]> git.uio.no Git - u/mrichter/AliRoot.git/blobdiff - TRD/AliTRDgeometry.cxx
Changing GetZv to GetZ
[u/mrichter/AliRoot.git] / TRD / AliTRDgeometry.cxx
index bdcdc3e1213a0bba28ba44874b8aa51e0f31f6d5..86238e7f1704e7513027cbcf78a03d3decd5cfc5 100644 (file)
@@ -185,42 +185,42 @@ ClassImp(AliTRDgeometry)
   const Int_t    AliTRDgeometry::fgkRowmaxC1  = 16;
 
   const Double_t AliTRDgeometry::fgkTime0Base = 300.65;
-  const Float_t  AliTRDgeometry::fgkTime0[6]  = { fgkTime0Base + 0 * (Cheight() + Cspace()) 
-                                                , fgkTime0Base + 1 * (Cheight() + Cspace()) 
-                                                , fgkTime0Base + 2 * (Cheight() + Cspace()) 
-                                                , fgkTime0Base + 3 * (Cheight() + Cspace()) 
-                                                , fgkTime0Base + 4 * (Cheight() + Cspace()) 
-                                                , fgkTime0Base + 5 * (Cheight() + Cspace())};
+const Float_t  AliTRDgeometry::fgkTime0[6]  = { static_cast<Float_t>(fgkTime0Base + 0 * (Cheight() + Cspace())) 
+                                                , static_cast<Float_t>(fgkTime0Base + 1 * (Cheight() + Cspace())) 
+                                                , static_cast<Float_t>(fgkTime0Base + 2 * (Cheight() + Cspace())) 
+                                                , static_cast<Float_t>(fgkTime0Base + 3 * (Cheight() + Cspace())) 
+                                                , static_cast<Float_t>(fgkTime0Base + 4 * (Cheight() + Cspace())) 
+                                                , static_cast<Float_t>(fgkTime0Base + 5 * (Cheight() + Cspace()))};
 
   const Double_t AliTRDgeometry::fgkXtrdBeg   = 288.43; // Values depend on position of TRD
   const Double_t AliTRDgeometry::fgkXtrdEnd   = 366.33; // mother volume inside space frame !!!
 
-//_____________________________________________________________________________
-AliTRDgeometry::AliTRDgeometry()
-  :AliGeometry()
-  ,fClusterMatrixArray(0)
-  ,fPadPlaneArray(0)
-{
-  //
-  // AliTRDgeometry default constructor
-  //
+  // The outer width of the chambers
+  const Float_t AliTRDgeometry::fgkCwidth[kNlayer] = {  90.4,  94.8,  99.3, 103.7, 108.1, 112.6 };
+  
+  // The outer lengths of the chambers
+  // Includes the spacings between the chambers!
+  const Float_t AliTRDgeometry::fgkClength[kNlayer][kNstack] = { { 124.0, 124.0, 110.0, 124.0, 124.0 }
+                                                             , { 124.0, 124.0, 110.0, 124.0, 124.0 }
+                                                             , { 131.0, 131.0, 110.0, 131.0, 131.0 }
+                                                             , { 138.0, 138.0, 110.0, 138.0, 138.0 }
+                                                             , { 145.0, 145.0, 110.0, 145.0, 145.0 }
+                                                             , { 147.0, 147.0, 110.0, 147.0, 147.0 } };
 
-  Init();
+        Char_t  AliTRDgeometry::fgSMstatus[kNsector]         = { 1, 1, 1, 1, 1, 1, 1, 1, 1
+                                                              , 1, 1, 1, 1, 1, 1, 1, 1, 1 };
 
-}
+  TObjArray* AliTRDgeometry::fgClusterMatrixArray = NULL;
+
+  TObjArray* AliTRDgeometry::fgPadPlaneArray = NULL;
 
 //_____________________________________________________________________________
-AliTRDgeometry::AliTRDgeometry(const AliTRDgeometry &g)
-  :AliGeometry(g)
-  ,fClusterMatrixArray(0)
-  ,fPadPlaneArray(0)
+AliTRDgeometry::AliTRDgeometry()
 {
   //
-  // AliTRDgeometry copy constructor
+  // AliTRDgeometry default constructor
   //
 
-  Init();
-
 }
 
 //_____________________________________________________________________________
@@ -230,84 +230,6 @@ AliTRDgeometry::~AliTRDgeometry()
   // AliTRDgeometry destructor
   //
 
-  if (fClusterMatrixArray) {
-    fClusterMatrixArray->Delete();
-    delete fClusterMatrixArray;
-    fClusterMatrixArray = 0;
-  }
-
-  if (fPadPlaneArray) {
-    fPadPlaneArray->Delete();
-    delete fPadPlaneArray;
-    fPadPlaneArray = 0;
-  }
-
-}
-
-//_____________________________________________________________________________
-AliTRDgeometry &AliTRDgeometry::operator=(const AliTRDgeometry &g)
-{
-  //
-  // Assignment operator
-  //
-
-  if (this != &g) {
-    Init();
-  }
-
-  return *this;
-
-}
-
-//_____________________________________________________________________________
-void AliTRDgeometry::Init()
-{
-  //
-  // Initializes the geometry parameter
-  //
-
-  Int_t istack;
-  Int_t ilayer;
-  Int_t isector;
-
-  // The outer width of the chambers
-  fCwidth[0] =  90.4;
-  fCwidth[1] =  94.8;
-  fCwidth[2] =  99.3;
-  fCwidth[3] = 103.7;
-  fCwidth[4] = 108.1;
-  fCwidth[5] = 112.6;
-
-  // The outer lengths of the chambers
-  // Includes the spacings between the chambers!
-  Float_t length[kNlayer][kNstack]   = { { 124.0, 124.0, 110.0, 124.0, 124.0 }
-                                      , { 124.0, 124.0, 110.0, 124.0, 124.0 }
-                                       , { 131.0, 131.0, 110.0, 131.0, 131.0 }
-                                       , { 138.0, 138.0, 110.0, 138.0, 138.0 }
-                                       , { 145.0, 145.0, 110.0, 145.0, 145.0 }
-                                      , { 147.0, 147.0, 110.0, 147.0, 147.0 } };
-
-  for (istack = 0; istack < kNstack; istack++) {
-    for (ilayer = 0; ilayer < kNlayer; ilayer++) {
-      fClength[ilayer][istack] = length[ilayer][istack];
-    }
-  }
-
-  // The rotation matrix elements
-  Float_t phi = 0.0;
-  for (isector = 0; isector < fgkNsector; isector++) {
-    phi = 2.0 * TMath::Pi() /  (Float_t) fgkNsector * ((Float_t) isector + 0.5);
-    fRotB11[isector] = TMath::Cos(phi);
-    fRotB12[isector] = TMath::Sin(phi);
-    fRotB21[isector] = TMath::Sin(phi);
-    fRotB22[isector] = TMath::Cos(phi);
-  }
-  // SM status
-  for (Int_t i = 0; i < kNsector; i++) {
-    fSMstatus[i] = 1;
-  }
-
 }
 
 //_____________________________________________________________________________
@@ -317,16 +239,17 @@ void AliTRDgeometry::CreatePadPlaneArray()
   // Creates the array of AliTRDpadPlane objects
   //
 
-  if (fPadPlaneArray) {
-    fPadPlaneArray->Delete();
-    delete fPadPlaneArray;
-  }
+  if (fgPadPlaneArray)
+    return;
+
+  static TObjArray padPlaneArray(fgkNlayer * fgkNstack);
+  padPlaneArray.SetOwner(kTRUE);
 
-  fPadPlaneArray = new TObjArray(fgkNlayer * fgkNstack);  
+  fgPadPlaneArray = &padPlaneArray;
   for (Int_t ilayer = 0; ilayer < fgkNlayer; ilayer++) {
     for (Int_t istack = 0; istack < fgkNstack; istack++) {
       Int_t ipp = GetDetectorSec(ilayer,istack);
-      fPadPlaneArray->AddAt(CreatePadPlane(ilayer,istack),ipp);
+      fgPadPlaneArray->AddAt(CreatePadPlane(ilayer,istack),ipp);
     }
   }
 
