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 1.46  2003/02/11 16:54:07  hristov
  19 Updated AliTrackReference class (S.Radomski)
  20
  21 Revision 1.45  2003/01/14 10:50:20  alibrary
  22 Cleanup of STEER coding conventions
  23
  24 Revision 1.44  2002/11/21 22:43:32  alibrary
  25 Removing AliMC and AliMCProcess
  26
  27 Revision 1.43  2002/10/14 14:57:43  hristov
  28 Merging the VirtualMC branch to the main development branch (HEAD)
  29
  30 Revision 1.40.6.2  2002/07/24 10:09:01  alibrary
  31 Updating VirtualMC
  32
  33 Revision 1.42  2002/06/12 14:56:56  kowal2
  34 Added track length to the reference hits
  35
  36 Revision 1.41  2002/05/27 14:33:15  hristov
  37 The new class AliTrackReference used (M.Ivanov)
  38
  39 Revision 1.40  2002/01/21 17:12:00  kowal2
  40 New track hits structure using root containers
  41
  42 Revision 1.39  2001/05/16 14:57:25  alibrary
  43 New files for folders and Stack
  44
  45 Revision 1.38  2001/05/08 16:03:06  kowal2
  46 Geometry update according to the latest technical spec.
  47
  48 Revision 1.37  2001/04/27 15:23:07  kowal2
  49 Correct materian in the central part of the inner containment vessel
  50
  51 Revision 1.36  2001/04/26 06:15:12  kowal2
  52 Corrected bug in the inner containment vessel (cones)
  53
  54 Revision 1.35  2001/04/24 11:17:33  kowal2
  55 New TPC geometry.
  56
  57 Revision 1.34  2001/04/23 10:20:18  hristov
  58 Constant casted to avoid ambiguity
  59
  60 Revision 1.33  2001/04/20 08:16:47  kowal2
  61 Protection against too small betaGamma. Thanks to Ivana and Yves.
  62
  63 Revision 1.32  2001/03/13 13:07:34  kowal2
  64 Corrected bug in the TPC mother volume geometry.
  65 Thanks to A. Morsch
  66
  67 Revision 1.31  2000/11/30 11:48:50  kowal2
  68 TLorentzVector.h adde to satisfy the latest changes by Federico
  69
  70 Revision 1.30  2000/11/14 10:48:57  kowal2
  71 Correct material used for TSA4. Thanks to J. Barbosa.
  72
  73 Revision 1.29  2000/11/06 17:24:10  kowal2
  74 Corrected bug in the outer containment vessel and
  75 the outer field cage geometry.
  76 Thanks to J. Barbosa.
  77
  78 Revision 1.28  2000/11/02 16:55:24  kowal2
  79 Corrected bug in the inner containment vessel geometry.
  80 Thanks to J. Belikov
  81
  82 Revision 1.27  2000/11/02 07:24:11  kowal2
  83 Correction in the TPC geometry.
  84 Changes due to the new hit structure.
  85
  86 Revision 1.26  2000/10/05 16:16:29  kowal2
  87 Corrections of the hit recording algorithm.
  88
  89 Revision 1.25  2000/10/02 21:28:18  fca
  90 Removal of useless dependecies via forward declarations
  91
  92 Revision 1.24  2000/08/28 10:02:30  kowal2
  93 Corrected bug in the StepManager
  94
  95 Revision 1.23  2000/07/10 20:57:39  hristov
  96 Update of TPC code and macros by M.Kowalski
  97
  98 Revision 1.22  2000/06/30 12:07:50  kowal2
  99 Updated from the TPC-PreRelease branch
 100
 101 Revision 1.21.2.4  2000/06/26 07:39:42  kowal2
 102 Changes to obey the coding rules
 103
 104 Revision 1.21.2.3  2000/06/25 08:38:41  kowal2
 105 Splitted from AliTPCtracking
 106
 107 Revision 1.21.2.2  2000/06/16 12:58:13  kowal2
 108 Changed parameter settings
 109
 110 Revision 1.21.2.1  2000/06/09 07:15:07  kowal2
 111
 112 Defaults loaded automatically (hard-wired)
 113 Optional parameters can be set via macro called in the constructor
 114
 115 Revision 1.21  2000/05/15 10:00:30  kowal2
 116 Corrected bug in the TPC geometry, thanks to Ivana Hrivnacova
 117
 118 Revision 1.20  2000/04/17 09:37:33  kowal2
 119 removed obsolete AliTPCDigitsDisplay.C
 120
 121 Revision 1.19.8.2  2000/04/10 08:31:52  kowal2
 122
 123 Different geometry for different sectors
 124 Updated readout chambers
 125 Some modifications to StepManager by J.Belikov
 126
 127 Revision 1.19.8.1  2000/04/10 07:56:53  kowal2
 128 Not used anymore - removed
 129
 130 Revision 1.19  1999/11/04 17:28:07  fca
 131 Correct barrel part of HV Degrader
 132
 133 Revision 1.18  1999/10/14 16:52:08  fca
 134 Only use PDG codes and not GEANT ones
 135
 136 Revision 1.17  1999/10/08 06:27:23  fca
 137 Corrected bug in the HV degrader geometry, thanks to G.Tabary
 138
 139 Revision 1.16  1999/10/04 13:39:54  fca
 140 Correct array index problem
 141
 142 Revision 1.15  1999/09/29 09:24:34  fca
 143 Introduction of the Copyright and cvs Log
 144
 145 */
 146
 147 //
 148 ///////////////////////////////////////////////////////////////////////////////
 149 //                                                                           //
 150 //  Time Projection Chamber version 2 -- detailed TPC and slow simulation    //
 151 //                                                                           //
 152 //Begin_Html
 153 /*
 154 <img src="picts/AliTPCv2Class.gif">
 155 */
 156 //End_Html
 157 //                                                                           //
 158 //                                                                           //
 159 ///////////////////////////////////////////////////////////////////////////////
 160
 161 #include <stdlib.h>
 162
 163 #include <TMath.h>
 164 #include <TPDGCode.h>
 165
 166 #include "AliConst.h"
 167 #include "AliRun.h"
 168 #include "AliTPCDigitsArray.h"
 169 #include "AliTPCParam.h"
 170 #include "AliTPCParamSR.h"
 171 #include "AliTPCTrackHitsV2.h"
 172 #include "AliTPCv2.h"
 173 #include "TLorentzVector.h"
 174
 175 ClassImp(AliTPCv2)
 176
 177 //_____________________________________________________________________________
 178 AliTPCv2::AliTPCv2(const char *name, const char *title) :
 179   AliTPC(name, title)
 180 {
 181   //
 182   // Standard constructor for Time Projection Chamber version 2
 183   //
 184   fIdSens=0;
 185   fIdLSec=0;
 186   fIdUSec=0;
 187
 188   SetBufferSize(128000);
 189
 190   SetGasMixt(2,20,10,-1,0.9,0.1,0.); // Ne-CO2 90-10
 191
 192   // Default sectors
 193
 194   SetSecAL(4);
 195   SetSecAU(4);
 196   SetSecLows(1,  2,  3, 19, 20, 21);
 197   SetSecUps(37, 38, 39, 37+18, 38+18, 39+18, -1, -1, -1, -1, -1, -1);
 198   SetSens(1); // sensitive strips set
 199
 200   if (fTPCParam)
 201      fTPCParam->Write(fTPCParam->GetTitle());
 202 }
 203
 204 //_____________________________________________________________________________
 205 void AliTPCv2::CreateGeometry()
 206 {
 207   //
 208   // Create the geometry of Time Projection Chamber version 2
 209   //
 210   //Begin_Html
 211   /*
 212     <img src="picts/AliTPC.gif">
 213   */
 214   //End_Html
 215   //Begin_Html
 216   /*
 217     <img src="picts/AliTPCv2Tree.gif">
 218   */
 219   //End_Html
 220
 221
 222   Int_t *idtmed = fIdtmed->GetArray();
 223
 224   Float_t dm[50];
 225   Int_t idrotm[120];
 226
 227   Int_t nRotMat = 0;
 228
 229   Int_t i,ifl1=0;
