TPC/AliTPCv2.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 /*
  17 $Log$
  18 Revision 1.45  2003/01/14 10:50:20  alibrary
  19 Cleanup of STEER coding conventions
  20
  21 Revision 1.44  2002/11/21 22:43:32  alibrary
  22 Removing AliMC and AliMCProcess
  23
  24 Revision 1.43  2002/10/14 14:57:43  hristov
  25 Merging the VirtualMC branch to the main development branch (HEAD)
  26
  27 Revision 1.40.6.2  2002/07/24 10:09:01  alibrary
  28 Updating VirtualMC
  29
  30 Revision 1.42  2002/06/12 14:56:56  kowal2
  31 Added track length to the reference hits
  32
  33 Revision 1.41  2002/05/27 14:33:15  hristov
  34 The new class AliTrackReference used (M.Ivanov)
  35
  36 Revision 1.40  2002/01/21 17:12:00  kowal2
  37 New track hits structure using root containers
  38
  39 Revision 1.39  2001/05/16 14:57:25  alibrary
  40 New files for folders and Stack
  41
  42 Revision 1.38  2001/05/08 16:03:06  kowal2
  43 Geometry update according to the latest technical spec.
  44
  45 Revision 1.37  2001/04/27 15:23:07  kowal2
  46 Correct materian in the central part of the inner containment vessel
  47
  48 Revision 1.36  2001/04/26 06:15:12  kowal2
  49 Corrected bug in the inner containment vessel (cones)
  50
  51 Revision 1.35  2001/04/24 11:17:33  kowal2
  52 New TPC geometry.
  53
  54 Revision 1.34  2001/04/23 10:20:18  hristov
  55 Constant casted to avoid ambiguity
  56
  57 Revision 1.33  2001/04/20 08:16:47  kowal2
  58 Protection against too small betaGamma. Thanks to Ivana and Yves.
  59
  60 Revision 1.32  2001/03/13 13:07:34  kowal2
  61 Corrected bug in the TPC mother volume geometry.
  62 Thanks to A. Morsch
  63
  64 Revision 1.31  2000/11/30 11:48:50  kowal2
  65 TLorentzVector.h adde to satisfy the latest changes by Federico
  66
  67 Revision 1.30  2000/11/14 10:48:57  kowal2
  68 Correct material used for TSA4. Thanks to J. Barbosa.
  69
  70 Revision 1.29  2000/11/06 17:24:10  kowal2
  71 Corrected bug in the outer containment vessel and
  72 the outer field cage geometry.
  73 Thanks to J. Barbosa.
  74
  75 Revision 1.28  2000/11/02 16:55:24  kowal2
  76 Corrected bug in the inner containment vessel geometry.
  77 Thanks to J. Belikov
  78
  79 Revision 1.27  2000/11/02 07:24:11  kowal2
  80 Correction in the TPC geometry.
  81 Changes due to the new hit structure.
  82
  83 Revision 1.26  2000/10/05 16:16:29  kowal2
  84 Corrections of the hit recording algorithm.
  85
  86 Revision 1.25  2000/10/02 21:28:18  fca
  87 Removal of useless dependecies via forward declarations
  88
  89 Revision 1.24  2000/08/28 10:02:30  kowal2
  90 Corrected bug in the StepManager
  91
  92 Revision 1.23  2000/07/10 20:57:39  hristov
  93 Update of TPC code and macros by M.Kowalski
  94
  95 Revision 1.22  2000/06/30 12:07:50  kowal2
  96 Updated from the TPC-PreRelease branch
  97
  98 Revision 1.21.2.4  2000/06/26 07:39:42  kowal2
  99 Changes to obey the coding rules
 100
 101 Revision 1.21.2.3  2000/06/25 08:38:41  kowal2
 102 Splitted from AliTPCtracking
 103
 104 Revision 1.21.2.2  2000/06/16 12:58:13  kowal2
 105 Changed parameter settings
 106
 107 Revision 1.21.2.1  2000/06/09 07:15:07  kowal2
 108
 109 Defaults loaded automatically (hard-wired)
 110 Optional parameters can be set via macro called in the constructor
 111
 112 Revision 1.21  2000/05/15 10:00:30  kowal2
 113 Corrected bug in the TPC geometry, thanks to Ivana Hrivnacova
 114
 115 Revision 1.20  2000/04/17 09:37:33  kowal2
 116 removed obsolete AliTPCDigitsDisplay.C
 117
 118 Revision 1.19.8.2  2000/04/10 08:31:52  kowal2
 119
 120 Different geometry for different sectors
 121 Updated readout chambers
 122 Some modifications to StepManager by J.Belikov
 123
 124 Revision 1.19.8.1  2000/04/10 07:56:53  kowal2
 125 Not used anymore - removed
 126
 127 Revision 1.19  1999/11/04 17:28:07  fca
 128 Correct barrel part of HV Degrader
 129
 130 Revision 1.18  1999/10/14 16:52:08  fca
 131 Only use PDG codes and not GEANT ones
 132
 133 Revision 1.17  1999/10/08 06:27:23  fca
 134 Corrected bug in the HV degrader geometry, thanks to G.Tabary
 135
 136 Revision 1.16  1999/10/04 13:39:54  fca
 137 Correct array index problem
 138
 139 Revision 1.15  1999/09/29 09:24:34  fca
 140 Introduction of the Copyright and cvs Log
 141
 142 */
 143
 144 //
 145 ///////////////////////////////////////////////////////////////////////////////
 146 //                                                                           //
 147 //  Time Projection Chamber version 2 -- detailed TPC and slow simulation    //
 148 //                                                                           //
 149 //Begin_Html
 150 /*
 151 <img src="picts/AliTPCv2Class.gif">
 152 */
 153 //End_Html
 154 //                                                                           //
 155 //                                                                           //
 156 ///////////////////////////////////////////////////////////////////////////////
 157
 158 #include <stdlib.h>
 159
 160 #include <TMath.h>
 161 #include <TPDGCode.h>
 162
 163 #include "AliConst.h"
 164 #include "AliRun.h"
 165 #include "AliTPCDigitsArray.h"
 166 #include "AliTPCParam.h"
 167 #include "AliTPCParamSR.h"
 168 #include "AliTPCTrackHitsV2.h"
 169 #include "AliTPCv2.h"
 170 #include "TLorentzVector.h"
 171
 172 ClassImp(AliTPCv2)
 173
 174 //_____________________________________________________________________________
 175 AliTPCv2::AliTPCv2(const char *name, const char *title) :
 176   AliTPC(name, title)
 177 {
 178   //
 179   // Standard constructor for Time Projection Chamber version 2
 180   //
 181   fIdSens=0;
 182   fIdLSec=0;
 183   fIdUSec=0;
 184
 185   SetBufferSize(128000);
 186
 187   SetGasMixt(2,20,10,-1,0.9,0.1,0.); // Ne-CO2 90-10
 188
 189   // Default sectors
 190
 191   SetSecAL(4);
 192   SetSecAU(4);
 193   SetSecLows(1,  2,  3, 19, 20, 21);
 194   SetSecUps(37, 38, 39, 37+18, 38+18, 39+18, -1, -1, -1, -1, -1, -1);
 195   SetSens(1); // sensitive strips set
 196
 197   if (fTPCParam)
 198      fTPCParam->Write(fTPCParam->GetTitle());
 199 }
 200
 201 //_____________________________________________________________________________
 202 void AliTPCv2::CreateGeometry()
 203 {
 204   //
 205   // Create the geometry of Time Projection Chamber version 2
 206   //
 207   //Begin_Html
 208   /*
 209     <img src="picts/AliTPC.gif">
 210   */
 211   //End_Html
 212   //Begin_Html
 213   /*
 214     <img src="picts/AliTPCv2Tree.gif">
 215   */
 216   //End_Html
 217
 218
 219   Int_t *idtmed = fIdtmed->GetArray();
 220
 221   Float_t dm[50];
 222   Int_t idrotm[120];
 223
 224   Int_t nRotMat = 0;
 225
 226   Int_t i,ifl1=0;
 227
 228   // number of sectors
 229
