reveng tag added
[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$Log$
8230f242 18Revision 1.19 2000/06/07 16:27:32 cblume
19Try to remove compiler warnings on Sun and HP
20
9d0b222b 21Revision 1.18 2000/05/08 16:17:27 cblume
22Merge TRD-develop
23
6f1e466d 24Revision 1.17.2.1 2000/05/08 14:59:16 cblume
25Made inline function non-virtual. Bug fix in setting sensitive chamber
26
27Revision 1.17 2000/02/28 19:10:26 cblume
28Include the new TRD classes
29
851d3db9 30Revision 1.16.4.1 2000/02/28 18:04:35 cblume
31Change to new hit version, introduce geometry class, and move digitization and clustering to AliTRDdigitizer/AliTRDclusterizerV1
32
33Revision 1.16 1999/11/05 22:50:28 fca
34Do not use Atan, removed from ROOT too
35
90f8d287 36Revision 1.15 1999/11/02 17:20:19 fca
37initialise nbytes before using it
38
036da493 39Revision 1.14 1999/11/02 17:15:54 fca
40Correct ansi scoping not accepted by HP compilers
41
0549c011 42Revision 1.13 1999/11/02 17:14:51 fca
43Correct ansi scoping not accepted by HP compilers
44
9c767df4 45Revision 1.12 1999/11/02 16:35:56 fca
46New version of TRD introduced
47
5c7f4665 48Revision 1.11 1999/11/01 20:41:51 fca
49Added protections against using the wrong version of FRAME
50
ab76897d 51Revision 1.10 1999/09/29 09:24:35 fca
52Introduction of the Copyright and cvs Log
53
4c039060 54*/
55
fe4da5cc 56///////////////////////////////////////////////////////////////////////////////
57// //
5c7f4665 58// Transition Radiation Detector version 2 -- slow simulator //
fe4da5cc 59// //
60//Begin_Html
61/*
5c7f4665 62<img src="picts/AliTRDfullClass.gif">
fe4da5cc 63*/
64//End_Html
65// //
66// //
67///////////////////////////////////////////////////////////////////////////////
68
69#include <TMath.h>
fe4da5cc 70#include <TVector.h>
5c7f4665 71#include <TRandom.h>
fe4da5cc 72
fe4da5cc 73#include "AliRun.h"
fe4da5cc 74#include "AliMC.h"
d3f347ff 75#include "AliConst.h"
5c7f4665 76
851d3db9 77#include "AliTRDv1.h"
78#include "AliTRDmatrix.h"
79#include "AliTRDgeometry.h"
80
fe4da5cc 81ClassImp(AliTRDv1)
82
8230f242 83
84//_____________________________________________________________________________
85AliTRDv1::AliTRDv1():AliTRD()
86{
87 //
88 // Default constructor
89 //
90
91 fIdSens = 0;
92
93 fIdChamber1 = 0;
94 fIdChamber2 = 0;
95 fIdChamber3 = 0;
96
97 fSensSelect = 0;
98 fSensPlane = -1;
99 fSensChamber = -1;
100 fSensSector = -1;
101 fSensSectorRange = 0;
102
103 fDeltaE = NULL;
104
105}
106
fe4da5cc 107//_____________________________________________________________________________
108AliTRDv1::AliTRDv1(const char *name, const char *title)
109 :AliTRD(name, title)
110{
111 //
851d3db9 112 // Standard constructor for Transition Radiation Detector version 1
fe4da5cc 113 //
82bbf98a 114
9d0b222b 115 fIdSens = 0;
82bbf98a 116
9d0b222b 117 fIdChamber1 = 0;
118 fIdChamber2 = 0;
119 fIdChamber3 = 0;
5c7f4665 120
9d0b222b 121 fSensSelect = 0;
122 fSensPlane = -1;
123 fSensChamber = -1;
124 fSensSector = -1;
8230f242 125 fSensSectorRange = 0;
5c7f4665 126
9d0b222b 127 fDeltaE = NULL;
5c7f4665 128
129 SetBufferSize(128000);
130
131}
132
8230f242 133//_____________________________________________________________________________
134AliTRDv1::AliTRDv1(AliTRDv1 &trd)
135{
136 //
137 // Copy constructor
138 //
139
140 trd.Copy(*this);
141
142}
143
5c7f4665 144//_____________________________________________________________________________
145AliTRDv1::~AliTRDv1()
146{
82bbf98a 147
5c7f4665 148 if (fDeltaE) delete fDeltaE;
82bbf98a 149
fe4da5cc 150}
151
8230f242 152
153//_____________________________________________________________________________
154void AliTRDv1::Copy(AliTRDv1 &trd)
155{
156 //
157 // Copy function
158 //
159
160 trd.fIdSens = fIdSens;
161
162 trd.fIdChamber1 = fIdChamber1;
163 trd.fIdChamber2 = fIdChamber2;
164 trd.fIdChamber3 = fIdChamber3;
165
166 trd.fSensSelect = fSensSelect;
167 trd.fSensPlane = fSensPlane;
168 trd.fSensChamber = fSensChamber;
169 trd.fSensSector = fSensSector;
170 trd.fSensSectorRange = fSensSectorRange;
171
172 trd.fDeltaE = NULL;
173
174}
175
fe4da5cc 176//_____________________________________________________________________________
177void AliTRDv1::CreateGeometry()
178{
179 //
851d3db9 180 // Create the GEANT geometry for the Transition Radiation Detector - Version 1
5c7f4665 181 // This version covers the full azimuth.
