TOF/AliTOFv0.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   *
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  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.                  *
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  15
  16 /*
  17 $Log$
  18 Revision 1.9  1999/09/29 09:24:33  fca
  19 Introduction of the Copyright and cvs Log
  20
  21 */
  22
  23 ///////////////////////////////////////////////////////////////////////////////
  24 //                                                                           //
  25 //  Time Of Flight: design of C.Williams                FCA                  //
  26 //  This class contains the functions for version 1 of the Time Of Flight    //
  27 //  detector.                                                                //
  28 //
  29 //  VERSION WITH 5 MODULES AND TILTED STRIPS
  30 //
  31 //   WITH HOLES FOR PHOS AND HMPID inside the
  32 //   SPACE FRAME WITH HOLES
  33 //
  34 //
  35 //   Authors:
  36 //
  37 //   Alessio Seganti
  38 //   Domenico Vicinanza
  39 //
  40 //   University of Salerno - Italy
  41 //
  42 //
  43 //Begin_Html
  44 /*
  45 <img src="picts/AliTOFv0Class.gif">
  46 */
  47 //End_Html
  48 //                                                                           //
  49 ///////////////////////////////////////////////////////////////////////////////
  50
  51 #include "AliTOFv0.h"
  52 #include "AliRun.h"
  53 #include "AliConst.h"
  54
  55 ClassImp(AliTOFv0)
  56
  57 //_____________________________________________________________________________
  58 AliTOFv0::AliTOFv0()
  59 {
  60   //
  61   // Default constructor
  62   //
  63 }
  64
  65 //_____________________________________________________________________________
  66 AliTOFv0::AliTOFv0(const char *name, const char *title)
  67        : AliTOF(name,title)
  68 {
  69   //
  70   // Standard constructor
  71   //
  72 }
  73
  74 //_____________________________________________________________________________
  75 void AliTOFv0::CreateGeometry()
  76 {
  77   //
  78   // Create geometry for Time Of Flight version 0
  79   //
  80   //Begin_Html
  81   /*
  82     <img src="picts/AliTOFv0.gif">
  83   */
  84   //End_Html
  85   //
  86   // Creates common geometry
  87   //
  88   AliTOF::CreateGeometry();
  89 }
  90
  91 //_____________________________________________________________________________
  92 void AliTOFv0::TOFpc(Float_t xtof, Float_t ytof, Float_t zlen1,
  93                      Float_t zlen2, Float_t zlen3, Float_t ztof0)
  94 {
  95   //
  96   // Definition of the Time Of Fligh Resistive Plate Chambers
  97   // xFLT, yFLT, zFLT - sizes of TOF modules (large)
  98
  99   Float_t  ycoor;
 100   Float_t par[10];
 101   Int_t idrotm[100];
 102   Int_t nrot = 0;
 103
 104   Int_t *idtmed = fIdtmed->GetArray()-499;
 105
 106
 107   par[0] =  xtof / 2.;
 108   par[1] =  ytof / 2.;
 109   par[2] = zlen1 / 2.;
 110   gMC->Gsvolu("FTO1", "BOX ", idtmed[506], par, 3);
 111   par[2] = zlen2 / 2.;
 112   gMC->Gsvolu("FTO2", "BOX ", idtmed[506], par, 3);
