TRD/AliTRDSimParam.cxx

   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 // Class containing constant simulation parameters                        //
  21 //                                                                        //
  22 // Request an instance with AliTRDSimParam::Instance()                    //
  23 // Then request the needed values                                         //
  24 //                                                                        //
  25 ////////////////////////////////////////////////////////////////////////////
  26
  27 #include <TMath.h>
  28
  29 #include "AliRun.h"
  30
  31 #include "AliTRDSimParam.h"
  32
  33 ClassImp(AliTRDSimParam)
  34
  35 AliTRDSimParam *AliTRDSimParam::fgInstance   = 0;
  36 Bool_t          AliTRDSimParam::fgTerminated = kFALSE;
  37
  38 //_ singleton implementation __________________________________________________
  39 AliTRDSimParam* AliTRDSimParam::Instance()
  40 {
  41   //
  42   // Singleton implementation
  43   // Returns an instance of this class, it is created if neccessary
  44   //
  45
  46   if (fgTerminated != kFALSE) {
  47     return 0;
  48   }
  49
  50   if (fgInstance == 0) {
  51     fgInstance = new AliTRDSimParam();
  52   }
  53
  54   return fgInstance;
  55
  56 }
  57
  58 //_ singleton implementation __________________________________________________
  59 void AliTRDSimParam::Terminate()
  60 {
  61   //
  62   // Singleton implementation
  63   // Deletes the instance of this class and sets the terminated flag,
  64   // instances cannot be requested anymore
  65   // This function can be called several times.
  66   //
  67
  68   fgTerminated = kTRUE;
  69
  70   if (fgInstance != 0) {
  71     delete fgInstance;
  72     fgInstance = 0;
  73   }
  74
  75 }
  76
  77 //_____________________________________________________________________________
  78 AliTRDSimParam::AliTRDSimParam()
  79   :TObject()
  80   ,fGasGain(0.0)
  81   ,fNoise(0.0)
  82   ,fChipGain(0.0)
  83   ,fADCoutRange(0.0)
  84   ,fADCinRange(0.0)
  85   ,fADCbaseline(0)
  86   ,fDiffusionOn(kFALSE)
  87   ,fElAttachOn(kFALSE)
  88   ,fElAttachProp(0.0)
  89   ,fTRFOn(kFALSE)
  90   ,fTRFsmp(0)
  91   ,fTRFbin(0)
  92   ,fTRFlo(0.0)
  93   ,fTRFhi(0.0)
  94   ,fTRFwid(0.0)
  95   ,fCTOn(kFALSE)
  96   ,fCTsmp(0)
  97   ,fAnodeWireOffset(0.0)
  98   ,fPadCoupling(0.0)
  99   ,fTimeCoupling(0.0)
 100   ,fTimeStructOn(kFALSE)
 101   ,fPRFOn(kFALSE)
 102   ,fGasMixture(0)
 103 {
 104   //
 105   // Default constructor
 106   //
 107
 108   Init();
 109
 110 }
 111
 112 //_____________________________________________________________________________
 113 void AliTRDSimParam::Init()
 114 {
 115   //
 116   // Default initializiation
 117   //
 118
 119   // The default parameter for the digitization
 120   fGasGain           = 4000.0;
 121   fChipGain          =   12.4;
 122   fNoise             = 1250.0;
 123   fADCoutRange       = 1023.0;          // 10-bit ADC
 124   fADCinRange        = 2000.0;          // 2V input range
 125   // Go back to 0 again, just to be consistent with reconstruction
 126   fADCbaseline       =      0;
 127   //fADCbaseline       =   10;
 128
 129   // Diffusion on
 130   fDiffusionOn       = kTRUE;
 131
 132   // Propability for electron attachment
 133   fElAttachOn        = kFALSE;
 134   fElAttachProp      = 0.0;
 135
 136   // The time response function
 137   fTRFOn             = kTRUE;
 138
 139   // The cross talk
 140   fCTOn              = kTRUE;
 141
 142   // The pad coupling factor
 143   // Use 0.46, instead of the theroetical value 0.3, since it reproduces better
 144   // the test beam data, even tough it is not understood why.