@@ -357,150 +280,125 @@ AliTRDpadPlane *AliTRDgeometry::CreatePadPlane(Int_t ilayer, Int_t istack)
   //
   // The pad plane parameter
   //
+  const Float_t kTiltAngle = 2.0;
   switch (ilayer) {
   case 0:
     if (istack == 2) {
       // L0C0 type
       padPlane->SetNrows(12);
       padPlane->SetLength(108.0);
-      padPlane->SetWidth(92.2);
       padPlane->SetLengthOPad(8.0);
-      padPlane->SetWidthOPad(0.515);
       padPlane->SetLengthIPad(9.0);
-      padPlane->SetWidthIPad(0.635);
-      padPlane->SetTiltingAngle(2.0);
     }
     else {
       // L0C1 type
       padPlane->SetNrows(16);
       padPlane->SetLength(122.0);
-      padPlane->SetWidth(92.2);
       padPlane->SetLengthOPad(7.5);
-      padPlane->SetWidthOPad(0.515);
       padPlane->SetLengthIPad(7.5);
-      padPlane->SetWidthIPad(0.635);
-      padPlane->SetTiltingAngle(2.0);
     }
+    padPlane->SetWidth(92.2);
+    padPlane->SetWidthOPad(0.515);
+    padPlane->SetWidthIPad(0.635);
+    padPlane->SetTiltingAngle(-kTiltAngle);
     break;
   case 1:
     if (istack == 2) {
       // L1C0 type
       padPlane->SetNrows(12);
       padPlane->SetLength(108.0);
-      padPlane->SetWidth(96.6);
       padPlane->SetLengthOPad(8.0);
-      padPlane->SetWidthOPad(0.585);
       padPlane->SetLengthIPad(9.0);
-      padPlane->SetWidthIPad(0.665);
-      padPlane->SetTiltingAngle(-2.0);
     }
     else {
       // L1C1 type
       padPlane->SetNrows(16);
       padPlane->SetLength(122.0);
-      padPlane->SetWidth(96.6);
       padPlane->SetLengthOPad(7.5);
-      padPlane->SetWidthOPad(0.585);
       padPlane->SetLengthIPad(7.5);
-      padPlane->SetWidthIPad(0.665);
-      padPlane->SetTiltingAngle(-2.0);
     }
+    padPlane->SetWidth(96.6);
+    padPlane->SetWidthOPad(0.585);
+    padPlane->SetWidthIPad(0.665);
+    padPlane->SetTiltingAngle(kTiltAngle);
     break;
   case 2:
     if (istack == 2) {
       // L2C0 type
       padPlane->SetNrows(12);
       padPlane->SetLength(108.0);
-      padPlane->SetWidth(101.1);
       padPlane->SetLengthOPad(8.0);
-      padPlane->SetWidthOPad(0.705);
       padPlane->SetLengthIPad(9.0);
-      padPlane->SetWidthIPad(0.695);
-      padPlane->SetTiltingAngle(2.0);
     }
     else {
       // L2C1 type
       padPlane->SetNrows(16);
       padPlane->SetLength(129.0);
-      padPlane->SetWidth(101.1);
       padPlane->SetLengthOPad(7.5);
-      padPlane->SetWidthOPad(0.705);
       padPlane->SetLengthIPad(8.0);
-      padPlane->SetWidthIPad(0.695);
-      padPlane->SetTiltingAngle(2.0);
     }
+    padPlane->SetWidth(101.1);
+    padPlane->SetWidthOPad(0.705);
+    padPlane->SetWidthIPad(0.695);
+    padPlane->SetTiltingAngle(-kTiltAngle);
     break;
   case 3:
     if (istack == 2) {
       // L3C0 type
       padPlane->SetNrows(12);
       padPlane->SetLength(108.0);
-      padPlane->SetWidth(105.5);
       padPlane->SetLengthOPad(8.0);
-      padPlane->SetWidthOPad(0.775);
       padPlane->SetLengthIPad(9.0);
-      padPlane->SetWidthIPad(0.725);
-      padPlane->SetTiltingAngle(-2.0);
     }
     else {
       // L3C1 type
       padPlane->SetNrows(16);
       padPlane->SetLength(136.0);
-      padPlane->SetWidth(105.5);
       padPlane->SetLengthOPad(7.5);
-      padPlane->SetWidthOPad(0.775);
       padPlane->SetLengthIPad(8.5);
-      padPlane->SetWidthIPad(0.725);
-      padPlane->SetTiltingAngle(-2.0);
     }
+    padPlane->SetWidth(105.5);
+    padPlane->SetWidthOPad(0.775);
+    padPlane->SetWidthIPad(0.725);
+    padPlane->SetTiltingAngle(kTiltAngle);
     break;
   case 4:
     if (istack == 2) {
       // L4C0 type
       padPlane->SetNrows(12);
       padPlane->SetLength(108.0);
-      padPlane->SetWidth(109.9);
       padPlane->SetLengthOPad(8.0);
-      padPlane->SetWidthOPad(0.845);
-      padPlane->SetLengthIPad(9.0);
-      padPlane->SetWidthIPad(0.755);
-      padPlane->SetTiltingAngle(2.0);
     }
     else {
       // L4C1 type
       padPlane->SetNrows(16);
       padPlane->SetLength(143.0);
-      padPlane->SetWidth(109.9);
       padPlane->SetLengthOPad(7.5);
-      padPlane->SetWidthOPad(0.845);
-      padPlane->SetLengthIPad(9.0);
-      padPlane->SetWidthIPad(0.755);
-      padPlane->SetTiltingAngle(2.0);
     }
+    padPlane->SetWidth(109.9);
+    padPlane->SetWidthOPad(0.845);
+    padPlane->SetLengthIPad(9.0);
+    padPlane->SetWidthIPad(0.755);
+    padPlane->SetTiltingAngle(-kTiltAngle);
     break;
   case 5:
     if (istack == 2) {
       // L5C0 type
       padPlane->SetNrows(12);
       padPlane->SetLength(108.0);
-      padPlane->SetWidth(114.4);
       padPlane->SetLengthOPad(8.0);
-      padPlane->SetWidthOPad(0.965);
-      padPlane->SetLengthIPad(9.0);
-      padPlane->SetWidthIPad(0.785);
-      padPlane->SetTiltingAngle(-2.0);
     }
     else {
       // L5C1 type
       padPlane->SetNrows(16);
       padPlane->SetLength(145.0);
-      padPlane->SetWidth(114.4);
       padPlane->SetLengthOPad(8.5);
-      padPlane->SetWidthOPad(0.965);
-      padPlane->SetLengthIPad(9.0);
-      padPlane->SetWidthIPad(0.785);
-      padPlane->SetTiltingAngle(-2.0);
     }
+    padPlane->SetWidth(114.4);
+    padPlane->SetWidthOPad(0.965);
+    padPlane->SetLengthIPad(9.0);
+    padPlane->SetWidthIPad(0.785);
+    padPlane->SetTiltingAngle(kTiltAngle);
     break;
   };
 
@@ -509,7 +407,7 @@ AliTRDpadPlane *AliTRDgeometry::CreatePadPlane(Int_t ilayer, Int_t istack)
   //
   // Row direction
   //
-  Double_t row = fClength[ilayer][istack] / 2.0
+  Double_t row = fgkClength[ilayer][istack] / 2.0
                - fgkRpadW
                - padPlane->GetLengthRim();
   for (Int_t ir = 0; ir < padPlane->GetNrows(); ir++) {
@@ -525,7 +423,7 @@ AliTRDpadPlane *AliTRDgeometry::CreatePadPlane(Int_t ilayer, Int_t istack)
   //
   // Column direction
   //
-  Double_t col = - fCwidth[ilayer] / 2.0
+  Double_t col = - fgkCwidth[ilayer] / 2.0
                  - fgkCroW
                  + padPlane->GetWidthRim();
   for (Int_t ic = 0; ic < padPlane->GetNcols(); ic++) {
@@ -540,13 +438,13 @@ AliTRDpadPlane *AliTRDgeometry::CreatePadPlane(Int_t ilayer, Int_t istack)
   }
   // Calculate the offset to translate from the local ROC system into
   // the local supermodule system, which is used for clusters
-  Double_t rowTmp = fClength[ilayer][0]
-                 + fClength[ilayer][1]
-                  + fClength[ilayer][2] / 2.0;
+  Double_t rowTmp = fgkClength[ilayer][0]
+                 + fgkClength[ilayer][1]
+                  + fgkClength[ilayer][2] / 2.0;
   for (Int_t jstack = 0; jstack < istack; jstack++) {
-    rowTmp -= fClength[ilayer][jstack];
+    rowTmp -= fgkClength[ilayer][jstack];
   }
-  padPlane->SetPadRowSMOffset(rowTmp - fClength[ilayer][istack]/2.0);
+  padPlane->SetPadRowSMOffset(rowTmp - fgkClength[ilayer][istack]/2.0);
 
   return padPlane;
 
@@ -608,8 +506,9 @@ void AliTRDgeometry::CreateGeometry(Int_t *idtmed)
   Float_t parTrd[kNparTrd];
   Float_t parCha[kNparCha];
 
-  Char_t  cTagV[100];
-  Char_t  cTagM[100];
+  const Int_t kTag = 100;
+  Char_t  cTagV[kTag];
+  Char_t  cTagM[kTag];
 
