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1 | /************************************************************************** | |
2 | * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. * | |
3 | * * | |
4 | * Author: The ALICE Off-line Project. * | |
5 | * Contributors are mentioned in the code where appropriate. * | |
6 | * * | |
7 | * Permission to use, copy, modify and distribute this software and its * | |
8 | * documentation strictly for non-commercial purposes is hereby granted * | |
9 | * without fee, provided that the above copyright notice appears in all * | |
10 | * copies and that both the copyright notice and this permission notice * | |
11 | * appear in the supporting documentation. The authors make no claims * | |
12 | * about the suitability of this software for any purpose. It is * | |
13 | * provided "as is" without express or implied warranty. * | |
14 | **************************************************************************/ | |
15 | ||
16 | /* $Id$ */ | |
17 | ||
18 | //////////////////////////////////////////////////////////////////////////// | |
19 | // // | |
20 | // Transition Radiation Detector version 1 -- slow simulator // | |
21 | // // | |
22 | //////////////////////////////////////////////////////////////////////////// | |
23 | ||
24 | #include <stdlib.h> | |
25 | ||
26 | #include <TF1.h> | |
27 | #include <TLorentzVector.h> | |
28 | #include <TMath.h> | |
29 | #include <TRandom.h> | |
30 | #include <TVector.h> | |
31 | #include <TVirtualMC.h> | |
32 | #include <TGeoManager.h> | |
33 | ||
34 | #include "AliConst.h" | |
35 | #include "AliLog.h" | |
36 | #include "AliMC.h" | |
37 | #include "AliRun.h" | |
38 | ||
39 | #include "AliTRDgeometry.h" | |
40 | #include "AliTRDhit.h" | |
41 | #include "AliTRDsim.h" | |
42 | #include "AliTRDv1.h" | |
43 | ||
44 | ClassImp(AliTRDv1) | |
45 | ||
46 | //_____________________________________________________________________________ | |
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) | |
57 | { | |
58 | // | |
59 | // Default constructor | |
60 | // | |
61 | ||
62 | } | |
63 | ||
64 | //_____________________________________________________________________________ | |
65 | AliTRDv1::AliTRDv1(const char *name, const char *title) | |
66 | :AliTRD(name,title) | |
67 | ,fTRon(kTRUE) | |
68 | ,fTR(NULL) | |
69 | ,fTypeOfStepManager(2) | |
70 | ,fStepSize(0.1) | |
71 | ,fDeltaE(NULL) | |
72 | ,fDeltaG(NULL) | |
73 | ,fTrackLength0(0) | |
74 | ,fPrimaryTrackPid(0) | |
75 | { | |
76 | // | |
77 | // Standard constructor for Transition Radiation Detector version 1 | |
78 | // | |
79 | ||
80 | SetBufferSize(128000); | |
81 | ||
82 | } | |
83 | ||
84 | //_____________________________________________________________________________ | |
85 | AliTRDv1::~AliTRDv1() | |
86 | { | |
87 | // | |
88 | // AliTRDv1 destructor | |
89 | // | |
90 | ||
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 | } | |
105 | ||
106 | } | |
107 | ||
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 | ||
178 | gGeoManager->SetAlignableEntry(symName.Data(),volPath.Data()); | |
179 | ||
180 | } | |
181 | } | |
182 | } | |
183 | ||
184 | } | |
185 | ||
186 | //_____________________________________________________________________________ | |
187 | void AliTRDv1::CreateGeometry() | |
188 | { | |
189 | // | |
190 | // Create the GEANT geometry for the Transition Radiation Detector - Version 1 | |
191 | // This version covers the full azimuth. | |
192 | // | |
193 | ||
194 | // Check that FRAME is there otherwise we have no place where to put the TRD | |
195 | AliModule* frame = gAlice->GetModule("FRAME"); | |
196 | if (!frame) { | |
197 | AliError("TRD needs FRAME to be present\n"); | |
198 | return; | |
199 | } | |
200 | ||
201 | // Define the chambers | |
202 | AliTRD::CreateGeometry(); | |
203 | ||
204 | } | |
205 | ||
206 | //_____________________________________________________________________________ | |
207 | void AliTRDv1::CreateMaterials() | |
208 | { | |
209 | // | |
210 | // Create materials for the Transition Radiation Detector version 1 | |
211 | // | |
212 | ||
213 | AliTRD::CreateMaterials(); | |
214 | ||
215 | } | |
216 | ||
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 | ||
228 | // Ionization energy | |
229 | const Float_t kWion = 23.53; | |
230 | ||