 113   par[2] = zlen3 / 2.;
 114   gMC->Gsvolu("FTO3", "BOX ", idtmed[506], par, 3);
 115
 116
 117 // Positioning of modules
 118
 119    Float_t zcoor;
 120
 121    Float_t zcor1 = ztof0 - zlen1/2;
 122    Float_t zcor2 = ztof0 - zlen1 - zlen2/2.;
 123    Float_t zcor3 = 0.;
 124
 125    AliMatrix(idrotm[0], 90., 0., 0., 0., 90, -90.);
 126    AliMatrix(idrotm[1], 90., 180., 0., 0., 90, 90.);
 127    gMC->Gspos("FTO1", 1, "BTO1", 0,  zcor1, 0, idrotm[0], "ONLY");
 128    gMC->Gspos("FTO1", 2, "BTO1", 0, -zcor1, 0, idrotm[1], "ONLY");
 129    zcoor = (zlen1/2.);
 130    gMC->Gspos("FTO1", 1, "BTO2", 0,  zcoor, 0, idrotm[0], "ONLY");
 131    zcoor = 0.;
 132    gMC->Gspos("FTO1", 1, "BTO3", 0,  zcoor, 0, idrotm[0], "ONLY");
 133
 134    gMC->Gspos("FTO2", 1, "BTO1", 0,  zcor2, 0, idrotm[0], "ONLY");
 135    gMC->Gspos("FTO2", 2, "BTO1", 0, -zcor2, 0, idrotm[1], "ONLY");
 136    zcoor = -zlen2/2.;
 137    gMC->Gspos("FTO2", 0, "BTO2", 0,  zcoor, 0, idrotm[0], "ONLY");
 138
 139    gMC->Gspos("FTO3", 0, "BTO1", 0, zcor3,  0, idrotm[0], "ONLY");
 140
 141 // Subtraction the distance to TOF module boundaries
 142
 143   Float_t db = 7.;
 144   Float_t xFLT, yFLT, zFLT1, zFLT2, zFLT3;
 145
 146   xFLT = xtof -(.5 +.5)*2;
 147   yFLT = ytof;
 148   zFLT1 = zlen1 - db;
 149   zFLT2 = zlen2 - db;
 150   zFLT3 = zlen3 - db;
 151
 152 // Sizes of MRPC pads
 153
 154   Float_t yPad = 0.505;
 155
 156 // Large not sensitive volumes with CO2
 157   par[0] = xFLT/2;
 158   par[1] = yFLT/2;
 159
 160   cout <<"************************* TOF geometry **************************"<<endl;
 161
 162   par[2] = (zFLT1 / 2.);
 163   gMC->Gsvolu("FLT1", "BOX ", idtmed[506], par, 3); // CO2
 164   gMC->Gspos("FLT1", 0, "FTO1", 0., 0., 0., 0, "ONLY");
 165
 166   par[2] = (zFLT2 / 2.);
 167   gMC->Gsvolu("FLT2", "BOX ", idtmed[506], par, 3); // CO2
 168   gMC->Gspos("FLT2", 0, "FTO2", 0., 0., 0., 0, "ONLY");
 169
 170   par[2] = (zFLT3 / 2.);
 171   gMC->Gsvolu("FLT3", "BOX ", idtmed[506], par, 3); // CO2
 172   gMC->Gspos("FLT3", 0, "FTO3", 0., 0., 0., 0, "ONLY");
 173
 174 ////////// Layers before detector ////////////////////
 175
 176 // Alluminium layer in front 1.0 mm thick at the beginning
 177   par[0] = -1;
 178   par[1] = 0.1;
 179   par[2] = -1;
 180   ycoor = -yFLT/2 + par[1];
 181   gMC->Gsvolu("FMY1", "BOX ", idtmed[508], par, 3); // Alluminium
 182   gMC->Gspos("FMY1", 0, "FLT1", 0., ycoor, 0., 0, "ONLY");
 183   gMC->Gsvolu("FMY2", "BOX ", idtmed[508], par, 3); // Alluminium
 184   gMC->Gspos("FMY2", 0, "FLT2", 0., ycoor, 0., 0, "ONLY");
 185   gMC->Gsvolu("FMY3", "BOX ", idtmed[508], par, 3); // Alluminium
 186   gMC->Gspos("FMY3", 0, "FLT3", 0., ycoor, 0., 0, "ONLY");
 187
 188 // Honeycomb layer (1cm of special polyethilene)
 189   ycoor = ycoor + par[1];
 190   par[0] = -1;
 191   par[1] = 0.5;
 192   par[2] = -1;
 193   ycoor = ycoor + par[1];
 194   gMC->Gsvolu("FPL1", "BOX ", idtmed[503], par, 3); // Hony
 195   gMC->Gspos("FPL1", 0, "FLT1", 0., ycoor, 0., 0, "ONLY");