   // There are three TRD volumes for the supermodules in order to accomodate
   // the different arrangements in front of PHOS
@@ -623,26 +522,26 @@ void AliTRDgeometry::CreateGeometry(Int_t *idtmed)
   parTrd[1] = fgkSwidth2/2.0;
   parTrd[2] = fgkSlength/2.0;
   parTrd[3] = fgkSheight/2.0;
-  gMC->Gsvolu("UTR1","TRD1",idtmed[1302-1],parTrd,kNparTrd);
-  gMC->Gsvolu("UTR2","TRD1",idtmed[1302-1],parTrd,kNparTrd);
-  gMC->Gsvolu("UTR3","TRD1",idtmed[1302-1],parTrd,kNparTrd);
+  TVirtualMC::GetMC()->Gsvolu("UTR1","TRD1",idtmed[1302-1],parTrd,kNparTrd);
+  TVirtualMC::GetMC()->Gsvolu("UTR2","TRD1",idtmed[1302-1],parTrd,kNparTrd);
+  TVirtualMC::GetMC()->Gsvolu("UTR3","TRD1",idtmed[1302-1],parTrd,kNparTrd);
   // The outer aluminum plates of the super module (Al)
   parTrd[0] = fgkSwidth1/2.0;
   parTrd[1] = fgkSwidth2/2.0;
   parTrd[2] = fgkSlength/2.0;
   parTrd[3] = fgkSheight/2.0;
-  gMC->Gsvolu("UTS1","TRD1",idtmed[1301-1],parTrd,kNparTrd);
-  gMC->Gsvolu("UTS2","TRD1",idtmed[1301-1],parTrd,kNparTrd);
-  gMC->Gsvolu("UTS3","TRD1",idtmed[1301-1],parTrd,kNparTrd);
+  TVirtualMC::GetMC()->Gsvolu("UTS1","TRD1",idtmed[1301-1],parTrd,kNparTrd);
+  TVirtualMC::GetMC()->Gsvolu("UTS2","TRD1",idtmed[1301-1],parTrd,kNparTrd);
+  TVirtualMC::GetMC()->Gsvolu("UTS3","TRD1",idtmed[1301-1],parTrd,kNparTrd);
   // The inner part of the TRD mother volume for one sector (Air), 
   // full length in z-direction
   parTrd[0] = fgkSwidth1/2.0 - fgkSMpltT;
   parTrd[1] = fgkSwidth2/2.0 - fgkSMpltT;
   parTrd[2] = fgkSlength/2.0;
   parTrd[3] = fgkSheight/2.0 - fgkSMpltT;
-  gMC->Gsvolu("UTI1","TRD1",idtmed[1302-1],parTrd,kNparTrd);
-  gMC->Gsvolu("UTI2","TRD1",idtmed[1302-1],parTrd,kNparTrd);
-  gMC->Gsvolu("UTI3","TRD1",idtmed[1302-1],parTrd,kNparTrd);
+  TVirtualMC::GetMC()->Gsvolu("UTI1","TRD1",idtmed[1302-1],parTrd,kNparTrd);
+  TVirtualMC::GetMC()->Gsvolu("UTI2","TRD1",idtmed[1302-1],parTrd,kNparTrd);
+  TVirtualMC::GetMC()->Gsvolu("UTI3","TRD1",idtmed[1302-1],parTrd,kNparTrd);
 
   // The inner part of the TRD mother volume for services in front
   // of the supermodules  (Air), 
@@ -650,8 +549,8 @@ void AliTRDgeometry::CreateGeometry(Int_t *idtmed)
   parTrd[1] = fgkSwidth2/2.0;
   parTrd[2] = fgkFlength/2.0;
   parTrd[3] = fgkSheight/2.0;
-  gMC->Gsvolu("UTF1","TRD1",idtmed[1302-1],parTrd,kNparTrd);
-  gMC->Gsvolu("UTF2","TRD1",idtmed[1302-1],parTrd,kNparTrd);
+  TVirtualMC::GetMC()->Gsvolu("UTF1","TRD1",idtmed[1302-1],parTrd,kNparTrd);
+  TVirtualMC::GetMC()->Gsvolu("UTF2","TRD1",idtmed[1302-1],parTrd,kNparTrd);
 
   for (Int_t istack = 0; istack < kNstack; istack++) {
     for (Int_t ilayer = 0; ilayer < kNlayer; ilayer++) {  
@@ -660,72 +559,72 @@ void AliTRDgeometry::CreateGeometry(Int_t *idtmed)
 
       // The lower part of the readout chambers (drift volume + radiator) 
       // The aluminum frames 
-      sprintf(cTagV,"UA%02d",iDet);
-      parCha[0] = fCwidth[ilayer]/2.0;
-      parCha[1] = fClength[ilayer][istack]/2.0 - fgkHspace/2.0;
+      snprintf(cTagV,kTag,"UA%02d",iDet);
+      parCha[0] = fgkCwidth[ilayer]/2.0;
+      parCha[1] = fgkClength[ilayer][istack]/2.0 - fgkHspace/2.0;
       parCha[2] = fgkCraH/2.0 + fgkCdrH/2.0;
-      gMC->Gsvolu(cTagV,"BOX ",idtmed[1301-1],parCha,kNparCha);
+      TVirtualMC::GetMC()->Gsvolu(cTagV,"BOX ",idtmed[1301-1],parCha,kNparCha);
       // The additional aluminum on the frames
       // This part has not the correct shape but is just supposed to
       // represent the missing material. The correct form of the L-shaped
       // profile would not fit into the alignable volume. 
-      sprintf(cTagV,"UZ%02d",iDet);
+      snprintf(cTagV,kTag,"UZ%02d",iDet);
       parCha[0] = fgkCalWmod/2.0;
-      parCha[1] = fClength[ilayer][istack]/2.0 - fgkHspace/2.0;
+      parCha[1] = fgkClength[ilayer][istack]/2.0 - fgkHspace/2.0;
       parCha[2] = fgkCalHmod/2.0;
-      gMC->Gsvolu(cTagV,"BOX ",idtmed[1301-1],parCha,kNparCha);
+      TVirtualMC::GetMC()->Gsvolu(cTagV,"BOX ",idtmed[1301-1],parCha,kNparCha);
       // The additional Wacosit on the frames
-      sprintf(cTagV,"UP%02d",iDet);
+      snprintf(cTagV,kTag,"UP%02d",iDet);
       parCha[0] = fgkCwsW/2.0;
-      parCha[1] = fClength[ilayer][istack]/2.0 - fgkHspace/2.0;
+      parCha[1] = fgkClength[ilayer][istack]/2.0 - fgkHspace/2.0;
       parCha[2] = fgkCwsH/2.0;
-      gMC->Gsvolu(cTagV,"BOX ",idtmed[1307-1],parCha,kNparCha);
+      TVirtualMC::GetMC()->Gsvolu(cTagV,"BOX ",idtmed[1307-1],parCha,kNparCha);
       // The Wacosit frames 
-      sprintf(cTagV,"UB%02d",iDet);
-      parCha[0] = fCwidth[ilayer]/2.0 - fgkCalT; 
+      snprintf(cTagV,kTag,"UB%02d",iDet);
+      parCha[0] = fgkCwidth[ilayer]/2.0 - fgkCalT; 
       parCha[1] = -1.0;
       parCha[2] = -1.0;
-      gMC->Gsvolu(cTagV,"BOX ",idtmed[1307-1],parCha,kNparCha);
+      TVirtualMC::GetMC()->Gsvolu(cTagV,"BOX ",idtmed[1307-1],parCha,kNparCha);
       // The glue around the radiator
-      sprintf(cTagV,"UX%02d",iDet);
-      parCha[0] = fCwidth[ilayer]/2.0 - fgkCalT - fgkCclsT; 
-      parCha[1] = fClength[ilayer][istack]/2.0 - fgkHspace/2.0 - fgkCclfT;
+      snprintf(cTagV,kTag,"UX%02d",iDet);
+      parCha[0] = fgkCwidth[ilayer]/2.0 - fgkCalT - fgkCclsT; 
+      parCha[1] = fgkClength[ilayer][istack]/2.0 - fgkHspace/2.0 - fgkCclfT;
       parCha[2] = fgkCraH/2.0;
-      gMC->Gsvolu(cTagV,"BOX ",idtmed[1311-1],parCha,kNparCha);
+      TVirtualMC::GetMC()->Gsvolu(cTagV,"BOX ",idtmed[1311-1],parCha,kNparCha);
       // The inner part of radiator (air)
-      sprintf(cTagV,"UC%02d",iDet);
-      parCha[0] = fCwidth[ilayer]/2.0 - fgkCalT - fgkCclsT - fgkCglT; 
-      parCha[1] = fClength[ilayer][istack]/2.0 - fgkHspace/2.0 - fgkCclfT - fgkCglT;
+      snprintf(cTagV,kTag,"UC%02d",iDet);
+      parCha[0] = fgkCwidth[ilayer]/2.0 - fgkCalT - fgkCclsT - fgkCglT; 
+      parCha[1] = fgkClength[ilayer][istack]/2.0 - fgkHspace/2.0 - fgkCclfT - fgkCglT;
       parCha[2] = -1.0;
-      gMC->Gsvolu(cTagV,"BOX ",idtmed[1302-1],parCha,kNparCha);
+      TVirtualMC::GetMC()->Gsvolu(cTagV,"BOX ",idtmed[1302-1],parCha,kNparCha);
 