231 | // Maximum number of TR photons per track | |
232 | const Int_t kNTR = 50; | |
233 | ||
234 | TLorentzVector mom; | |
235 | TLorentzVector pos; | |
236 | ||
237 | Float_t eTR[kNTR]; | |
238 | Int_t nTR; | |
239 | ||
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 | } | |
247 | ||
248 | // Loop through the TR photons | |
249 | for (Int_t iTR = 0; iTR < nTR; iTR++) { | |
250 | ||
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; | |
255 | ||
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()) { | |
262 | continue; | |
263 | } | |
264 | } | |
265 | else { | |
266 | continue; | |
267 | } | |
268 | ||
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())) { | |
281 | continue; | |
282 | } | |
283 | } | |
284 | else { | |
285 | continue; | |
286 | } | |
287 | ||
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; | |
294 | ||
295 | // Create the charge | |
296 | Int_t q = ((Int_t) (energyeV / kWion)); | |
297 | ||
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); | |
305 | ||
306 | } | |
307 | ||
308 | } | |
309 | ||
310 | //_____________________________________________________________________________ | |
311 | void AliTRDv1::Init() | |
312 | { | |
313 | // | |
314 | // Initialise Transition Radiation Detector after geometry has been built. | |
315 | // | |
316 | ||
317 | AliTRD::Init(); | |
318 | ||
319 | AliDebug(1,"Slow simulator\n"); | |
320 | ||
321 | // Switch on TR simulation as default | |
322 | if (!fTRon) { | |
323 | AliInfo("TR simulation off"); | |
324 | } | |
325 | else { | |
326 | fTR = new AliTRDsim(); | |
327 | } | |
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 | |
334 | Float_t poti = TMath::Log(kPoti); | |
335 | Float_t eEnd = TMath::Log(kEend); | |
336 | ||
337 | // Ermilova distribution for the delta-ray spectrum | |
338 | fDeltaE = new TF1("deltae" ,Ermilova ,poti,eEnd,0); | |
339 | ||
340 | // Geant3 distribution for the delta-ray spectrum | |
341 | fDeltaG = new TF1("deltag",IntSpecGeant,2.421257,28.536469,0); | |
342 | ||
343 | AliDebug(1,"+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++"); | |
344 | ||
345 | } | |
346 | ||
347 | //_____________________________________________________________________________ | |
348 | void AliTRDv1::StepManager() | |
349 | { | |
350 | // | |
351 | // Slow simulator. Every charged track produces electron cluster as hits | |
352 | // along its path across the drift volume. | |
353 | // | |
354 | ||
355 | switch (fTypeOfStepManager) { | |
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."); | |
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 | ||
381 | fTypeOfStepManager = t; | |
382 | AliInfo(Form("Step Manager type %d was selected",fTypeOfStepManager)); | |
383 | ||
384 | } | |
385 | ||
386 | //_____________________________________________________________________________ | |
387 | void AliTRDv1::StepManagerGeant() | |
388 | { | |
389 | // | |
390 | // Slow simulator. Every charged track produces electron cluster as hits | |
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 | // | |
395 | // Version by A. Bercuci | |
396 | // | |
397 | ||
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 | ||
409 | Double_t pTot = 0; | |
410 | Double_t eDelta; | |
411 | Double_t betaGamma; | |
412 | Double_t pp; | |
413 | Double_t stepSize = 0; | |
414 | ||
415 | Bool_t drRegion = kFALSE; | |
416 | Bool_t amRegion = kFALSE; | |
417 | ||
418 | TString cIdPath; | |
419 | Char_t cIdSector[3]; | |
420 | cIdSector[2] = 0; | |
421 | ||
422 | TString cIdCurrent; | |
423 | TString cIdSensDr = "J"; | |
424 | TString cIdSensAm = "K"; | |
425 | Char_t cIdChamber[3]; | |
426 | cIdChamber[2] = 0; | |
427 | ||
428 | TLorentzVector pos; | |
429 | TLorentzVector mom; | |
430 | ||
431 | TArrayI processes; | |
432 | ||
433 | const Int_t kNplan = AliTRDgeometry::Nplan(); | |
434 | const Int_t kNcham = AliTRDgeometry::Ncham(); | |
435 | const Int_t kNdetsec = kNplan * kNcham; | |
436 | ||
437 | const Double_t kBig = 1.0e+12; // Infinitely big | |
438 | const Float_t kWion = 23.53; // Ionization energy | |
439 | const Float_t kPTotMaxEl = 0.002; // Maximum momentum for e+ e- g | |
440 | ||
441 | // Minimum energy for the step size adjustment | |
442 | const Float_t kEkinMinStep = 1.0e-5; | |
443 | // energy threshold for production of delta electrons | |