d3f347ff 182 //
183
82bbf98a 184 // Check that FRAME is there otherwise we have no place where to put the TRD
8230f242 185 AliModule* frame = gAlice->GetModule("FRAME");
186 if (!frame) return;
d3f347ff 187
82bbf98a 188 // Define the chambers
189 AliTRD::CreateGeometry();
d3f347ff 190
fe4da5cc 191}
192
193//_____________________________________________________________________________
194void AliTRDv1::CreateMaterials()
195{
196 //
851d3db9 197 // Create materials for the Transition Radiation Detector version 1
fe4da5cc 198 //
82bbf98a 199
d3f347ff 200 AliTRD::CreateMaterials();
82bbf98a 201
fe4da5cc 202}
203
5c7f4665 204//_____________________________________________________________________________
205void AliTRDv1::Init()
206{
207 //
208 // Initialise Transition Radiation Detector after geometry has been built.
5c7f4665 209 //
210
211 AliTRD::Init();
212
851d3db9 213 printf(" Slow simulator\n\n");
214 if (fSensSelect) {
215 if (fSensPlane >= 0)
216 printf(" Only plane %d is sensitive\n",fSensPlane);
217 if (fSensChamber >= 0)
218 printf(" Only chamber %d is sensitive\n",fSensChamber);
9d0b222b 219 if (fSensSector >= 0) {
220 Int_t sens1 = fSensSector;
221 Int_t sens2 = fSensSector + fSensSectorRange;
222 sens2 -= ((Int_t) (sens2 / kNsect)) * kNsect;
223 printf(" Only sectors %d - %d are sensitive\n",sens1,sens2-1);
224 }
851d3db9 225 }
226 printf("\n");
5c7f4665 227
228 // First ionization potential (eV) for the gas mixture (90% Xe + 10% CO2)
229 const Float_t kPoti = 12.1;
230 // Maximum energy (50 keV);
231 const Float_t kEend = 50000.0;
232 // Ermilova distribution for the delta-ray spectrum
8230f242 233 Float_t poti = TMath::Log(kPoti);
234 Float_t eEnd = TMath::Log(kEend);
235 fDeltaE = new TF1("deltae",Ermilova,poti,eEnd,0);
5c7f4665 236
237 // Identifier of the sensitive volume (drift region)
238 fIdSens = gMC->VolId("UL05");
82bbf98a 239
240 // Identifier of the TRD-driftchambers
241 fIdChamber1 = gMC->VolId("UCIO");
242 fIdChamber2 = gMC->VolId("UCIM");
243 fIdChamber3 = gMC->VolId("UCII");
244
5c7f4665 245 for (Int_t i = 0; i < 80; i++) printf("*");
246 printf("\n");
247
fe4da5cc 248}
249
5c7f4665 250//_____________________________________________________________________________
251void AliTRDv1::SetSensPlane(Int_t iplane)
252{
253 //
851d3db9 254 // Defines the hit-sensitive plane (0-5)
5c7f4665 255 //
82bbf98a 256
851d3db9 257 if ((iplane < 0) || (iplane > 5)) {
5c7f4665 258 printf("Wrong input value: %d\n",iplane);
259 printf("Use standard setting\n");
851d3db9 260 fSensPlane = -1;
261 fSensSelect = 0;
5c7f4665 262 return;
263 }
82bbf98a 264
5c7f4665 265 fSensSelect = 1;
266 fSensPlane = iplane;
82bbf98a 267
5c7f4665 268}
269
270//_____________________________________________________________________________
271void AliTRDv1::SetSensChamber(Int_t ichamber)
272{
273 //
851d3db9 274 // Defines the hit-sensitive chamber (0-4)
5c7f4665 275 //
276
851d3db9 277 if ((ichamber < 0) || (ichamber > 4)) {
5c7f4665 278 printf("Wrong input value: %d\n",ichamber);
279 printf("Use standard setting\n");
851d3db9 280 fSensChamber = -1;
281 fSensSelect = 0;
5c7f4665 282 return;
283 }
284
285 fSensSelect = 1;
286 fSensChamber = ichamber;
287
288}
289
290//_____________________________________________________________________________