 230   Int_t nInnerSector = fTPCParam->GetNInnerSector()/2;
 231   Int_t nOuterSector = fTPCParam->GetNOuterSector()/2;
 232
 233   // ---------------------------------------------------
 234   //        sector specification check
 235   // ---------------------------------------------------
 236   if (fSecAL >= 0) {
 237     ifl1 = 0;
 238
 239     for (i = 0; i < 6; ++i) {
 240       if (fSecLows[i] >= 0 && fSecLows[i] < 2*nInnerSector) {
 241         ifl1 = 1;
 242         printf("%s: *** SECTOR %d selected\n",ClassName(),fSecLows[i]);
 243       }
 244     }
 245
 246   } else {
 247     printf("%s: *** ALL LOWER SECTORS SELECTED ***\n",ClassName());
 248     ifl1 = 1;
 249   }
 250
 251   if (ifl1 == 0) {
 252     printf("%s: *** ERROR: AT LEAST ONE LOWER SECTOR MUST BE SPECIFIED ***\n",ClassName());
 253     printf("%s: !!! PROGRAM STOPPED !!!\n",ClassName());
 254     exit(1);
 255   }
 256
 257   if (fSecAU >= 0) {
 258
 259     for (i = 0; i < 12; ++i) {
 260       if (fSecUps[i] > 2*nInnerSector-1 &&
 261           fSecUps[i] < 2*(nInnerSector+nOuterSector)) {
 262         printf("%s: *** SECTOR %d selected\n",ClassName(),fSecUps[i]);
 263       }
 264     }
 265
 266   } else {
 267     printf("%s: *** ALL UPPER SECTORS SELECTED ***\n",ClassName());
 268   }
 269
 270
 271
 272   //--------------------------------------------------------------------
 273
 274   //
 275   //  Mother volume TPC (Air) - all volumes will be positioned in it
 276   //
 277
 278   dm[0]=0.;
 279   dm[1]=360.;
 280   dm[2]=8.;
 281
 282   //
 283
 284   dm[3]=-283.7;
 285   dm[4]=65.6;
 286   dm[5]=278.;
 287
 288   //
 289
 290   dm[6]=-253.6;
 291   dm[7]=65.6;
 292   dm[8]=278.;
 293
 294   //
 295
 296   dm[9]=-73.3;
 297   dm[10]=60.9;
 298   dm[11]=278.;
 299
 300   //
 301
 302   dm[12]=-73.3;
 303   dm[13]=56.9;
 304   dm[14]=278.;
 305
 306   //
 307
 308   dm[15]=73.3;
 309   dm[16]=56.9;
 310   dm[17]=278.;
 311
 312   //
 313
 314   dm[18]=73.3;
 315   dm[19]=60.9;
 316   dm[20]=278.;
 317
 318   //
 319
 320   dm[21]=253.6;
 321   dm[22]=65.6;
 322   dm[23]=278.;
 323
 324   //
 325
 326   dm[24]=283.7;
 327   dm[25]=65.6;
 328   dm[26]=278.;
 329
 330   gMC->Gsvolu("TPC ","PCON",idtmed[0],dm,27);
 331
 332   // outer part
 333
 334   //-------------------------------------------------------------------
 335   //   Tpc Outer INsulator (CO2) - contains cont. vessel and field cage
 336   //-------------------------------------------------------------------
 337
 338   dm[0]= 0.;
 339   dm[1]= 360.;
 340   dm[2]= 6.;
 341
 342   //
 343
 344   dm[3]=-253.6;
 345   dm[4]=258.;
 346   dm[5]=275.5;
 347
 348   //
 349
 350   dm[6]=-250.6;
 351   dm[7]=258.;
 352   dm[8]=275.5;
 353
 354   //
 355
 356   dm[9]=-250.6;
 357   dm[10]=258.;
 358   dm[11]=278.;
 359
 360   //
 361
 362   dm[12]=253.6;
 363   dm[13]=258.;
 364   dm[14]=278.;
 365
 366   //
 367
 368   dm[15]=253.6;
 369   dm[16]=264.8;
 370   dm[17]=278.;
 371
 372   //
 373
 374   dm[18]=256.6;
 375   dm[19]=264.8;
 376   dm[20]=278.;
 377
 378   gMC->Gsvolu("TOIN","PCON",idtmed[3],dm,21);
 379
 380   //----------------------------------------------------------------
 381   // Tpc Outer Contaiment Vessel
 382   //  mother volume - Al, daughters - composite (sandwich)
 383   //----------------------------------------------------------------
 384
 385   dm[0]=0.;
 386   dm[1]=360.;
 387   dm[2]=6.;
 388
 389   //
 390
 391   dm[3]=-250.6;
 392   dm[4]=270.4;
 393   dm[5]=278.;
 394
 395   //
 396
 397   dm[6]=-247.6;
 398   dm[7]=270.4;
 399   dm[8]=278.;
 400
 401   //
 402
 403   dm[9]=-247.6;
 404   dm[10]=274.8124;
 405   dm[11]=278.;
 406
 407   //
 408
 409   dm[12]=253.6;
 410   dm[13]=274.8124;
 411   dm[14]=278.;
 412
 413   //
 414
 415   dm[15]=253.6;
 416   dm[16]=264.8;
 417   dm[17]=278.;
 418
 419   //
 420
 421   dm[18]=256.6;
 422   dm[19]=264.8;
 423   dm[20]=278.;
 424
 425   gMC->Gsvolu("TOCV","PCON",idtmed[4],dm,21);
 426
 427   // Daughter volumes - sandwich
 428
 429   // Tpc SAndwich 1 - Al
 430
 431   dm[0]=274.8124;
 432   dm[1]=278.;
 433   dm[2]=252.1;
 434
 435   gMC->Gsvolu("TSA1","TUBE",idtmed[4],dm,3);
 436
 437   // Tpc SAndwich 2 - epoxy glue (I use Lexan)
 438
 439   dm[0] += 5.e-3;
 440   dm[1] -= 5.e-3;
 441
 442   gMC->Gsvolu("TSA2","TUBE",idtmed[14],dm,3);
 443
 444   // Tpc SAndwich 3 - Tedlar
 445
 446   dm[0] += 0.01;
 447   dm[1] -= 0.01;
 448
 449   gMC->Gsvolu("TSA3","TUBE",idtmed[9],dm,3);
 450
 451
 452   // Tpc SAndwich 4 - fiber glass (G10)
 453
 454   dm[0] += 3.8e-3;
 455   dm[1] -= 3.8e-3;
 456
 457   gMC->Gsvolu("TSA4","TUBE",idtmed[12],dm,3);
 458
 459   // Tpc SAndwich 5 - NOMEX honeycomb
 460
 461   dm[0] += 0.075;
 462   dm[1] -= 0.075;
 463
 464   gMC->Gsvolu("TSA5","TUBE",idtmed[6],dm,3);
 465
 466   // 5->4->3->2->1->TCOV
 467
 468
 469   gMC->Gspos("TSA5",1,"TSA4",0.,0.,0.,0,"ONLY");
 470   gMC->Gspos("TSA4",1,"TSA3",0.,0.,0.,0,"ONLY");
 471   gMC->Gspos("TSA3",1,"TSA2",0.,0.,0.,0,"ONLY");
 472   gMC->Gspos("TSA2",1,"TSA1",0.,0.,0.,0,"ONLY");
 473
 474   gMC->Gspos("TSA1",1,"TOCV",0.,0.,3.,0,"ONLY");
 475
 476   // TCOV-> TOIN
 477
 478   gMC->Gspos("TOCV",1,"TOIN",0.,0.,0.,0,"ONLY");
 479
 480   //-------------------------------------------------------
 481   //  Tpc Outer Field Cage
 482   //  mother volume - Al, daughters - composite (sandwich)
 483   //-------------------------------------------------------
 484
 485   dm[0]=0.;
 486   dm[1]=360.;
 487   dm[2]=6.;
 488
 489   //
 490
 491   dm[3]=-253.6;
 492   dm[4]=258.;
 493   dm[5]=275.5;
 494
 495   //
 496
 497   dm[6]=-250.6;
 498   dm[7]=258.;
 499   dm[8]=275.5;
 500
 501   //
 502
 503   dm[9]=-250.6;
 504   dm[10]=258.;
 505   dm[11]=260.0476;
 506
 507   //
 508
 509   dm[12]=250.6;
 510   dm[13]=258.;
 511   dm[14]=260.0476;
 512
 513   //
 514
 515   dm[15]=250.6;
 516   dm[16]=258.;
 517   dm[17]=275.5;
 518
 519   //
 520
 521   dm[18]=253.6;
 522   dm[19]=258.;
 523   dm[20]=275.5;
 524
 525   gMC->Gsvolu("TOFC","PCON",idtmed[4],dm,21);
 526
 527   // Daughter volumes
 528
 529   // Tpc SAndwich 6 - Tedlar
 530
 531   dm[0]= 258.;
 532   dm[1]= 260.0476;
 533   dm[2]= 252.1;
 534
 535   gMC->Gsvolu("TSA6","TUBE",idtmed[9],dm,3);
 536
 537   // Tpc SAndwich 7 - fiber glass
 538
 539   dm[0] += 3.8e-3;
 540   dm[1] -= 3.8e-3;
 541
 542   gMC->Gsvolu("TSA7","TUBE",idtmed[12],dm,3);
 543
 544
 545   // Tpc SAndwich 8 - NOMEX
 546
 547   dm[0] += 0.02;
 548   dm[1] -= 0.02;
 549
 550   gMC->Gsvolu("TSA8","TUBE",idtmed[6],dm,3);
 551
 552   // 8->7->6->TOFC
 553
 554   gMC->Gspos("TSA8",1,"TSA7",0.,0.,0.,0,"ONLY");
 555   gMC->Gspos("TSA7",1,"TSA6",0.,0.,0.,0,"ONLY");
 556   gMC->Gspos("TSA6",1,"TOFC",0.,0.,0.,0,"ONLY");
 557
 558   // TOFC->TOIN