 145   fPadCoupling       = 0.46;
 146
 147   // The time coupling factor (same number as for the TPC)
 148   fTimeCoupling      = 0.4;
 149
 150   // Distance of first Anode wire from first pad edge
 151   fAnodeWireOffset   = 0.25;
 152
 153   // Use drift time maps
 154   fTimeStructOn      = kTRUE;
 155
 156   // The pad response function
 157   fPRFOn             = kTRUE;
 158
 159   // The gas mixture, default Xenon
 160   fGasMixture        = kXenon;
 161
 162   ReInit();
 163
 164 }
 165
 166 //_____________________________________________________________________________
 167 AliTRDSimParam::~AliTRDSimParam()
 168 {
 169   //
 170   // Destructor
 171   //
 172
 173   if (fTRFsmp) {
 174     delete [] fTRFsmp;
 175     fTRFsmp = 0;
 176   }
 177
 178   if (fCTsmp) {
 179     delete [] fCTsmp;
 180     fCTsmp  = 0;
 181   }
 182
 183 }
 184
 185 //_____________________________________________________________________________
 186 AliTRDSimParam::AliTRDSimParam(const AliTRDSimParam &p)
 187   :TObject(p)
 188   ,fGasGain(p.fGasGain)
 189   ,fNoise(p.fNoise)
 190   ,fChipGain(p.fChipGain)
 191   ,fADCoutRange(p.fADCoutRange)
 192   ,fADCinRange(p.fADCinRange)
 193   ,fADCbaseline(p.fADCbaseline)
 194   ,fDiffusionOn(p.fDiffusionOn)
 195   ,fElAttachOn(p.fElAttachOn)
 196   ,fElAttachProp(p.fElAttachProp)
 197   ,fTRFOn(p.fTRFOn)
 198   ,fTRFsmp(0)
 199   ,fTRFbin(p.fTRFbin)
 200   ,fTRFlo(p.fTRFlo)
 201   ,fTRFhi(p.fTRFhi)
 202   ,fTRFwid(p.fTRFwid)
 203   ,fCTOn(p.fCTOn)
 204   ,fCTsmp(0)
 205   ,fAnodeWireOffset(p.fAnodeWireOffset)
 206   ,fPadCoupling(p.fPadCoupling)
 207   ,fTimeCoupling(p.fTimeCoupling)
 208   ,fTimeStructOn(p.fTimeStructOn)
 209   ,fPRFOn(p.fPRFOn)
 210   ,fGasMixture(p.fGasMixture)
 211 {
 212   //
 213   // Copy constructor
 214   //
 215
 216   Int_t iBin = 0;
 217
 218   if (((AliTRDSimParam &) p).fTRFsmp) {
 219     delete [] ((AliTRDSimParam &) p).fTRFsmp;
 220   }
 221   ((AliTRDSimParam &) p).fTRFsmp = new Float_t[fTRFbin];
 222   for (iBin = 0; iBin < fTRFbin; iBin++) {
 223     ((AliTRDSimParam &) p).fTRFsmp[iBin] = fTRFsmp[iBin];
 224   }
 225
 226   if (((AliTRDSimParam &) p).fCTsmp) {
 227     delete [] ((AliTRDSimParam &) p).fCTsmp;
 228   }
 229   ((AliTRDSimParam &) p).fCTsmp  = new Float_t[fTRFbin];
 230   for (iBin = 0; iBin < fTRFbin; iBin++) {
 231     ((AliTRDSimParam &) p).fCTsmp[iBin] = fCTsmp[iBin];
 232   }
 233
 234 }
 235
 236 //_____________________________________________________________________________
 237 AliTRDSimParam &AliTRDSimParam::operator=(const AliTRDSimParam &p)
 238 {
 239   //
 240   // Assignment operator
 241   //
 242
 243   if (this != &p) {
 244     ((AliTRDSimParam &) p).Copy(*this);
 245   }
 246
 247   return *this;
 248
 249 }
 250
 251 //_____________________________________________________________________________
 252 void AliTRDSimParam::Copy(TObject &p) const
 253 {
 254   //
 255   // Copy function