 230
 231   // number of sectors
 232
 233   Int_t nInnerSector = fTPCParam->GetNInnerSector()/2;
 234   Int_t nOuterSector = fTPCParam->GetNOuterSector()/2;
 235
 236   // ---------------------------------------------------
 237   //        sector specification check
 238   // ---------------------------------------------------
 239   if (fSecAL >= 0) {
 240     ifl1 = 0;
 241
 242     for (i = 0; i < 6; ++i) {
 243       if (fSecLows[i] >= 0 && fSecLows[i] < 2*nInnerSector) {
 244         ifl1 = 1;
 245         printf("%s: *** SECTOR %d selected\n",ClassName(),fSecLows[i]);
 246       }
 247     }
 248
 249   } else {
 250     printf("%s: *** ALL LOWER SECTORS SELECTED ***\n",ClassName());
 251     ifl1 = 1;
 252   }
 253
 254   if (ifl1 == 0) {
 255     printf("%s: *** ERROR: AT LEAST ONE LOWER SECTOR MUST BE SPECIFIED ***\n",ClassName());
 256     printf("%s: !!! PROGRAM STOPPED !!!\n",ClassName());
 257     exit(1);
 258   }
 259
 260   if (fSecAU >= 0) {
 261
 262     for (i = 0; i < 12; ++i) {
 263       if (fSecUps[i] > 2*nInnerSector-1 &&
 264           fSecUps[i] < 2*(nInnerSector+nOuterSector)) {
 265         printf("%s: *** SECTOR %d selected\n",ClassName(),fSecUps[i]);
 266       }
 267     }
 268
 269   } else {
 270     printf("%s: *** ALL UPPER SECTORS SELECTED ***\n",ClassName());
 271   }
 272
 273
 274
 275   //--------------------------------------------------------------------
 276
 277   //
 278   //  Mother volume TPC (Air) - all volumes will be positioned in it
 279   //
 280
 281   dm[0]=0.;
 282   dm[1]=360.;
 283   dm[2]=8.;
 284
 285   //
 286
 287   dm[3]=-283.7;
 288   dm[4]=65.6;
 289   dm[5]=278.;
 290
 291   //
 292
 293   dm[6]=-253.6;
 294   dm[7]=65.6;
 295   dm[8]=278.;
 296
 297   //
 298
 299   dm[9]=-73.3;
 300   dm[10]=60.9;
 301   dm[11]=278.;
 302
 303   //
 304
 305   dm[12]=-73.3;
 306   dm[13]=56.9;
 307   dm[14]=278.;
 308
 309   //
 310
 311   dm[15]=73.3;
 312   dm[16]=56.9;
 313   dm[17]=278.;
 314
 315   //
 316
 317   dm[18]=73.3;
 318   dm[19]=60.9;
 319   dm[20]=278.;
 320
 321   //
 322
 323   dm[21]=253.6;
 324   dm[22]=65.6;
 325   dm[23]=278.;
 326
 327   //
 328
 329   dm[24]=283.7;
 330   dm[25]=65.6;
 331   dm[26]=278.;
 332
 333   gMC->Gsvolu("TPC ","PCON",idtmed[0],dm,27);
 334
 335   // outer part
 336
 337   //-------------------------------------------------------------------
 338   //   Tpc Outer INsulator (CO2) - contains cont. vessel and field cage
 339   //-------------------------------------------------------------------
 340
 341   dm[0]= 0.;
 342   dm[1]= 360.;
 343   dm[2]= 6.;
 344
 345   //
 346
 347   dm[3]=-253.6;
 348   dm[4]=258.;
 349   dm[5]=275.5;
 350
 351   //
 352
 353   dm[6]=-250.6;
 354   dm[7]=258.;
 355   dm[8]=275.5;
 356
 357   //
 358
 359   dm[9]=-250.6;
 360   dm[10]=258.;
 361   dm[11]=278.;
 362
 363   //
 364
 365   dm[12]=253.6;
 366   dm[13]=258.;
 367   dm[14]=278.;
 368
 369   //
 370
 371   dm[15]=253.6;
 372   dm[16]=264.8;
 373   dm[17]=278.;
 374
 375   //
 376
 377   dm[18]=256.6;
 378   dm[19]=264.8;
 379   dm[20]=278.;
 380
 381   gMC->Gsvolu("TOIN","PCON",idtmed[3],dm,21);
 382
 383   //----------------------------------------------------------------
 384   // Tpc Outer Contaiment Vessel
 385   //  mother volume - Al, daughters - composite (sandwich)
 386   //----------------------------------------------------------------
 387
 388   dm[0]=0.;
 389   dm[1]=360.;
 390   dm[2]=6.;
 391
 392   //
 393
 394   dm[3]=-250.6;
 395   dm[4]=270.4;
 396   dm[5]=278.;
 397
 398   //
 399
 400   dm[6]=-247.6;
 401   dm[7]=270.4;
 402   dm[8]=278.;
 403
 404   //
 405
 406   dm[9]=-247.6;
 407   dm[10]=274.8124;
 408   dm[11]=278.;
 409
 410   //
 411
 412   dm[12]=253.6;
 413   dm[13]=274.8124;
 414   dm[14]=278.;
 415
 416   //
 417
 418   dm[15]=253.6;
 419   dm[16]=264.8;
 420   dm[17]=278.;
 421
 422   //
 423
 424   dm[18]=256.6;
 425   dm[19]=264.8;
 426   dm[20]=278.;
 427
 428   gMC->Gsvolu("TOCV","PCON",idtmed[4],dm,21);
 429
 430   // Daughter volumes - sandwich
 431
 432   // Tpc SAndwich 1 - Al
 433
 434   dm[0]=274.8124;
 435   dm[1]=278.;
 436   dm[2]=252.1;
 437
 438   gMC->Gsvolu("TSA1","TUBE",idtmed[4],dm,3);
 439
 440   // Tpc SAndwich 2 - epoxy glue (I use Lexan)
 441
 442   dm[0] += 5.e-3;
 443   dm[1] -= 5.e-3;
 444
 445   gMC->Gsvolu("TSA2","TUBE",idtmed[14],dm,3);
 446
 447   // Tpc SAndwich 3 - Tedlar
 448
 449   dm[0] += 0.01;
 450   dm[1] -= 0.01;
 451
 452   gMC->Gsvolu("TSA3","TUBE",idtmed[9],dm,3);
 453
 454
 455   // Tpc SAndwich 4 - fiber glass (G10)
 456
 457   dm[0] += 3.8e-3;
 458   dm[1] -= 3.8e-3;
 459
 460   gMC->Gsvolu("TSA4","TUBE",idtmed[12],dm,3);
 461
 462   // Tpc SAndwich 5 - NOMEX honeycomb
 463
 464   dm[0] += 0.075;
 465   dm[1] -= 0.075;
 466
 467   gMC->Gsvolu("TSA5","TUBE",idtmed[6],dm,3);
 468
 469   // 5->4->3->2->1->TCOV
 470
 471
 472   gMC->Gspos("TSA5",1,"TSA4",0.,0.,0.,0,"ONLY");
 473   gMC->Gspos("TSA4",1,"TSA3",0.,0.,0.,0,"ONLY");
 474   gMC->Gspos("TSA3",1,"TSA2",0.,0.,0.,0,"ONLY");
 475   gMC->Gspos("TSA2",1,"TSA1",0.,0.,0.,0,"ONLY");
 476
 477   gMC->Gspos("TSA1",1,"TOCV",0.,0.,3.,0,"ONLY");
 478
 479   // TCOV-> TOIN
 480
 481   gMC->Gspos("TOCV",1,"TOIN",0.,0.,0.,0,"ONLY");
 482
 483   //-------------------------------------------------------
 484   //  Tpc Outer Field Cage
 485   //  mother volume - Al, daughters - composite (sandwich)
 486   //-------------------------------------------------------
 487
 488   dm[0]=0.;
 489   dm[1]=360.;
 490   dm[2]=6.;
 491
 492   //
 493
 494   dm[3]=-253.6;
 495   dm[4]=258.;
 496   dm[5]=275.5;
 497
 498   //
 499
 500   dm[6]=-250.6;
 501   dm[7]=258.;
 502   dm[8]=275.5;
 503
 504   //
 505
 506   dm[9]=-250.6;
 507   dm[10]=258.;
 508   dm[11]=260.0476;
 509
 510   //
 511
 512   dm[12]=250.6;
 513   dm[13]=258.;
 514   dm[14]=260.0476;
 515
 516   //
 517
 518   dm[15]=250.6;
 519   dm[16]=258.;
 520   dm[17]=269.6;
 521
 522   //
 523
 524   dm[18]=253.6;
 525   dm[19]=258.;
 526   dm[20]=269.6;
 527
 528   gMC->Gsvolu("TOFC","PCON",idtmed[4],dm,21);
 529
 530   // Daughter volumes
 531
 532   // Tpc SAndwich 6 - Tedlar
 533
 534   dm[0]= 258.;
 535   dm[1]= 260.0476;
 536   dm[2]= 252.1;
 537
 538   gMC->Gsvolu("TSA6","TUBE",idtmed[9],dm,3);
 539
 540   // Tpc SAndwich 7 - fiber glass
 541
 542   dm[0] += 3.8e-3;
 543   dm[1] -= 3.8e-3;
 544
 545   gMC->Gsvolu("TSA7","TUBE",idtmed[12],dm,3);
 546
 547
 548   // Tpc SAndwich 8 - NOMEX
 549
 550   dm[0] += 0.02;
 551   dm[1] -= 0.02;
 552
 553   gMC->Gsvolu("TSA8","TUBE",idtmed[6],dm,3);
 554
 555   // 8->7->6->TOFC
 556
 557   gMC->Gspos("TSA8",1,"TSA7",0.,0.,0.,0,"ONLY");
 558   gMC->Gspos("TSA7",1,"TSA6",0.,0.,0.,0,"ONLY");
 559   gMC->Gspos("TSA6",1,"TOFC",0.,0.,0.,0,"ONLY");