 559
 560   gMC->Gspos("TOFC",1,"TOIN",0.,0.,0.,0,"ONLY");
 561
 562   // TOIN->TPC
 563
 564   gMC->Gspos("TOIN",1,"TPC ",0.,0.,0.,0,"ONLY");
 565
 566   // inner part
 567
 568   //--------------------------------------------------------------------
 569   // Tpc Inner INsulator (CO2) - inner f.c. will be placed there
 570   // Inner containment vessel will be placed directly in the TPC
 571   //--------------------------------------------------------------------
 572
 573   dm[0]=0.;
 574   dm[1]=360.;
 575   dm[2]=4.;
 576
 577   //
 578
 579   dm[3]=-253.6;
 580   dm[4]=65.9;
 581   dm[5]=79.2;
 582
 583   //
 584
 585   dm[6]=-73.3;
 586   dm[7]=61.2;
 587   dm[8]=79.2;
 588
 589   //
 590
 591   dm[9]=73.3;
 592   dm[10]=61.2;
 593   dm[11]=79.2;
 594
 595   //
 596
 597   dm[12]=253.6;
 598   dm[13]=65.9;
 599   dm[14]=79.2;
 600
 601   gMC->Gsvolu("TIIN","PCON",idtmed[3],dm,15);
 602
 603   // the middle part of the F.C. is thinner - carve out the strip - Ne-CO2
 604
 605   dm[0]=79.16;
 606   dm[1]=79.2;
 607   dm[2]=88.;
 608
 609   gMC->Gsvolu("TII1","TUBE",idtmed[1],dm,3);
 610
 611   gMC->Gspos("TII1",1,"TIIN",0.,0.,0.,0,"ONLY");
 612
 613   //-----------------------------------------------------
 614   // Tpc Inner Field Cage
 615   // mother volume - Al, daughters - composite (sandwich)
 616   //------------------------------------------------------
 617
 618   dm[0]=0.;
 619   dm[1]=360.;
 620   dm[2]=10.;
 621
 622   //
 623
 624   dm[3]=-253.6;
 625   dm[4]=70.3;
 626   dm[5]=79.2;
 627
 628   //
 629
 630   dm[6]=-250.6;
 631   dm[7]=70.3;
 632   dm[8]=79.2;
 633
 634   //
 635
 636   dm[9]=-250.6;
 637   dm[10]=77.0524;
 638   dm[11]=79.2;
 639
 640   //
 641
 642   dm[12]=-88.;
 643   dm[13]=77.0524;
 644   dm[14]=79.2;
 645
 646   //
 647
 648   dm[15]=-88.;
 649   dm[16]=77.0924;
 650   dm[17]=79.16;
 651
 652   //
 653
 654   dm[18]=88.;
 655   dm[19]=77.0924;
 656   dm[20]=79.16;
 657
 658   //
 659
 660   dm[21]=88.;
 661   dm[22]=77.0524;
 662   dm[23]=79.2;
 663
 664   //
 665
 666   dm[24]=250.6;
 667   dm[25]=77.0524;
 668   dm[26]=79.2;
 669
 670   //
 671
 672   dm[27]=250.6;
 673   dm[28]=70.3;
 674   dm[29]=79.2;
 675
 676   //
 677
 678   dm[30]=253.6;
 679   dm[31]=70.3;
 680   dm[32]=79.2;
 681
 682   gMC->Gsvolu("TIFC","PCON",idtmed[4],dm,33);
 683
 684   // daughter volumes - central part
 685
 686   // Tpc Sandwich 9 -Tedlar
 687
 688   dm[0]=77.0924;
 689   dm[1]=79.16;
 690   dm[2]=88.;
 691
 692   gMC->Gsvolu("TSA9","TUBE",idtmed[9],dm,3);
 693
 694   // Tpc Sandwich 10 - fiber glass (G10)
 695
 696   dm[0] += 3.8e-3;
 697   dm[1] -= 3.8e-3;
 698
 699   gMC->Gsvolu("TS10","TUBE",idtmed[12],dm,3);
 700
 701   // Tpc Sandwich 11 - NOMEX
 702
 703   dm[0] += 0.03;
 704   dm[1] -= 0.03;
 705
 706   gMC->Gsvolu("TS11","TUBE",idtmed[6],dm,3);
 707
 708   // 11->10->9->TIFC
 709
 710   gMC->Gspos("TS11",1,"TS10",0.,0.,0.,0,"ONLY");
 711   gMC->Gspos("TS10",1,"TSA9",0.,0.,0.,0,"ONLY");
 712
 713   gMC->Gspos("TSA9",1,"TIFC",0.,0.,0.,0,"ONLY");
 714
 715   // daughter volumes - outer parts (reinforced)
 716
 717   // Tpc Sandwich 12 -Tedlar
 718
 719   dm[0]=77.0524;
 720   dm[1]=79.2;
 721   dm[2]=82.05;
 722
 723   gMC->Gsvolu("TS12","TUBE",idtmed[9],dm,3);
 724
 725   // Tpc Sandwich 13 - fiber glass (G10)
 726
 727   dm[0] += 3.8e-3;
 728   dm[1] -= 3.8e-3;
 729
 730   gMC->Gsvolu("TS13","TUBE",idtmed[12],dm,3);
 731
 732   // Tpc Sandwich 14 - NOMEX
 733
 734   dm[0] += 0.07;
 735   dm[1] -= 0.07;
 736
 737   gMC->Gsvolu("TS14","TUBE",idtmed[6],dm,3);
 738
 739   // 14->13->12->TIFC
 740
 741   gMC->Gspos("TS14",1,"TS13",0.,0.,0.,0,"ONLY");
 742   gMC->Gspos("TS13",1,"TS12",0.,0.,0.,0,"ONLY");
 743
 744   gMC->Gspos("TS12",1,"TIFC",0.,0.,170.05,0,"ONLY");
 745   gMC->Gspos("TS12",2,"TIFC",0.,0.,-170.05,0,"ONLY");
 746
 747   // place this inside the inner insulator
 748
 749   gMC->Gspos("TIFC",1,"TIIN",0.,0.,0.,0,"ONLY");
 750
 751   // and now in the TPC...
 752
 753   gMC->Gspos("TIIN",1,"TPC ",0.,0.,0.,0,"ONLY");
 754
 755   //---------------------------------------------------------
 756   // Tpc Inner Containment vessel - Cones
 757   //---------------------------------------------------------
 758
 759   dm[0]=0.;
 760   dm[1]=360.;
 761   dm[2]=8.;
 762
 763   //
 764
 765   dm[3]=71.8;
 766   dm[4]=56.9;
 767   dm[5]=59.4;
 768
 769   //
 770
 771   dm[6]=73.;
 772   dm[7]=56.9;
 773   dm[8]=59.4;
 774
 775   //
 776
 777   dm[9]=73.;
 778   dm[10]=56.9;
 779   dm[11]=61.2;
 780
 781   //
 782
 783   dm[12]=73.3;
 784   dm[13]=56.9;
 785   dm[14]=61.2;
 786
 787   //
 788
 789   dm[15]=73.3;
 790   dm[16]=60.9;
 791   dm[17]=61.2;
 792
 793   //
 794
 795   dm[18]=253.6;
 796   dm[19]=65.6;
 797   dm[20]=65.9;
 798
 799   //
 800
 801   dm[21]=253.6;
 802   dm[22]=65.6;
 803   dm[23]=74.6;
 804
 805   //
 806
 807   dm[24]=256.6;
 808   dm[25]=65.6;
 809   dm[26]=74.6;
 810
 811   gMC->Gsvolu("TICC","PCON",idtmed[4],dm,27);
 812
 813   Float_t phi1,phi2,phi3,theta1,theta2,theta3; // rotation angles
 814
 815   // reflection matrix
 816
 817   theta1 = 90.;
 818   phi1   = 0.;
 819   theta2 = 90.;
 820   phi2   = 270.;
 821   theta3 = 180.;
 822   phi3   = 0.;
 823
 824   AliMatrix(idrotm[nRotMat], theta1, phi1, theta2, phi2, theta3, phi3);
 825
 826   gMC->Gspos("TICC",1,"TPC ",0.,0.,0.,0,"ONLY");
 827   gMC->Gspos("TICC",2,"TPC ",0.,0.,0.,idrotm[nRotMat],"ONLY");
 828
 829
 830   //---------------------------------------------------------
 831   // Tpc Inner Containment vessel - Middle part -Al
 832   //---------------------------------------------------------
 833
 834   dm[0]=0.;
 835   dm[1]=360.;
 836   dm[2]=6.;
 837
 838   //
 839
 840   dm[3]=-71.6;
 841   dm[4]=60.2;
 842   dm[5]=61.2;
 843
 844   //
 845
 846   dm[6]=-69.1;
 847   dm[7]=60.2;
 848   dm[8]=61.2;
 849
 850   //
 851
 852   dm[9]=-69.1;
 853   dm[10]=60.6224;
 854   dm[11]=61.2;
 855
 856   //
 857
 858   dm[12]=69.1;
 859   dm[13]=60.6224;
 860   dm[14]=61.2;
 861
 862   //
 863
 864   dm[15]=69.1;
 865   dm[16]=60.2;
 866   dm[17]=61.2;
 867
 868   //
 869
 870   dm[18]=71.6;
 871   dm[19]=60.2;
 872   dm[20]=61.2;
 873
 874   gMC->Gsvolu("TICM","PCON",idtmed[4],dm,21);
 875
 876   // Tpc Sandwich 15 - Al
 877
 878   dm[0]=60.6224;
 879   dm[1]=61.2;
 880   dm[2]=70.1;
 881
 882   gMC->Gsvolu("TS15","TUBE",idtmed[4],dm,3);
 883
 884   // Tpc Sandwich 16 -  epoxy glue
 885
 886   dm[0] += 5.e-3;
 887   dm[1] -= 5.e-3;
 888
 889   gMC->Gsvolu("TS16","TUBE",idtmed[14],dm,3);
 890
 891   // Tpc Sandwich 17 - Tedlar
 892
 893   dm[0] += 0.01;
 894   dm[1] -= 0.01;
 895
 896   gMC->Gsvolu("TS17","TUBE",idtmed[9],dm,3);
 897
 898   // Tpc Sandwich 18 - carbon fiber
 899