 256   //
 257
 258   AliTRDSimParam *target = dynamic_cast<AliTRDSimParam *> (&p);
 259   if (!target) {
 260     return;
 261   }
 262
 263   target->fGasGain            = fGasGain;
 264   target->fNoise              = fNoise;
 265   target->fChipGain           = fChipGain;
 266   target->fADCoutRange        = fADCoutRange;
 267   target->fADCinRange         = fADCinRange;
 268   target->fADCbaseline        = fADCbaseline;
 269   target->fDiffusionOn        = fDiffusionOn;
 270   target->fElAttachOn         = fElAttachOn;
 271   target->fElAttachProp       = fElAttachProp;
 272   target->fTRFOn              = fTRFOn;
 273   target->fTRFbin             = fTRFbin;
 274   target->fTRFlo              = fTRFlo;
 275   target->fTRFhi              = fTRFhi;
 276   target->fTRFwid             = fTRFwid;
 277   target->fCTOn               = fCTOn;
 278   target->fAnodeWireOffset    = fAnodeWireOffset;
 279   target->fPadCoupling        = fPadCoupling;
 280   target->fTimeCoupling       = fTimeCoupling;
 281   target->fPRFOn              = fPRFOn;
 282   target->fGasMixture         = fGasMixture;
 283
 284   if (target->fTRFsmp) {
 285     delete[] target->fTRFsmp;
 286   }
 287   target->fTRFsmp = new Float_t[fTRFbin];
 288   for (Int_t iBin = 0; iBin < fTRFbin; iBin++) {
 289     target->fTRFsmp[iBin] = fTRFsmp[iBin];
 290   }
 291
 292   if (target->fCTsmp) {
 293     delete[] target->fCTsmp;
 294   }
 295   target->fCTsmp  = new Float_t[fTRFbin];
 296   for (Int_t iBin = 0; iBin < fTRFbin; iBin++) {
 297     target->fCTsmp[iBin]  = fCTsmp[iBin];
 298   }
 299
 300 }
 301
 302 //_____________________________________________________________________________
 303 void AliTRDSimParam::ReInit()
 304 {
 305   //
 306   // Reinitializes the parameter class after a change
 307   //
 308
 309   if      (fGasMixture == kXenon) {
 310     // The range and the binwidth for the sampled TRF
 311     fTRFbin = 200;
 312     // Start 0.2 mus before the signal
 313     fTRFlo  = -0.4;
 314     // End the maximum drift time after the signal
 315     fTRFhi  =  3.58;
 316   }
 317   else if (fGasMixture == kArgon) {
 318     // The range and the binwidth for the sampled TRF
 319     fTRFbin =  50;
 320     // Start 0.2 mus before the signal
 321     fTRFlo  =  0.02;
 322     // End the maximum drift time after the signal
 323     fTRFhi  =  1.98;
 324   }
 325   else {
 326     AliFatal("Not a valid gas mixture!");
 327     exit(1);
 328   }
 329   fTRFwid = (fTRFhi - fTRFlo) / ((Float_t) fTRFbin);
 330
 331   // Create the sampled TRF
 332   SampleTRF();
 333
 334 }
 335
 336 //_____________________________________________________________________________
 337 void AliTRDSimParam::SampleTRF()
 338 {
 339   //
 340   // Samples the new time response function.
 341   //
 342
 343   Int_t ipasa = 0;
 344
 345   // Xenon
 346   // From Antons measurements with Fe55 source, adjusted by C. Lippmann.