444 | const Float_t kECut = 1.0e4; | |
445 | // Parameters entering the parametrized range for delta electrons | |
446 | const Float_t kRa = 5.37e-4; | |
447 | const Float_t kRb = 0.9815; | |
448 | const Float_t kRc = 3.123e-3; | |
449 | // Gas density -> To be made user adjustable ! | |
450 | // [0.85*0.00549+0.15*0.00186 (Xe-CO2 85-15)] | |
451 | const Float_t kRho = 0.004945 ; | |
452 | ||
453 | // Plateau value of the energy-loss for electron in xenon | |
454 | // The averaged value (26/3/99) | |
455 | const Float_t kPlateau = 1.55; | |
456 | // dN1/dx|min for the gas mixture (90% Xe + 10% CO2) | |
457 | const Float_t kPrim = 19.34; | |
458 | // First ionization potential (eV) for the gas mixture (90% Xe + 10% CO2) | |
459 | const Float_t kPoti = 12.1; | |
460 | // PDG code electron | |
461 | const Int_t kPdgElectron = 11; | |
462 | ||
463 | // Set the maximum step size to a very large number for all | |
464 | // neutral particles and those outside the driftvolume | |
465 | gMC->SetMaxStep(kBig); | |
466 | ||
467 | // Use only charged tracks | |
468 | if (( gMC->TrackCharge() ) && | |
469 | (!gMC->IsTrackDisappeared())) { | |
470 | ||
471 | // Inside a sensitive volume? | |
472 | drRegion = kFALSE; | |
473 | amRegion = kFALSE; | |
474 | cIdCurrent = gMC->CurrentVolName(); | |
475 | if (cIdSensDr == cIdCurrent[1]) { | |
476 | drRegion = kTRUE; | |
477 | } | |
478 | if (cIdSensAm == cIdCurrent[1]) { | |
479 | amRegion = kTRUE; | |
480 | } | |
481 | if (drRegion || amRegion) { | |
482 | ||
483 | // The hit coordinates and charge | |
484 | gMC->TrackPosition(pos); | |
485 | hits[0] = pos[0]; | |
486 | hits[1] = pos[1]; | |
487 | hits[2] = pos[2]; | |
488 | ||
489 | // The sector number (0 - 17), according to standard coordinate system | |
490 | cIdPath = gGeoManager->GetPath(); | |
491 | cIdSector[0] = cIdPath[21]; | |
492 | cIdSector[1] = cIdPath[22]; | |
493 | sec = atoi(cIdSector); | |
494 | ||
495 | // The plane and chamber number | |
496 | cIdChamber[0] = cIdCurrent[2]; | |
497 | cIdChamber[1] = cIdCurrent[3]; | |
498 | Int_t idChamber = (atoi(cIdChamber) % kNdetsec); | |
499 | cha = kNcham - ((Int_t) idChamber / kNplan) - 1; | |
500 | pla = ((Int_t) idChamber % kNplan); | |
501 | ||
502 | // The detector number | |
503 | det = fGeometry->GetDetector(pla,cha,sec); | |
504 | ||
505 | // Special hits only in the drift region | |
506 | if ((drRegion) && | |
507 | (gMC->IsTrackEntering())) { | |
508 | ||
509 | // Create a track reference at the entrance of each | |
510 | // chamber that contains the momentum components of the particle | |
511 | gMC->TrackMomentum(mom); | |
512 | AddTrackReference(gAlice->GetMCApp()->GetCurrentTrackNumber()); | |
513 | ||
514 | // Create the hits from TR photons if electron/positron is | |
515 | // entering the drift volume | |
516 | if ((fTR) && | |
517 | (TMath::Abs(gMC->TrackPid()) == kPdgElectron)) { | |
518 | CreateTRhit(det); | |
519 | } | |
520 | ||
521 | } | |
522 | else if ((amRegion) && | |
523 | (gMC->IsTrackExiting())) { | |
524 | ||
525 | // Create a track reference at the exit of each | |
526 | // chamber that contains the momentum components of the particle | |
527 | gMC->TrackMomentum(mom); | |
528 | AddTrackReference(gAlice->GetMCApp()->GetCurrentTrackNumber()); | |
529 | ||
530 | } | |
531 | ||
532 | // Calculate the energy of the delta-electrons | |
533 | // modified by Alex Bercuci (A.Bercuci@gsi.de) on 26.01.06 | |
534 | // take into account correlation with the underlying GEANT tracking | |
535 | // mechanism. see | |
536 | // http://www-linux.gsi.de/~abercuci/Contributions/TRD/index.html | |
537 | // | |
538 | // determine the most significant process (last on the processes list) | |
539 | // which caused this hit | |
540 | gMC->StepProcesses(processes); | |
541 | Int_t nofprocesses = processes.GetSize(); | |
542 | Int_t pid; | |
543 | if (!nofprocesses) { | |
544 | pid = 0; | |
545 | } | |
546 | else { | |
547 | pid = processes[nofprocesses-1]; | |
548 | } | |
549 | ||
550 | // Generate Edep according to GEANT parametrisation | |
551 | eDelta = TMath::Exp(fDeltaG->GetRandom()) - kPoti; | |
552 | eDelta = TMath::Max(eDelta,0.0); | |
553 | Float_t prRange = 0.0; | |
554 | Float_t range = gMC->TrackLength() - fTrackLength0; | |
