | , 0.5900280, 0.395897, 0.268741, 0.185320 | |
1151 | , 0.1292120, 0.103545, 0.0949525, 0.101535 | |
1152 | , 0.1276380, 0.134216, 0.123816, 0.104557 | |
1153 | , 0.0751843, 0.0521745, 0.0373546, 0.0275391 | |
1154 | , 0.0204713, 0.0169234, 0.0154552, 0.0139194 | |
1155 | , 0.0125592, 0.0113638, 0.0107354, 0.0102137 | |
1156 | , 0.00845984, 0.00683338, 0.00556836, 0.00456874 | |
1157 | , 0.0036227, 0.00285991, 0.00226664, 0.00172234 | |
1158 | , 0.00131226, 0.00100284, 0.000465492, 7.26607e-05 | |
1159 | , 3.63304e-06, 0.0000000, 0.0000000 }; | |
1160 | ||
1161 | Int_t i; | |
a328fff9 | 1162 | Double_t energy = x[0]; |
a328fff9 | 1163 | |
030b4415 | 1164 | for (i = 0; i < npts; i++) { |
1165 | if (energy < arre[i]) { | |
1166 | break; | |
1167 | } | |
1168 | } | |
a328fff9 | 1169 | |
030b4415 | 1170 | if (i == 0) { |
1171 | AliErrorGeneral("AliTRDv1::IntSpecGeant","Given energy value is too small or zero"); | |
1172 | } | |
a328fff9 | 1173 | |
96efaf83 | 1174 | return arrdnde[i]; |
a328fff9 | 1175 | |
1176 | } |