 196   gMC->Gsvolu("FPL2", "BOX ", idtmed[503], par, 3); // Hony
 197   gMC->Gspos("FPL2", 0, "FLT2", 0., ycoor, 0., 0, "ONLY");
 198   gMC->Gsvolu("FPL3", "BOX ", idtmed[503], par, 3); // Hony
 199   gMC->Gspos("FPL3", 0, "FLT3", 0., ycoor, 0., 0, "ONLY");
 200
 201 ///////////////// Detector itself //////////////////////
 202
 203   const Float_t StripWidth = 7.81;//cm
 204   const Float_t DeadBound = 1.;//cm non-sensitive between the pad edge and the boundary of the strip
 205   const Int_t nx = 40; // number of pads along x
 206   const Int_t nz = 2;  // number of pads along z
 207   const Float_t Gap=4.; //cm  distance between the strip axis
 208   const Float_t Space = 5.5; //cm distance from the front plate of the box
 209
 210   Float_t zSenStrip;
 211   zSenStrip = StripWidth-2*DeadBound;//cm
 212
 213   par[0] = -1;
 214   par[1] = yPad/2;
 215   par[2] = StripWidth/2.;
 216
 217   // Glass Layer of detector
 218   gMC->Gsvolu("FSTR","BOX",idtmed[514],par,3);
 219
 220   // Freon for non-sesitive boundaries
 221   par[0] = -1;
 222   par[1] = 0.110/2;
 223   par[2] = -1;
 224   gMC->Gsvolu("FNSF","BOX",idtmed[512],par,3);
 225   gMC->Gspos("FNSF",0,"FSTR",0.,0.,0.,0,"ONLY");
 226   // Mylar for non-sesitive boundaries
 227   par[1] = 0.025;
 228   gMC->Gsvolu("FMYI","BOX",idtmed[510],par,3);
 229   gMC->Gspos("FMYI",0,"FNSF",0.,0.,0.,0,"ONLY");
 230
 231   // Mylar for outer layers
 232   par[1] = 0.035/2;
 233   ycoor = -yPad/2.+par[1];
 234   gMC->Gsvolu("FMYX","BOX",idtmed[510],par,3);
 235   gMC->Gspos("FMYX",1,"FSTR",0.,ycoor,0.,0,"ONLY");
 236   gMC->Gspos("FMYX",2,"FSTR",0.,-ycoor,0.,0,"ONLY");
 237   ycoor += par[1];
 238
 239   // Graphyte layers
 240   par[1] = 0.003/2;
 241   ycoor += par[1];
 242   gMC->Gsvolu("FGRL","BOX",idtmed[502],par,3);
 243   gMC->Gspos("FGRL",1,"FSTR",0.,ycoor,0.,0,"ONLY");
 244   gMC->Gspos("FGRL",2,"FSTR",0.,-ycoor,0.,0,"ONLY");
 245
 246   // Freon sensitive layer
 247   par[0] = -1;
 248   par[1] = 0.110/2.;
 249   par[2] = zSenStrip/2.;
 250   gMC->Gsvolu("FCFC","BOX",idtmed[513],par,3);
 251   gMC->Gspos("FCFC",0,"FNSF",0.,0.,0.,0,"ONLY");
 252
 253   // Pad definition x & z
 254   gMC->Gsdvn("FLZ","FCFC", nz, 3);
 255   gMC->Gsdvn("FLX","FLZ" , nx, 1);
 256
 257   // MRPC pixel itself
 258 //  par[0] = -1;
 259 //  par[1] = -1;
 260 //  par[2] = -1;
 261 //  gMC->Gsvolu("FPAD", "BOX ", idtmed[513], par, 3);
 262 //  gMC->Gspos("FPAD", 0, "FLX", 0., 0., 0., 0, "ONLY");
 263
 264
 265 ////  Positioning the Strips  (FSTR) in the FLT volumes  /////
 266
 267
 268   // 3 (Central) Plate
 269   Float_t t = zFLT1+zFLT2+zFLT3/2.+7.*2.5;//Half Width of Barrel
 270   Float_t zpos = 0;
 271   Float_t ang;
 272   Float_t Offset;
 273   Float_t last;
 274   nrot = 0;
 275   Int_t i=1,j=1;
 276   zcoor=0;
 277   Int_t UpDown=-1; // UpDown=-1 -> Upper strip, UpDown=+1 -> Lower strip
 278
 279   do{
 280      ang = atan(zcoor/t);
 281      ang = ang*180/3.141592654;
 282      AliMatrix (idrotm[nrot], 90., 0., 90.-ang,90.,ang, 0.);
 283      AliMatrix (idrotm[nrot+1], 90., 180., 90.+ang,90.,ang, 0);