555 | // merge GEANT tracker information with locally cooked one | |
556 | if (gAlice->GetMCApp()->GetCurrentTrackNumber() == fPrimaryTrackPid) { | |
557 | if (pid == 27) { | |
558 | if (eDelta >= kECut) { | |
559 | prRange = kRa * eDelta * 0.001 | |
560 | * (1.0 - kRb / (1.0 + kRc * eDelta * 0.001)) / kRho; | |
561 | if (prRange >= (3.7 - range)) { | |
562 | eDelta *= 0.1; | |
563 | } | |
564 | } | |
565 | } | |
566 | else if (pid == 1) { | |
567 | if (eDelta < kECut) { | |
568 | eDelta *= 0.5; | |
569 | } | |
570 | else { | |
571 | prRange = kRa * eDelta * 0.001 | |
572 | * (1.0 - kRb / (1.0 + kRc * eDelta * 0.001)) / kRho; | |
573 | if (prRange >= ((AliTRDgeometry::DrThick() | |
574 | + AliTRDgeometry::AmThick()) - range)) { | |
575 | eDelta *= 0.05; | |
576 | } | |
577 | else { | |
578 | eDelta *= 0.5; | |
579 | } | |
580 | } | |
581 | } | |
582 | else { | |
583 | eDelta = 0.0; | |
584 | } | |
585 | } | |
586 | else { | |
587 | eDelta = 0.0; | |
588 | } | |
589 | ||
590 | // Generate the electron cluster size | |
591 | if (eDelta > 0.0) { | |
592 | ||
593 | qTot = ((Int_t) (eDelta / kWion) + 1); | |
594 | ||
595 | // Create a new dEdx hit | |
596 | AddHit(gAlice->GetMCApp()->GetCurrentTrackNumber() | |
597 | ,det | |
598 | ,hits | |
599 | ,qTot | |
600 | ,drRegion); | |
601 | ||
602 | } | |
603 | ||
604 | // Calculate the maximum step size for the next tracking step | |
605 | // Produce only one hit if Ekin is below cutoff | |
606 | aMass = gMC->TrackMass(); | |
607 | if ((gMC->Etot() - aMass) > kEkinMinStep) { | |
608 | ||
609 | // The energy loss according to Bethe Bloch | |
610 | iPdg = TMath::Abs(gMC->TrackPid()); | |
611 | if ((iPdg != kPdgElectron) || | |
612 | ((iPdg == kPdgElectron) && | |
613 | (pTot < kPTotMaxEl))) { | |
614 | gMC->TrackMomentum(mom); | |
615 | pTot = mom.Rho(); | |
616 | betaGamma = pTot / aMass; | |
617 | pp = BetheBlochGeant(betaGamma); | |
618 | // Take charge > 1 into account | |
619 | charge = gMC->TrackCharge(); | |
620 | if (TMath::Abs(charge) > 1) { | |
621 | pp = pp * charge*charge; | |
622 | } | |
623 | } | |
624 | else { | |
625 | // Electrons above 20 Mev/c are at the plateau | |
626 | pp = kPrim * kPlateau; | |
627 | } | |
628 | ||
629 | Int_t nsteps = 0; | |
630 | do { | |
631 | nsteps = gRandom->Poisson(pp); | |
632 | } while(!nsteps); | |
633 | stepSize = 1.0 / nsteps; | |
634 | gMC->SetMaxStep(stepSize); | |
635 | ||
636 | } | |
637 | ||
638 | } | |
639 | ||
640 | } | |
641 | ||
642 | } | |
643 | ||
644 | //_____________________________________________________________________________ | |
645 | void AliTRDv1::StepManagerErmilova() | |
646 | { | |
647 | // | |
648 | // Slow simulator. Every charged track produces electron cluster as hits | |
649 | // along its path across the drift volume. The step size is set acording | |
650 | // to Bethe-Bloch. The energy distribution of the delta electrons follows | |
651 | // a spectrum taken from Ermilova et al. | |
652 | // | |
653 | ||
654 | Int_t pla = 0; | |
655 | Int_t cha = 0; | |
656 | Int_t sec = 0; | |
657 | Int_t det = 0; | |
658 | Int_t iPdg; | |
659 | Int_t qTot; | |
660 | ||
661 | Float_t hits[3]; | |
662 | Double_t random[1]; | |
663 | Float_t charge; | |
664 | Float_t aMass; | |
665 | ||
666 | Double_t pTot = 0.0; | |
667 | Double_t eDelta; | |
668 | Double_t betaGamma; | |
669 | Double_t pp; | |
670 | Double_t stepSize; | |
671 | ||
672 | Bool_t drRegion = kFALSE; | |
673 | Bool_t amRegion = kFALSE; | |
674 | ||
675 | TString cIdPath; | |
676 | Char_t cIdSector[3]; | |
677 | cIdSector[2] = 0; | |
678 | ||
679 | TString cIdCurrent; | |
680 | TString cIdSensDr = "J"; | |
681 | TString cIdSensAm = "K"; | |
682 | Char_t cIdChamber[3]; | |
683 | cIdChamber[2] = 0; | |
684 | ||
685 | TLorentzVector pos; | |
686 | TLorentzVector mom; | |
687 | ||
688 | const Int_t kNplan = AliTRDgeometry::Nplan(); | |
689 | const Int_t kNcham = AliTRDgeometry::Ncham(); | |
690 | const Int_t kNdetsec = kNplan * kNcham; | |
691 | ||
692 | const Double_t kBig = 1.0e+12; // Infinitely big | |
693 | const Float_t kWion = 23.53; // Ionization energy | |
694 | const Float_t kPTotMaxEl = 0.002; // Maximum momentum for e+ e- g | |
695 | ||
696 | // Minimum energy for the step size adjustment | |
697 | const Float_t kEkinMinStep = 1.0e-5; | |
698 | ||
699 | // Plateau value of the energy-loss for electron in xenon | |