       // The upper part of the readout chambers (amplification volume)
       // The Wacosit frames
-      sprintf(cTagV,"UD%02d",iDet);
-      parCha[0] = fCwidth[ilayer]/2.0 + fgkCroW;
-      parCha[1] = fClength[ilayer][istack]/2.0 - fgkHspace/2.0;
+      snprintf(cTagV,kTag,"UD%02d",iDet);
+      parCha[0] = fgkCwidth[ilayer]/2.0 + fgkCroW;
+      parCha[1] = fgkClength[ilayer][istack]/2.0 - fgkHspace/2.0;
       parCha[2] = fgkCamH/2.0;
-      gMC->Gsvolu(cTagV,"BOX ",idtmed[1307-1],parCha,kNparCha);
+      TVirtualMC::GetMC()->Gsvolu(cTagV,"BOX ",idtmed[1307-1],parCha,kNparCha);
       // The inner part of the Wacosit frame (air)
-      sprintf(cTagV,"UE%02d",iDet);
-      parCha[0] = fCwidth[ilayer]/2.0 + fgkCroW - fgkCcuTb; 
-      parCha[1] = fClength[ilayer][istack]/2.0 - fgkHspace/2.0 - fgkCcuTa;
+      snprintf(cTagV,kTag,"UE%02d",iDet);
+      parCha[0] = fgkCwidth[ilayer]/2.0 + fgkCroW - fgkCcuTb; 
+      parCha[1] = fgkClength[ilayer][istack]/2.0 - fgkHspace/2.0 - fgkCcuTa;
       parCha[2] = -1.;
-      gMC->Gsvolu(cTagV,"BOX ",idtmed[1302-1],parCha,kNparCha);
+      TVirtualMC::GetMC()->Gsvolu(cTagV,"BOX ",idtmed[1302-1],parCha,kNparCha);
 
       // The back panel, including pad plane and readout boards
       // The aluminum frames
-      sprintf(cTagV,"UF%02d",iDet);
-      parCha[0] = fCwidth[ilayer]/2.0 + fgkCroW;
-      parCha[1] = fClength[ilayer][istack]/2.0 - fgkHspace/2.0;
+      snprintf(cTagV,kTag,"UF%02d",iDet);
+      parCha[0] = fgkCwidth[ilayer]/2.0 + fgkCroW;
+      parCha[1] = fgkClength[ilayer][istack]/2.0 - fgkHspace/2.0;
       parCha[2] = fgkCroH/2.0;
-      gMC->Gsvolu(cTagV,"BOX ",idtmed[1301-1],parCha,kNparCha);
+      TVirtualMC::GetMC()->Gsvolu(cTagV,"BOX ",idtmed[1301-1],parCha,kNparCha);
       // The inner part of the aluminum frames
-      sprintf(cTagV,"UG%02d",iDet);
-      parCha[0] = fCwidth[ilayer]/2.0 + fgkCroW - fgkCauT; 
-      parCha[1] = fClength[ilayer][istack]/2.0 - fgkHspace/2.0 - fgkCauT;
+      snprintf(cTagV,kTag,"UG%02d",iDet);
+      parCha[0] = fgkCwidth[ilayer]/2.0 + fgkCroW - fgkCauT; 
+      parCha[1] = fgkClength[ilayer][istack]/2.0 - fgkHspace/2.0 - fgkCauT;
       parCha[2] = -1.0;
-      gMC->Gsvolu(cTagV,"BOX ",idtmed[1302-1],parCha,kNparCha);
+      TVirtualMC::GetMC()->Gsvolu(cTagV,"BOX ",idtmed[1302-1],parCha,kNparCha);
 
       //
       // The material layers inside the chambers
@@ -735,101 +634,101 @@ void AliTRDgeometry::CreateGeometry(Int_t *idtmed)
       parCha[0] = -1.0;
       parCha[1] = -1.0;
       parCha[2] = fgkRMyThick/2.0;
-      sprintf(cTagV,"URMY%02d",iDet);
-      gMC->Gsvolu(cTagV,"BOX ",idtmed[1327-1],parCha,kNparCha);
+      snprintf(cTagV,kTag,"URMY%02d",iDet);
+      TVirtualMC::GetMC()->Gsvolu(cTagV,"BOX ",idtmed[1327-1],parCha,kNparCha);
       // Carbon layer (radiator)
       parCha[0] = -1.0;
       parCha[1] = -1.0;
       parCha[2] = fgkRCbThick/2.0;
-      sprintf(cTagV,"URCB%02d",iDet);
-      gMC->Gsvolu(cTagV,"BOX ",idtmed[1326-1],parCha,kNparCha);
+      snprintf(cTagV,kTag,"URCB%02d",iDet);
+      TVirtualMC::GetMC()->Gsvolu(cTagV,"BOX ",idtmed[1326-1],parCha,kNparCha);
       // Araldite layer (radiator)
       parCha[0] = -1.0;
       parCha[1] = -1.0;
       parCha[2] = fgkRGlThick/2.0;
-      sprintf(cTagV,"URGL%02d",iDet);
-      gMC->Gsvolu(cTagV,"BOX ",idtmed[1311-1],parCha,kNparCha);
+      snprintf(cTagV,kTag,"URGL%02d",iDet);
+      TVirtualMC::GetMC()->Gsvolu(cTagV,"BOX ",idtmed[1311-1],parCha,kNparCha);
       // Rohacell layer (radiator)
       parCha[0] = -1.0;
       parCha[1] = -1.0;
       parCha[2] = fgkRRhThick/2.0;
-      sprintf(cTagV,"URRH%02d",iDet);
-      gMC->Gsvolu(cTagV,"BOX ",idtmed[1315-1],parCha,kNparCha);
+      snprintf(cTagV,kTag,"URRH%02d",iDet);
+      TVirtualMC::GetMC()->Gsvolu(cTagV,"BOX ",idtmed[1315-1],parCha,kNparCha);
       // Fiber layer (radiator)
       parCha[0] = -1.0;
       parCha[1] = -1.0;
       parCha[2] = fgkRFbThick/2.0;
-      sprintf(cTagV,"URFB%02d",iDet);
-      gMC->Gsvolu(cTagV,"BOX ",idtmed[1328-1],parCha,kNparCha);
+      snprintf(cTagV,kTag,"URFB%02d",iDet);
+      TVirtualMC::GetMC()->Gsvolu(cTagV,"BOX ",idtmed[1328-1],parCha,kNparCha);
 
       // Xe/Isobutane layer (drift volume) 
-      parCha[0] = fCwidth[ilayer]/2.0 - fgkCalT - fgkCclsT;
-      parCha[1] = fClength[ilayer][istack]/2.0 - fgkHspace/2.0 - fgkCclfT;
+      parCha[0] = fgkCwidth[ilayer]/2.0 - fgkCalT - fgkCclsT;
+      parCha[1] = fgkClength[ilayer][istack]/2.0 - fgkHspace/2.0 - fgkCclfT;
       parCha[2] = fgkDrThick/2.0;
-      sprintf(cTagV,"UJ%02d",iDet);
-      gMC->Gsvolu(cTagV,"BOX ",idtmed[1309-1],parCha,kNparCha);
+      snprintf(cTagV,kTag,"UJ%02d",iDet);
+      TVirtualMC::GetMC()->Gsvolu(cTagV,"BOX ",idtmed[1309-1],parCha,kNparCha);
 
       // Xe/Isobutane layer (amplification volume)
       parCha[0] = -1.0;
       parCha[1] = -1.0;
       parCha[2] = fgkAmThick/2.0;
-      sprintf(cTagV,"UK%02d",iDet);
-      gMC->Gsvolu(cTagV,"BOX ",idtmed[1309-1],parCha,kNparCha);  
+      snprintf(cTagV,kTag,"UK%02d",iDet);
+      TVirtualMC::GetMC()->Gsvolu(cTagV,"BOX ",idtmed[1309-1],parCha,kNparCha);  
       // Cu layer (wire plane)
       parCha[0] = -1.0;
       parCha[1] = -1.0;
       parCha[2] = fgkWrThick/2.0;
-      sprintf(cTagV,"UW%02d",iDet);
-      gMC->Gsvolu(cTagV,"BOX ",idtmed[1303-1],parCha,kNparCha);
+      snprintf(cTagV,kTag,"UW%02d",iDet);
+      TVirtualMC::GetMC()->Gsvolu(cTagV,"BOX ",idtmed[1303-1],parCha,kNparCha);
 
