Only one initializer for a default argument
[u/mrichter/AliRoot.git] / TRD / AliTRDv1.cxx
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4c039060 1/**************************************************************************
2 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
3 * *
4 * Author: The ALICE Off-line Project. *
5 * Contributors are mentioned in the code where appropriate. *
6 * *
7 * Permission to use, copy, modify and distribute this software and its *
8 * documentation strictly for non-commercial purposes is hereby granted *
9 * without fee, provided that the above copyright notice appears in all *
10 * copies and that both the copyright notice and this permission notice *
11 * appear in the supporting documentation. The authors make no claims *
12 * about the suitability of this software for any purpose. It is *
13 * provided "as is" without express or implied warranty. *
14 **************************************************************************/
15
16/*
17$Log$
9d0b222b 18Revision 1.18 2000/05/08 16:17:27 cblume
19Merge TRD-develop
20
6f1e466d 21Revision 1.17.2.1 2000/05/08 14:59:16 cblume
22Made inline function non-virtual. Bug fix in setting sensitive chamber
23
24Revision 1.17 2000/02/28 19:10:26 cblume
25Include the new TRD classes
26
851d3db9 27Revision 1.16.4.1 2000/02/28 18:04:35 cblume
28Change to new hit version, introduce geometry class, and move digitization and clustering to AliTRDdigitizer/AliTRDclusterizerV1
29
30Revision 1.16 1999/11/05 22:50:28 fca
31Do not use Atan, removed from ROOT too
32
90f8d287 33Revision 1.15 1999/11/02 17:20:19 fca
34initialise nbytes before using it
35
036da493 36Revision 1.14 1999/11/02 17:15:54 fca
37Correct ansi scoping not accepted by HP compilers
38
0549c011 39Revision 1.13 1999/11/02 17:14:51 fca
40Correct ansi scoping not accepted by HP compilers
41
9c767df4 42Revision 1.12 1999/11/02 16:35:56 fca
43New version of TRD introduced
44
5c7f4665 45Revision 1.11 1999/11/01 20:41:51 fca
46Added protections against using the wrong version of FRAME
47
ab76897d 48Revision 1.10 1999/09/29 09:24:35 fca
49Introduction of the Copyright and cvs Log
50
4c039060 51*/
52
fe4da5cc 53///////////////////////////////////////////////////////////////////////////////
54// //
5c7f4665 55// Transition Radiation Detector version 2 -- slow simulator //
fe4da5cc 56// //
57//Begin_Html
58/*
5c7f4665 59<img src="picts/AliTRDfullClass.gif">
fe4da5cc 60*/
61//End_Html
62// //
63// //
64///////////////////////////////////////////////////////////////////////////////
65
66#include <TMath.h>
fe4da5cc 67#include <TVector.h>
5c7f4665 68#include <TRandom.h>
fe4da5cc 69
fe4da5cc 70#include "AliRun.h"
fe4da5cc 71#include "AliMC.h"
d3f347ff 72#include "AliConst.h"
5c7f4665 73
851d3db9 74#include "AliTRDv1.h"
75#include "AliTRDmatrix.h"
76#include "AliTRDgeometry.h"
77
fe4da5cc 78ClassImp(AliTRDv1)
79
80//_____________________________________________________________________________
81AliTRDv1::AliTRDv1(const char *name, const char *title)
82 :AliTRD(name, title)
83{
84 //
851d3db9 85 // Standard constructor for Transition Radiation Detector version 1
fe4da5cc 86 //
82bbf98a 87
9d0b222b 88 fIdSens = 0;
82bbf98a 89
9d0b222b 90 fIdChamber1 = 0;
91 fIdChamber2 = 0;
92 fIdChamber3 = 0;
5c7f4665 93
9d0b222b 94 fSensSelect = 0;
95 fSensPlane = -1;
96 fSensChamber = -1;
97 fSensSector = -1;
98 fSensSectorRange = 0;
5c7f4665 99
9d0b222b 100 fDeltaE = NULL;
5c7f4665 101
102 SetBufferSize(128000);
103
104}
105
106//_____________________________________________________________________________
107AliTRDv1::~AliTRDv1()
108{
82bbf98a 109
5c7f4665 110 if (fDeltaE) delete fDeltaE;
82bbf98a 111
fe4da5cc 112}
113
114//_____________________________________________________________________________
115void AliTRDv1::CreateGeometry()
116{
117 //
851d3db9 118 // Create the GEANT geometry for the Transition Radiation Detector - Version 1
5c7f4665 119 // This version covers the full azimuth.