 284      ycoor = -14.5+ Space; //2 cm over front plate
 285      ycoor += (1-(UpDown+1)/2)*Gap;
 286      gMC->Gspos("FSTR",j  ,"FLT3",0.,ycoor, zcoor,idrotm[nrot],  "ONLY");
 287      gMC->Gspos("FSTR",j+1,"FLT3",0.,ycoor,-zcoor,idrotm[nrot+1],"ONLY");
 288      ang  = ang*3.141592654/180;
 289
 290      zcoor=zcoor-(zSenStrip/2)/TMath::Cos(ang)+UpDown*Gap*TMath::Tan(ang)-(zSenStrip/2)/TMath::Cos(ang);
 291      UpDown*= -1; // Alternate strips
 292      i++;
 293      j+=2;
 294   } while (zcoor-(StripWidth/2)*TMath::Cos(ang)>-t+zFLT1+zFLT2+7*2.5);
 295
 296   ycoor = -29./2.+ Space; //2 cm over front plate
 297
 298   // Plate  2
 299   zpos = -zFLT3/2-7.;
 300   ang  = atan(zpos/sqrt(2*t*t-zpos*zpos));
 301   Offset = StripWidth*TMath::Cos(ang)/2;
 302   zpos -= Offset;
 303   nrot = 0;
 304   i=1;
 305   // UpDown has not to be reinitialized, so that the arrangement of the strips can continue coherently
 306
 307   do {
 308      ang = atan(zpos/sqrt(2*t*t-zpos*zpos));
 309      ang = ang*180/3.141592654;
 310      AliMatrix (idrotm[nrot], 90., 0., 90.-ang,90.,ang, 0.);
 311      ycoor = -29./2.+ Space ; //2 cm over front plate
 312      ycoor += (1-(UpDown+1)/2)*Gap;
 313      zcoor = zpos+(zFLT3/2.+7+zFLT2/2); // Moves to the system of the centre of the modulus FLT2
 314      gMC->Gspos("FSTR",i, "FLT2", 0., ycoor, zcoor,idrotm[nrot], "ONLY");
 315      ang  = ang*3.141592654/180;
 316      zpos = zpos - (zSenStrip/2)/TMath::Cos(ang)+UpDown*Gap*TMath::Tan(ang)-(zSenStrip/2)/TMath::Cos(ang);
 317      last = StripWidth*TMath::Cos(ang)/2;
 318      UpDown*=-1;
 319      i++;
 320   } while (zpos-(StripWidth/2)*TMath::Cos(ang)>-t+zFLT1+7);
 321
 322   // Plate  1
 323   zpos = -t+zFLT1+3.5;
 324   ang = atan(zpos/sqrt(2*t*t-zpos*zpos));
 325   Offset = StripWidth*TMath::Cos(ang)/2.;
 326   zpos -= Offset;
 327   nrot = 0;
 328   i=0;
 329   ycoor= -29./2.+Space+Gap/2;
 330
 331  do {
 332      ang = atan(zpos/sqrt(2*t*t-zpos*zpos));
 333      ang = ang*180/3.141592654;
 334      AliMatrix (idrotm[nrot], 90., 0., 90.-ang,90.,ang, 0.);
 335      i++;
 336      zcoor = zpos+(zFLT1/2+zFLT2+zFLT3/2+7.*2.);
 337      gMC->Gspos("FSTR",i, "FLT1", 0., ycoor, zcoor,idrotm[nrot], "ONLY");
 338      ang  = ang *3.141592654/180;
 339      zpos = zpos - zSenStrip/TMath::Cos(ang);
 340      last = StripWidth*TMath::Cos(ang)/2.;
 341   }  while (zpos>-t+7.+last);
 342
 343 printf("#######################################################\n");
 344 printf("     Distance from the bound of the FLT3: zFLT3- %f cm \n", zpos+(zSenStrip/2)/TMath::Cos(ang));
 345      ang = atan(zpos/sqrt(2*t*t-zpos*zpos));
 346      zpos = zpos - zSenStrip/TMath::Cos(ang);
 347 printf("NEXT Distance from the bound of the FLT3: zFLT3- %f cm \n", zpos+(zSenStrip/2)/TMath::Cos(ang));
 348 printf("#######################################################\n");
 349
 350 ////////// Layers after detector /////////////////
 351
 352 // Honeycomb layer after (3cm)
 353
 354   Float_t OverSpace = Space + 7.3;
 355 ///  StripWidth*TMath::Sin(ang) + 1.3;
 356
 357   par[0] = -1;