 900   dm[0] += 3.8e-3;
 901   dm[1] -= 3.8e-3;
 902
 903   gMC->Gsvolu("TS18","TUBE",idtmed[15],dm,3);
 904
 905   // Tpc Sandwich 19 - Nomex
 906
 907   dm[0] += 0.02;
 908   dm[1] -= 0.02;
 909
 910   gMC->Gsvolu("TS19","TUBE",idtmed[6],dm,3);
 911
 912   // 19->18->17->16->15-> TICM
 913
 914   gMC->Gspos("TS19",1,"TS18",0.,0.,0.,0,"ONLY");
 915   gMC->Gspos("TS18",1,"TS17",0.,0.,0.,0,"ONLY");
 916   gMC->Gspos("TS17",1,"TS16",0.,0.,0.,0,"ONLY");
 917   gMC->Gspos("TS16",1,"TS15",0.,0.,0.,0,"ONLY");
 918
 919   gMC->Gspos("TS15",1,"TICM ",0.,0.,0.,0,"ONLY");
 920
 921
 922   // TPc inner cont. vessel Joints
 923
 924   dm[0]=60.2;
 925   dm[1]=61.2;
 926   dm[2]=0.5;
 927
 928   gMC->Gsvolu("TPJ1","TUBE",idtmed[4],dm,3);
 929
 930   gMC->Gspos("TPJ1",1,"TPC ",0.,0.,72.3,0,"ONLY");
 931   gMC->Gspos("TPJ1",2,"TPC ",0.,0.,-72.3,0,"ONLY");
 932
 933   //
 934
 935   dm[0]=0.;
 936   dm[1]=360.;
 937   dm[2]=4.;
 938
 939   //
 940
 941   dm[3]=70.8;
 942   dm[4]=58.4;
 943   dm[5]=60.1;
 944
 945   //
 946
 947   dm[6]=71.2;
 948   dm[7]=58.4;
 949   dm[8]=60.1;
 950
 951   //
 952
 953   dm[9]=71.2;
 954   dm[10]=58.4;
 955   dm[11]=59.4;
 956
 957   //
 958
 959   dm[12]=71.6;
 960   dm[13]=58.4;
 961   dm[14]=59.4;
 962
 963   gMC->Gsvolu("TPJ2","PCON",idtmed[4],dm,15);
 964
 965   gMC->Gspos("TPJ2",1,"TPC ",0.,0.,0.,0,"ONLY");
 966   gMC->Gspos("TPJ2",2,"TPC ",0.,0.,0.,idrotm[nRotMat],"ONLY");
 967
 968
 969
 970   // Tpc Inner Containment vessel Seal (Viton, I use Lexan for a time being)
 971
 972   dm[0]=58.4;
 973   dm[1]=61.2;
 974   dm[2]=0.1;
 975
 976   gMC->Gsvolu("TICS","TUBE",idtmed[14],dm,3);
 977
 978   gMC->Gspos("TICS",1,"TPC ",0.,0.,71.7,0,"ONLY");
 979   gMC->Gspos("TICS",2,"TPC ",0.,0.,-71.7,0,"ONLY");
 980
 981   // TICM -> TPC
 982
 983   gMC->Gspos("TICM",1,"TPC ",0.,0.,0.,0,"ONLY");
 984
 985   //
 986
 987   nRotMat++; // prepare for the next rotation matrix
 988
 989   //---------------------------------------------------------
 990   //  Tpc Dift Gas volume Nonsensitive (Ne-CO2 90/10)
 991   //  and its daughters (HV membrane, rods, readout chambers)
 992   //---------------------------------------------------------
 993
 994   dm[0]= 79.2;
 995   dm[1]= 258.0;
 996   dm[2]= 253.6;
 997
 998   gMC->Gsvolu("TDGN","TUBE",idtmed[1],dm,3);
 999
1000   // sector opening angles
1001
1002   Float_t innerOpenAngle = fTPCParam->GetInnerAngle();
1003   Float_t outerOpenAngle = fTPCParam->GetOuterAngle();
1004
1005   // sector angle shift
1006
1007   Float_t innerAngleShift = fTPCParam->GetInnerAngleShift();
1008
1009
1010   // All above parameters are identical for inner and outer
1011   // sectors. The distinction is kept for the historical reasons
1012   // and eventually will disappear.
1013
1014   Float_t tanAlpha = TMath::Tan(0.5*innerOpenAngle);
1015   Float_t cosAlpha = TMath::Sqrt(1.+tanAlpha*tanAlpha);
1016   Float_t space;
1017
1018   //-------------------------------------------------------------------------
1019   //   Tpc Inner Readout Chambers
1020   //-------------------------------------------------------------------------
1021
1022   dm[0]= 14.483;
1023   dm[1]= 23.3345;
1024   dm[2]= 1.6; // thickness
1025   dm[3]= 25.1;
1026
1027   gMC->Gsvolu("TIRC","TRD1",idtmed[4],dm,4);
1028
1029   // this volume will be positioned in the empty space
1030   // of the end-cap to avoid overlaps
1031
1032   dm[0]= 13.7305;
1033   dm[1]= 21.1895;
1034   dm[2]= 2.25;
1035   dm[3]= 21.15;
1036
1037   gMC->Gsvolu("TIC1","TRD1",idtmed[4],dm,4);
1038
1039
1040   //------------------------------------------------
1041   // Tpc Inner readout chamber Pad Plane
1042   //------------------------------------------------
1043
1044   dm[0]= 14.483;
1045   dm[1]= 23.3345;
1046   dm[2]= 0.5;
1047   dm[3]= 25.1;
1048
1049   gMC->Gsvolu("TIPP","TRD1",idtmed[12],dm,4);
1050
1051   //
1052
1053   dm[0] -= 1.218511934;
1054   dm[1] -= 1.218511934;
1055   dm[2] = 0.35;
1056
1057   gMC->Gsvolu("TIC3","TRD1",idtmed[1],dm,4);
1058
1059   gMC->Gspos("TIC3",1,"TIPP",0.,0.15,0.,0,"ONLY");
1060
1061   gMC->Gspos("TIPP",1,"TIRC",0.,1.1,0.,0,"ONLY");
1062
1063
1064   //----------------------------------------------
1065   // Tpc Readout Chambers Empty spaces - for both
1066   // inner and outer sectors
1067   //----------------------------------------------
1068
1069   gMC->Gsvolu("TRCE","TRD1",idtmed[0],dm,0);
1070
1071   // Inner sector - 4 spaces
1072
1073
1074   dm[3] = 4.7625;
1075   dm[0] = 12.472;
1076
1077   Float_t rr = 90.52;
1078   Float_t zz;
1079
1080   zz= -12.7875;
1081
1082   space = rr*tanAlpha-dm[0];
1083
1084   for(Int_t nsLow=0;nsLow<4;nsLow++){
1085
1086     rr += 9.525;
1087     dm[1]= rr*tanAlpha - space;
1088
1089     dm[2]=0.8;
1090
1091     gMC->Gsposp("TRCE",nsLow+1,"TIRC",0.,-0.8,zz,0,"ONLY",dm,4);
1092
1093     //
1094
1095     dm[2] = 1.2;
1096
1097     gMC->Gsposp("TRCE",nsLow+5,"TIC1",0.,1.05,zz-2.1,0,"ONLY",dm,4);
1098
1099     rr += 0.4;
1100     dm[0] = rr*tanAlpha - space;
1101     zz += (0.4+9.525);
1102
1103   }
1104
1105   dm[0]= 12.472;
1106   // dm[1] - this is the dm[1] from the previous TRCE
1107   dm[2]= 1.05;
1108   dm[3]= 19.65;
1109
1110   gMC->Gsposp("TRCE",9,"TIC1",0.,-1.2,0.,0,"ONLY",dm,4);
1111
1112   //
1113   // TPc Space for Connectors
1114   //
1115
1116   dm[0]= .3;
1117   dm[1]= .3;
1118   dm[2]= 4.5;
1119
1120   gMC->Gsvolu("TPSC","BOX ",idtmed[0],dm,3);
1121
1122   // TPC Connectors
1123
1124   dm[0]= .25;
1125   dm[1]= .15;
1126   dm[2]= 3.75;
1127
1128   gMC->Gsvolu("TPCC","BOX ",idtmed[13],dm,3);
1129
1130   gMC->Gspos("TPCC",1,"TPSC",0.,0.15,0.,0,"ONLY");
1131
1132   zz = -12.7875;
1133
1134
1135   Float_t alpha;
1136   Float_t astep;
1137
1138   // inner part of the inner sector - 2 x 20 holes
1139
1140   astep = 20.00096874/19.;
1141
1142   alpha = 10.00048437-astep;
1143
1144   Float_t x1,x2;
1145
1146     x1 = 13.31175725;
1147     x1 -= 0.996357832;
1148
1149     x2 = 15.06180253;
1150     x2 -= 1.163028812;
1151
1152   Int_t ncon;
1153
1154   for(ncon=0;ncon<20;ncon++){
1155
1156     phi1 = 0.;
1157     theta1 = 90.+alpha;
1158     phi2=90.;
1159     theta2 = 90.;
1160     phi3 = (alpha>0) ? 0. : 180.;
1161     theta3 = TMath::Abs(alpha);
1162
1163     AliMatrix(idrotm[nRotMat], theta1, phi1, theta2, phi2, theta3, phi3);
1164
1165
1166
1167     gMC->Gspos("TPSC",ncon+1,"TIRC",x1,0.3,-12.7875,idrotm[nRotMat],"ONLY");
1168     gMC->Gspos("TPSC",ncon+21,"TIRC",x2,0.3,-2.8625,idrotm[nRotMat],"ONLY");
1169
1170
1171     x1 -= 1.296357833;
1172     x2 -= 1.463028812;
1173
1174     alpha -= astep;
1175     nRotMat++;
1176
1177   }
1178
1179   // outer part of the inner sector - 2 x 25 holes
1180
1181    astep = 20.00096874/24.;
1182    alpha = 10.00048437-astep;