       // Cu layer (pad plane)
       parCha[0] = -1.0;
       parCha[1] = -1.0;
       parCha[2] = fgkPPdThick/2.0;
-      sprintf(cTagV,"UPPD%02d",iDet);
-      gMC->Gsvolu(cTagV,"BOX ",idtmed[1305-1],parCha,kNparCha);
+      snprintf(cTagV,kTag,"UPPD%02d",iDet);
+      TVirtualMC::GetMC()->Gsvolu(cTagV,"BOX ",idtmed[1305-1],parCha,kNparCha);
       // G10 layer (pad plane)
       parCha[0] = -1.0;
       parCha[1] = -1.0;
       parCha[2] = fgkPPpThick/2.0;
-      sprintf(cTagV,"UPPP%02d",iDet);
-      gMC->Gsvolu(cTagV,"BOX ",idtmed[1313-1],parCha,kNparCha);
+      snprintf(cTagV,kTag,"UPPP%02d",iDet);
+      TVirtualMC::GetMC()->Gsvolu(cTagV,"BOX ",idtmed[1313-1],parCha,kNparCha);
       // Araldite layer (glue)
       parCha[0] = -1.0;
       parCha[1] = -1.0;
       parCha[2] = fgkPGlThick/2.0;
-      sprintf(cTagV,"UPGL%02d",iDet);
-      gMC->Gsvolu(cTagV,"BOX ",idtmed[1311-1],parCha,kNparCha);
+      snprintf(cTagV,kTag,"UPGL%02d",iDet);
+      TVirtualMC::GetMC()->Gsvolu(cTagV,"BOX ",idtmed[1311-1],parCha,kNparCha);
       // Carbon layer (carbon fiber mats)
       parCha[0] = -1.0;
       parCha[1] = -1.0;
       parCha[2] = fgkPCbThick/2.0;
-      sprintf(cTagV,"UPCB%02d",iDet);
-      gMC->Gsvolu(cTagV,"BOX ",idtmed[1326-1],parCha,kNparCha);
+      snprintf(cTagV,kTag,"UPCB%02d",iDet);
+      TVirtualMC::GetMC()->Gsvolu(cTagV,"BOX ",idtmed[1326-1],parCha,kNparCha);
       // Aramide layer (honeycomb)
       parCha[0] = -1.0;
       parCha[1] = -1.0;
       parCha[2] = fgkPHcThick/2.0;
-      sprintf(cTagV,"UPHC%02d",iDet);
-      gMC->Gsvolu(cTagV,"BOX ",idtmed[1310-1],parCha,kNparCha);
+      snprintf(cTagV,kTag,"UPHC%02d",iDet);
+      TVirtualMC::GetMC()->Gsvolu(cTagV,"BOX ",idtmed[1310-1],parCha,kNparCha);
       // G10 layer (PCB readout board)
       parCha[0] = -1.0;
       parCha[1] = -1.0;
       parCha[2] = fgkPPcThick/2;
-      sprintf(cTagV,"UPPC%02d",iDet);
-      gMC->Gsvolu(cTagV,"BOX ",idtmed[1313-1],parCha,kNparCha);
+      snprintf(cTagV,kTag,"UPPC%02d",iDet);
+      TVirtualMC::GetMC()->Gsvolu(cTagV,"BOX ",idtmed[1313-1],parCha,kNparCha);
       // Cu layer (traces in readout board)
       parCha[0] = -1.0;
       parCha[1] = -1.0;
       parCha[2] = fgkPRbThick/2.0;
-      sprintf(cTagV,"UPRB%02d",iDet);
-      gMC->Gsvolu(cTagV,"BOX ",idtmed[1306-1],parCha,kNparCha);
+      snprintf(cTagV,kTag,"UPRB%02d",iDet);
+      TVirtualMC::GetMC()->Gsvolu(cTagV,"BOX ",idtmed[1306-1],parCha,kNparCha);
       // Cu layer (other material on in readout board, incl. screws)
       parCha[0] = -1.0;
       parCha[1] = -1.0;
       parCha[2] = fgkPElThick/2.0;
-      sprintf(cTagV,"UPEL%02d",iDet);
-      gMC->Gsvolu(cTagV,"BOX ",idtmed[1304-1],parCha,kNparCha);
+      snprintf(cTagV,kTag,"UPEL%02d",iDet);
+      TVirtualMC::GetMC()->Gsvolu(cTagV,"BOX ",idtmed[1304-1],parCha,kNparCha);
 
       //
       // Position the layers in the chambers
@@ -840,113 +739,113 @@ void AliTRDgeometry::CreateGeometry(Int_t *idtmed)
       // Lower part
       // Mylar layers (radiator)
       zpos =  fgkRMyThick/2.0 - fgkCraH/2.0;
-      sprintf(cTagV,"URMY%02d",iDet);
-      sprintf(cTagM,"UC%02d",iDet);
-      gMC->Gspos(cTagV,1,cTagM,xpos,ypos,zpos,0,"ONLY");
+      snprintf(cTagV,kTag,"URMY%02d",iDet);
+      snprintf(cTagM,kTag,"UC%02d",iDet);
+      TVirtualMC::GetMC()->Gspos(cTagV,1,cTagM,xpos,ypos,zpos,0,"ONLY");
       zpos = -fgkRMyThick/2.0 + fgkCraH/2.0;
-      sprintf(cTagV,"URMY%02d",iDet);
-      sprintf(cTagM,"UC%02d",iDet);
-      gMC->Gspos(cTagV,2,cTagM,xpos,ypos,zpos,0,"ONLY");
+      snprintf(cTagV,kTag,"URMY%02d",iDet);
+      snprintf(cTagM,kTag,"UC%02d",iDet);
+      TVirtualMC::GetMC()->Gspos(cTagV,2,cTagM,xpos,ypos,zpos,0,"ONLY");
       // Carbon layers (radiator)
       zpos =  fgkRCbThick/2.0 + fgkRMyThick - fgkCraH/2.0;
-      sprintf(cTagV,"URCB%02d",iDet);
-      sprintf(cTagM,"UC%02d",iDet);
-      gMC->Gspos(cTagV,1,cTagM,xpos,ypos,zpos,0,"ONLY");
+      snprintf(cTagV,kTag,"URCB%02d",iDet);
+      snprintf(cTagM,kTag,"UC%02d",iDet);
+      TVirtualMC::GetMC()->Gspos(cTagV,1,cTagM,xpos,ypos,zpos,0,"ONLY");
       zpos = -fgkRCbThick/2.0 - fgkRMyThick + fgkCraH/2.0;
-      sprintf(cTagV,"URCB%02d",iDet);
-      sprintf(cTagM,"UC%02d",iDet);
-      gMC->Gspos(cTagV,2,cTagM,xpos,ypos,zpos,0,"ONLY");
+      snprintf(cTagV,kTag,"URCB%02d",iDet);
+      snprintf(cTagM,kTag,"UC%02d",iDet);
+      TVirtualMC::GetMC()->Gspos(cTagV,2,cTagM,xpos,ypos,zpos,0,"ONLY");
       // Carbon layers (radiator)
       zpos =  fgkRGlThick/2.0 + fgkRCbThick + fgkRMyThick - fgkCraH/2.0;
-      sprintf(cTagV,"URGL%02d",iDet);
-      sprintf(cTagM,"UC%02d",iDet);
-      gMC->Gspos(cTagV,1,cTagM,xpos,ypos,zpos,0,"ONLY");
+      snprintf(cTagV,kTag,"URGL%02d",iDet);
+      snprintf(cTagM,kTag,"UC%02d",iDet);
+      TVirtualMC::GetMC()->Gspos(cTagV,1,cTagM,xpos,ypos,zpos,0,"ONLY");
       zpos = -fgkRGlThick/2.0 - fgkRCbThick - fgkRMyThick + fgkCraH/2.0;
-      sprintf(cTagV,"URGL%02d",iDet);
-      sprintf(cTagM,"UC%02d",iDet);
-      gMC->Gspos(cTagV,2,cTagM,xpos,ypos,zpos,0,"ONLY");
+      snprintf(cTagV,kTag,"URGL%02d",iDet);
+      snprintf(cTagM,kTag,"UC%02d",iDet);
+      TVirtualMC::GetMC()->Gspos(cTagV,2,cTagM,xpos,ypos,zpos,0,"ONLY");
       // Rohacell layers (radiator)
       zpos =  fgkRRhThick/2.0 + fgkRGlThick + fgkRCbThick + fgkRMyThick - fgkCraH/2.0;
-      sprintf(cTagV,"URRH%02d",iDet);
-      sprintf(cTagM,"UC%02d",iDet);
-      gMC->Gspos(cTagV,1,cTagM,xpos,ypos,zpos,0,"ONLY");
+      snprintf(cTagV,kTag,"URRH%02d",iDet);
+      snprintf(cTagM,kTag,"UC%02d",iDet);
+      TVirtualMC::GetMC()->Gspos(cTagV,1,cTagM,xpos,ypos,zpos,0,"ONLY");
       zpos = -fgkRRhThick/2.0 - fgkRGlThick - fgkRCbThick - fgkRMyThick + fgkCraH/2.0;
-      sprintf(cTagV,"URRH%02d",iDet);
-      sprintf(cTagM,"UC%02d",iDet);
-      gMC->Gspos(cTagV,2,cTagM,xpos,ypos,zpos,0,"ONLY");
+      snprintf(cTagV,kTag,"URRH%02d",iDet);
+      snprintf(cTagM,kTag,"UC%02d",iDet);
+      TVirtualMC::GetMC()->Gspos(cTagV,2,cTagM,xpos,ypos,zpos,0,"ONLY");
       // Fiber layers (radiator)
       zpos =  0.0;
-      sprintf(cTagV,"URFB%02d",iDet);
-      sprintf(cTagM,"UC%02d",iDet);
-      gMC->Gspos(cTagV,1,cTagM,xpos,ypos,zpos,0,"ONLY");
+      snprintf(cTagV,kTag,"URFB%02d",iDet);
+      snprintf(cTagM,kTag,"UC%02d",iDet);
+      TVirtualMC::GetMC()->Gspos(cTagV,1,cTagM,xpos,ypos,zpos,0,"ONLY");
 