d3f347ff 120 //
121
82bbf98a 122 // Check that FRAME is there otherwise we have no place where to put the TRD
123 AliModule* FRAME = gAlice->GetModule("FRAME");
124 if (!FRAME) return;
d3f347ff 125
82bbf98a 126 // Define the chambers
127 AliTRD::CreateGeometry();
d3f347ff 128
fe4da5cc 129}
130
131//_____________________________________________________________________________
132void AliTRDv1::CreateMaterials()
133{
134 //
851d3db9 135 // Create materials for the Transition Radiation Detector version 1
fe4da5cc 136 //
82bbf98a 137
d3f347ff 138 AliTRD::CreateMaterials();
82bbf98a 139
fe4da5cc 140}
141
142//_____________________________________________________________________________
5c7f4665 143void AliTRDv1::Init()
144{
145 //
146 // Initialise Transition Radiation Detector after geometry has been built.
5c7f4665 147 //
148
149 AliTRD::Init();
150
851d3db9 151 printf(" Slow simulator\n\n");
152 if (fSensSelect) {
153 if (fSensPlane >= 0)
154 printf(" Only plane %d is sensitive\n",fSensPlane);
155 if (fSensChamber >= 0)
156 printf(" Only chamber %d is sensitive\n",fSensChamber);
9d0b222b 157 if (fSensSector >= 0) {
158 Int_t sens1 = fSensSector;
159 Int_t sens2 = fSensSector + fSensSectorRange;
160 sens2 -= ((Int_t) (sens2 / kNsect)) * kNsect;
161 printf(" Only sectors %d - %d are sensitive\n",sens1,sens2-1);
162 }
851d3db9 163 }
164 printf("\n");
5c7f4665 165
166 // First ionization potential (eV) for the gas mixture (90% Xe + 10% CO2)
167 const Float_t kPoti = 12.1;
168 // Maximum energy (50 keV);
169 const Float_t kEend = 50000.0;
170 // Ermilova distribution for the delta-ray spectrum
171 Float_t Poti = TMath::Log(kPoti);
172 Float_t Eend = TMath::Log(kEend);
173 fDeltaE = new TF1("deltae",Ermilova,Poti,Eend,0);
174
175 // Identifier of the sensitive volume (drift region)
176 fIdSens = gMC->VolId("UL05");
82bbf98a 177
178 // Identifier of the TRD-driftchambers
179 fIdChamber1 = gMC->VolId("UCIO");
180 fIdChamber2 = gMC->VolId("UCIM");
181 fIdChamber3 = gMC->VolId("UCII");
182
5c7f4665 183 for (Int_t i = 0; i < 80; i++) printf("*");
184 printf("\n");
185
fe4da5cc 186}
187
188//_____________________________________________________________________________
5c7f4665 189void AliTRDv1::SetSensPlane(Int_t iplane)
190{
191 //
851d3db9 192 // Defines the hit-sensitive plane (0-5)
5c7f4665 193 //
82bbf98a 194
851d3db9 195 if ((iplane < 0) || (iplane > 5)) {
5c7f4665 196 printf("Wrong input value: %d\n",iplane);
197 printf("Use standard setting\n");
851d3db9 198 fSensPlane = -1;
199 fSensSelect = 0;
5c7f4665 200 return;
201 }
82bbf98a 202
5c7f4665 203 fSensSelect = 1;
204 fSensPlane = iplane;
82bbf98a 205
5c7f4665 206}
207
208//_____________________________________________________________________________
209void AliTRDv1::SetSensChamber(Int_t ichamber)
210{
211 //
851d3db9 212 // Defines the hit-sensitive chamber (0-4)
5c7f4665 213 //
214
851d3db9 215 if ((ichamber < 0) || (ichamber > 4)) {
5c7f4665 216 printf("Wrong input value: %d\n",ichamber);
217 printf("Use standard setting\n");
851d3db9 218 fSensChamber = -1;
219 fSensSelect = 0;
5c7f4665 220 return;
221 }
222
223 fSensSelect = 1;
224 fSensChamber = ichamber;
225
226}
227
228//_____________________________________________________________________________
229void AliTRDv1::SetSensSector(Int_t isector)
230{
231 //
851d3db9 232 // Defines the hit-sensitive sector (0-17)
5c7f4665 233 //
234
9d0b222b 235 SetSensSector(isector,1);
236
237}
238
239//_____________________________________________________________________________
240void AliTRDv1::SetSensSector(Int_t isector, Int_t nsector)
241{
242 //
243 // Defines a range of hit-sensitive sectors. The range is defined by
244 // <isector> (0-17) as the starting point and <nsector> as the number
245 // of sectors to be included.