1183
1184    x1 = 16.81184781;
1185    x1 -= 1.016295986;
1186
1187    x2 = 18.5618931;
1188    x2 -= 1.150914854;
1189
1190   for(ncon=0;ncon<25;ncon++){
1191
1192     phi1 = 0.;
1193     theta1 = 90.+alpha;
1194     phi2=90.;
1195     theta2 = 90.;
1196     phi3 = (alpha>0) ? 0. : 180.;
1197     theta3 = TMath::Abs(alpha);
1198
1199     AliMatrix(idrotm[nRotMat], theta1, phi1, theta2, phi2, theta3, phi3);
1200
1201
1202
1203     gMC->Gspos("TPSC",ncon+41,"TIRC",x1,0.3,7.0625,idrotm[nRotMat],"ONLY");
1204     gMC->Gspos("TPSC",ncon+66,"TIRC",x2,0.3,16.9875,idrotm[nRotMat],"ONLY");
1205
1206
1207     x1 -= 1.316295986;
1208     x2 -= 1.450914854;
1209
1210     alpha -= astep;
1211     nRotMat++;
1212
1213   }
1214
1215   //--------------------------------------------------------------------------
1216   //  TPC Outer Readout Chambers
1217   //  this is NOT a final design
1218   //--------------------------------------------------------------------------
1219
1220   dm[0]= 23.3875;
1221   dm[1]= 43.524;
1222   dm[2]= 1.5; //thickness
1223   dm[3]= 57.1;
1224
1225   gMC->Gsvolu("TORC","TRD1",idtmed[4],dm,4);
1226
1227   //------------------------------------------------
1228   // Tpc Outer readout chamber Pad Plane
1229   //------------------------------------------------
1230
1231   dm[2]= 0.5;
1232
1233   gMC->Gsvolu("TOPP","TRD1",idtmed[12],dm,4);
1234
1235   dm[0] -= 1.218511934;
1236   dm[1] -= 1.218511934;
1237   dm[2] = 0.35;
1238
1239   gMC->Gsvolu("TOC3","TRD1",idtmed[1],dm,4);
1240
1241   gMC->Gspos("TOC3",1,"TOPP",0.,0.15,0.,0,"ONLY");
1242
1243   gMC->Gspos("TOPP",1,"TORC",0.,1.0,0.,0,"ONLY");
1244
1245   // empty space
1246
1247   dm[0]= 21.035;
1248   dm[1]= 38.7205;
1249   dm[2]= 0.7;
1250   dm[3]= 50.15;
1251
1252   gMC->Gsposp("TRCE",10,"TORC",0.,-0.8,-2.15,0,"ONLY",dm,4);
1253
1254   dm[0]= 22.2935;
1255   dm[1]= 40.5085;
1256   dm[2]= 2.25;
1257   dm[3]= 51.65;
1258
1259   gMC->Gsvolu("TOC1","TRD1",idtmed[4],dm,4);
1260
1261   dm[0]= 21.35;
1262   dm[1]= 38.7205;
1263   dm[2]= 2.25;
1264   dm[3]= 50.15;
1265
1266   gMC->Gsposp("TRCE",11,"TOC1",0.,0.,0.,0,"ONLY",dm,4);
1267
1268   //-----------------------------------------------
1269   // Tpc Services Support Wheel
1270   //-----------------------------------------------
1271
1272   dm[0]=0.;
1273   dm[1]=360.;
1274   dm[2]=18.;
1275   dm[3]=2.;
1276
1277   dm[4]= -5.;
1278   dm[5]= 77.017;
1279   dm[6]= 255.267;
1280
1281   dm[7]= 5.;
1282   dm[8]= dm[5];
1283   dm[9]= dm[6];
1284
1285   gMC->Gsvolu("TSSW","PGON",idtmed[4],dm,10);
1286
1287   // Tpc Services Wheel Cover
1288
1289   dm[4]= -0.5;
1290   dm[7]= 0.5;
1291
1292   gMC->Gsvolu("TSWC","PGON",idtmed[4],dm,10);
1293
1294   // Tpc Service wheel Cover Empty space
1295
1296   dm[0]= 10.99;
1297   dm[1]= 39.599;
1298   dm[2]= .5;
1299   dm[3]= 81.125;
1300
1301   gMC->Gsvolu("TSCE","TRD1",idtmed[0],dm,4);
1302
1303   // Tpc services Wheel Empty Spaces
1304
1305   dm[0]= 13.18017507;
1306   dm[1]= 44.61045938;
1307   dm[2]= 4.;
1308   dm[3]= 89.125;
1309
1310   gMC->Gsvolu("TWES","TRD1",idtmed[0],dm,4);
1311
1312   // Tpc Services Wheel Bars
1313
1314   gMC->Gsvolu("TSWB","TRD1",idtmed[4],dm,0);
1315
1316   // bars-> TWES
1317
1318   dm[2]= 4.;
1319   dm[3]= .4;
1320
1321   dm[0]= 13.8149522;
1322   dm[1]= 13.95601379;
1323
1324   gMC->Gsposp("TSWB",1,"TWES",0.,0.,-85.125,0,"ONLY",dm,4);
1325
1326   dm[0]= 43.83462067;
1327   dm[1]= 43.97568225;
1328
1329   gMC->Gsposp("TSWB",2,"TWES",0.,0.,85.125,0,"ONLY",dm,4);
1330
1331   // TPc ELectronics - right now 30% X0 Si
1332
1333   dm[0]= 14.03813696;
1334   dm[1]= 43.3524075;
1335   dm[2]= 1.404;
1336   dm[3]= 83.125;
1337
1338   gMC->Gsvolu("TPEL","TRD1",idtmed[11],dm,4);
1339   gMC->Gspos("TPEL",1,"TWES",0.,0.,0.,0,"ONLY");
1340
1341   //--------------------------------------------------------------------------
1342   //  End caps
1343   //--------------------------------------------------------------------------
1344
1345   // TPc Main Wheel - Al
1346
1347   dm[0]= 74.9;
1348   dm[1]= 264.4;
1349   dm[2]= 3.0;
1350
1351   gMC->Gsvolu("TPMW","TUBE",idtmed[4],dm,3);
1352
1353   //--------------------------------------------------------------------------
1354   //  Tpc Empty Space for the Readout chambers
1355   //--------------------------------------------------------------------------
1356
1357   Float_t rLow= 86.2;
1358   Float_t rUp= 243.5;
1359   Float_t dR = 0.5*(rUp-rLow);
1360
1361   space= 1.5/cosAlpha; // wheel ribs are 3.0 cm wide
1362
1363   dm[0]= rLow*tanAlpha-space;
1364   dm[1]= rUp*tanAlpha-space;
1365   dm[2] = 3.0;
1366   dm[3]= dR;
1367
1368   gMC->Gsvolu("TESR","TRD1",idtmed[0],dm,4);
1369
1370   // TIC1->TESR
1371
1372   gMC->Gspos("TIC1",1,"TESR",0.,0.75,-dR+23.97,0,"ONLY");
1373
1374   // TOC1->TESR
1375
1376   gMC->Gspos("TOC1",1,"TESR",0.,0.75,dR-55.02,0,"ONLY");
1377
1378   // Tpc Empty Space Bars - Al (daughters of TESR)
1379
1380   Float_t zBar;
1381
1382   gMC->Gsvolu("TESB","TRD1",idtmed[4],dm,0);
1383
1384   // lower bar
1385
1386   dm[0]= rLow*tanAlpha-space;
1387   dm[1]= 88.7*tanAlpha-space;
1388   dm[2]= 2.25;
1389   dm[3]= 1.275;
1390
1391   zBar = -dR+dm[3];
1392
1393   gMC->Gsposp("TESB",1,"TESR",0.,0.75,zBar,0,"ONLY",dm,4);
1394
1395   // middle bar
1396
1397   dm[0]= 131.65*tanAlpha-space;
1398   dm[1]= 136.5*tanAlpha-space;
1399   dm[3]= 2.425;
1400
1401   zBar = -dR +131.65+dm[3]-rLow;
1402
1403   gMC->Gsposp("TESB",2,"TESR",0.,0.75,zBar,0,"ONLY",dm,4);
1404
1405   // upper bar
1406
1407   dm[0]= 240.4*tanAlpha-space;
1408   dm[1]= rUp*tanAlpha-space;
1409   dm[3]= 1.55;
1410
1411   zBar = dR-dm[3];
1412
1413   gMC->Gsposp("TESB",3,"TESR",0.,0.75,zBar,0,"ONLY",dm,4);
1414
1415   //------------------------------------------------------
1416   //  TPc Lower "S" Sectors
1417   //------------------------------------------------------
1418
1419
1420   Float_t inSecLowEdge = fTPCParam->GetInnerRadiusLow();
1421   Float_t inSecUpEdge =  fTPCParam->GetInnerRadiusUp();
1422
1423   dm[0] = inSecLowEdge*TMath::Tan(0.5*innerOpenAngle)-0.01;
1424   dm[1] = inSecUpEdge*TMath::Tan(0.5*innerOpenAngle)-0.01;
1425   dm[2] = 0.5*(250. - 5.e-3);
1426   dm[3] = 0.5*(inSecUpEdge-inSecLowEdge);
1427
1428   gMC->Gsvolu("TPLS", "TRD1", idtmed[2], dm, 4); // sensitive
1429
1430
1431   //----------------------------------------------------------
1432   //  TPc Upper Sectors
1433   //----------------------------------------------------------
1434
1435   Float_t ouSecLowEdge = fTPCParam->GetOuterRadiusLow();
1436   Float_t ouSecUpEdge = fTPCParam->GetOuterRadiusUp();
1437
1438   dm[0] = ouSecLowEdge*TMath::Tan(0.5*outerOpenAngle)-0.01;
1439   dm[1] = ouSecUpEdge*TMath::Tan(0.5*outerOpenAngle)-0.01;
1440   dm[2] = 0.5*(250. - 5.e-3);