291void AliTRDv1::SetSensSector(Int_t isector)
292{
293 //
851d3db9 294 // Defines the hit-sensitive sector (0-17)
5c7f4665 295 //
296
9d0b222b 297 SetSensSector(isector,1);
298
299}
300
301//_____________________________________________________________________________
302void AliTRDv1::SetSensSector(Int_t isector, Int_t nsector)
303{
304 //
305 // Defines a range of hit-sensitive sectors. The range is defined by
306 // <isector> (0-17) as the starting point and <nsector> as the number
307 // of sectors to be included.
308 //
309
851d3db9 310 if ((isector < 0) || (isector > 17)) {
9d0b222b 311 printf("Wrong input value <isector>: %d\n",isector);
5c7f4665 312 printf("Use standard setting\n");
9d0b222b 313 fSensSector = -1;
314 fSensSectorRange = 0;
315 fSensSelect = 0;
5c7f4665 316 return;
317 }
318
9d0b222b 319 if ((nsector < 1) || (nsector > 18)) {
320 printf("Wrong input value <nsector>: %d\n",nsector);
321 printf("Use standard setting\n");
322 fSensSector = -1;
323 fSensSectorRange = 0;
324 fSensSelect = 0;
325 return;
326 }
327
328 fSensSelect = 1;
329 fSensSector = isector;
330 fSensSectorRange = nsector;
5c7f4665 331
332}
333
334//_____________________________________________________________________________
335void AliTRDv1::StepManager()
336{
337 //
5c7f4665 338 // Slow simulator. Every charged track produces electron cluster as hits
339 // along its path across the drift volume. The step size is set acording
340 // to Bethe-Bloch. The energy distribution of the delta electrons follows
341 // a spectrum taken from Ermilova et al.
342 //
343
344 Int_t iIdSens, icSens;
345 Int_t iIdSpace, icSpace;
346 Int_t iIdChamber, icChamber;
851d3db9 347 Int_t pla = 0;
348 Int_t cha = 0;
349 Int_t sec = 0;
350 Int_t iPdg;
5c7f4665 351
9d0b222b 352 Int_t det[1];
353
5c7f4665 354 Float_t hits[4];
355 Float_t random[1];
356 Float_t charge;
357 Float_t aMass;
358
359 Double_t pTot;
360 Double_t qTot;
361 Double_t eDelta;
362 Double_t betaGamma, pp;
363
364 TLorentzVector pos, mom;
82bbf98a 365 TClonesArray &lhits = *fHits;
366
851d3db9 367 const Double_t kBig = 1.0E+12;
5c7f4665 368
369 // Ionization energy
851d3db9 370 const Float_t kWion = 22.04;
5c7f4665 371 // Maximum energy for e+ e- g for the step-size calculation
851d3db9 372 const Float_t kPTotMax = 0.002;
5c7f4665 373 // Plateau value of the energy-loss for electron in xenon
374 // taken from: Allison + Comb, Ann. Rev. Nucl. Sci. (1980), 30, 253
375 //const Double_t kPlateau = 1.70;
376 // the averaged value (26/3/99)
851d3db9 377 const Float_t kPlateau = 1.55;
5c7f4665 378 // dN1/dx|min for the gas mixture (90% Xe + 10% CO2)
851d3db9 379 const Float_t kPrim = 48.0;
5c7f4665 380 // First ionization potential (eV) for the gas mixture (90% Xe + 10% CO2)
851d3db9 381 const Float_t kPoti = 12.1;
382
383 // PDG code electron
8230f242 384 const Int_t kPdgElectron = 11;
5c7f4665 385
386 // Set the maximum step size to a very large number for all
387 // neutral particles and those outside the driftvolume
388 gMC->SetMaxStep(kBig);
389
390 // Use only charged tracks
391 if (( gMC->TrackCharge() ) &&
392 (!gMC->IsTrackStop() ) &&
393 (!gMC->IsTrackDisappeared())) {
fe4da5cc 394
5c7f4665 395 // Inside a sensitive volume?