246 //
247
851d3db9 248 if ((isector < 0) || (isector > 17)) {
9d0b222b 249 printf("Wrong input value <isector>: %d\n",isector);
5c7f4665 250 printf("Use standard setting\n");
9d0b222b 251 fSensSector = -1;
252 fSensSectorRange = 0;
253 fSensSelect = 0;
5c7f4665 254 return;
255 }
256
9d0b222b 257 if ((nsector < 1) || (nsector > 18)) {
258 printf("Wrong input value <nsector>: %d\n",nsector);
259 printf("Use standard setting\n");
260 fSensSector = -1;
261 fSensSectorRange = 0;
262 fSensSelect = 0;
263 return;
264 }
265
266 fSensSelect = 1;
267 fSensSector = isector;
268 fSensSectorRange = nsector;
5c7f4665 269
270}
271
272//_____________________________________________________________________________
273void AliTRDv1::StepManager()
274{
275 //
5c7f4665 276 // Slow simulator. Every charged track produces electron cluster as hits
277 // along its path across the drift volume. The step size is set acording
278 // to Bethe-Bloch. The energy distribution of the delta electrons follows
279 // a spectrum taken from Ermilova et al.
280 //
281
282 Int_t iIdSens, icSens;
283 Int_t iIdSpace, icSpace;
284 Int_t iIdChamber, icChamber;
851d3db9 285 Int_t pla = 0;
286 Int_t cha = 0;
287 Int_t sec = 0;
288 Int_t iPdg;
5c7f4665 289
9d0b222b 290 Int_t det[1];
291
5c7f4665 292 Float_t hits[4];
293 Float_t random[1];
294 Float_t charge;
295 Float_t aMass;
296
297 Double_t pTot;
298 Double_t qTot;
299 Double_t eDelta;
300 Double_t betaGamma, pp;
301
302 TLorentzVector pos, mom;
82bbf98a 303 TClonesArray &lhits = *fHits;
304
851d3db9 305 const Double_t kBig = 1.0E+12;
5c7f4665 306
307 // Ionization energy
851d3db9 308 const Float_t kWion = 22.04;
5c7f4665 309 // Maximum energy for e+ e- g for the step-size calculation
851d3db9 310 const Float_t kPTotMax = 0.002;
5c7f4665 311 // Plateau value of the energy-loss for electron in xenon
312 // taken from: Allison + Comb, Ann. Rev. Nucl. Sci. (1980), 30, 253
313 //const Double_t kPlateau = 1.70;
314 // the averaged value (26/3/99)
851d3db9 315 const Float_t kPlateau = 1.55;
5c7f4665 316 // dN1/dx|min for the gas mixture (90% Xe + 10% CO2)
851d3db9 317 const Float_t kPrim = 48.0;
5c7f4665 318 // First ionization potential (eV) for the gas mixture (90% Xe + 10% CO2)
851d3db9 319 const Float_t kPoti = 12.1;
320
321 // PDG code electron
322 const Int_t pdgElectron = 11;
5c7f4665 323
324 // Set the maximum step size to a very large number for all
325 // neutral particles and those outside the driftvolume
326 gMC->SetMaxStep(kBig);
327
328 // Use only charged tracks
329 if (( gMC->TrackCharge() ) &&
330 (!gMC->IsTrackStop() ) &&
331 (!gMC->IsTrackDisappeared())) {
fe4da5cc 332
5c7f4665 333 // Inside a sensitive volume?