       // Xe/Isobutane layer (drift volume) 
       zpos = fgkDrZpos;
-      sprintf(cTagV,"UJ%02d",iDet);
-      sprintf(cTagM,"UB%02d",iDet);
-      gMC->Gspos(cTagV,1,cTagM,xpos,ypos,zpos,0,"ONLY");
+      snprintf(cTagV,kTag,"UJ%02d",iDet);
+      snprintf(cTagM,kTag,"UB%02d",iDet);
+      TVirtualMC::GetMC()->Gspos(cTagV,1,cTagM,xpos,ypos,zpos,0,"ONLY");
 
       // Upper part
       // Xe/Isobutane layer (amplification volume)
       zpos = fgkAmZpos;
-      sprintf(cTagV,"UK%02d",iDet);
-      sprintf(cTagM,"UE%02d",iDet);
-      gMC->Gspos(cTagV,1,cTagM,xpos,ypos,zpos,0,"ONLY");
+      snprintf(cTagV,kTag,"UK%02d",iDet);
+      snprintf(cTagM,kTag,"UE%02d",iDet);
+      TVirtualMC::GetMC()->Gspos(cTagV,1,cTagM,xpos,ypos,zpos,0,"ONLY");
       // Cu layer (wire planes inside amplification volume)
       zpos = fgkWrZposA; 
-      sprintf(cTagV,"UW%02d",iDet);
-      sprintf(cTagM,"UK%02d",iDet);
-      gMC->Gspos(cTagV,1,cTagM,xpos,ypos,zpos,0,"ONLY");
+      snprintf(cTagV,kTag,"UW%02d",iDet);
+      snprintf(cTagM,kTag,"UK%02d",iDet);
+      TVirtualMC::GetMC()->Gspos(cTagV,1,cTagM,xpos,ypos,zpos,0,"ONLY");
       zpos = fgkWrZposB; 
-      sprintf(cTagV,"UW%02d",iDet);
-      sprintf(cTagM,"UK%02d",iDet);
-      gMC->Gspos(cTagV,2,cTagM,xpos,ypos,zpos,0,"ONLY");
+      snprintf(cTagV,kTag,"UW%02d",iDet);
+      snprintf(cTagM,kTag,"UK%02d",iDet);
+      TVirtualMC::GetMC()->Gspos(cTagV,2,cTagM,xpos,ypos,zpos,0,"ONLY");
 
       // Back panel + pad plane + readout part
       // Cu layer (pad plane)
       zpos =  fgkPPdThick/2.0 - fgkCroH/2.0;
-      sprintf(cTagV,"UPPD%02d",iDet);
-      sprintf(cTagM,"UG%02d",iDet);
-      gMC->Gspos(cTagV,1,cTagM,xpos,ypos,zpos,0,"ONLY");
+      snprintf(cTagV,kTag,"UPPD%02d",iDet);
+      snprintf(cTagM,kTag,"UG%02d",iDet);
+      TVirtualMC::GetMC()->Gspos(cTagV,1,cTagM,xpos,ypos,zpos,0,"ONLY");
       // G10  layer (pad plane)
       zpos =  fgkPPpThick/2.0 + fgkPPdThick - fgkCroH/2.0;
-      sprintf(cTagV,"UPPP%02d",iDet);
-      sprintf(cTagM,"UG%02d",iDet);
-      gMC->Gspos(cTagV,1,cTagM,xpos,ypos,zpos,0,"ONLY");
+      snprintf(cTagV,kTag,"UPPP%02d",iDet);
+      snprintf(cTagM,kTag,"UG%02d",iDet);
+      TVirtualMC::GetMC()->Gspos(cTagV,1,cTagM,xpos,ypos,zpos,0,"ONLY");
       // Araldite layer (glue)
       zpos =  fgkPGlThick/2.0 + fgkPPpThick + fgkPPdThick - fgkCroH/2.0;
-      sprintf(cTagV,"UPGL%02d",iDet);
-      sprintf(cTagM,"UG%02d",iDet);
-      gMC->Gspos(cTagV,1,cTagM,xpos,ypos,zpos,0,"ONLY");
+      snprintf(cTagV,kTag,"UPGL%02d",iDet);
+      snprintf(cTagM,kTag,"UG%02d",iDet);
+      TVirtualMC::GetMC()->Gspos(cTagV,1,cTagM,xpos,ypos,zpos,0,"ONLY");
       // Carbon layers (carbon fiber mats)
       zpos =  fgkPCbThick/2.0 + fgkPGlThick + fgkPPpThick + fgkPPdThick - fgkCroH/2.0;
-      sprintf(cTagV,"UPCB%02d",iDet);
-      sprintf(cTagM,"UG%02d",iDet);
-      gMC->Gspos(cTagV,1,cTagM,xpos,ypos,zpos,0,"ONLY");
+      snprintf(cTagV,kTag,"UPCB%02d",iDet);
+      snprintf(cTagM,kTag,"UG%02d",iDet);
+      TVirtualMC::GetMC()->Gspos(cTagV,1,cTagM,xpos,ypos,zpos,0,"ONLY");
       zpos = -fgkPCbThick/2.0 - fgkPPcThick - fgkPRbThick - fgkPElThick + fgkCroH/2.0;
-      sprintf(cTagV,"UPCB%02d",iDet);
-      sprintf(cTagM,"UG%02d",iDet);
-      gMC->Gspos(cTagV,2,cTagM,xpos,ypos,zpos,0,"ONLY");
+      snprintf(cTagV,kTag,"UPCB%02d",iDet);
+      snprintf(cTagM,kTag,"UG%02d",iDet);
+      TVirtualMC::GetMC()->Gspos(cTagV,2,cTagM,xpos,ypos,zpos,0,"ONLY");
       // Aramide layer (honeycomb)
       zpos =  fgkPHcThick/2.0 + fgkPCbThick + fgkPGlThick + fgkPPpThick + fgkPPdThick - fgkCroH/2.0;
-      sprintf(cTagV,"UPHC%02d",iDet);
-      sprintf(cTagM,"UG%02d",iDet);
-      gMC->Gspos(cTagV,1,cTagM,xpos,ypos,zpos,0,"ONLY");
+      snprintf(cTagV,kTag,"UPHC%02d",iDet);
+      snprintf(cTagM,kTag,"UG%02d",iDet);
+      TVirtualMC::GetMC()->Gspos(cTagV,1,cTagM,xpos,ypos,zpos,0,"ONLY");
       // G10 layer (PCB readout board)
       zpos = -fgkPPcThick/2.0 - fgkPRbThick - fgkPElThick + fgkCroH/2.0;
-      sprintf(cTagV,"UPPC%02d",iDet);
-      sprintf(cTagM,"UG%02d",iDet);
-      gMC->Gspos(cTagV,1,cTagM,xpos,ypos,zpos,0,"ONLY");
+      snprintf(cTagV,kTag,"UPPC%02d",iDet);
+      snprintf(cTagM,kTag,"UG%02d",iDet);
+      TVirtualMC::GetMC()->Gspos(cTagV,1,cTagM,xpos,ypos,zpos,0,"ONLY");
       // Cu layer (traces in readout board)
       zpos = -fgkPRbThick/2.0 - fgkPElThick + fgkCroH/2.0;
-      sprintf(cTagV,"UPRB%02d",iDet);
-      sprintf(cTagM,"UG%02d",iDet);
-      gMC->Gspos(cTagV,1,cTagM,xpos,ypos,zpos,0,"ONLY");
+      snprintf(cTagV,kTag,"UPRB%02d",iDet);
+      snprintf(cTagM,kTag,"UG%02d",iDet);
+      TVirtualMC::GetMC()->Gspos(cTagV,1,cTagM,xpos,ypos,zpos,0,"ONLY");
       // Cu layer (other materials on readout board, incl. screws)
       zpos = -fgkPElThick/2.0 + fgkCroH/2.0;
-      sprintf(cTagV,"UPEL%02d",iDet);
-      sprintf(cTagM,"UG%02d",iDet);
-      gMC->Gspos(cTagV,1,cTagM,xpos,ypos,zpos,0,"ONLY");
+      snprintf(cTagV,kTag,"UPEL%02d",iDet);
+      snprintf(cTagM,kTag,"UG%02d",iDet);
+      TVirtualMC::GetMC()->Gspos(cTagV,1,cTagM,xpos,ypos,zpos,0,"ONLY");
 