82bbf98a 396 iIdSens = gMC->CurrentVolID(icSens);
397 if (iIdSens == fIdSens) {
398
82bbf98a 399 iIdSpace = gMC->CurrentVolOffID(4,icSpace );
400 iIdChamber = gMC->CurrentVolOffID(1,icChamber);
fe4da5cc 401
5c7f4665 402 // Calculate the energy of the delta-electrons
403 eDelta = TMath::Exp(fDeltaE->GetRandom()) - kPoti;
404 eDelta = TMath::Max(eDelta,0.0);
405
406 // The number of secondary electrons created
407 qTot = (Double_t) ((Int_t) (eDelta / kWion) + 1);
408
409 // The hit coordinates and charge
410 gMC->TrackPosition(pos);
411 hits[0] = pos[0];
412 hits[1] = pos[1];
413 hits[2] = pos[2];
414 hits[3] = qTot;
415
851d3db9 416 // The sector number (0 - 17)
417 // The numbering goes clockwise and starts at y = 0
418 Float_t phi = kRaddeg*TMath::ATan2(pos[0],pos[1]);
419 if (phi < 90.)
420 phi = phi + 270.;
421 else
422 phi = phi - 90.;
423 sec = ((Int_t) (phi / 20));
82bbf98a 424
d3f347ff 425 // The chamber number
851d3db9 426 // 0: outer left
427 // 1: middle left
428 // 2: inner
429 // 3: middle right
430 // 4: outer right
82bbf98a 431 if (iIdChamber == fIdChamber1)
851d3db9 432 cha = (hits[2] < 0 ? 0 : 4);
82bbf98a 433 else if (iIdChamber == fIdChamber2)
851d3db9 434 cha = (hits[2] < 0 ? 1 : 3);
82bbf98a 435 else if (iIdChamber == fIdChamber3)
851d3db9 436 cha = 2;
82bbf98a 437
fe4da5cc 438 // The plane number
851d3db9 439 // The numbering starts at the innermost plane
440 pla = icChamber - TMath::Nint((Float_t) (icChamber / 7)) * 6 - 1;
82bbf98a 441
5c7f4665 442 // Check on selected volumes
443 Int_t addthishit = 1;
444 if (fSensSelect) {
6f1e466d 445 if ((fSensPlane >= 0) && (pla != fSensPlane )) addthishit = 0;
446 if ((fSensChamber >= 0) && (cha != fSensChamber)) addthishit = 0;
9d0b222b 447 if (fSensSector >= 0) {
448 Int_t sens1 = fSensSector;
449 Int_t sens2 = fSensSector + fSensSectorRange;
450 sens2 -= ((Int_t) (sens2 / kNsect)) * kNsect;
451 if (sens1 < sens2) {
452 if ((sec < sens1) || (sec >= sens2)) addthishit = 0;
453 }
454 else {
455 if ((sec < sens1) && (sec >= sens2)) addthishit = 0;
456 }
457 }
5c7f4665 458 }
459
460 // Add this hit
461 if (addthishit) {
462
9d0b222b 463 det[0] = fGeometry->GetDetector(pla,cha,sec);
851d3db9 464 new(lhits[fNhits++]) AliTRDhit(fIshunt
465 ,gAlice->CurrentTrack()
9d0b222b 466 ,det
851d3db9 467 ,hits);
5c7f4665 468
469 // The energy loss according to Bethe Bloch
470 gMC->TrackMomentum(mom);
471 pTot = mom.Rho();
851d3db9 472 iPdg = TMath::Abs(gMC->TrackPid());
8230f242 473 if ( (iPdg != kPdgElectron) ||
474 ((iPdg == kPdgElectron) && (pTot < kPTotMax))) {
5c7f4665 475 aMass = gMC->TrackMass();
476 betaGamma = pTot / aMass;
477 pp = kPrim * BetheBloch(betaGamma);
478 // Take charge > 1 into account
479 charge = gMC->TrackCharge();
480 if (TMath::Abs(charge) > 1) pp = pp * charge*charge;
481 }
482 // Electrons above 20 Mev/c are at the plateau
483 else {
484 pp = kPrim * kPlateau;
485 }
486
487 // Calculate the maximum step size for the next tracking step
488 if (pp > 0) {
489 do
490 gMC->Rndm(random,1);
491 while ((random[0] == 1.) || (random[0] == 0.));
492 gMC->SetMaxStep( - TMath::Log(random[0]) / pp);
493 }
494
495 }
496 else {
497 // set step size to maximal value
498 gMC->SetMaxStep(kBig);
499 }
d3f347ff 500
501 }
502
5c7f4665 503 }
504
505}
506
507//_____________________________________________________________________________
508Double_t AliTRDv1::BetheBloch(Double_t bg)
509{
510 //
511 // Parametrization of the Bethe-Bloch-curve
512 // The parametrization is the same as for the TPC and is taken from Lehrhaus.