1441   dm[3] = 0.5*(ouSecUpEdge-ouSecLowEdge);
1442
1443   gMC->Gsvolu("TPUS", "TRD1", idtmed[2], dm, 4); // sensitive
1444
1445
1446
1447   // sensitive strips
1448
1449     gMC->Gsvolu("TPSS","TRD1",idtmed[2],dm,0); // sensitive
1450
1451     Int_t nofStrips,nstr;
1452     Float_t r1,r2,zs;
1453     Float_t stripThick = 0.01; // 100 microns
1454     Float_t deadSpace;
1455
1456     // inner sector
1457
1458
1459     // if all lower sectors selected define only 1 strip
1460
1461     nofStrips=((fSecAL <0)||(fSecAL>=0 && fSens<0)) ? 1 : fTPCParam->GetNRowLow();
1462     deadSpace = fTPCParam->GetInnerWireMount();
1463
1464     dm[2] = 0.5*(250. - 5.e-3);
1465     dm[3] = 0.5 * stripThick;
1466
1467     for(nstr=0;nstr<nofStrips;nstr++){
1468
1469       r1 = fTPCParam->GetPadRowRadiiLow(nstr);
1470       r2 = r1 + stripThick;
1471       dm[0] = r1 * TMath::Tan(0.5*innerOpenAngle) - deadSpace;
1472       dm[1] = r2 * TMath::Tan(0.5*innerOpenAngle) - deadSpace;
1473       zs = -inSecLowEdge -0.5*(inSecUpEdge-inSecLowEdge);
1474       zs += r1;
1475       zs += dm[3];
1476
1477       gMC->Gsposp("TPSS", nstr+1, "TPLS", 0., 0., zs, 0, "ONLY", dm, 4);
1478
1479
1480     }
1481
1482     // strips only if several upper sectors selected end fSens > 0
1483
1484     if(fSecAU >=0 && fSens >0){
1485
1486     Int_t nsSave = nofStrips;
1487
1488     // outer sector
1489
1490     nofStrips = fTPCParam->GetNRowUp();
1491     deadSpace = fTPCParam->GetOuterWireMount();
1492
1493     dm[2] = 0.5*(250. - 5.e-3);
1494     dm[3] = 0.5 * stripThick;
1495
1496
1497     for(nstr=0;nstr<nofStrips;nstr++){
1498
1499       r1 = fTPCParam->GetPadRowRadiiUp(nstr);
1500       r2 = r1 + stripThick;
1501       dm[0] = r1 * TMath::Tan(0.5*outerOpenAngle) - deadSpace;
1502       dm[1] = r2 * TMath::Tan(0.5*outerOpenAngle) - deadSpace;
1503       zs = -ouSecLowEdge -0.5*(ouSecUpEdge-ouSecLowEdge);
1504       zs += r1;
1505       zs += dm[3];
1506
1507       gMC->Gsposp("TPSS", nstr+1+nsSave, "TPUS", 0., 0., zs, 0, "ONLY", dm, 4);
1508
1509      }
1510     }
1511
1512
1513   //-------------------------------------------------------
1514   //  positioning of the empty spaces into the main wheel
1515   //  and readout chambers and sectors into the drift gas
1516   //-------------------------------------------------------
1517
1518   Float_t rCenter,xc,yc;
1519   Float_t rInner,rOuter; // center of the inner and outer chamber
1520
1521   rCenter = rLow+dR;
1522
1523   rInner = 108.07;
1524   rOuter = 190.68;
1525
1526
1527   for(Int_t ns=0; ns<nInnerSector;ns++){
1528
1529     phi1 = ns * innerOpenAngle + innerAngleShift;
1530     phi1 *= kRaddeg; // in degrees
1531
1532     phi1 = (Float_t)TMath::Nint(phi1) + 270.;
1533
1534     if (phi1 > 360.) phi1 -= 360.;
1535
1536     theta1 = 90.;
1537     phi2   = 90.;
1538     theta2 = 180.;
1539     phi3   = ns * innerOpenAngle + innerAngleShift;
1540     phi3 *= kRaddeg; // in degrees
1541
1542     phi3 = (Float_t)TMath::Nint(phi3);
1543
1544     if(phi3 > 360.) phi3 -= 360.;
1545
1546     theta3 = 90.;
1547
1548     // "holes"->End plate
1549
1550     xc = rCenter*TMath::Cos(phi3*kDegrad);
1551     yc = rCenter*TMath::Sin(phi3*kDegrad);
1552
1553     AliMatrix(idrotm[nRotMat], theta1, phi1, theta2, phi2, theta3, phi3);
1554
1555     gMC->Gspos("TESR",ns+1,"TPMW",xc,yc,0.,idrotm[nRotMat],"ONLY");
1556
1557     // TSCE->TSWC (services wheel volumes)
1558
1559     xc = 166.142*TMath::Cos(phi3*kDegrad);
1560     yc = 166.142*TMath::Sin(phi3*kDegrad);
1561
1562     gMC->Gspos("TSCE",ns+1,"TSWC",xc,yc,0.,idrotm[nRotMat],"ONLY");
1563     gMC->Gspos("TWES",ns+1,"TSSW",xc,yc,0.,idrotm[nRotMat],"ONLY");
1564
1565
1566     // readout chambers->TDGN (drift gas)
1567
1568     xc = rInner*TMath::Cos(phi3*kDegrad);
1569     yc = rInner*TMath::Sin(phi3*kDegrad);
1570
1571     gMC->Gspos("TIRC",ns+1,"TDGN",xc,yc,252.,idrotm[nRotMat],"ONLY");
1572
1573     // here lower sectors
1574
1575     if(fSecAL <0){
1576
1577       // all lower sectors are positioned
1578
1579       gMC->Gspos("TPLS",ns+1,"TDGN",xc,yc,125.0025,idrotm[nRotMat],"ONLY");
1580       gMC->
1581         Gspos("TPLS",ns+nInnerSector+1,"TDGN",xc,yc,-125.0025,idrotm[nRotMat],"ONLY");
1582     }
1583     else{
1584
1585       // only selected sectors are positioned (up to 6 sectors)
1586
1587       for(Int_t sel=0;sel<6;sel++){
1588
1589         if(fSecLows[sel] == ns){
1590           gMC->Gspos("TPLS",ns+1,"TDGN",xc,yc,125.0025,idrotm[nRotMat],"ONLY");
1591         }
1592         else if(fSecLows[sel] == ns+nInnerSector){
1593          gMC->
1594          Gspos("TPLS",ns+nInnerSector+1,"TDGN",xc,yc,-125.0025,idrotm[nRotMat],"ONLY");
1595         }
1596       }
1597     } // lower sectors finished
1598
1599
1600     xc = rOuter*TMath::Cos(phi3*kDegrad);
1601     yc = rOuter*TMath::Sin(phi3*kDegrad);
1602
1603     gMC->Gspos("TORC",ns+1,"TDGN",xc,yc,252.1,idrotm[nRotMat],"ONLY");
1604
1605     // here upper sectors
1606
1607     if(fSecAU <0){
1608
1609       // all upper sectors
1610
1611       gMC->Gspos("TPUS",ns+1,"TDGN",xc,yc,125.0025,idrotm[nRotMat],"ONLY");
1612       gMC->
1613         Gspos("TPUS",ns+nOuterSector+1,"TDGN",xc,yc,-125.0025,idrotm[nRotMat],"ONLY");
1614     }
1615     else{
1616
1617       // only selected sectors (up to 12)
1618
1619       for(Int_t sel=0;sel<12;sel++){
1620         if(fSecUps[sel] == ns+2*nInnerSector){
1621           gMC->Gspos("TPUS",ns+1,"TDGN",xc,yc,125.0025,idrotm[nRotMat],"ONLY");
1622         }
1623         else if(fSecUps[sel] == ns+2*nInnerSector+nOuterSector){
1624          gMC->
1625           Gspos("TPUS",ns+nOuterSector+1,"TDGN",xc,yc,-125.0025,idrotm[nRotMat],"ONLY");
1626         }
1627       }
1628     } // upper sectors finished
1629
1630
1631     nRotMat++;
1632
1633     theta2 = 0.; // reflection
1634
1635     AliMatrix(idrotm[nRotMat], theta1, phi1, theta2, phi2, theta3, phi3);
1636
1637     xc = rInner*TMath::Cos(phi3*kDegrad);
1638     yc = rInner*TMath::Sin(phi3*kDegrad);
1639
1640     gMC->Gspos("TIRC",ns+nInnerSector+1,"TDGN",xc,yc,-252.,idrotm[nRotMat],"ONLY");
1641
1642     xc = rOuter*TMath::Cos(phi3*kDegrad);
1643     yc = rOuter*TMath::Sin(phi3*kDegrad);
1644
1645     gMC->Gspos("TORC",ns+nOuterSector+1,"TDGN",xc,yc,-252.1,idrotm[nRotMat],"ONLY");
1646
1647     nRotMat++;
1648
1649   }
1650   // TPMW->TPC
1651
1652   gMC->Gspos("TPMW",1,"TPC ",0.,0.,256.6,0,"ONLY");
1653   gMC->Gspos("TPMW",2,"TPC ",0.,0.,-256.6,idrotm[0],"ONLY");
1654
1655   //---------------------------------------------------------
1656   //  Tpc High Voltage Membrane - 100 microns of mylar
1657   //---------------------------------------------------------
1658
1659   dm[0]=82.8;
1660   dm[1]=252.;