700 | // The averaged value (26/3/99) | |
701 | const Float_t kPlateau = 1.55; | |
702 | // dN1/dx|min for the gas mixture (90% Xe + 10% CO2) | |
703 | const Float_t kPrim = 48.0; | |
704 | // First ionization potential (eV) for the gas mixture (90% Xe + 10% CO2) | |
705 | const Float_t kPoti = 12.1; | |
706 | // PDG code electron | |
707 | const Int_t kPdgElectron = 11; | |
708 | ||
709 | // Set the maximum step size to a very large number for all | |
710 | // neutral particles and those outside the driftvolume | |
711 | gMC->SetMaxStep(kBig); | |
712 | ||
713 | // Use only charged tracks | |
714 | if (( gMC->TrackCharge() ) && | |
715 | (!gMC->IsTrackDisappeared())) { | |
716 | ||
717 | // Inside a sensitive volume? | |
718 | drRegion = kFALSE; | |
719 | amRegion = kFALSE; | |
720 | cIdCurrent = gMC->CurrentVolName(); | |
721 | if (cIdSensDr == cIdCurrent[1]) { | |
722 | drRegion = kTRUE; | |
723 | } | |
724 | if (cIdSensAm == cIdCurrent[1]) { | |
725 | amRegion = kTRUE; | |
726 | } | |
727 | if (drRegion || amRegion) { | |
728 | ||
729 | // The hit coordinates and charge | |
730 | gMC->TrackPosition(pos); | |
731 | hits[0] = pos[0]; | |
732 | hits[1] = pos[1]; | |
733 | hits[2] = pos[2]; | |
734 | ||
735 | // The sector number (0 - 17), according to standard coordinate system | |
736 | cIdPath = gGeoManager->GetPath(); | |
737 | cIdSector[0] = cIdPath[21]; | |
738 | cIdSector[1] = cIdPath[22]; | |
739 | sec = atoi(cIdSector); | |
740 | ||
741 | // The plane and chamber number | |
742 | cIdChamber[0] = cIdCurrent[2]; | |
743 | cIdChamber[1] = cIdCurrent[3]; | |
744 | Int_t idChamber = (atoi(cIdChamber) % kNdetsec); | |
745 | cha = kNcham - ((Int_t) idChamber / kNplan) - 1; | |
746 | pla = ((Int_t) idChamber % kNplan); | |
747 | ||
748 | // The detector number | |
749 | det = fGeometry->GetDetector(pla,cha,sec); | |
750 | ||
751 | // Special hits only in the drift region | |
752 | if ((drRegion) && | |
753 | (gMC->IsTrackEntering())) { | |
754 | ||
755 | // Create a track reference at the entrance of each | |
756 | // chamber that contains the momentum components of the particle | |
757 | gMC->TrackMomentum(mom); | |
758 | AddTrackReference(gAlice->GetMCApp()->GetCurrentTrackNumber()); | |
759 | ||
760 | // Create the hits from TR photons if electron/positron is | |
761 | // entering the drift volume | |
762 | if ((fTR) && | |
763 | (TMath::Abs(gMC->TrackPid()) == kPdgElectron)) { | |
764 | CreateTRhit(det); | |
765 | } | |
766 | ||
767 | } | |
768 | else if ((amRegion) && | |
769 | (gMC->IsTrackExiting())) { | |
770 | ||
771 | // Create a track reference at the exit of each | |
772 | // chamber that contains the momentum components of the particle | |
773 | gMC->TrackMomentum(mom); | |
774 | AddTrackReference(gAlice->GetMCApp()->GetCurrentTrackNumber()); | |
775 | ||
776 | } | |
777 | ||
778 | // Calculate the energy of the delta-electrons | |
779 | eDelta = TMath::Exp(fDeltaE->GetRandom()) - kPoti; | |
780 | eDelta = TMath::Max(eDelta,0.0); | |
781 | ||
782 | // Generate the electron cluster size | |
783 | if (eDelta > 0.0) { | |
784 | ||
785 | qTot = ((Int_t) (eDelta / kWion) + 1); | |
786 | ||
787 | // Create a new dEdx hit | |
788 | if (drRegion) { | |
789 | AddHit(gAlice->GetMCApp()->GetCurrentTrackNumber() | |
790 | ,det | |
791 | ,hits | |
792 | ,qTot | |
793 | ,kTRUE); | |
794 | } | |
795 | else { | |
796 | AddHit(gAlice->GetMCApp()->GetCurrentTrackNumber() | |
797 | ,det | |
798 | ,hits | |
799 | ,qTot | |
800 | ,kFALSE); | |
801 | } | |
802 | ||
803 | } | |
804 | ||
805 | // Calculate the maximum step size for the next tracking step | |
806 | // Produce only one hit if Ekin is below cutoff | |
807 | aMass = gMC->TrackMass(); | |
808 | if ((gMC->Etot() - aMass) > kEkinMinStep) { | |
809 | ||
810 | // The energy loss according to Bethe Bloch | |
811 | iPdg = TMath::Abs(gMC->TrackPid()); | |
812 | if ((iPdg != kPdgElectron) || | |
813 | ((iPdg == kPdgElectron) && | |
814 | (pTot < kPTotMaxEl))) { | |
815 | gMC->TrackMomentum(mom); | |
816 | pTot = mom.Rho(); | |
817 | betaGamma = pTot / aMass; | |
818 | pp = kPrim * BetheBloch(betaGamma); | |
819 | // Take charge > 1 into account | |
820 | charge = gMC->TrackCharge(); | |
821 | if (TMath::Abs(charge) > 1) { | |
822 | pp = pp * charge*charge; | |