       // Position the inner volumes of the chambers in the frames
       xpos = 0.0;
@@ -954,31 +853,31 @@ void AliTRDgeometry::CreateGeometry(Int_t *idtmed)
 
       // The inner part of the radiator (air)
       zpos = 0.0;
-      sprintf(cTagV,"UC%02d",iDet);
-      sprintf(cTagM,"UX%02d",iDet);
-      gMC->Gspos(cTagV,1,cTagM,xpos,ypos,zpos,0,"ONLY");
+      snprintf(cTagV,kTag,"UC%02d",iDet);
+      snprintf(cTagM,kTag,"UX%02d",iDet);
+      TVirtualMC::GetMC()->Gspos(cTagV,1,cTagM,xpos,ypos,zpos,0,"ONLY");
       // The glue around the radiator
       zpos = fgkCraH/2.0 - fgkCdrH/2.0 - fgkCraH/2.0;
-      sprintf(cTagV,"UX%02d",iDet);
-      sprintf(cTagM,"UB%02d",iDet);
-      gMC->Gspos(cTagV,1,cTagM,xpos,ypos,zpos,0,"ONLY");
+      snprintf(cTagV,kTag,"UX%02d",iDet);
+      snprintf(cTagM,kTag,"UB%02d",iDet);
+      TVirtualMC::GetMC()->Gspos(cTagV,1,cTagM,xpos,ypos,zpos,0,"ONLY");
       // The lower Wacosit frame inside the aluminum frame
       zpos = 0.0;
-      sprintf(cTagV,"UB%02d",iDet);
-      sprintf(cTagM,"UA%02d",iDet);
-      gMC->Gspos(cTagV,1,cTagM,xpos,ypos,zpos,0,"ONLY");
+      snprintf(cTagV,kTag,"UB%02d",iDet);
+      snprintf(cTagM,kTag,"UA%02d",iDet);
+      TVirtualMC::GetMC()->Gspos(cTagV,1,cTagM,xpos,ypos,zpos,0,"ONLY");
 
       // The inside of the upper Wacosit frame
       zpos = 0.0;
-      sprintf(cTagV,"UE%02d",iDet);
-      sprintf(cTagM,"UD%02d",iDet);
-      gMC->Gspos(cTagV,1,cTagM,xpos,ypos,zpos,0,"ONLY");
+      snprintf(cTagV,kTag,"UE%02d",iDet);
+      snprintf(cTagM,kTag,"UD%02d",iDet);
+      TVirtualMC::GetMC()->Gspos(cTagV,1,cTagM,xpos,ypos,zpos,0,"ONLY");
 
       // The inside of the upper aluminum frame
       zpos = 0.0;
-      sprintf(cTagV,"UG%02d",iDet);
-      sprintf(cTagM,"UF%02d",iDet);
-      gMC->Gspos(cTagV,1,cTagM,xpos,ypos,zpos,0,"ONLY");      
+      snprintf(cTagV,kTag,"UG%02d",iDet);
+      snprintf(cTagM,kTag,"UF%02d",iDet);
+      TVirtualMC::GetMC()->Gspos(cTagV,1,cTagM,xpos,ypos,zpos,0,"ONLY");      
 
     }
   }
@@ -998,16 +897,16 @@ void AliTRDgeometry::CreateGeometry(Int_t *idtmed)
   xpos = 0.0;
   ypos = 0.0;
   zpos = 0.0;
-  gMC->Gspos("UTI1",1,"UTS1",xpos,ypos,zpos,0,"ONLY");
-  gMC->Gspos("UTI2",1,"UTS2",xpos,ypos,zpos,0,"ONLY");
-  gMC->Gspos("UTI3",1,"UTS3",xpos,ypos,zpos,0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTI1",1,"UTS1",xpos,ypos,zpos,0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTI2",1,"UTS2",xpos,ypos,zpos,0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTI3",1,"UTS3",xpos,ypos,zpos,0,"ONLY");
 
   xpos = 0.0;
   ypos = 0.0;
   zpos = 0.0;
-  gMC->Gspos("UTS1",1,"UTR1",xpos,ypos,zpos,0,"ONLY");
-  gMC->Gspos("UTS2",1,"UTR2",xpos,ypos,zpos,0,"ONLY");
-  gMC->Gspos("UTS3",1,"UTR3",xpos,ypos,zpos,0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTS1",1,"UTR1",xpos,ypos,zpos,0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTS2",1,"UTR2",xpos,ypos,zpos,0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTS3",1,"UTR3",xpos,ypos,zpos,0,"ONLY");
 
   // Put the TRD volumes into the space frame mother volumes
   // if enabled via status flag
@@ -1016,22 +915,22 @@ void AliTRDgeometry::CreateGeometry(Int_t *idtmed)
   zpos = 0.0;
   for (Int_t isector = 0; isector < kNsector; isector++) {
     if (GetSMstatus(isector)) {
-      sprintf(cTagV,"BTRD%d",isector);
+      snprintf(cTagV,kTag,"BTRD%d",isector);
       switch (isector) {
       case 13:
       case 14:
       case 15:
         // Double carbon, w/o middle stack
-        gMC->Gspos("UTR3",1,cTagV,xpos,ypos,zpos,0,"ONLY");
+        TVirtualMC::GetMC()->Gspos("UTR3",1,cTagV,xpos,ypos,zpos,0,"ONLY");
         break;
       case 11:
       case 12:
        // Double carbon, all stacks
-        gMC->Gspos("UTR2",1,cTagV,xpos,ypos,zpos,0,"ONLY");
+        TVirtualMC::GetMC()->Gspos("UTR2",1,cTagV,xpos,ypos,zpos,0,"ONLY");
         break;
       default:
        // Standard supermodule
-        gMC->Gspos("UTR1",1,cTagV,xpos,ypos,zpos,0,"ONLY");
+        TVirtualMC::GetMC()->Gspos("UTR1",1,cTagV,xpos,ypos,zpos,0,"ONLY");
       };
     }
   }
@@ -1043,9 +942,9 @@ void AliTRDgeometry::CreateGeometry(Int_t *idtmed)
   zpos = 0.0;
   for (Int_t isector = 0; isector < kNsector; isector++) {
     if (GetSMstatus(isector)) {
-      sprintf(cTagV,"BTRD%d",isector);
-      gMC->Gspos("UTF1",1,cTagV,xpos, ypos,zpos,0,"ONLY");
-      gMC->Gspos("UTF2",1,cTagV,xpos,-ypos,zpos,0,"ONLY");
+      snprintf(cTagV,kTag,"BTRD%d",isector);
+      TVirtualMC::GetMC()->Gspos("UTF1",1,cTagV,xpos, ypos,zpos,0,"ONLY");
+      TVirtualMC::GetMC()->Gspos("UTF2",1,cTagV,xpos,-ypos,zpos,0,"ONLY");
     }
   }
 
@@ -1071,8 +970,9 @@ void AliTRDgeometry::CreateFrame(Int_t *idtmed)
   Float_t ypos  = 0.0;
   Float_t zpos  = 0.0;
 