 560
 561   // TOFC->TOIN
 562   // TOFC overlaps with
 563
 564   gMC->Gspos("TOFC",1,"TOIN",0.,0.,0.,0,"ONLY");
 565
 566   // TOIN->TPC
 567
 568   gMC->Gspos("TOIN",1,"TPC ",0.,0.,0.,0,"ONLY");
 569
 570   // inner part
 571
 572   //--------------------------------------------------------------------
 573   // Tpc Inner INsulator (CO2) - inner f.c. will be placed there
 574   // Inner containment vessel will be placed directly in the TPC
 575   //--------------------------------------------------------------------
 576
 577   dm[0]=0.;
 578   dm[1]=360.;
 579   dm[2]=4.;
 580
 581   //
 582
 583   dm[3]=-253.6;
 584   dm[4]=65.9;
 585   dm[5]=79.2;
 586
 587   //
 588
 589   dm[6]=-73.3;
 590   dm[7]=61.2;
 591   dm[8]=79.2;
 592
 593   //
 594
 595   dm[9]=73.3;
 596   dm[10]=61.2;
 597   dm[11]=79.2;
 598
 599   //
 600
 601   dm[12]=253.6;
 602   dm[13]=65.9;
 603   dm[14]=79.2;
 604
 605   gMC->Gsvolu("TIIN","PCON",idtmed[3],dm,15);
 606
 607   // the middle part of the F.C. is thinner - carve out the strip - Ne-CO2
 608
 609   dm[0]=79.16;
 610   dm[1]=79.2;
 611   dm[2]=88.;
 612
 613   gMC->Gsvolu("TII1","TUBE",idtmed[1],dm,3);
 614
 615   gMC->Gspos("TII1",1,"TIIN",0.,0.,0.,0,"ONLY");
 616
 617   //-----------------------------------------------------
 618   // Tpc Inner Field Cage
 619   // mother volume - Al, daughters - composite (sandwich)
 620   //------------------------------------------------------
 621
 622   dm[0]=0.;
 623   dm[1]=360.;
 624   dm[2]=10.;
 625
 626   //
 627
 628   dm[3]=-253.6;
 629   dm[4]=70.3;
 630   dm[5]=79.2;
 631
 632   //
 633
 634   dm[6]=-250.6;
 635   dm[7]=70.3;
 636   dm[8]=79.2;
 637
 638   //
 639
 640   dm[9]=-250.6;
 641   dm[10]=77.0524;
 642   dm[11]=79.2;
 643
 644   //
 645
 646   dm[12]=-88.;
 647   dm[13]=77.0524;
 648   dm[14]=79.2;
 649
 650   //
 651
 652   dm[15]=-88.;
 653   dm[16]=77.0924;
 654   dm[17]=79.16;
 655
 656   //
 657
 658   dm[18]=88.;
 659   dm[19]=77.0924;
 660   dm[20]=79.16;
 661
 662   //
 663
 664   dm[21]=88.;
 665   dm[22]=77.0524;
 666   dm[23]=79.2;
 667
 668   //
 669
 670   dm[24]=250.6;
 671   dm[25]=77.0524;
 672   dm[26]=79.2;
 673
 674   //
 675
 676   dm[27]=250.6;
 677   dm[28]=70.3;
 678   dm[29]=79.2;
 679
 680   //
 681
 682   dm[30]=253.6;
 683   dm[31]=70.3;
 684   dm[32]=79.2;
 685
 686   gMC->Gsvolu("TIFC","PCON",idtmed[4],dm,33);
 687
 688   // daughter volumes - central part
 689
 690   // Tpc Sandwich 9 -Tedlar
 691
 692   dm[0]=77.0924;
 693   dm[1]=79.16;
 694   dm[2]=88.;
 695
 696   gMC->Gsvolu("TSA9","TUBE",idtmed[9],dm,3);
 697
 698   // Tpc Sandwich 10 - fiber glass (G10)
 699
 700   dm[0] += 3.8e-3;
 701   dm[1] -= 3.8e-3;
 702
 703   gMC->Gsvolu("TS10","TUBE",idtmed[12],dm,3);
 704
 705   // Tpc Sandwich 11 - NOMEX
 706
 707   dm[0] += 0.03;
 708   dm[1] -= 0.03;
 709
 710   gMC->Gsvolu("TS11","TUBE",idtmed[6],dm,3);
 711
 712   // 11->10->9->TIFC
 713
 714   gMC->Gspos("TS11",1,"TS10",0.,0.,0.,0,"ONLY");
 715   gMC->Gspos("TS10",1,"TSA9",0.,0.,0.,0,"ONLY");
 716
 717   gMC->Gspos("TSA9",1,"TIFC",0.,0.,0.,0,"ONLY");
 718
 719   // daughter volumes - outer parts (reinforced)
 720
 721   // Tpc Sandwich 12 -Tedlar
 722
 723   dm[0]=77.0524;
 724   dm[1]=79.2;
 725   dm[2]=82.05;
 726
 727   gMC->Gsvolu("TS12","TUBE",idtmed[9],dm,3);
 728
 729   // Tpc Sandwich 13 - fiber glass (G10)
 730
 731   dm[0] += 3.8e-3;
 732   dm[1] -= 3.8e-3;
 733
 734   gMC->Gsvolu("TS13","TUBE",idtmed[12],dm,3);
 735
 736   // Tpc Sandwich 14 - NOMEX
 737
 738   dm[0] += 0.07;
 739   dm[1] -= 0.07;
 740
 741   gMC->Gsvolu("TS14","TUBE",idtmed[6],dm,3);
 742
 743   // 14->13->12->TIFC
 744
 745   gMC->Gspos("TS14",1,"TS13",0.,0.,0.,0,"ONLY");
 746   gMC->Gspos("TS13",1,"TS12",0.,0.,0.,0,"ONLY");
 747
 748   gMC->Gspos("TS12",1,"TIFC",0.,0.,170.05,0,"ONLY");
 749   gMC->Gspos("TS12",2,"TIFC",0.,0.,-170.05,0,"ONLY");
 750
 751   // place this inside the inner insulator
 752
 753   gMC->Gspos("TIFC",1,"TIIN",0.,0.,0.,0,"ONLY");
 754
 755   // and now in the TPC...
 756
 757   gMC->Gspos("TIIN",1,"TPC ",0.,0.,0.,0,"ONLY");
 758
 759   //---------------------------------------------------------
 760   // Tpc Inner Containment vessel - Cones
 761   //---------------------------------------------------------
 762
 763   dm[0]=0.;
 764   dm[1]=360.;
 765   dm[2]=8.;
 766
 767   //
 768
 769   dm[3]=71.8;
 770   dm[4]=56.9;
 771   dm[5]=59.4;
 772
 773   //
 774
 775   dm[6]=73.;
 776   dm[7]=56.9;
 777   dm[8]=59.4;
 778
 779   //
 780
 781   dm[9]=73.;
 782   dm[10]=56.9;
 783   dm[11]=61.2;
 784
 785   //
 786
 787   dm[12]=73.3;
 788   dm[13]=56.9;
 789   dm[14]=61.2;
 790
 791   //
 792
 793   dm[15]=73.3;
 794   dm[16]=60.9;
 795   dm[17]=61.2;
 796
 797   //
 798
 799   dm[18]=253.6;
 800   dm[19]=65.6;
 801   dm[20]=65.9;
 802
 803   //
 804
 805   dm[21]=253.6;
 806   dm[22]=65.6;
 807   dm[23]=74.6;
 808
 809   //
 810
 811   dm[24]=256.6;
 812   dm[25]=65.6;
 813   dm[26]=74.6;
 814
 815   gMC->Gsvolu("TICC","PCON",idtmed[4],dm,27);
 816
 817   Float_t phi1,phi2,phi3,theta1,theta2,theta3; // rotation angles
 818
 819   // reflection matrix
 820
 821   theta1 = 90.;
 822   phi1   = 0.;
 823   theta2 = 90.;
 824   phi2   = 270.;
 825   theta3 = 180.;
 826   phi3   = 0.;
 827
 828   AliMatrix(idrotm[nRotMat], theta1, phi1, theta2, phi2, theta3, phi3);
 829
 830   gMC->Gspos("TICC",1,"TPC ",0.,0.,0.,0,"ONLY");
 831   gMC->Gspos("TICC",2,"TPC ",0.,0.,0.,idrotm[nRotMat],"ONLY");
 832
 833
 834   //---------------------------------------------------------
 835   // Tpc Inner Containment vessel - Middle part -Al
 836   //---------------------------------------------------------
 837
 838   dm[0]=0.;
 839   dm[1]=360.;
 840   dm[2]=6.;
 841
 842   //
 843
 844   dm[3]=-71.6;
 845   dm[4]=60.2;
 846   dm[5]=61.2;
 847
 848   //
 849
 850   dm[6]=-69.1;
 851   dm[7]=60.2;
 852   dm[8]=61.2;
 853
 854   //
 855
 856   dm[9]=-69.1;
 857   dm[10]=60.6224;
 858   dm[11]=61.2;
 859
 860   //
 861
 862   dm[12]=69.1;
 863   dm[13]=60.6224;
 864   dm[14]=61.2;
 865
 866   //
 867
 868   dm[15]=69.1;
 869   dm[16]=60.2;
 870   dm[17]=61.2;
 871
 872   //
 873
 874   dm[18]=71.6;
 875   dm[19]=60.2;
 876   dm[20]=61.2;
 877
 878   gMC->Gsvolu("TICM","PCON",idtmed[4],dm,21);
 879
 880   // Tpc Sandwich 15 - Al
 881
 882   dm[0]=60.6224;
 883   dm[1]=61.2;
 884   dm[2]=70.1;
 885
 886   gMC->Gsvolu("TS15","TUBE",idtmed[4],dm,3);
 887
 888   // Tpc Sandwich 16 -  epoxy glue
 889
 890   dm[0] += 5.e-3;
 891   dm[1] -= 5.e-3;
 892
 893   gMC->Gsvolu("TS16","TUBE",idtmed[14],dm,3);
 894
 895   // Tpc Sandwich 17 - Tedlar
 896
 897   dm[0] += 0.01;
 898   dm[1] -= 0.01;
 899
 900   gMC->Gsvolu("TS17","TUBE",idtmed[9],dm,3);
 901