1661   dm[2]=0.005;
1662
1663   gMC->Gsvolu("THVM","TUBE",idtmed[8],dm,3);
1664
1665   gMC->Gspos("THVM",1,"TDGN",0.,0.,0.,0,"ONLY");
1666
1667   // Tpc High Voltage membrane Holders
1668
1669   gMC->Gsvolu("THVH","TUBE",idtmed[4],dm,0);
1670
1671
1672
1673   // inner
1674
1675   dm[0]=79.3;
1676   dm[1]=82.8;
1677   dm[2]=0.2;
1678
1679   gMC->Gsposp("THVH",1,"TDGN",0.,0.,0.,0,"ONLY",dm,3);
1680
1681   // outer
1682
1683   dm[0]= 252.;
1684   dm[1]= 257.9;
1685   dm[2]= 0.4;
1686
1687   gMC->Gsposp("THVH",2,"TDGN",0.,0.,0.,0,"ONLY",dm,3);
1688
1689   //----------------------------------------------------------
1690   // TPc Support Rods - MAKROLON
1691   //----------------------------------------------------------
1692
1693   dm[0]= 0.9;
1694   dm[1]= 1.2;
1695
1696   gMC->Gsvolu("TPSR","TUBE",idtmed[7],dm,0); // inner and outer rods differ
1697
1698
1699   for(Int_t nrod=0;nrod<18;nrod++){
1700     Float_t angle=innerOpenAngle*(Float_t)nrod;
1701
1702     xc=81.5*TMath::Cos(angle);
1703     yc=81.5*TMath::Sin(angle);
1704
1705     dm[2]=126.7;
1706
1707     gMC->Gsposp("TPSR",nrod+1,"TDGN",xc,yc,126.9,0,"ONLY",dm,3);
1708     gMC->Gsposp("TPSR",nrod+19,"TDGN",xc,yc,-126.9,0,"ONLY",dm,3);
1709
1710     dm[2]=126.6;
1711
1712     xc=254.25*TMath::Cos(angle);
1713     yc=254.25*TMath::Sin(angle);
1714
1715     // rod number 54 contans the HV cable
1716
1717     if(nrod<17) {
1718       gMC->Gsposp("TPSR",nrod+37,"TDGN",xc,yc,127.,0,"ONLY",dm,3);
1719       gMC->Gsposp("TPSR",nrod+54,"TDGN",xc,yc,-127.,0,"ONLY",dm,3);
1720     }
1721
1722   }
1723
1724   //----------------------------------------------------------
1725   // Tpc High Voltage Rod - MAKROLON + Copper cable
1726   //----------------------------------------------------------
1727
1728   // rod with cable (Left)
1729
1730   dm[0]=0.;
1731   dm[1]=2.25;
1732   dm[2]=126.6;
1733
1734   gMC->Gsvolu("THVL","TUBE",idtmed[7],dm,3);
1735
1736   // HV cable
1737
1738   dm[0]=0.;
1739   dm[1]=0.3;
1740   dm[2]=126.6;
1741
1742   gMC->Gsvolu("THVC","TUBE",idtmed[10],dm,3);
1743
1744   // empty space
1745
1746   dm[0]=0.3;
1747   dm[1]=1.;
1748   dm[2]=126.6;
1749
1750   gMC->Gsvolu("THVE","TUBE",idtmed[1],dm,3);
1751
1752   gMC->Gspos("THVC",1,"THVL",0.,0.,0.,0,"ONLY");
1753   gMC->Gspos("THVE",1,"THVL",0.,0.,0.,0,"ONLY");
1754
1755   // rod without cable
1756
1757   dm[0]=1.8;
1758   dm[1]=2.25;
1759   dm[2]=126.6;
1760
1761   gMC->Gsvolu("THVR","TUBE",idtmed[7],dm,3);
1762
1763   gMC->Gspos("THVL",1,"TDGN",xc,yc,-127.,0,"ONLY");
1764   gMC->Gspos("THVR",1,"TDGN",xc,yc,127.,0,"ONLY");
1765
1766   gMC->Gspos("TDGN",1,"TPC ",0.,0.,0.,0,"ONLY");
1767
1768   // services wheel cover -> wheel
1769
1770
1771   gMC->Gspos("TSWC",1,"TSSW",0.,0.,4.5,0,"ONLY");
1772   gMC->Gspos("TSWC",2,"TSSW",0.,0.,-4.5,0,"ONLY");
1773
1774
1775   // put the wheel into the TPC
1776
1777   gMC->Gspos("TSSW",1,"TPC ",0.,0.,278.7,0,"ONLY");
1778   gMC->Gspos("TSSW",2,"TPC ",0.,0.,-278.7,0,"ONLY");
1779
1780   //
1781
1782   gMC->Gsord("TPMW",6);
1783   gMC->Gsord("TSSW",6);
1784   gMC->Gsord("TSWC",6);
1785   if(fSecAL >=0)  gMC->Gsord("TPLS",3);
1786   if(fSecAU >=0 && fSens >0)  gMC->Gsord("TPUS",3);
1787   gMC->Gsord("TDGN",6);
1788
1789   // put the TPC into ALIC (main mother volume)
1790
1791   gMC->Gspos("TPC ",1,"ALIC",0.,0.,0.,0,"ONLY");
1792
1793
1794
1795 } // end of function
1796
1797 //_____________________________________________________________________________
1798 void AliTPCv2::DrawDetector()
1799 {
1800   //
1801   // Draw a shaded view of the Time Projection Chamber version 1
1802   //
1803
1804   // Set everything unseen
1805   gMC->Gsatt("*", "seen", -1);
1806   //
1807   // Set ALIC mother transparent
1808   gMC->Gsatt("ALIC","SEEN",0);
1809   //
1810   // Set the volumes visible
1811   //
1812
1813   gMC->Gsatt("TPC ","SEEN",0);
1814   gMC->Gsatt("TOIN","SEEN",1);
1815   gMC->Gsatt("TOIN","COLO",7);
1816   gMC->Gsatt("TOCV","SEEN",1);
1817   gMC->Gsatt("TOCV","COLO",4);
1818   gMC->Gsatt("TSA1","SEEN",0);
1819   gMC->Gsatt("TSA2","SEEN",0);
1820   gMC->Gsatt("TSA3","SEEN",0);
1821   gMC->Gsatt("TSA4","SEEN",0);
1822   gMC->Gsatt("TSA5","SEEN",0);
1823   gMC->Gsatt("TOFC","SEEN",1);
1824   gMC->Gsatt("TOFC","COLO",4);
1825   gMC->Gsatt("TSA6","SEEN",0);
1826   gMC->Gsatt("TSA7","SEEN",0);
1827   gMC->Gsatt("TSA8","SEEN",0);
1828   gMC->Gsatt("TIIN","SEEN",1);
1829   gMC->Gsatt("TIIN","COLO",7);
1830   gMC->Gsatt("TII1","SEEN",0);
1831   gMC->Gsatt("TIFC","SEEN",1);
1832   gMC->Gsatt("TIFC","COLO",4);
1833   gMC->Gsatt("TSA9","SEEN",0);
1834   gMC->Gsatt("TS10","SEEN",0);
1835   gMC->Gsatt("TS11","SEEN",0);
1836   gMC->Gsatt("TS12","SEEN",0);
1837   gMC->Gsatt("TS13","SEEN",0);
1838   gMC->Gsatt("TS14","SEEN",0);
1839   gMC->Gsatt("TICC","SEEN",0);
1840   gMC->Gsatt("TICM","SEEN",0);
1841   gMC->Gsatt("TS15","SEEN",0);
1842   gMC->Gsatt("TS16","SEEN",0);
1843   gMC->Gsatt("TS17","SEEN",0);
1844   gMC->Gsatt("TS18","SEEN",0);
1845   gMC->Gsatt("TS19","SEEN",0);
1846   gMC->Gsatt("TPJ1","SEEN",0);
1847   gMC->Gsatt("TPJ2","SEEN",0);
1848   gMC->Gsatt("TICS","SEEN",0);
1849   gMC->Gsatt("TDGN","SEEN",0);
1850   gMC->Gsatt("TIRC","SEEN",0);
1851   gMC->Gsatt("TIC1","SEEN",1);
1852   gMC->Gsatt("TIPP","SEEN",0);
1853   gMC->Gsatt("TIC3","SEEN",0);
1854   gMC->Gsatt("TRCE","SEEN",0);
1855   gMC->Gsatt("TPSC","SEEN",0);
1856   gMC->Gsatt("TPCC","SEEN",0);
1857   gMC->Gsatt("TORC","SEEN",0);
1858   gMC->Gsatt("TOPP","SEEN",0);
1859   gMC->Gsatt("TOC3","SEEN",0);
1860   gMC->Gsatt("TOC1","SEEN",1);
1861   gMC->Gsatt("TSSW","SEEN",1);
1862   gMC->Gsatt("TSWC","SEEN",1);
1863   gMC->Gsatt("TSSW","COLO",3);
1864   gMC->Gsatt("TSWC","COLO",3);
1865   gMC->Gsatt("TSCE","COLO",6);
1866   gMC->Gsatt("TSCE","SEEN",1);
1867   gMC->Gsatt("TWES","SEEN",0);
1868   gMC->Gsatt("TSWB","SEEN",0);
1869   gMC->Gsatt("TPEL","SEEN",0);
1870   gMC->Gsatt("TPMW","SEEN",1);
1871   gMC->Gsatt("TESR","SEEN",1);
1872   gMC->Gsatt("TPMW","COLO",12);
1873   gMC->Gsatt("TIC1","COLO",5);
1874   gMC->Gsatt("TOC1","COLO",5);
1875   gMC->Gsatt("TESB","SEEN",0);
1876   gMC->Gsatt("THVM","SEEN",1);
1877   gMC->Gsatt("THVM","COLO",11);
1878   gMC->Gsatt("THVH","SEEN",0);
1879   gMC->Gsatt("TPSR","SEEN",0);
1880   gMC->Gsatt("THVL","SEEN",0);
1881   gMC->Gsatt("THVC","SEEN",0);
1882   gMC->Gsatt("THVE","SEEN",0);
1883   gMC->Gsatt("THVR","SEEN",0);
1884   gMC->Gsatt("TPSS","SEEN",0);
1885   gMC->Gsatt("TPUS","SEEN",0);
1886   gMC->Gsatt("TPLS","SEEN",0);
1887
1888   //
1889   gMC->Gdopt("hide", "on");
1890   gMC->Gdopt("shad", "on");
1891   gMC->Gsatt("*", "fill", 7);
1892   gMC->SetClipBox(".");
1893   gMC->SetClipBox("TPMW",-300,300,-300,300,254.,270.);
1894   gMC->SetClipBox("TESR",-300,300,-300,300,254.,270.);