82bbf98a 334 iIdSens = gMC->CurrentVolID(icSens);
335 if (iIdSens == fIdSens) {
336
82bbf98a 337 iIdSpace = gMC->CurrentVolOffID(4,icSpace );
338 iIdChamber = gMC->CurrentVolOffID(1,icChamber);
fe4da5cc 339
5c7f4665 340 // Calculate the energy of the delta-electrons
341 eDelta = TMath::Exp(fDeltaE->GetRandom()) - kPoti;
342 eDelta = TMath::Max(eDelta,0.0);
343
344 // The number of secondary electrons created
345 qTot = (Double_t) ((Int_t) (eDelta / kWion) + 1);
346
347 // The hit coordinates and charge
348 gMC->TrackPosition(pos);
349 hits[0] = pos[0];
350 hits[1] = pos[1];
351 hits[2] = pos[2];
352 hits[3] = qTot;
353
851d3db9 354 // The sector number (0 - 17)
355 // The numbering goes clockwise and starts at y = 0
356 Float_t phi = kRaddeg*TMath::ATan2(pos[0],pos[1]);
357 if (phi < 90.)
358 phi = phi + 270.;
359 else
360 phi = phi - 90.;
361 sec = ((Int_t) (phi / 20));
82bbf98a 362
d3f347ff 363 // The chamber number
851d3db9 364 // 0: outer left
365 // 1: middle left
366 // 2: inner
367 // 3: middle right
368 // 4: outer right
82bbf98a 369 if (iIdChamber == fIdChamber1)
851d3db9 370 cha = (hits[2] < 0 ? 0 : 4);
82bbf98a 371 else if (iIdChamber == fIdChamber2)
851d3db9 372 cha = (hits[2] < 0 ? 1 : 3);
82bbf98a 373 else if (iIdChamber == fIdChamber3)
851d3db9 374 cha = 2;
82bbf98a 375
fe4da5cc 376 // The plane number
851d3db9 377 // The numbering starts at the innermost plane
378 pla = icChamber - TMath::Nint((Float_t) (icChamber / 7)) * 6 - 1;
82bbf98a 379
5c7f4665 380 // Check on selected volumes
381 Int_t addthishit = 1;
382 if (fSensSelect) {
6f1e466d 383 if ((fSensPlane >= 0) && (pla != fSensPlane )) addthishit = 0;
384 if ((fSensChamber >= 0) && (cha != fSensChamber)) addthishit = 0;
9d0b222b 385 if (fSensSector >= 0) {
386 Int_t sens1 = fSensSector;
387 Int_t sens2 = fSensSector + fSensSectorRange;
388 sens2 -= ((Int_t) (sens2 / kNsect)) * kNsect;
389 if (sens1 < sens2) {
390 if ((sec < sens1) || (sec >= sens2)) addthishit = 0;
391 }
392 else {
393 if ((sec < sens1) && (sec >= sens2)) addthishit = 0;
394 }
395 }
5c7f4665 396 }
397
398 // Add this hit
399 if (addthishit) {
400
9d0b222b 401 det[0] = fGeometry->GetDetector(pla,cha,sec);
851d3db9 402 new(lhits[fNhits++]) AliTRDhit(fIshunt
403 ,gAlice->CurrentTrack()
9d0b222b 404 ,det
851d3db9 405 ,hits);
5c7f4665 406
407 // The energy loss according to Bethe Bloch
408 gMC->TrackMomentum(mom);
409 pTot = mom.Rho();
851d3db9 410 iPdg = TMath::Abs(gMC->TrackPid());
411 if ( (iPdg != pdgElectron) ||
412 ((iPdg == pdgElectron) && (pTot < kPTotMax))) {
5c7f4665 413 aMass = gMC->TrackMass();
414 betaGamma = pTot / aMass;
415 pp = kPrim * BetheBloch(betaGamma);
416 // Take charge > 1 into account
417 charge = gMC->TrackCharge();
418 if (TMath::Abs(charge) > 1) pp = pp * charge*charge;
419 }
420 // Electrons above 20 Mev/c are at the plateau
421 else {
422 pp = kPrim * kPlateau;
423 }
424
425 // Calculate the maximum step size for the next tracking step
426 if (pp > 0) {
427 do
428 gMC->Rndm(random,1);
429 while ((random[0] == 1.) || (random[0] == 0.));
430 gMC->SetMaxStep( - TMath::Log(random[0]) / pp);
431 }
432
433 }
434 else {
435 // set step size to maximal value
436 gMC->SetMaxStep(kBig);
437 }
d3f347ff 438
439 }
440
5c7f4665 441 }
442
443}
444
445//_____________________________________________________________________________
446Double_t AliTRDv1::BetheBloch(Double_t bg)
447{
448 //
449 // Parametrization of the Bethe-Bloch-curve
450 // The parametrization is the same as for the TPC and is taken from Lehrhaus.