 358   par[1] = 0.6;
 359   par[2] = -1;
 360   ycoor = -yFLT/2 + OverSpace + par[1];
 361   gMC->Gsvolu("FPE1", "BOX ", idtmed[503], par, 3); // Hony
 362   gMC->Gspos("FPE1", 0, "FLT1", 0., ycoor, 0., 0, "ONLY");
 363   gMC->Gsvolu("FPE2", "BOX ", idtmed[503], par, 3); // Hony
 364   gMC->Gspos("FPE2", 0, "FLT2", 0., ycoor, 0., 0, "ONLY");
 365   gMC->Gsvolu("FPE3", "BOX ", idtmed[503], par, 3); // Hony
 366   gMC->Gspos("FPE3", 0, "FLT3", 0., ycoor, 0., 0, "ONLY");
 367
 368 // Electronics (Cu) after
 369   ycoor += par[1];
 370   par[0] = -1;
 371   par[1] = 1.43*0.05 / 2.; // 5% of X0
 372   par[2] = -1;
 373   ycoor += par[1];
 374   gMC->Gsvolu("FEC1", "BOX ", idtmed[501], par, 3); // Cu
 375   gMC->Gspos("FEC1", 0, "FLT1", 0., ycoor, 0., 0, "ONLY");
 376   gMC->Gsvolu("FEC2", "BOX ", idtmed[501], par, 3); // Cu
 377   gMC->Gspos("FEC2", 0, "FLT2", 0., ycoor, 0., 0, "ONLY");
 378   gMC->Gsvolu("FEC3", "BOX ", idtmed[501], par, 3); // Cu
 379   gMC->Gspos("FEC3", 0, "FLT3", 0., ycoor, 0., 0, "ONLY");
 380
 381 // Cooling water after
 382   ycoor += par[1];
 383   par[0] = -1;
 384   par[1] = 36.1*0.02 / 2.; // 2% of X0
 385   par[2] = -1;
 386   ycoor += par[1];
 387   gMC->Gsvolu("FWA1", "BOX ", idtmed[515], par, 3); // Water
 388   gMC->Gspos("FWA1", 0, "FLT1", 0., ycoor, 0., 0, "ONLY");
 389   gMC->Gsvolu("FWA2", "BOX ", idtmed[515], par, 3); // Water
 390   gMC->Gspos("FWA2", 0, "FLT2", 0., ycoor, 0., 0, "ONLY");
 391   gMC->Gsvolu("FWA3", "BOX ", idtmed[515], par, 3); // Water
 392   gMC->Gspos("FWA3", 0, "FLT3", 0., ycoor, 0., 0, "ONLY");
 393
 394 //back plate honycomb (2cm)
 395   par[0] = -1;
 396   par[1] = 2 / 2.;
 397   par[2] = -1;
 398   ycoor = yFLT/2 - par[1];
 399   gMC->Gsvolu("FEG1", "BOX ", idtmed[503], par, 3); // Hony
 400   gMC->Gspos("FEG1", 0, "FLT1", 0., ycoor, 0., 0, "ONLY");
 401   gMC->Gsvolu("FEG2", "BOX ", idtmed[503], par, 3); // Hony
 402   gMC->Gspos("FEG2", 0, "FLT2", 0., ycoor, 0., 0, "ONLY");
 403   gMC->Gsvolu("FEG3", "BOX ", idtmed[503], par, 3); // Hony
 404   gMC->Gspos("FEG3", 0, "FLT3", 0., ycoor, 0., 0, "ONLY");
 405 }
 406
 407 //_____________________________________________________________________________
 408 void AliTOFv0::DrawModule()
 409 {
 410   //
 411   // Draw a shaded view of the Time Of Flight version 1
 412   //
 413   // Set everything unseen
 414   gMC->Gsatt("*", "seen", -1);
 415   //
 416   // Set ALIC mother transparent
 417   gMC->Gsatt("ALIC","SEEN",0);
 418   //
 419   // Set the volumes visible
 420   gMC->Gsatt("ALIC","SEEN",0);
 421   gMC->Gsatt("FBAR","SEEN",1);
 422   gMC->Gsatt("FTO1","SEEN",1);
 423   gMC->Gsatt("FTO2","SEEN",1);
 424   gMC->Gsatt("FTO3","SEEN",1);
 425   gMC->Gsatt("FBT1","SEEN",1);
 426   gMC->Gsatt("FBT2","SEEN",1);
 427   gMC->Gsatt("FBT3","SEEN",1);
 428   gMC->Gsatt("FDT1","SEEN",1);
 429   gMC->Gsatt("FDT2","SEEN",1);
 430   gMC->Gsatt("FDT3","SEEN",1);
 431   gMC->Gsatt("FLT1","SEEN",1);
 432   gMC->Gsatt("FLT2","SEEN",1);
 433   gMC->Gsatt("FLT3","SEEN",1);
 434   gMC->Gsatt("FPL1","SEEN",1);