 902   // Tpc Sandwich 18 - carbon fiber
 903
 904   dm[0] += 3.8e-3;
 905   dm[1] -= 3.8e-3;
 906
 907   gMC->Gsvolu("TS18","TUBE",idtmed[15],dm,3);
 908
 909   // Tpc Sandwich 19 - Nomex
 910
 911   dm[0] += 0.02;
 912   dm[1] -= 0.02;
 913
 914   gMC->Gsvolu("TS19","TUBE",idtmed[6],dm,3);
 915
 916   // 19->18->17->16->15-> TICM
 917
 918   gMC->Gspos("TS19",1,"TS18",0.,0.,0.,0,"ONLY");
 919   gMC->Gspos("TS18",1,"TS17",0.,0.,0.,0,"ONLY");
 920   gMC->Gspos("TS17",1,"TS16",0.,0.,0.,0,"ONLY");
 921   gMC->Gspos("TS16",1,"TS15",0.,0.,0.,0,"ONLY");
 922
 923   gMC->Gspos("TS15",1,"TICM ",0.,0.,0.,0,"ONLY");
 924
 925
 926   // TPc inner cont. vessel Joints
 927
 928   dm[0]=60.2;
 929   dm[1]=61.2;
 930   dm[2]=0.5;
 931
 932   gMC->Gsvolu("TPJ1","TUBE",idtmed[4],dm,3);
 933
 934   gMC->Gspos("TPJ1",1,"TPC ",0.,0.,72.3,0,"ONLY");
 935   gMC->Gspos("TPJ1",2,"TPC ",0.,0.,-72.3,0,"ONLY");
 936
 937   //
 938
 939   dm[0]=0.;
 940   dm[1]=360.;
 941   dm[2]=4.;
 942
 943   //
 944
 945   dm[3]=70.8;
 946   dm[4]=58.4;
 947   dm[5]=60.1;
 948
 949   //
 950
 951   dm[6]=71.2;
 952   dm[7]=58.4;
 953   dm[8]=60.1;
 954
 955   //
 956
 957   dm[9]=71.2;
 958   dm[10]=58.4;
 959   dm[11]=59.4;
 960
 961   //
 962
 963   dm[12]=71.6;
 964   dm[13]=58.4;
 965   dm[14]=59.4;
 966
 967   gMC->Gsvolu("TPJ2","PCON",idtmed[4],dm,15);
 968
 969   gMC->Gspos("TPJ2",1,"TPC ",0.,0.,0.,0,"ONLY");
 970   gMC->Gspos("TPJ2",2,"TPC ",0.,0.,0.,idrotm[nRotMat],"ONLY");
 971
 972
 973
 974   // Tpc Inner Containment vessel Seal (Viton, I use Lexan for a time being)
 975
 976   dm[0]=58.4;
 977   dm[1]=61.2;
 978   dm[2]=0.1;
 979
 980   gMC->Gsvolu("TICS","TUBE",idtmed[14],dm,3);
 981
 982   gMC->Gspos("TICS",1,"TPC ",0.,0.,71.7,0,"ONLY");
 983   gMC->Gspos("TICS",2,"TPC ",0.,0.,-71.7,0,"ONLY");
 984
 985   // TICM -> TPC
 986
 987   gMC->Gspos("TICM",1,"TPC ",0.,0.,0.,0,"ONLY");
 988
 989   //
 990
 991   nRotMat++; // prepare for the next rotation matrix
 992
 993   //---------------------------------------------------------
 994   //  Tpc Dift Gas volume Nonsensitive (Ne-CO2 90/10)
 995   //  and its daughters (HV membrane, rods, readout chambers)
 996   //---------------------------------------------------------
 997
 998   dm[0]= 79.2;
 999   dm[1]= 258.0;
1000   dm[2]= 253.6;
1001
1002   gMC->Gsvolu("TDGN","TUBE",idtmed[1],dm,3);
1003
1004   // sector opening angles
1005
1006   Float_t innerOpenAngle = fTPCParam->GetInnerAngle();
1007   Float_t outerOpenAngle = fTPCParam->GetOuterAngle();
1008
1009   // sector angle shift
1010
1011   Float_t innerAngleShift = fTPCParam->GetInnerAngleShift();
1012
1013
1014   // All above parameters are identical for inner and outer
1015   // sectors. The distinction is kept for the historical reasons
1016   // and eventually will disappear.
1017
1018   Float_t tanAlpha = TMath::Tan(0.5*innerOpenAngle);
1019   Float_t cosAlpha = TMath::Sqrt(1.+tanAlpha*tanAlpha);
1020   Float_t space;
1021
1022   //-------------------------------------------------------------------------
1023   //   Tpc Inner Readout Chambers
1024   //-------------------------------------------------------------------------
1025
1026   dm[0]= 14.483;
1027   dm[1]= 23.3345;
1028   dm[2]= 1.6; // thickness
1029   dm[3]= 25.1;
1030
1031   gMC->Gsvolu("TIRC","TRD1",idtmed[4],dm,4);
1032
1033   // this volume will be positioned in the empty space
1034   // of the end-cap to avoid overlaps
1035
1036   dm[0]= 13.7305;
1037   dm[1]= 21.1895;
1038   dm[2]= 2.25;
1039   dm[3]= 21.15;
1040
1041   gMC->Gsvolu("TIC1","TRD1",idtmed[4],dm,4);
1042
1043
1044   //------------------------------------------------
1045   // Tpc Inner readout chamber Pad Plane
1046   //------------------------------------------------
1047
1048   dm[0]= 14.483;
1049   dm[1]= 23.3345;
1050   dm[2]= 0.5;
1051   dm[3]= 25.1;
1052
1053   gMC->Gsvolu("TIPP","TRD1",idtmed[12],dm,4);
1054
1055   //
1056
1057   dm[0] -= 1.218511934;
1058   dm[1] -= 1.218511934;
1059   dm[2] = 0.35;
1060
1061   gMC->Gsvolu("TIC3","TRD1",idtmed[1],dm,4);
1062
1063   gMC->Gspos("TIC3",1,"TIPP",0.,0.15,0.,0,"ONLY");
1064
1065   gMC->Gspos("TIPP",1,"TIRC",0.,1.1,0.,0,"ONLY");
1066
1067
1068   //----------------------------------------------
1069   // Tpc Readout Chambers Empty spaces - for both
1070   // inner and outer sectors
1071   //----------------------------------------------
1072
1073   gMC->Gsvolu("TRCE","TRD1",idtmed[0],dm,0);
1074
1075   // Inner sector - 4 spaces
1076
1077
1078   dm[3] = 4.7625;
1079   dm[0] = 12.472;
1080
1081   Float_t rr = 90.52;
1082   Float_t zz;
1083
1084   zz= -12.7875;
1085
1086   space = rr*tanAlpha-dm[0];
1087
1088   for(Int_t nsLow=0;nsLow<4;nsLow++){
1089
1090     rr += 9.525;
1091     dm[1]= rr*tanAlpha - space;
1092
1093     dm[2]=0.8;
1094
1095     gMC->Gsposp("TRCE",nsLow+1,"TIRC",0.,-0.8,zz,0,"ONLY",dm,4);
1096
1097     //
1098
1099     dm[2] = 1.2;
1100
1101     gMC->Gsposp("TRCE",nsLow+5,"TIC1",0.,1.05,zz-2.1,0,"ONLY",dm,4);
1102
1103     rr += 0.4;
1104     dm[0] = rr*tanAlpha - space;
1105     zz += (0.4+9.525);
1106
1107   }
1108
1109   dm[0]= 12.472;
1110   // dm[1] - this is the dm[1] from the previous TRCE
1111   dm[2]= 1.05;
1112   dm[3]= 19.65;
1113
1114   gMC->Gsposp("TRCE",9,"TIC1",0.,-1.2,0.,0,"ONLY",dm,4);
1115
1116   //
1117   // TPc Space for Connectors
1118   //
1119
1120   dm[0]= .3;
1121   dm[1]= .3;
1122   dm[2]= 4.5;
1123
1124   gMC->Gsvolu("TPSC","BOX ",idtmed[0],dm,3);
1125
1126   // TPC Connectors
1127
1128   dm[0]= .25;
1129   dm[1]= .15;
1130   dm[2]= 3.75;
1131
1132   gMC->Gsvolu("TPCC","BOX ",idtmed[13],dm,3);
1133
1134   gMC->Gspos("TPCC",1,"TPSC",0.,0.15,0.,0,"ONLY");
1135
1136   zz = -12.7875;
1137
1138
1139   Float_t alpha;
1140   Float_t astep;
1141
1142   // inner part of the inner sector - 2 x 20 holes
1143
1144   astep = 20.00096874/19.;
1145
1146   alpha = 10.00048437-astep;
1147
1148   Float_t x1,x2;
1149
1150     x1 = 13.31175725;
1151     x1 -= 0.996357832;
1152
1153     x2 = 15.06180253;
1154     x2 -= 1.163028812;
1155
1156   Int_t ncon;
1157
1158   for(ncon=0;ncon<20;ncon++){
1159
1160     phi1 = 0.;
1161     theta1 = 90.+alpha;
1162     phi2=90.;
1163     theta2 = 90.;
1164     phi3 = (alpha>0) ? 0. : 180.;
1165     theta3 = TMath::Abs(alpha);
1166
1167     AliMatrix(idrotm[nRotMat], theta1, phi1, theta2, phi2, theta3, phi3);
1168
1169
1170
1171     gMC->Gspos("TPSC",ncon+1,"TIRC",x1,0.3,-12.7875,idrotm[nRotMat],"ONLY");
1172     gMC->Gspos("TPSC",ncon+21,"TIRC",x2,0.3,-2.8625,idrotm[nRotMat],"ONLY");
1173
1174
1175     x1 -= 1.296357833;
1176     x2 -= 1.463028812;
1177
1178     alpha -= astep;
1179     nRotMat++;
1180
1181   }
1182
1183   // outer part of the inner sector - 2 x 25 holes
1184
1185    astep = 20.00096874/24.;