 347   // time bins are -0.4, -0.38, -0.36, ...., 3.54, 3.56, 3.58 microseconds
 348   const Int_t kNpasa     = 200;  // kNpasa should be equal to fTRFbin!
 349   Float_t xtalk[kNpasa];
 350   Float_t signal[kNpasa]     = { 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000
 351                                , 0.0002, 0.0007, 0.0026, 0.0089, 0.0253, 0.0612, 0.1319
 352                                , 0.2416, 0.3913, 0.5609, 0.7295, 0.8662, 0.9581, 1.0000
 353                                , 0.9990, 0.9611, 0.8995, 0.8269, 0.7495, 0.6714, 0.5987
 354                                , 0.5334, 0.4756, 0.4249, 0.3811, 0.3433, 0.3110, 0.2837
 355                                , 0.2607, 0.2409, 0.2243, 0.2099, 0.1974, 0.1868, 0.1776
 356                                , 0.1695, 0.1627, 0.1566, 0.1509, 0.1457, 0.1407, 0.1362
 357                                , 0.1317, 0.1274, 0.1233, 0.1196, 0.1162, 0.1131, 0.1102
 358                                , 0.1075, 0.1051, 0.1026, 0.1004, 0.0979, 0.0956, 0.0934
 359                                , 0.0912, 0.0892, 0.0875, 0.0858, 0.0843, 0.0829, 0.0815
 360                                , 0.0799, 0.0786, 0.0772, 0.0757, 0.0741, 0.0729, 0.0718
 361                                , 0.0706, 0.0692, 0.0680, 0.0669, 0.0655, 0.0643, 0.0630
 362                                , 0.0618, 0.0607, 0.0596, 0.0587, 0.0576, 0.0568, 0.0558
 363                                , 0.0550, 0.0541, 0.0531, 0.0522, 0.0513, 0.0505, 0.0497
 364                                , 0.0490, 0.0484, 0.0474, 0.0465, 0.0457, 0.0449, 0.0441
 365                                , 0.0433, 0.0425, 0.0417, 0.0410, 0.0402, 0.0395, 0.0388
 366                                , 0.0381, 0.0374, 0.0368, 0.0361, 0.0354, 0.0348, 0.0342
 367                                , 0.0336, 0.0330, 0.0324, 0.0318, 0.0312, 0.0306, 0.0301
 368                                , 0.0296, 0.0290, 0.0285, 0.0280, 0.0275, 0.0270, 0.0265
 369                                , 0.0260, 0.0256, 0.0251, 0.0246, 0.0242, 0.0238, 0.0233
 370                                , 0.0229, 0.0225, 0.0221, 0.0217, 0.0213, 0.0209, 0.0206
 371                                , 0.0202, 0.0198, 0.0195, 0.0191, 0.0188, 0.0184, 0.0181
 372                                , 0.0178, 0.0175, 0.0171, 0.0168, 0.0165, 0.0162, 0.0159
 373                                , 0.0157, 0.0154, 0.0151, 0.0148, 0.0146, 0.0143, 0.0140
 374                                , 0.0138, 0.0135, 0.0133, 0.0131, 0.0128, 0.0126, 0.0124
 375                                , 0.0121, 0.0119, 0.0120, 0.0115, 0.0113, 0.0111, 0.0109
 376                                , 0.0107, 0.0105, 0.0103, 0.0101, 0.0100, 0.0098, 0.0096
 377                                , 0.0094, 0.0092, 0.0091, 0.0089, 0.0088, 0.0086, 0.0084
 378                                , 0.0083, 0.0081, 0.0080, 0.0078 };
 379   signal[0] = 0.0;
 380   signal[1] = 0.0;
 381   signal[2] = 0.0;
 382   // With undershoot, positive peak corresponds to ~3% of the main signal:
 383   for (ipasa = 3; ipasa < kNpasa; ipasa++) {