823 | } | |
824 | } | |
825 | else { | |
826 | // Electrons above 20 Mev/c are at the plateau | |
827 | pp = kPrim * kPlateau; | |
828 | } | |
829 | ||
830 | if (pp > 0.0) { | |
831 | do { | |
832 | gMC->GetRandom()->RndmArray(1,random); | |
833 | } | |
834 | while ((random[0] == 1.0) || | |
835 | (random[0] == 0.0)); | |
836 | stepSize = - TMath::Log(random[0]) / pp; | |
837 | gMC->SetMaxStep(stepSize); | |
838 | } | |
839 | ||
840 | } | |
841 | ||
842 | } | |
843 | ||
844 | } | |
845 | ||
846 | } | |
847 | ||
848 | //_____________________________________________________________________________ | |
849 | void AliTRDv1::StepManagerFixedStep() | |
850 | { | |
851 | // | |
852 | // Slow simulator. Every charged track produces electron cluster as hits | |
853 | // along its path across the drift volume. The step size is fixed in | |
854 | // this version of the step manager. | |
855 | // | |
856 | ||
857 | // PDG code electron | |
858 | const Int_t kPdgElectron = 11; | |
859 | ||
860 | Int_t pla = 0; | |
861 | Int_t cha = 0; | |
862 | Int_t sec = 0; | |
863 | Int_t det = 0; | |
864 | Int_t qTot; | |
865 | ||
866 | Float_t hits[3]; | |
867 | Double_t eDep; | |
868 | ||
869 | Bool_t drRegion = kFALSE; | |
870 | Bool_t amRegion = kFALSE; | |
871 | ||
872 | TString cIdPath; | |
873 | Char_t cIdSector[3]; | |
874 | cIdSector[2] = 0; | |
875 | ||
876 | TString cIdCurrent; | |
877 | TString cIdSensDr = "J"; | |
878 | TString cIdSensAm = "K"; | |
879 | Char_t cIdChamber[3]; | |
880 | cIdChamber[2] = 0; | |
881 | ||
882 | TLorentzVector pos; | |
883 | TLorentzVector mom; | |
884 | ||
885 | const Int_t kNplan = AliTRDgeometry::Nplan(); | |
886 | const Int_t kNcham = AliTRDgeometry::Ncham(); | |
887 | const Int_t kNdetsec = kNplan * kNcham; | |
888 | ||
889 | const Double_t kBig = 1.0e+12; | |
890 | ||
891 | const Float_t kWion = 23.53; // Ionization energy | |
892 | const Float_t kEkinMinStep = 1.0e-5; // Minimum energy for the step size adjustment | |
893 | ||
894 | // Set the maximum step size to a very large number for all | |
895 | // neutral particles and those outside the driftvolume | |
896 | gMC->SetMaxStep(kBig); | |
897 | ||
898 | // If not charged track or already stopped or disappeared, just return. | |
899 | if ((!gMC->TrackCharge()) || | |
900 | gMC->IsTrackDisappeared()) { | |
901 | return; | |
902 | } | |
903 | ||
904 | // Inside a sensitive volume? | |
905 | cIdCurrent = gMC->CurrentVolName(); | |
906 | ||
907 | if (cIdSensDr == cIdCurrent[1]) { | |
908 | drRegion = kTRUE; | |
909 | } | |
910 | if (cIdSensAm == cIdCurrent[1]) { | |
911 | amRegion = kTRUE; | |
912 | } | |
913 | ||
914 | if ((!drRegion) && | |
915 | (!amRegion)) { | |
916 | return; | |
917 | } | |
918 | ||
919 | // The hit coordinates and charge | |
920 | gMC->TrackPosition(pos); | |
921 | hits[0] = pos[0]; | |
922 | hits[1] = pos[1]; | |
923 | hits[2] = pos[2]; | |
924 | ||
925 | // The sector number (0 - 17), according to standard coordinate system | |
926 | cIdPath = gGeoManager->GetPath(); | |
927 | cIdSector[0] = cIdPath[21]; | |
928 | cIdSector[1] = cIdPath[22]; | |
929 | sec = atoi(cIdSector); | |
930 | ||
931 | // The plane and chamber number | |
932 | cIdChamber[0] = cIdCurrent[2]; | |
933 | cIdChamber[1] = cIdCurrent[3]; | |
934 | Int_t idChamber = (atoi(cIdChamber) % kNdetsec); | |
935 | cha = kNcham - ((Int_t) idChamber / kNplan) - 1; | |
936 | pla = ((Int_t) idChamber % kNplan); | |
937 | ||
938 | // The detector number | |
939 | det = fGeometry->GetDetector(pla,cha,sec); | |
940 | ||
941 | // 0: InFlight 1:Entering 2:Exiting | |
942 | Int_t trkStat = 0; | |
943 | ||
944 | // Special hits only in the drift region | |
945 | if ((drRegion) && | |
946 | (gMC->IsTrackEntering())) { | |
947 | ||
948 | // Create a track reference at the entrance of each | |
949 | // chamber that contains the momentum components of the particle | |
950 | gMC->TrackMomentum(mom); | |
951 | AddTrackReference(gAlice->GetMCApp()->GetCurrentTrackNumber()); | |
952 | trkStat = 1; | |
953 | ||
954 | // Create the hits from TR photons if electron/positron is | |
955 | // entering the drift volume | |
956 | if ((fTR) && | |
957 | (TMath::Abs(gMC->TrackPid()) == kPdgElectron)) { | |
958 | CreateTRhit(det); | |
959 | } | |
960 | ||
961 | } | |
962 | else if ((amRegion) && | |