1186    alpha = 10.00048437-astep;
1187
1188    x1 = 16.81184781;
1189    x1 -= 1.016295986;
1190
1191    x2 = 18.5618931;
1192    x2 -= 1.150914854;
1193
1194   for(ncon=0;ncon<25;ncon++){
1195
1196     phi1 = 0.;
1197     theta1 = 90.+alpha;
1198     phi2=90.;
1199     theta2 = 90.;
1200     phi3 = (alpha>0) ? 0. : 180.;
1201     theta3 = TMath::Abs(alpha);
1202
1203     AliMatrix(idrotm[nRotMat], theta1, phi1, theta2, phi2, theta3, phi3);
1204
1205
1206
1207     gMC->Gspos("TPSC",ncon+41,"TIRC",x1,0.3,7.0625,idrotm[nRotMat],"ONLY");
1208     gMC->Gspos("TPSC",ncon+66,"TIRC",x2,0.3,16.9875,idrotm[nRotMat],"ONLY");
1209
1210
1211     x1 -= 1.316295986;
1212     x2 -= 1.450914854;
1213
1214     alpha -= astep;
1215     nRotMat++;
1216
1217   }
1218
1219   //--------------------------------------------------------------------------
1220   //  TPC Outer Readout Chambers
1221   //  this is NOT a final design
1222   //--------------------------------------------------------------------------
1223
1224   dm[0]= 23.3875;
1225   dm[1]= 43.524;
1226   dm[2]= 1.5; //thickness
1227   dm[3]= 57.1;
1228
1229   gMC->Gsvolu("TORC","TRD1",idtmed[4],dm,4);
1230
1231   //------------------------------------------------
1232   // Tpc Outer readout chamber Pad Plane
1233   //------------------------------------------------
1234
1235   dm[2]= 0.5;
1236
1237   gMC->Gsvolu("TOPP","TRD1",idtmed[12],dm,4);
1238
1239   dm[0] -= 1.218511934;
1240   dm[1] -= 1.218511934;
1241   dm[2] = 0.35;
1242
1243   gMC->Gsvolu("TOC3","TRD1",idtmed[1],dm,4);
1244
1245   gMC->Gspos("TOC3",1,"TOPP",0.,0.15,0.,0,"ONLY");
1246
1247   gMC->Gspos("TOPP",1,"TORC",0.,1.0,0.,0,"ONLY");
1248
1249   // empty space
1250
1251   dm[0]= 21.035;
1252   dm[1]= 38.7205;
1253   dm[2]= 0.7;
1254   dm[3]= 50.15;
1255
1256   gMC->Gsposp("TRCE",10,"TORC",0.,-0.8,-2.15,0,"ONLY",dm,4);
1257
1258   dm[0]= 22.2935;
1259   dm[1]= 40.5085;
1260   dm[2]= 2.25;
1261   dm[3]= 51.65;
1262
1263   gMC->Gsvolu("TOC1","TRD1",idtmed[4],dm,4);
1264
1265   dm[0]= 21.35;
1266   dm[1]= 38.7205;
1267   dm[2]= 2.25;
1268   dm[3]= 50.15;
1269
1270   gMC->Gsposp("TRCE",11,"TOC1",0.,0.,0.,0,"ONLY",dm,4);
1271
1272   //-----------------------------------------------
1273   // Tpc Services Support Wheel
1274   //-----------------------------------------------
1275
1276   dm[0]=0.;
1277   dm[1]=360.;
1278   dm[2]=18.;
1279   dm[3]=2.;
1280
1281   dm[4]= -5.;
1282   dm[5]= 77.017;
1283   dm[6]= 255.267;
1284
1285   dm[7]= 5.;
1286   dm[8]= dm[5];
1287   dm[9]= dm[6];
1288
1289   gMC->Gsvolu("TSSW","PGON",idtmed[4],dm,10);
1290
1291   // Tpc Services Wheel Cover
1292
1293   dm[4]= -0.5;
1294   dm[7]= 0.5;
1295
1296   gMC->Gsvolu("TSWC","PGON",idtmed[4],dm,10);
1297
1298   // Tpc Service wheel Cover Empty space
1299
1300   dm[0]= 10.99;
1301   dm[1]= 39.599;
1302   dm[2]= .5;
1303   dm[3]= 81.125;
1304
1305   gMC->Gsvolu("TSCE","TRD1",idtmed[0],dm,4);
1306
1307   // Tpc services Wheel Empty Spaces
1308
1309   dm[0]= 13.18017507;
1310   dm[1]= 44.61045938;
1311   dm[2]= 4.;
1312   dm[3]= 89.125;
1313
1314   gMC->Gsvolu("TWES","TRD1",idtmed[0],dm,4);
1315
1316   // Tpc Services Wheel Bars
1317
1318   gMC->Gsvolu("TSWB","TRD1",idtmed[4],dm,0);
1319
1320   // bars-> TWES
1321
1322   dm[2]= 4.;
1323   dm[3]= .4;
1324
1325   dm[0]= 13.8149522;
1326   dm[1]= 13.95601379;
1327
1328   gMC->Gsposp("TSWB",1,"TWES",0.,0.,-85.125,0,"ONLY",dm,4);
1329
1330   dm[0]= 43.83462067;
1331   dm[1]= 43.97568225;
1332
1333   gMC->Gsposp("TSWB",2,"TWES",0.,0.,85.125,0,"ONLY",dm,4);
1334
1335   // TPc ELectronics - right now 30% X0 Si
1336
1337   dm[0]= 14.03813696;
1338   dm[1]= 43.3524075;
1339   dm[2]= 1.404;
1340   dm[3]= 83.125;
1341
1342   gMC->Gsvolu("TPEL","TRD1",idtmed[11],dm,4);
1343   gMC->Gspos("TPEL",1,"TWES",0.,0.,0.,0,"ONLY");
1344
1345   //--------------------------------------------------------------------------
1346   //  End caps
1347   //--------------------------------------------------------------------------
1348
1349   // TPc Main Wheel - Al
1350
1351   dm[0]= 74.9;
1352   dm[1]= 264.4;
1353   dm[2]= 3.0;
1354
1355   gMC->Gsvolu("TPMW","TUBE",idtmed[4],dm,3);
1356
1357   //--------------------------------------------------------------------------
1358   //  Tpc Empty Space for the Readout chambers
1359   //--------------------------------------------------------------------------
1360
1361   Float_t rLow= 86.2;
1362   Float_t rUp= 243.5;
1363   Float_t dR = 0.5*(rUp-rLow);
1364
1365   space= 1.5/cosAlpha; // wheel ribs are 3.0 cm wide
1366
1367   dm[0]= rLow*tanAlpha-space;
1368   dm[1]= rUp*tanAlpha-space;
1369   dm[2] = 3.0;
1370   dm[3]= dR;
1371
1372   gMC->Gsvolu("TESR","TRD1",idtmed[0],dm,4);
1373
1374   // TIC1->TESR
1375
1376   gMC->Gspos("TIC1",1,"TESR",0.,0.75,-dR+23.97,0,"ONLY");
1377
1378   // TOC1->TESR
1379
1380   gMC->Gspos("TOC1",1,"TESR",0.,0.75,dR-55.02,0,"ONLY");
1381
1382   // Tpc Empty Space Bars - Al (daughters of TESR)
1383
1384   Float_t zBar;
1385
1386   gMC->Gsvolu("TESB","TRD1",idtmed[4],dm,0);
1387
1388   // lower bar
1389
1390   dm[0]= rLow*tanAlpha-space;
1391   dm[1]= 88.7*tanAlpha-space;
1392   dm[2]= 2.25;
1393   dm[3]= 1.275;
1394
1395   zBar = -dR+dm[3];
1396
1397   gMC->Gsposp("TESB",1,"TESR",0.,0.75,zBar,0,"ONLY",dm,4);
1398
1399   // middle bar
1400
1401   dm[0]= 131.65*tanAlpha-space;
1402   dm[1]= 136.5*tanAlpha-space;
1403   dm[3]= 2.425;
1404
1405   zBar = -dR +131.65+dm[3]-rLow;
1406
1407   gMC->Gsposp("TESB",2,"TESR",0.,0.75,zBar,0,"ONLY",dm,4);
1408
1409   // upper bar
1410
1411   dm[0]= 240.4*tanAlpha-space;
1412   dm[1]= rUp*tanAlpha-space;
1413   dm[3]= 1.55;
1414
1415   zBar = dR-dm[3];
1416
1417   gMC->Gsposp("TESB",3,"TESR",0.,0.75,zBar,0,"ONLY",dm,4);
1418
1419   //------------------------------------------------------
1420   //  TPc Lower "S" Sectors
1421   //------------------------------------------------------
1422
1423
1424   Float_t inSecLowEdge = fTPCParam->GetInnerRadiusLow();
1425   Float_t inSecUpEdge =  fTPCParam->GetInnerRadiusUp();
1426
1427   dm[0] = inSecLowEdge*TMath::Tan(0.5*innerOpenAngle)-0.01;
1428   dm[1] = inSecUpEdge*TMath::Tan(0.5*innerOpenAngle)-0.01;
1429   dm[2] = 0.5*(250. - 5.e-3);
1430   dm[3] = 0.5*(inSecUpEdge-inSecLowEdge);
1431
1432   gMC->Gsvolu("TPLS", "TRD1", idtmed[2], dm, 4); // sensitive
1433
1434
1435   //----------------------------------------------------------
1436   //  TPc Upper Sectors
1437   //----------------------------------------------------------
1438
1439   Float_t ouSecLowEdge = fTPCParam->GetOuterRadiusLow();
1440   Float_t ouSecUpEdge = fTPCParam->GetOuterRadiusUp();
1441
1442   dm[0] = ouSecLowEdge*TMath::Tan(0.5*outerOpenAngle)-0.01;
1443   dm[1] = ouSecUpEdge*TMath::Tan(0.5*outerOpenAngle)-0.01;