 384     xtalk[ipasa] = 0.2 * (signal[ipasa-2] - signal[ipasa-3]);
 385   }
 386   xtalk[0]  = 0.0;
 387   xtalk[1]  = 0.0;
 388   xtalk[2]  = 0.0;
 389
 390   // Argon
 391   // Ar measurement with Fe55 source by Anton
 392   // time bins are 0.02, 0.06, 0.10, ...., 1.90, 1.94, 1.98 microseconds
 393   const Int_t kNpasaAr = 50;
 394   Float_t xtalkAr[kNpasaAr];
 395   Float_t signalAr[kNpasaAr] = { -0.01,  0.01,  0.00,  0.00,  0.01
 396                                , -0.01,  0.01,  2.15, 22.28, 55.53
 397                                , 68.52, 58.21, 40.92, 27.12, 18.49
 398                                , 13.42, 10.48,  8.67,  7.49,  6.55
 399                                ,  5.71,  5.12,  4.63,  4.22,  3.81
 400                                ,  3.48,  3.20,  2.94,  2.77,  2.63
 401                                ,  2.50,  2.37,  2.23,  2.13,  2.03
 402                                ,  1.91,  1.83,  1.75,  1.68,  1.63
 403                                ,  1.56,  1.49,  1.50,  1.49,  1.29
 404                                ,  1.19,  1.21,  1.21,  1.20,  1.10 };
 405   // Normalization to maximum
 406   for (ipasa = 0; ipasa < kNpasaAr; ipasa++) {
 407     signalAr[ipasa] /= 68.52;
 408   }
 409   signalAr[0] = 0.0;
 410   signalAr[1] = 0.0;
 411   signalAr[2] = 0.0;
 412   // With undershoot, positive peak corresponds to ~3% of the main signal:
 413   for (ipasa = 3; ipasa < kNpasaAr; ipasa++) {
 414     xtalkAr[ipasa] = 0.2 * (signalAr[ipasa-2] - signalAr[ipasa-3]);
 415   }
 416   xtalkAr[0]  = 0.0;
 417   xtalkAr[1]  = 0.0;
 418   xtalkAr[2]  = 0.0;
 419
 420   if (fTRFsmp) {
 421     delete [] fTRFsmp;
 422   }
 423   fTRFsmp = new Float_t[fTRFbin];
 424
 425   if (fCTsmp)  {
 426     delete [] fCTsmp;
 427   }
 428   fCTsmp  = new Float_t[fTRFbin];
 429
 430   for (Int_t iBin = 0; iBin < fTRFbin; iBin++) {
 431     if (fGasMixture == kXenon) {
 432       fTRFsmp[iBin] = signal[iBin];
 433       fCTsmp[iBin]  = xtalk[iBin];
 434     }
 435     else {
 436       fTRFsmp[iBin] = signalAr[iBin];
 437       fCTsmp[iBin]  = xtalkAr[iBin];
 438     }
 439   }
 440
 441 }
 442
 443 //_____________________________________________________________________________
 444 Double_t AliTRDSimParam::TimeResponse(Double_t time) const
 445 {
 446   //
 447   // Applies the preamp shaper time response
 448   // (We assume a signal rise time of 0.2us = fTRFlo/2.
 449   //
 450
 451   Int_t iBin = ((Int_t) ((time - fTRFlo/2.0) / fTRFwid));
 452   if ((iBin >=       0) &&
 453       (iBin <  fTRFbin)) {
 454     return fTRFsmp[iBin];
 455   }
 456   else {
 457     return 0.0;
 458   }
 459
 460 }
 461
 462 //_____________________________________________________________________________
 463 Double_t AliTRDSimParam::CrossTalk(Double_t time) const
 464 {
 465   //
 466   // Applies the pad-pad capacitive cross talk
 467   //
 468
 469   Int_t iBin = ((Int_t) ((time - fTRFlo) / fTRFwid));
 470   if ((iBin >=       0) &&
 471       (iBin <  fTRFbin)) {
 472     return fCTsmp[iBin];
 473   }
 474   else {
 475     return 0.0;
 476   }
 477
 478 }