963 | (gMC->IsTrackExiting())) { | |
964 | ||
965 | // Create a track reference at the exit of each | |
966 | // chamber that contains the momentum components of the particle | |
967 | gMC->TrackMomentum(mom); | |
968 | AddTrackReference(gAlice->GetMCApp()->GetCurrentTrackNumber()); | |
969 | trkStat = 2; | |
970 | ||
971 | } | |
972 | ||
973 | // Calculate the charge according to GEANT Edep | |
974 | // Create a new dEdx hit | |
975 | eDep = TMath::Max(gMC->Edep(),0.0) * 1.0e+09; | |
976 | qTot = (Int_t) (eDep / kWion); | |
977 | if ((qTot) || | |
978 | (trkStat)) { | |
979 | AddHit(gAlice->GetMCApp()->GetCurrentTrackNumber() | |
980 | ,det | |
981 | ,hits | |
982 | ,qTot | |
983 | ,drRegion); | |
984 | } | |
985 | ||
986 | // Set Maximum Step Size | |
987 | // Produce only one hit if Ekin is below cutoff | |
988 | if ((gMC->Etot() - gMC->TrackMass()) < kEkinMinStep) { | |
989 | return; | |
990 | } | |
991 | gMC->SetMaxStep(fStepSize); | |
992 | ||
993 | } | |
994 | ||
995 | //_____________________________________________________________________________ | |
996 | Double_t AliTRDv1::BetheBloch(Double_t bg) | |
997 | { | |
998 | // | |
999 | // Parametrization of the Bethe-Bloch-curve | |
1000 | // The parametrization is the same as for the TPC and is taken from Lehrhaus. | |
1001 | // | |
1002 | ||
1003 | // This parameters have been adjusted to averaged values from GEANT | |
1004 | const Double_t kP1 = 7.17960e-02; | |
1005 | const Double_t kP2 = 8.54196; | |
1006 | const Double_t kP3 = 1.38065e-06; | |
1007 | const Double_t kP4 = 5.30972; | |
1008 | const Double_t kP5 = 2.83798; | |
1009 | ||
1010 | // Lower cutoff of the Bethe-Bloch-curve to limit step sizes | |
1011 | const Double_t kBgMin = 0.8; | |
1012 | const Double_t kBBMax = 6.83298; | |
1013 | ||
1014 | if (bg > kBgMin) { | |
1015 | Double_t yy = bg / TMath::Sqrt(1.0 + bg*bg); | |
1016 | Double_t aa = TMath::Power(yy,kP4); | |
1017 | Double_t bb = TMath::Power((1.0/bg),kP5); | |
1018 | bb = TMath::Log(kP3 + bb); | |
1019 | return ((kP2 - aa - bb) * kP1 / aa); | |
1020 | } | |
1021 | else { | |
1022 | return kBBMax; | |
1023 | } | |
1024 | ||
1025 | } | |
1026 | ||
1027 | //_____________________________________________________________________________ | |
1028 | Double_t AliTRDv1::BetheBlochGeant(Double_t bg) | |
1029 | { | |
1030 | // | |
1031 | // Return dN/dx (number of primary collisions per centimeter) | |
1032 | // for given beta*gamma factor. | |
1033 | // | |
1034 | // Implemented by K.Oyama according to GEANT 3 parametrization shown in | |
1035 | // A.Andronic's webpage: http://www-alice.gsi.de/trd/papers/dedx/dedx.html | |
1036 | // This must be used as a set with IntSpecGeant. | |
1037 | // | |
1038 | ||
1039 | Int_t i = 0; | |
1040 | ||
1041 | Double_t arrG[20] = { 1.100000, 1.200000, 1.300000, 1.500000 | |
1042 | , 1.800000, 2.000000, 2.500000, 3.000000 | |
1043 | , 4.000000, 7.000000, 10.000000, 20.000000 | |
1044 | , 40.000000, 70.000000, 100.000000, 300.000000 | |
1045 | , 600.000000, 1000.000000, 3000.000000, 10000.000000 }; | |
1046 | ||
1047 | Double_t arrNC[20] = { 75.009056, 45.508083, 35.299252, 27.116327 | |
1048 | , 22.734999, 21.411915, 19.934095, 19.449375 | |
1049 | , 19.344431, 20.185553, 21.027925, 22.912676 | |
1050 | , 24.933352, 26.504053, 27.387468, 29.566597 | |
1051 | , 30.353779, 30.787134, 31.129285, 31.157350 }; | |
1052 | ||
1053 | // Betagamma to gamma | |
1054 | Double_t g = TMath::Sqrt(1.0 + bg*bg); | |
1055 | ||
1056 | // Find the index just before the point we need. | |
1057 | for (i = 0; i < 18; i++) { | |
1058 | if ((arrG[i] < g) && | |
1059 | (arrG[i+1] > g)) { | |
1060 | break; | |
1061 | } | |
1062 | } | |
1063 | ||
1064 | // Simple interpolation. | |
1065 | Double_t pp = ((arrNC[i+1] - arrNC[i]) / (arrG[i+1] - arrG[i])) | |
1066 | * (g - arrG[i]) + arrNC[i]; | |
1067 | ||
1068 | return pp; | |
1069 | ||
1070 | } | |
1071 | ||
1072 | //_____________________________________________________________________________ | |
1073 | Double_t Ermilova(Double_t *x, Double_t *) | |
1074 | { | |
1075 | // | |
1076 | // Calculates the delta-ray energy distribution according to Ermilova. | |
1077 | // Logarithmic scale ! | |
1078 | // | |
1079 | ||
1080 | Double_t energy; | |
1081 | Double_t dpos; | |
1082 | Double_t dnde; | |