513 //
514
515 // This parameters have been adjusted to averaged values from GEANT
516 const Double_t kP1 = 7.17960e-02;
517 const Double_t kP2 = 8.54196;
518 const Double_t kP3 = 1.38065e-06;
519 const Double_t kP4 = 5.30972;
520 const Double_t kP5 = 2.83798;
521
522 // This parameters have been adjusted to Xe-data found in:
523 // Allison & Cobb, Ann. Rev. Nucl. Sci. (1980), 30, 253
524 //const Double_t kP1 = 0.76176E-1;
525 //const Double_t kP2 = 10.632;
526 //const Double_t kP3 = 3.17983E-6;
527 //const Double_t kP4 = 1.8631;
528 //const Double_t kP5 = 1.9479;
529
530 if (bg > 0) {
531 Double_t yy = bg / TMath::Sqrt(1. + bg*bg);
532 Double_t aa = TMath::Power(yy,kP4);
533 Double_t bb = TMath::Power((1./bg),kP5);
534 bb = TMath::Log(kP3 + bb);
535 return ((kP2 - aa - bb)*kP1 / aa);
536 }
537 else
538 return 0;
d3f347ff 539
fe4da5cc 540}
5c7f4665 541
542//_____________________________________________________________________________
543Double_t Ermilova(Double_t *x, Double_t *)
544{
545 //
546 // Calculates the delta-ray energy distribution according to Ermilova.
547 // Logarithmic scale !
548 //
549
550 Double_t energy;
551 Double_t dpos;
552 Double_t dnde;
553
554 Int_t pos1, pos2;
555
8230f242 556 const Int_t kNv = 31;
5c7f4665 557
8230f242 558 Float_t vxe[kNv] = { 2.3026, 2.9957, 3.4012, 3.6889, 3.9120
559 , 4.0943, 4.2485, 4.3820, 4.4998, 4.6052
560 , 4.7005, 5.0752, 5.2983, 5.7038, 5.9915
561 , 6.2146, 6.5221, 6.9078, 7.3132, 7.6009
562 , 8.0064, 8.5172, 8.6995, 8.9872, 9.2103
563 , 9.4727, 9.9035,10.3735,10.5966,10.8198
564 ,11.5129 };
5c7f4665 565
8230f242 566 Float_t vye[kNv] = { 80.0 , 31.0 , 23.3 , 21.1 , 21.0
567 , 20.9 , 20.8 , 20.0 , 16.0 , 11.0
568 , 8.0 , 6.0 , 5.2 , 4.6 , 4.0
569 , 3.5 , 3.0 , 1.4 , 0.67 , 0.44
570 , 0.3 , 0.18 , 0.12 , 0.08 , 0.056
571 , 0.04 , 0.023, 0.015, 0.011, 0.01
572 , 0.004 };
5c7f4665 573
574 energy = x[0];
575
576 // Find the position
577 pos1 = pos2 = 0;
578 dpos = 0;
579 do {
580 dpos = energy - vxe[pos2++];
581 }
582 while (dpos > 0);
583 pos2--;
8230f242 584 if (pos2 > kNv) pos2 = kNv;
5c7f4665 585 pos1 = pos2 - 1;
586
587 // Differentiate between the sampling points
588 dnde = (vye[pos1] - vye[pos2]) / (vxe[pos2] - vxe[pos1]);
589
590 return dnde;
591
592}