1444   dm[2] = 0.5*(250. - 5.e-3);
1445   dm[3] = 0.5*(ouSecUpEdge-ouSecLowEdge);
1446
1447   gMC->Gsvolu("TPUS", "TRD1", idtmed[2], dm, 4); // sensitive
1448
1449
1450
1451   // sensitive strips
1452
1453     gMC->Gsvolu("TPSS","TRD1",idtmed[2],dm,0); // sensitive
1454
1455     Int_t nofStrips,nstr;
1456     Float_t r1,r2,zs;
1457     Float_t stripThick = 0.01; // 100 microns
1458     Float_t deadSpace;
1459
1460     // inner sector
1461
1462
1463     // if all lower sectors selected define only 1 strip
1464
1465     nofStrips=((fSecAL <0)||(fSecAL>=0 && fSens<0)) ? 1 : fTPCParam->GetNRowLow();
1466     deadSpace = fTPCParam->GetInnerWireMount();
1467
1468     dm[2] = 0.5*(250. - 5.e-3);
1469     dm[3] = 0.5 * stripThick;
1470
1471     for(nstr=0;nstr<nofStrips;nstr++){
1472
1473       r1 = fTPCParam->GetPadRowRadiiLow(nstr);
1474       r2 = r1 + stripThick;
1475       dm[0] = r1 * TMath::Tan(0.5*innerOpenAngle) - deadSpace;
1476       dm[1] = r2 * TMath::Tan(0.5*innerOpenAngle) - deadSpace;
1477       zs = -inSecLowEdge -0.5*(inSecUpEdge-inSecLowEdge);
1478       zs += r1;
1479       zs += dm[3];
1480
1481       gMC->Gsposp("TPSS", nstr+1, "TPLS", 0., 0., zs, 0, "ONLY", dm, 4);
1482
1483
1484     }
1485
1486     // strips only if several upper sectors selected end fSens > 0
1487
1488     if(fSecAU >=0 && fSens >0){
1489
1490     Int_t nsSave = nofStrips;
1491
1492     // outer sector
1493
1494     nofStrips = fTPCParam->GetNRowUp();
1495     deadSpace = fTPCParam->GetOuterWireMount();
1496
1497     dm[2] = 0.5*(250. - 5.e-3);
1498     dm[3] = 0.5 * stripThick;
1499
1500
1501     for(nstr=0;nstr<nofStrips;nstr++){
1502
1503       r1 = fTPCParam->GetPadRowRadiiUp(nstr);
1504       r2 = r1 + stripThick;
1505       dm[0] = r1 * TMath::Tan(0.5*outerOpenAngle) - deadSpace;
1506       dm[1] = r2 * TMath::Tan(0.5*outerOpenAngle) - deadSpace;
1507       zs = -ouSecLowEdge -0.5*(ouSecUpEdge-ouSecLowEdge);
1508       zs += r1;
1509       zs += dm[3];
1510
1511       gMC->Gsposp("TPSS", nstr+1+nsSave, "TPUS", 0., 0., zs, 0, "ONLY", dm, 4);
1512
1513      }
1514     }
1515
1516
1517   //-------------------------------------------------------
1518   //  positioning of the empty spaces into the main wheel
1519   //  and readout chambers and sectors into the drift gas
1520   //-------------------------------------------------------
1521
1522   Float_t rCenter,xc,yc;
1523   Float_t rInner,rOuter; // center of the inner and outer chamber
1524
1525   rCenter = rLow+dR;
1526
1527   rInner = 108.07;
1528   rOuter = 190.68;
1529
1530
1531   for(Int_t ns=0; ns<nInnerSector;ns++){
1532
1533     phi1 = ns * innerOpenAngle + innerAngleShift;
1534     phi1 *= kRaddeg; // in degrees
1535
1536     phi1 = (Float_t)TMath::Nint(phi1) + 270.;
1537
1538     if (phi1 > 360.) phi1 -= 360.;
1539
1540     theta1 = 90.;
1541     phi2   = 90.;
1542     theta2 = 180.;
1543     phi3   = ns * innerOpenAngle + innerAngleShift;
1544     phi3 *= kRaddeg; // in degrees
1545
1546     phi3 = (Float_t)TMath::Nint(phi3);
1547
1548     if(phi3 > 360.) phi3 -= 360.;
1549
1550     theta3 = 90.;
1551
1552     // "holes"->End plate
1553
1554     xc = rCenter*TMath::Cos(phi3*kDegrad);
1555     yc = rCenter*TMath::Sin(phi3*kDegrad);
1556
1557     AliMatrix(idrotm[nRotMat], theta1, phi1, theta2, phi2, theta3, phi3);
1558
1559     gMC->Gspos("TESR",ns+1,"TPMW",xc,yc,0.,idrotm[nRotMat],"ONLY");
1560
1561     // TSCE->TSWC (services wheel volumes)
1562
1563     xc = 166.142*TMath::Cos(phi3*kDegrad);
1564     yc = 166.142*TMath::Sin(phi3*kDegrad);
1565
1566     gMC->Gspos("TSCE",ns+1,"TSWC",xc,yc,0.,idrotm[nRotMat],"ONLY");
1567     gMC->Gspos("TWES",ns+1,"TSSW",xc,yc,0.,idrotm[nRotMat],"ONLY");
1568
1569
1570     // readout chambers->TDGN (drift gas)
1571
1572     xc = rInner*TMath::Cos(phi3*kDegrad);
1573     yc = rInner*TMath::Sin(phi3*kDegrad);
1574
1575     gMC->Gspos("TIRC",ns+1,"TDGN",xc,yc,252.,idrotm[nRotMat],"ONLY");
1576
1577     // here lower sectors
1578
1579     if(fSecAL <0){
1580
1581       // all lower sectors are positioned
1582
1583       gMC->Gspos("TPLS",ns+1,"TDGN",xc,yc,125.0025,idrotm[nRotMat],"ONLY");
1584       gMC->
1585         Gspos("TPLS",ns+nInnerSector+1,"TDGN",xc,yc,-125.0025,idrotm[nRotMat],"ONLY");
1586     }
1587     else{
1588
1589       // only selected sectors are positioned (up to 6 sectors)
1590
1591       for(Int_t sel=0;sel<6;sel++){
1592
1593         if(fSecLows[sel] == ns){
1594           gMC->Gspos("TPLS",ns+1,"TDGN",xc,yc,125.0025,idrotm[nRotMat],"ONLY");
1595         }
1596         else if(fSecLows[sel] == ns+nInnerSector){
1597          gMC->
1598          Gspos("TPLS",ns+nInnerSector+1,"TDGN",xc,yc,-125.0025,idrotm[nRotMat],"ONLY");
1599         }
1600       }
1601     } // lower sectors finished
1602
1603
1604     xc = rOuter*TMath::Cos(phi3*kDegrad);
1605     yc = rOuter*TMath::Sin(phi3*kDegrad);
1606
1607     gMC->Gspos("TORC",ns+1,"TDGN",xc,yc,252.1,idrotm[nRotMat],"ONLY");
1608
1609     // here upper sectors
1610
1611     if(fSecAU <0){
1612
1613       // all upper sectors
1614
1615       gMC->Gspos("TPUS",ns+1,"TDGN",xc,yc,125.0025,idrotm[nRotMat],"ONLY");
1616       gMC->
1617         Gspos("TPUS",ns+nOuterSector+1,"TDGN",xc,yc,-125.0025,idrotm[nRotMat],"ONLY");
1618     }
1619     else{
1620
1621       // only selected sectors (up to 12)
1622
1623       for(Int_t sel=0;sel<12;sel++){
1624         if(fSecUps[sel] == ns+2*nInnerSector){
1625           gMC->Gspos("TPUS",ns+1,"TDGN",xc,yc,125.0025,idrotm[nRotMat],"ONLY");
1626         }
1627         else if(fSecUps[sel] == ns+2*nInnerSector+nOuterSector){
1628          gMC->
1629           Gspos("TPUS",ns+nOuterSector+1,"TDGN",xc,yc,-125.0025,idrotm[nRotMat],"ONLY");
1630         }
1631       }
1632     } // upper sectors finished
1633
1634
1635     nRotMat++;
1636
1637     theta2 = 0.; // reflection
1638
1639     AliMatrix(idrotm[nRotMat], theta1, phi1, theta2, phi2, theta3, phi3);
1640
1641     xc = rInner*TMath::Cos(phi3*kDegrad);
1642     yc = rInner*TMath::Sin(phi3*kDegrad);
1643
1644     gMC->Gspos("TIRC",ns+nInnerSector+1,"TDGN",xc,yc,-252.,idrotm[nRotMat],"ONLY");
1645
1646     xc = rOuter*TMath::Cos(phi3*kDegrad);
1647     yc = rOuter*TMath::Sin(phi3*kDegrad);
1648
1649     gMC->Gspos("TORC",ns+nOuterSector+1,"TDGN",xc,yc,-252.1,idrotm[nRotMat],"ONLY");
1650
1651     nRotMat++;
1652
1653   }
1654   // TPMW->TPC
1655
1656   gMC->Gspos("TPMW",1,"TPC ",0.,0.,256.6,0,"ONLY");
1657   gMC->Gspos("TPMW",2,"TPC ",0.,0.,-256.6,idrotm[0],"ONLY");
1658
1659   //---------------------------------------------------------
1660   //  Tpc High Voltage Membrane - 100 microns of mylar
1661   //---------------------------------------------------------
1662
1663   dm[0]=82.8;