1083 | ||
1084 | Int_t pos1; | |
1085 | Int_t pos2; | |
1086 | ||
1087 | const Int_t kNv = 31; | |
1088 | ||
1089 | Float_t vxe[kNv] = { 2.3026, 2.9957, 3.4012, 3.6889, 3.9120 | |
1090 | , 4.0943, 4.2485, 4.3820, 4.4998, 4.6052 | |
1091 | , 4.7005, 5.0752, 5.2983, 5.7038, 5.9915 | |
1092 | , 6.2146, 6.5221, 6.9078, 7.3132, 7.6009 | |
1093 | , 8.0064, 8.5172, 8.6995, 8.9872, 9.2103 | |
1094 | , 9.4727, 9.9035, 10.3735, 10.5966, 10.8198 | |
1095 | , 11.5129 }; | |
1096 | ||
1097 | Float_t vye[kNv] = { 80.0, 31.0, 23.3, 21.1, 21.0 | |
1098 | , 20.9, 20.8, 20.0, 16.0, 11.0 | |
1099 | , 8.0, 6.0, 5.2, 4.6, 4.0 | |
1100 | , 3.5, 3.0, 1.4, 0.67, 0.44 | |
1101 | , 0.3, 0.18, 0.12, 0.08, 0.056 | |
1102 | , 0.04, 0.023, 0.015, 0.011, 0.01 | |
1103 | , 0.004 }; | |
1104 | ||
1105 | energy = x[0]; | |
1106 | ||
1107 | // Find the position | |
1108 | pos1 = 0; | |
1109 | pos2 = 0; | |
1110 | dpos = 0; | |
1111 | do { | |
1112 | dpos = energy - vxe[pos2++]; | |
1113 | } | |
1114 | while (dpos > 0); | |
1115 | pos2--; | |
1116 | if (pos2 > kNv) { | |
1117 | pos2 = kNv - 1; | |
1118 | } | |
1119 | pos1 = pos2 - 1; | |
1120 | ||
1121 | // Differentiate between the sampling points | |
1122 | dnde = (vye[pos1] - vye[pos2]) / (vxe[pos2] - vxe[pos1]); | |
1123 | ||
1124 | return dnde; | |
1125 | ||
1126 | } | |
1127 | ||
1128 | //_____________________________________________________________________________ | |
1129 | Double_t IntSpecGeant(Double_t *x, Double_t *) | |
1130 | { | |
1131 | // | |
1132 | // Integrated spectrum from Geant3 | |
1133 | // | |
1134 | ||
1135 | const Int_t npts = 83; | |
1136 | Double_t arre[npts] = { 2.421257, 2.483278, 2.534301, 2.592230 | |
1137 | , 2.672067, 2.813299, 3.015059, 3.216819 | |
1138 | , 3.418579, 3.620338, 3.868209, 3.920198 | |
1139 | , 3.978284, 4.063923, 4.186264, 4.308605 | |
1140 | , 4.430946, 4.553288, 4.724261, 4.837736 | |
1141 | , 4.999842, 5.161949, 5.324056, 5.486163 | |
1142 | , 5.679688, 5.752998, 5.857728, 5.962457 | |
1143 | , 6.067185, 6.171914, 6.315653, 6.393674 | |
1144 | , 6.471694, 6.539689, 6.597658, 6.655627 | |
1145 | , 6.710957, 6.763648, 6.816338, 6.876198 | |
1146 | , 6.943227, 7.010257, 7.106285, 7.252151 | |
1147 | , 7.460531, 7.668911, 7.877290, 8.085670 | |
1148 | , 8.302979, 8.353585, 8.413120, 8.483500 | |
1149 | , 8.541030, 8.592857, 8.668865, 8.820485 | |
1150 | , 9.037086, 9.253686, 9.470286, 9.686887 | |
1151 | , 9.930838, 9.994655, 10.085822, 10.176990 | |
1152 | , 10.268158, 10.359325, 10.503614, 10.627565 | |
1153 | , 10.804637, 10.981709, 11.158781, 11.335854 | |
1154 | , 11.593397, 11.781165, 12.049404, 12.317644 | |
1155 | , 12.585884, 12.854123, 14.278421, 16.975889 | |
1156 | , 20.829416, 24.682943, 28.536469 }; | |
1157 | ||
1158 | Double_t arrdnde[npts] = { 10.960000, 10.960000, 10.359500, 9.811340 | |
1159 | , 9.1601500, 8.206670, 6.919630, 5.655430 | |
1160 | , 4.6221300, 3.777610, 3.019560, 2.591950 | |
1161 | , 2.5414600, 2.712920, 3.327460, 4.928240 | |
1162 | , 7.6185300, 10.966700, 12.225800, 8.094750 | |
1163 | , 3.3586900, 1.553650, 1.209600, 1.263840 | |
1164 | , 1.3241100, 1.312140, 1.255130, 1.165770 | |
1165 | , 1.0594500, 0.945450, 0.813231, 0.699837 | |
1166 | , 0.6235580, 2.260990, 2.968350, 2.240320 | |
1167 | , 1.7988300, 1.553300, 1.432070, 1.535520 | |
1168 | , 1.4429900, 1.247990, 1.050750, 0.829549 | |
1169 | , 0.5900280, 0.395897, 0.268741, 0.185320 | |
1170 | , 0.1292120, 0.103545, 0.0949525, 0.101535 | |
1171 | , 0.1276380, 0.134216, 0.123816, 0.104557 | |
1172 | , 0.0751843, 0.0521745, 0.0373546, 0.0275391 | |
1173 | , 0.0204713, 0.0169234, 0.0154552, 0.0139194 | |
1174 | , 0.0125592, 0.0113638, 0.0107354, 0.0102137 | |
1175 | , 0.00845984, 0.00683338, 0.00556836, 0.00456874 | |
1176 | , 0.0036227, 0.00285991, 0.00226664, 0.00172234 | |
1177 | , 0.00131226, 0.00100284, 0.000465492, 7.26607e-05 | |
1178 | , 3.63304e-06, 0.0000000, 0.0000000 }; | |
1179 | ||
1180 | Int_t i; | |
1181 | Double_t energy = x[0]; | |
1182 | ||
1183 | for (i = 0; i < npts; i++) { | |
1184 | if (energy < arre[i]) { | |
1185 | break; | |
1186 | } | |
1187 | } | |
1188 | ||
1189 | if (i == 0) { | |
1190 | AliErrorGeneral("AliTRDv1::IntSpecGeant","Given energy value is too small or zero"); | |
1191 | } | |
1192 | ||
1193 | return arrdnde[i]; | |
1194 | ||
1195 | } |