451 //
452
453 // This parameters have been adjusted to averaged values from GEANT
454 const Double_t kP1 = 7.17960e-02;
455 const Double_t kP2 = 8.54196;
456 const Double_t kP3 = 1.38065e-06;
457 const Double_t kP4 = 5.30972;
458 const Double_t kP5 = 2.83798;
459
460 // This parameters have been adjusted to Xe-data found in:
461 // Allison & Cobb, Ann. Rev. Nucl. Sci. (1980), 30, 253
462 //const Double_t kP1 = 0.76176E-1;
463 //const Double_t kP2 = 10.632;
464 //const Double_t kP3 = 3.17983E-6;
465 //const Double_t kP4 = 1.8631;
466 //const Double_t kP5 = 1.9479;
467
468 if (bg > 0) {
469 Double_t yy = bg / TMath::Sqrt(1. + bg*bg);
470 Double_t aa = TMath::Power(yy,kP4);
471 Double_t bb = TMath::Power((1./bg),kP5);
472 bb = TMath::Log(kP3 + bb);
473 return ((kP2 - aa - bb)*kP1 / aa);
474 }
475 else
476 return 0;
d3f347ff 477
fe4da5cc 478}
5c7f4665 479
480//_____________________________________________________________________________
481Double_t Ermilova(Double_t *x, Double_t *)
482{
483 //
484 // Calculates the delta-ray energy distribution according to Ermilova.
485 // Logarithmic scale !
486 //
487
488 Double_t energy;
489 Double_t dpos;
490 Double_t dnde;
491
492 Int_t pos1, pos2;
493
494 const Int_t nV = 31;
495
496 Float_t vxe[nV] = { 2.3026, 2.9957, 3.4012, 3.6889, 3.9120
497 , 4.0943, 4.2485, 4.3820, 4.4998, 4.6052
498 , 4.7005, 5.0752, 5.2983, 5.7038, 5.9915
499 , 6.2146, 6.5221, 6.9078, 7.3132, 7.6009
500 , 8.0064, 8.5172, 8.6995, 8.9872, 9.2103
501 , 9.4727, 9.9035,10.3735,10.5966,10.8198
502 ,11.5129 };
503
504 Float_t vye[nV] = { 80.0 , 31.0 , 23.3 , 21.1 , 21.0
505 , 20.9 , 20.8 , 20.0 , 16.0 , 11.0
506 , 8.0 , 6.0 , 5.2 , 4.6 , 4.0
507 , 3.5 , 3.0 , 1.4 , 0.67 , 0.44
508 , 0.3 , 0.18 , 0.12 , 0.08 , 0.056
509 , 0.04 , 0.023, 0.015, 0.011, 0.01
510 , 0.004 };
511
512 energy = x[0];
513
514 // Find the position
515 pos1 = pos2 = 0;
516 dpos = 0;
517 do {
518 dpos = energy - vxe[pos2++];
519 }
520 while (dpos > 0);
521 pos2--;
522 if (pos2 > nV) pos2 = nV;
523 pos1 = pos2 - 1;
524
525 // Differentiate between the sampling points
526 dnde = (vye[pos1] - vye[pos2]) / (vxe[pos2] - vxe[pos1]);
527
528 return dnde;
529
530}