1664   dm[1]=252.;
1665   dm[2]=0.005;
1666
1667   gMC->Gsvolu("THVM","TUBE",idtmed[8],dm,3);
1668
1669   gMC->Gspos("THVM",1,"TDGN",0.,0.,0.,0,"ONLY");
1670
1671   // Tpc High Voltage membrane Holders
1672
1673   gMC->Gsvolu("THVH","TUBE",idtmed[4],dm,0);
1674
1675
1676
1677   // inner
1678
1679   dm[0]=79.3;
1680   dm[1]=82.8;
1681   dm[2]=0.2;
1682
1683   gMC->Gsposp("THVH",1,"TDGN",0.,0.,0.,0,"ONLY",dm,3);
1684
1685   // outer
1686
1687   dm[0]= 252.;
1688   dm[1]= 257.9;
1689   dm[2]= 0.4;
1690
1691   gMC->Gsposp("THVH",2,"TDGN",0.,0.,0.,0,"ONLY",dm,3);
1692
1693   //----------------------------------------------------------
1694   // TPc Support Rods - MAKROLON
1695   //----------------------------------------------------------
1696
1697   dm[0]= 0.9;
1698   dm[1]= 1.2;
1699
1700   gMC->Gsvolu("TPSR","TUBE",idtmed[7],dm,0); // inner and outer rods differ
1701
1702
1703   for(Int_t nrod=0;nrod<18;nrod++){
1704     Float_t angle=innerOpenAngle*(Float_t)nrod;
1705
1706     xc=81.5*TMath::Cos(angle);
1707     yc=81.5*TMath::Sin(angle);
1708
1709     dm[2]=126.7;
1710
1711     gMC->Gsposp("TPSR",nrod+1,"TDGN",xc,yc,126.9,0,"ONLY",dm,3);
1712     gMC->Gsposp("TPSR",nrod+19,"TDGN",xc,yc,-126.9,0,"ONLY",dm,3);
1713
1714     dm[2]=126.6;
1715
1716     xc=254.25*TMath::Cos(angle);
1717     yc=254.25*TMath::Sin(angle);
1718
1719     // rod number 54 contans the HV cable
1720
1721     if(nrod<17) {
1722       gMC->Gsposp("TPSR",nrod+37,"TDGN",xc,yc,127.,0,"ONLY",dm,3);
1723       gMC->Gsposp("TPSR",nrod+54,"TDGN",xc,yc,-127.,0,"ONLY",dm,3);
1724     }
1725
1726   }
1727
1728   //----------------------------------------------------------
1729   // Tpc High Voltage Rod - MAKROLON + Copper cable
1730   //----------------------------------------------------------
1731
1732   // rod with cable (Left)
1733
1734   dm[0]=0.;
1735   dm[1]=2.25;
1736   dm[2]=126.6;
1737
1738   gMC->Gsvolu("THVL","TUBE",idtmed[7],dm,3);
1739
1740   // HV cable
1741
1742   dm[0]=0.;
1743   dm[1]=0.3;
1744   dm[2]=126.6;
1745
1746   gMC->Gsvolu("THVC","TUBE",idtmed[10],dm,3);
1747
1748   // empty space
1749
1750   dm[0]=0.3;
1751   dm[1]=1.;
1752   dm[2]=126.6;
1753
1754   gMC->Gsvolu("THVE","TUBE",idtmed[1],dm,3);
1755
1756   gMC->Gspos("THVC",1,"THVL",0.,0.,0.,0,"ONLY");
1757   gMC->Gspos("THVE",1,"THVL",0.,0.,0.,0,"ONLY");
1758
1759   // rod without cable
1760
1761   dm[0]=1.8;
1762   dm[1]=2.25;
1763   dm[2]=126.6;
1764
1765   gMC->Gsvolu("THVR","TUBE",idtmed[7],dm,3);
1766
1767   gMC->Gspos("THVL",1,"TDGN",xc,yc,-127.,0,"ONLY");
1768   gMC->Gspos("THVR",1,"TDGN",xc,yc,127.,0,"ONLY");
1769
1770   gMC->Gspos("TDGN",1,"TPC ",0.,0.,0.,0,"ONLY");
1771
1772   // services wheel cover -> wheel
1773
1774
1775   gMC->Gspos("TSWC",1,"TSSW",0.,0.,4.5,0,"ONLY");
1776   gMC->Gspos("TSWC",2,"TSSW",0.,0.,-4.5,0,"ONLY");
1777
1778
1779   // put the wheel into the TPC
1780
1781   gMC->Gspos("TSSW",1,"TPC ",0.,0.,278.7,0,"ONLY");
1782   gMC->Gspos("TSSW",2,"TPC ",0.,0.,-278.7,0,"ONLY");
1783
1784   //
1785
1786   gMC->Gsord("TPMW",6);
1787   gMC->Gsord("TSSW",6);
1788   gMC->Gsord("TSWC",6);
1789   if(fSecAL >=0)  gMC->Gsord("TPLS",3);
1790   if(fSecAU >=0 && fSens >0)  gMC->Gsord("TPUS",3);
1791   gMC->Gsord("TDGN",6);
1792
1793   // put the TPC into ALIC (main mother volume)
1794
1795   gMC->Gspos("TPC ",1,"ALIC",0.,0.,0.,0,"ONLY");
1796
1797
1798
1799 } // end of function
1800
1801 //_____________________________________________________________________________
1802 void AliTPCv2::DrawDetector()
1803 {
1804   //
1805   // Draw a shaded view of the Time Projection Chamber version 1
1806   //
1807
1808   // Set everything unseen
1809   gMC->Gsatt("*", "seen", -1);
1810   //
1811   // Set ALIC mother transparent
1812   gMC->Gsatt("ALIC","SEEN",0);
1813   //
1814   // Set the volumes visible
1815   //
1816
1817   gMC->Gsatt("TPC ","SEEN",0);
1818   gMC->Gsatt("TOIN","SEEN",1);
1819   gMC->Gsatt("TOIN","COLO",7);
1820   gMC->Gsatt("TOCV","SEEN",1);
1821   gMC->Gsatt("TOCV","COLO",4);
1822   gMC->Gsatt("TSA1","SEEN",0);
1823   gMC->Gsatt("TSA2","SEEN",0);
1824   gMC->Gsatt("TSA3","SEEN",0);
1825   gMC->Gsatt("TSA4","SEEN",0);
1826   gMC->Gsatt("TSA5","SEEN",0);
1827   gMC->Gsatt("TOFC","SEEN",1);
1828   gMC->Gsatt("TOFC","COLO",4);
1829   gMC->Gsatt("TSA6","SEEN",0);
1830   gMC->Gsatt("TSA7","SEEN",0);
1831   gMC->Gsatt("TSA8","SEEN",0);
1832   gMC->Gsatt("TIIN","SEEN",1);
1833   gMC->Gsatt("TIIN","COLO",7);
1834   gMC->Gsatt("TII1","SEEN",0);
1835   gMC->Gsatt("TIFC","SEEN",1);
1836   gMC->Gsatt("TIFC","COLO",4);
1837   gMC->Gsatt("TSA9","SEEN",0);
1838   gMC->Gsatt("TS10","SEEN",0);
1839   gMC->Gsatt("TS11","SEEN",0);
1840   gMC->Gsatt("TS12","SEEN",0);
1841   gMC->Gsatt("TS13","SEEN",0);
1842   gMC->Gsatt("TS14","SEEN",0);
1843   gMC->Gsatt("TICC","SEEN",0);
1844   gMC->Gsatt("TICM","SEEN",0);
1845   gMC->Gsatt("TS15","SEEN",0);
1846   gMC->Gsatt("TS16","SEEN",0);
1847   gMC->Gsatt("TS17","SEEN",0);
1848   gMC->Gsatt("TS18","SEEN",0);
1849   gMC->Gsatt("TS19","SEEN",0);
1850   gMC->Gsatt("TPJ1","SEEN",0);
1851   gMC->Gsatt("TPJ2","SEEN",0);
1852   gMC->Gsatt("TICS","SEEN",0);
1853   gMC->Gsatt("TDGN","SEEN",0);
1854   gMC->Gsatt("TIRC","SEEN",0);
1855   gMC->Gsatt("TIC1","SEEN",1);
1856   gMC->Gsatt("TIPP","SEEN",0);
1857   gMC->Gsatt("TIC3","SEEN",0);
1858   gMC->Gsatt("TRCE","SEEN",0);
1859   gMC->Gsatt("TPSC","SEEN",0);
1860   gMC->Gsatt("TPCC","SEEN",0);
1861   gMC->Gsatt("TORC","SEEN",0);
1862   gMC->Gsatt("TOPP","SEEN",0);
1863   gMC->Gsatt("TOC3","SEEN",0);
1864   gMC->Gsatt("TOC1","SEEN",1);
1865   gMC->Gsatt("TSSW","SEEN",1);
1866   gMC->Gsatt("TSWC","SEEN",1);
1867   gMC->Gsatt("TSSW","COLO",3);
1868   gMC->Gsatt("TSWC","COLO",3);
1869   gMC->Gsatt("TSCE","COLO",6);
1870   gMC->Gsatt("TSCE","SEEN",1);
1871   gMC->Gsatt("TWES","SEEN",0);
1872   gMC->Gsatt("TSWB","SEEN",0);
1873   gMC->Gsatt("TPEL","SEEN",0);
1874   gMC->Gsatt("TPMW","SEEN",1);
1875   gMC->Gsatt("TESR","SEEN",1);
1876   gMC->Gsatt("TPMW","COLO",12);
1877   gMC->Gsatt("TIC1","COLO",5);
1878   gMC->Gsatt("TOC1","COLO",5);
1879   gMC->Gsatt("TESB","SEEN",0);
1880   gMC->Gsatt("THVM","SEEN",1);
1881   gMC->Gsatt("THVM","COLO",11);
1882   gMC->Gsatt("THVH","SEEN",0);
1883   gMC->Gsatt("TPSR","SEEN",0);
1884   gMC->Gsatt("THVL","SEEN",0);
1885   gMC->Gsatt("THVC","SEEN",0);
1886   gMC->Gsatt("THVE","SEEN",0);
1887   gMC->Gsatt("THVR","SEEN",0);
1888   gMC->Gsatt("TPSS","SEEN",0);
1889   gMC->Gsatt("TPUS","SEEN",0);
1890   gMC->Gsatt("TPLS","SEEN",0);
1891
1892   //
1893   gMC->Gdopt("hide", "on");
1894   gMC->Gdopt("shad", "on");
1895   gMC->Gsatt("*", "fill", 7);
1896   gMC->SetClipBox(".");
1897   gMC->SetClipBox("TPMW",-300,300,-300,300,254.,270.);
1898   gMC->SetClipBox("TESR",-300,300,-300,300,254.,270.);