1895   gMC->SetClipBox("TSSW",-300,300,-300,300,283.,284.);
1896   gMC->SetClipBox("TSWC",-300,300,-300,300,283.,284.);
1897   gMC->SetClipBox("*", 0, 300, -300, 300, -290, 290);
1898   gMC->DefaultRange();
1899   gMC->Gdraw("alic", 40, 30, 0, 12, 9.5, .025, .025);
1900   gMC->Gdhead(1111, "Time Projection Chamber");
1901   gMC->Gdman(18, 4, "MAN");
1902   gMC->Gdopt("hide","off");
1903 }
1904
1905 //_____________________________________________________________________________
1906 void AliTPCv2::CreateMaterials()
1907 {
1908   //
1909   // Define materials for version 2 of the Time Projection Chamber
1910   //
1911
1912   AliTPC::CreateMaterials();
1913 }
1914
1915 //_____________________________________________________________________________
1916 void AliTPCv2::Init()
1917 {
1918   //
1919   // Initialises version 2 of the TPC after that it has been built
1920   //
1921
1922   Int_t *idtmed = fIdtmed->GetArray();
1923
1924   AliTPC::Init();
1925
1926
1927
1928   fIdSens=gMC->VolId("TPSS");
1929
1930   fIdLSec=gMC->VolId("TPLS"); // lower sector
1931   fIdUSec=gMC->VolId("TPUS"); // upper sector
1932
1933   gMC->SetMaxNStep(30000); // max. number of steps increased
1934
1935   gMC->Gstpar(idtmed[2],"LOSS",5); // specific energy loss
1936
1937   printf("%s: *** TPC version 2 initialized ***\n",ClassName());
1938   printf("%s: Maximum number of steps = %d\n",ClassName(),gMC->GetMaxNStep());
1939
1940   //
1941
1942 }
1943
1944 //_____________________________________________________________________________
1945 void AliTPCv2::StepManager()
1946 {
1947   //
1948   // Called for every step in the Time Projection Chamber
1949   //
1950
1951   //
1952   // parameters used for the energy loss calculations
1953   //
1954   const Float_t kprim = 14.35; // number of primary collisions per 1 cm
1955   const Float_t kpoti = 20.77e-9; // first ionization potential for Ne/CO2
1956   const Float_t kwIon = 35.97e-9; // energy for the ion-electron pair creation
1957
1958
1959   const Float_t kbig = 1.e10;
1960
1961   Int_t id,copy;
1962   Float_t hits[4];
1963   Int_t vol[2];
1964   TLorentzVector p;
1965
1966   vol[1]=0; // preset row number to 0
1967
1968   //
1969
1970   gMC->SetMaxStep(kbig);
1971
1972   if(!gMC->IsTrackAlive()) return; // particle has disappeared
1973
1974   Float_t charge = gMC->TrackCharge();
1975
1976   if(TMath::Abs(charge)<=0.) return; // take only charged particles
1977
1978   // check the sensitive volume
1979
1980   id = gMC->CurrentVolID(copy); // current volume Id
1981
1982   if ( (gMC->IsTrackEntering() || gMC->IsTrackExiting()) &&
1983        ((id == fIdLSec) || (id == fIdUSec)) ) {
1984
1985     AddTrackReference(gAlice->CurrentTrack(), gMC);
1986   }
1987
1988   if(id == fIdLSec){
1989     vol[0] = copy-1; // lower sector number
1990   }
1991   else if(id == fIdUSec){
1992     vol[0] = copy+fTPCParam->GetNInnerSector()-1; // upper sector number
1993   }
1994   else if(id == fIdSens && gMC->IsTrackEntering()){
1995
1996     // track is entering the sensitive strip
1997
1998     vol[1]= copy-1; // row number (absolute)
1999
2000     // sector type
2001
2002     id = gMC->CurrentVolOffID(1,copy);
2003
2004     if(id == fIdLSec){
2005
2006       // lower sector
2007
2008       vol[0] = copy-1; // sector number
2009
2010     }
2011     else {
2012
2013       // upper sector
2014
2015       vol[0] = copy-1+fTPCParam->GetNInnerSector(); // sector number
2016       vol[1] -= fTPCParam->GetNRowLow(); // row number (starts also from 0)
2017
2018     }
2019
2020     if(vol[1] == 0){
2021
2022       // because Jouri wants to have this
2023
2024       gMC->TrackMomentum(p);
2025       hits[0]=p[0];
2026       hits[1]=p[1];
2027       hits[2]=p[2];
2028       hits[3]=0.; // this hit has no energy loss
2029       // new(lhits[fNhits++]) AliTPChit(fIshunt,gAlice->CurrentTrack(),vol,hits);
2030
2031       AddHit(gAlice->CurrentTrack(), vol,hits);  //MI change
2032
2033     }
2034
2035      gMC->TrackPosition(p);
2036      hits[0]=p[0];
2037      hits[1]=p[1];
2038      hits[2]=p[2];
2039      hits[3]=0.; // this hit has no energy loss
2040      // new(lhits[fNhits++]) AliTPChit(fIshunt,gAlice->CurrentTrack(),vol,hits);
2041
2042      AddHit(gAlice->CurrentTrack(), vol,hits);  //MI change
2043
2044   }
2045   else return;
2046
2047   //-----------------------------------------------------------------
2048   //  charged particle is in the sensitive volume
2049   //-----------------------------------------------------------------
2050
2051   if(gMC->TrackStep() > 0) {
2052
2053     Int_t nel = (Int_t)(((gMC->Edep())-kpoti)/kwIon) + 1;
2054     nel=TMath::Min(nel,300); // 300 electrons corresponds to 10 keV
2055
2056     gMC->TrackPosition(p);
2057     hits[0]=p[0];
2058     hits[1]=p[1];
2059     hits[2]=p[2];
2060     hits[3]=(Float_t)nel;
2061
2062     // Add this hit
2063
2064     // new(lhits[fNhits++]) AliTPChit(fIshunt,gAlice->CurrentTrack(),vol,hits);
2065     if (fHitType&&2){
2066       gMC->TrackMomentum(p);
2067       Float_t momentum = TMath::Sqrt(p[0]*p[0]+p[1]*p[1]);
2068       Float_t precision =   (momentum>0.1) ? 0.002 :0.01;
2069       fTrackHits->SetHitPrecision(precision);
2070     }
2071     AddHit(gAlice->CurrentTrack(), vol,hits);  //MI change
2072
2073   }
2074
2075   // Stemax calculation for the next step
2076
2077   Float_t pp;
2078   TLorentzVector mom;
2079   gMC->TrackMomentum(mom);
2080   Float_t ptot=mom.Rho();
2081   Float_t betaGamma = ptot/gMC->TrackMass();
2082
2083   Int_t pid=gMC->TrackPid();
2084   if((pid==kElectron || pid==kPositron) && ptot > 0.002)
2085     {
2086       pp = kprim*1.58; // electrons above 20 MeV/c are on the plateau!
2087     }
2088   else
2089     {
2090
2091       betaGamma = TMath::Max(betaGamma,(Float_t)7.e-3); // protection against too small bg
2092       pp=kprim*BetheBloch(betaGamma);
2093
2094       if(TMath::Abs(charge) > 1.) pp *= (charge*charge);
2095     }
2096
2097   Double_t rnd = gMC->GetRandom()->Rndm();
2098
2099   gMC->SetMaxStep(-TMath::Log(rnd)/pp);
2100
2101 }
2102
2103 //_____________________________________________________________________________
2104 Float_t AliTPCv2::BetheBloch(Float_t bg)
2105 {
2106   //
2107   // Bethe-Bloch energy loss formula
2108   //
2109   const Double_t kp1=0.76176e-1;
2110   const Double_t kp2=10.632;
2111   const Double_t kp3=0.13279e-4;
2112   const Double_t kp4=1.8631;
2113   const Double_t kp5=1.9479;
2114
2115   Double_t dbg = (Double_t) bg;
2116
2117   Double_t beta = dbg/TMath::Sqrt(1.+dbg*dbg);
2118
2119   Double_t aa = TMath::Power(beta,kp4);
2120   Double_t bb = TMath::Power(1./dbg,kp5);
2121
2122   bb=TMath::Log(kp3+bb);
2123
2124   return ((Float_t)((kp2-aa-bb)*kp1/aa));
2125 }
2126
2127