 435   gMC->Gsatt("FPL2","SEEN",1);
 436   gMC->Gsatt("FPL3","SEEN",1);
 437   gMC->Gsatt("FLD1","SEEN",1);
 438   gMC->Gsatt("FLD2","SEEN",1);
 439   gMC->Gsatt("FLD3","SEEN",1);
 440   gMC->Gsatt("FLZ1","SEEN",1);
 441   gMC->Gsatt("FLZ2","SEEN",1);
 442   gMC->Gsatt("FLZ3","SEEN",1);
 443   gMC->Gsatt("FLX1","SEEN",1);
 444   gMC->Gsatt("FLX2","SEEN",1);
 445   gMC->Gsatt("FLX3","SEEN",1);
 446   gMC->Gsatt("FPA0","SEEN",1);
 447   //
 448   gMC->Gdopt("hide", "on");
 449   gMC->Gdopt("shad", "on");
 450   gMC->Gsatt("*", "fill", 7);
 451   gMC->SetClipBox(".");
 452   gMC->SetClipBox("*", 0, 1000, -1000, 1000, -1000, 1000);
 453   gMC->DefaultRange();
 454   gMC->Gdraw("alic", 40, 30, 0, 12, 9.5, .02, .02);
 455   gMC->Gdhead(1111, "Time Of Flight");
 456   gMC->Gdman(18, 4, "MAN");
 457   gMC->Gdopt("hide","off");
 458 }
 459
 460 //_____________________________________________________________________________
 461 void AliTOFv0::CreateMaterials()
 462 {
 463   //
 464   // Define materials for the Time Of Flight
 465   //
 466   AliTOF::CreateMaterials();
 467 }
 468
 469 //_____________________________________________________________________________
 470 void AliTOFv0::Init()
 471 {
 472   //
 473   // Initialise the detector after the geometry has been defined
 474   //
 475   AliTOF::Init();
 476   fIdFTO2=gMC->VolId("FTO2");
 477   fIdFTO3=gMC->VolId("FTO3");
 478   fIdFLT1=gMC->VolId("FLT1");
 479   fIdFLT2=gMC->VolId("FLT2");
 480   fIdFLT3=gMC->VolId("FLT3");
 481 }
 482
 483 //_____________________________________________________________________________
 484 void AliTOFv0::StepManager()
 485 {
 486   //
 487   // Procedure called at each step in the Time Of Flight
 488   //
 489   TLorentzVector mom, pos;
 490   Float_t hits[8];
 491   Int_t vol[3];
 492   Int_t copy, id, i;
 493   Int_t *idtmed = fIdtmed->GetArray()-499;
 494   if(gMC->GetMedium()==idtmed[514-1] &&
 495      gMC->IsTrackEntering() && gMC->TrackCharge()
 496      && gMC->CurrentVolID(copy)==fIdSens) {
 497     TClonesArray &lhits = *fHits;
 498     //
 499     // Record only charged tracks at entrance
 500     gMC->CurrentVolOffID(1,copy);
 501     vol[2]=copy;
 502     gMC->CurrentVolOffID(3,copy);
 503     vol[1]=copy;
 504     id=gMC->CurrentVolOffID(8,copy);
 505     vol[0]=copy;
 506     if(id==fIdFTO3) {
 507       vol[0]+=22;
 508       id=gMC->CurrentVolOffID(5,copy);
 509       if(id==fIdFLT3) vol[1]+=6;
 510     } else if (id==fIdFTO2) {
 511       vol[0]+=20;
 512       id=gMC->CurrentVolOffID(5,copy);
 513       if(id==fIdFLT2) vol[1]+=8;
 514     } else {
 515       id=gMC->CurrentVolOffID(5,copy);
 516       if(id==fIdFLT1) vol[1]+=14;
 517     }
 518     gMC->TrackPosition(pos);
 519     gMC->TrackMomentum(mom);
 520     //
 521     Double_t ptot=mom.Rho();
 522     Double_t norm=1/ptot;
 523     for(i=0;i<3;++i) {
 524       hits[i]=pos[i];
 525       hits[i+3]=mom[i]*norm;
 526     }
 527     hits[6]=ptot;
 528     hits[7]=pos[3];
 529     new(lhits[fNhits++]) AliTOFhit(fIshunt,gAlice->CurrentTrack(),vol,hits);
 530   }
 531 }
 532