1899   gMC->SetClipBox("TSSW",-300,300,-300,300,283.,284.);
1900   gMC->SetClipBox("TSWC",-300,300,-300,300,283.,284.);
1901   gMC->SetClipBox("*", 0, 300, -300, 300, -290, 290);
1902   gMC->DefaultRange();
1903   gMC->Gdraw("alic", 40, 30, 0, 12, 9.5, .025, .025);
1904   gMC->Gdhead(1111, "Time Projection Chamber");
1905   gMC->Gdman(18, 4, "MAN");
1906   gMC->Gdopt("hide","off");
1907 }
1908
1909 //_____________________________________________________________________________
1910 void AliTPCv2::CreateMaterials()
1911 {
1912   //
1913   // Define materials for version 2 of the Time Projection Chamber
1914   //
1915
1916   AliTPC::CreateMaterials();
1917 }
1918
1919 //_____________________________________________________________________________
1920 void AliTPCv2::Init()
1921 {
1922   //
1923   // Initialises version 2 of the TPC after that it has been built
1924   //
1925
1926   Int_t *idtmed = fIdtmed->GetArray();
1927
1928   AliTPC::Init();
1929
1930
1931
1932   fIdSens=gMC->VolId("TPSS");
1933
1934   fIdLSec=gMC->VolId("TPLS"); // lower sector
1935   fIdUSec=gMC->VolId("TPUS"); // upper sector
1936
1937   gMC->SetMaxNStep(30000); // max. number of steps increased
1938
1939   gMC->Gstpar(idtmed[2],"LOSS",5); // specific energy loss
1940
1941   printf("%s: *** TPC version 2 initialized ***\n",ClassName());
1942   printf("%s: Maximum number of steps = %d\n",ClassName(),gMC->GetMaxNStep());
1943
1944   //
1945
1946 }
1947
1948 //_____________________________________________________________________________
1949 void AliTPCv2::StepManager()
1950 {
1951   //
1952   // Called for every step in the Time Projection Chamber
1953   //
1954
1955   //
1956   // parameters used for the energy loss calculations
1957   //
1958   const Float_t kprim = 14.35; // number of primary collisions per 1 cm
1959   const Float_t kpoti = 20.77e-9; // first ionization potential for Ne/CO2
1960   const Float_t kwIon = 35.97e-9; // energy for the ion-electron pair creation
1961
1962
1963   const Float_t kbig = 1.e10;
1964
1965   Int_t id,copy;
1966   Float_t hits[4];
1967   Int_t vol[2];
1968   TLorentzVector p;
1969
1970   vol[1]=0; // preset row number to 0
1971
1972   //
1973
1974   gMC->SetMaxStep(kbig);
1975
1976   if(!gMC->IsTrackAlive()) return; // particle has disappeared
1977
1978   Float_t charge = gMC->TrackCharge();
1979
1980   if(TMath::Abs(charge)<=0.) return; // take only charged particles
1981
1982   // check the sensitive volume
1983
1984   id = gMC->CurrentVolID(copy); // current volume Id
1985
1986   if ( (gMC->IsTrackEntering() || gMC->IsTrackExiting()) &&
1987        ((id == fIdLSec) || (id == fIdUSec)) ) {
1988
1989     AddTrackReference(gAlice->CurrentTrack(), gMC);
1990   }
1991
1992   if(id == fIdLSec){
1993     vol[0] = copy-1; // lower sector number
1994   }
1995   else if(id == fIdUSec){
1996     vol[0] = copy+fTPCParam->GetNInnerSector()-1; // upper sector number
1997   }
1998   else if(id == fIdSens && gMC->IsTrackEntering()){
1999
2000     // track is entering the sensitive strip
2001
2002     vol[1]= copy-1; // row number (absolute)
2003
2004     // sector type
2005
2006     id = gMC->CurrentVolOffID(1,copy);
2007
2008     if(id == fIdLSec){
2009
2010       // lower sector
2011
2012       vol[0] = copy-1; // sector number
2013
2014     }
2015     else {
2016
2017       // upper sector
2018
2019       vol[0] = copy-1+fTPCParam->GetNInnerSector(); // sector number
2020       vol[1] -= fTPCParam->GetNRowLow(); // row number (starts also from 0)
2021
2022     }
2023
2024     if(vol[1] == 0){
2025
2026       // because Jouri wants to have this
2027
2028       gMC->TrackMomentum(p);
2029       hits[0]=p[0];
2030       hits[1]=p[1];
2031       hits[2]=p[2];
2032       hits[3]=0.; // this hit has no energy loss
2033       // new(lhits[fNhits++]) AliTPChit(fIshunt,gAlice->CurrentTrack(),vol,hits);
2034
2035       AddHit(gAlice->CurrentTrack(), vol,hits);  //MI change
2036
2037     }
2038
2039      gMC->TrackPosition(p);
2040      hits[0]=p[0];
2041      hits[1]=p[1];
2042      hits[2]=p[2];
2043      hits[3]=0.; // this hit has no energy loss
2044      // new(lhits[fNhits++]) AliTPChit(fIshunt,gAlice->CurrentTrack(),vol,hits);
2045
2046      AddHit(gAlice->CurrentTrack(), vol,hits);  //MI change
2047
2048   }
2049   else return;
2050
2051   //-----------------------------------------------------------------
2052   //  charged particle is in the sensitive volume
2053   //-----------------------------------------------------------------
2054
2055   if(gMC->TrackStep() > 0) {
2056
2057     Int_t nel = (Int_t)(((gMC->Edep())-kpoti)/kwIon) + 1;
2058     nel=TMath::Min(nel,300); // 300 electrons corresponds to 10 keV
2059
2060     gMC->TrackPosition(p);
2061     hits[0]=p[0];
2062     hits[1]=p[1];
2063     hits[2]=p[2];
2064     hits[3]=(Float_t)nel;
2065
2066     // Add this hit
2067
2068     // new(lhits[fNhits++]) AliTPChit(fIshunt,gAlice->CurrentTrack(),vol,hits);
2069     if (fHitType&&2){
2070       gMC->TrackMomentum(p);
2071       Float_t momentum = TMath::Sqrt(p[0]*p[0]+p[1]*p[1]);
2072       Float_t precision =   (momentum>0.1) ? 0.002 :0.01;
2073       fTrackHits->SetHitPrecision(precision);
2074     }
2075     AddHit(gAlice->CurrentTrack(), vol,hits);  //MI change
2076
2077   }
2078
2079   // Stemax calculation for the next step
2080
2081   Float_t pp;
2082   TLorentzVector mom;
2083   gMC->TrackMomentum(mom);
2084   Float_t ptot=mom.Rho();
2085   Float_t betaGamma = ptot/gMC->TrackMass();
2086
2087   Int_t pid=gMC->TrackPid();
2088   if((pid==kElectron || pid==kPositron) && ptot > 0.002)
2089     {
2090       pp = kprim*1.58; // electrons above 20 MeV/c are on the plateau!
2091     }
2092   else
2093     {
2094
2095       betaGamma = TMath::Max(betaGamma,(Float_t)7.e-3); // protection against too small bg
2096       pp=kprim*BetheBloch(betaGamma);
2097
2098       if(TMath::Abs(charge) > 1.) pp *= (charge*charge);
2099     }
2100
2101   Double_t rnd = gMC->GetRandom()->Rndm();
2102
2103   gMC->SetMaxStep(-TMath::Log(rnd)/pp);
2104
2105 }
2106
2107 //_____________________________________________________________________________
2108 Float_t AliTPCv2::BetheBloch(Float_t bg)
2109 {
2110   //
2111   // Bethe-Bloch energy loss formula
2112   //
2113   const Double_t kp1=0.76176e-1;
2114   const Double_t kp2=10.632;
2115   const Double_t kp3=0.13279e-4;
2116   const Double_t kp4=1.8631;
2117   const Double_t kp5=1.9479;
2118
2119   Double_t dbg = (Double_t) bg;
2120
2121   Double_t beta = dbg/TMath::Sqrt(1.+dbg*dbg);
2122
2123   Double_t aa = TMath::Power(beta,kp4);
2124   Double_t bb = TMath::Power(1./dbg,kp5);
2125
2126   bb=TMath::Log(kp3+bb);
2127
2128   return ((Float_t)((kp2-aa-bb)*kp1/aa));
2129 }
2130
2131