-  Char_t  cTagV[100];
-  Char_t  cTagM[100];
+  const Int_t kTag = 100;
+  Char_t  cTagV[kTag];
+  Char_t  cTagM[kTag];
 
   const Int_t kNparTRD = 4;
   Float_t parTRD[kNparTRD];
@@ -1084,13 +984,13 @@ void AliTRDgeometry::CreateFrame(Int_t *idtmed)
   // The rotation matrices
   const Int_t kNmatrix = 7;
   Int_t   matrix[kNmatrix];
-  gMC->Matrix(matrix[0], 100.0,   0.0,  90.0,  90.0,  10.0,   0.0);
-  gMC->Matrix(matrix[1],  80.0,   0.0,  90.0,  90.0,  10.0, 180.0);
-  gMC->Matrix(matrix[2],  90.0,   0.0,   0.0,   0.0,  90.0,  90.0);
-  gMC->Matrix(matrix[3],  90.0, 180.0,   0.0, 180.0,  90.0,  90.0);
-  gMC->Matrix(matrix[4], 170.0,   0.0,  80.0,   0.0,  90.0,  90.0);
-  gMC->Matrix(matrix[5], 170.0, 180.0,  80.0, 180.0,  90.0,  90.0);
-  gMC->Matrix(matrix[6], 180.0, 180.0,  90.0, 180.0,  90.0,  90.0);
+  TVirtualMC::GetMC()->Matrix(matrix[0], 100.0,   0.0,  90.0,  90.0,  10.0,   0.0);
+  TVirtualMC::GetMC()->Matrix(matrix[1],  80.0,   0.0,  90.0,  90.0,  10.0, 180.0);
+  TVirtualMC::GetMC()->Matrix(matrix[2],  90.0,   0.0,   0.0,   0.0,  90.0,  90.0);
+  TVirtualMC::GetMC()->Matrix(matrix[3],  90.0, 180.0,   0.0, 180.0,  90.0,  90.0);
+  TVirtualMC::GetMC()->Matrix(matrix[4], 170.0,   0.0,  80.0,   0.0,  90.0,  90.0);
+  TVirtualMC::GetMC()->Matrix(matrix[5], 170.0, 180.0,  80.0, 180.0,  90.0,  90.0);
+  TVirtualMC::GetMC()->Matrix(matrix[6], 180.0, 180.0,  90.0, 180.0,  90.0,  90.0);
 
   //
   // The carbon inserts in the top/bottom aluminum plates
@@ -1101,7 +1001,7 @@ void AliTRDgeometry::CreateFrame(Int_t *idtmed)
   parCrb[0] = 0.0;
   parCrb[1] = 0.0;
   parCrb[2] = 0.0;
-  gMC->Gsvolu("USCR","BOX ",idtmed[1326-1],parCrb,0);
+  TVirtualMC::GetMC()->Gsvolu("USCR","BOX ",idtmed[1326-1],parCrb,0);
   // Bottom 1 (all sectors)
   parCrb[0] =  77.49/2.0;
   parCrb[1] = 104.60/2.0;
@@ -1109,9 +1009,9 @@ void AliTRDgeometry::CreateFrame(Int_t *idtmed)
   xpos      =   0.0;
   ypos      =   0.0;
   zpos      = fgkSMpltT/2.0 - fgkSheight/2.0;
-  gMC->Gsposp("USCR", 1,"UTS1", xpos, ypos, zpos,0,"ONLY",parCrb,kNparCrb);
-  gMC->Gsposp("USCR", 2,"UTS2", xpos, ypos, zpos,0,"ONLY",parCrb,kNparCrb);
-  gMC->Gsposp("USCR", 3,"UTS3", xpos, ypos, zpos,0,"ONLY",parCrb,kNparCrb);
+  TVirtualMC::GetMC()->Gsposp("USCR", 1,"UTS1", xpos, ypos, zpos,0,"ONLY",parCrb,kNparCrb);
+  TVirtualMC::GetMC()->Gsposp("USCR", 2,"UTS2", xpos, ypos, zpos,0,"ONLY",parCrb,kNparCrb);
+  TVirtualMC::GetMC()->Gsposp("USCR", 3,"UTS3", xpos, ypos, zpos,0,"ONLY",parCrb,kNparCrb);
   // Bottom 2 (all sectors)
   parCrb[0] =  77.49/2.0;
   parCrb[1] =  55.80/2.0;
@@ -1119,12 +1019,12 @@ void AliTRDgeometry::CreateFrame(Int_t *idtmed)
   xpos      =   0.0;
   ypos      =  85.6;
   zpos      = fgkSMpltT/2.0 - fgkSheight/2.0;
-  gMC->Gsposp("USCR", 4,"UTS1", xpos, ypos, zpos,0,"ONLY",parCrb,kNparCrb);
-  gMC->Gsposp("USCR", 5,"UTS2", xpos, ypos, zpos,0,"ONLY",parCrb,kNparCrb);
-  gMC->Gsposp("USCR", 6,"UTS3", xpos, ypos, zpos,0,"ONLY",parCrb,kNparCrb);
-  gMC->Gsposp("USCR", 7,"UTS1", xpos,-ypos, zpos,0,"ONLY",parCrb,kNparCrb);
-  gMC->Gsposp("USCR", 8,"UTS2", xpos,-ypos, zpos,0,"ONLY",parCrb,kNparCrb);
-  gMC->Gsposp("USCR", 9,"UTS3", xpos,-ypos, zpos,0,"ONLY",parCrb,kNparCrb);
+  TVirtualMC::GetMC()->Gsposp("USCR", 4,"UTS1", xpos, ypos, zpos,0,"ONLY",parCrb,kNparCrb);
+  TVirtualMC::GetMC()->Gsposp("USCR", 5,"UTS2", xpos, ypos, zpos,0,"ONLY",parCrb,kNparCrb);
+  TVirtualMC::GetMC()->Gsposp("USCR", 6,"UTS3", xpos, ypos, zpos,0,"ONLY",parCrb,kNparCrb);
+  TVirtualMC::GetMC()->Gsposp("USCR", 7,"UTS1", xpos,-ypos, zpos,0,"ONLY",parCrb,kNparCrb);
+  TVirtualMC::GetMC()->Gsposp("USCR", 8,"UTS2", xpos,-ypos, zpos,0,"ONLY",parCrb,kNparCrb);
+  TVirtualMC::GetMC()->Gsposp("USCR", 9,"UTS3", xpos,-ypos, zpos,0,"ONLY",parCrb,kNparCrb);
   // Bottom 3 (all sectors)
   parCrb[0] =  77.49/2.0;
   parCrb[1] =  56.00/2.0;
@@ -1132,12 +1032,12 @@ void AliTRDgeometry::CreateFrame(Int_t *idtmed)
   xpos      =   0.0;
   ypos      = 148.5;
   zpos      = fgkSMpltT/2.0 - fgkSheight/2.0;
-  gMC->Gsposp("USCR",10,"UTS1", xpos, ypos, zpos,0,"ONLY",parCrb,kNparCrb);
-  gMC->Gsposp("USCR",11,"UTS2", xpos, ypos, zpos,0,"ONLY",parCrb,kNparCrb);
-  gMC->Gsposp("USCR",12,"UTS3", xpos, ypos, zpos,0,"ONLY",parCrb,kNparCrb);
-  gMC->Gsposp("USCR",13,"UTS1", xpos,-ypos, zpos,0,"ONLY",parCrb,kNparCrb);
-  gMC->Gsposp("USCR",14,"UTS2", xpos,-ypos, zpos,0,"ONLY",parCrb,kNparCrb);
-  gMC->Gsposp("USCR",15,"UTS3", xpos,-ypos, zpos,0,"ONLY",parCrb,kNparCrb);
+  TVirtualMC::GetMC()->Gsposp("USCR",10,"UTS1", xpos, ypos, zpos,0,"ONLY",parCrb,kNparCrb);
+  TVirtualMC::GetMC()->Gsposp("USCR",11,"UTS2", xpos, ypos, zpos,0,"ONLY",parCrb,kNparCrb);
+  TVirtualMC::GetMC()->Gsposp("USCR",12,"UTS3", xpos, ypos, zpos,0,"ONLY",parCrb,kNparCrb);
+  TVirtualMC::GetMC()->Gsposp("USCR",13,"UTS1", xpos,-ypos, zpos,0,"ONLY",parCrb,kNparCrb);
+  TVirtualMC::GetMC()->Gsposp("USCR",14,"UTS2", xpos,-ypos, zpos,0,"ONLY",parCrb,kNparCrb);
+  TVirtualMC::GetMC()->Gsposp("USCR",15,"UTS3", xpos,-ypos, zpos,0,"ONLY",parCrb,kNparCrb);
   // Bottom 4 (all sectors)
   parCrb[0] =  77.49/2.0;
   parCrb[1] = 118.00/2.0;
@@ -1145,12 +1045,12 @@ void AliTRDgeometry::CreateFrame(Int_t *idtmed)
   xpos      =   0.0;
   ypos      = 240.5;
   zpos      = fgkSMpltT/2.0 - fgkSheight/2.0;
-  gMC->Gsposp("USCR",16,"UTS1", xpos, ypos, zpos,0,"ONLY",parCrb,kNparCrb);
-  gMC->Gsposp("USCR",17,"UTS2", xpos, ypos, zpos,0,"ONLY",parCrb,kNparCrb);
-  gMC->Gsposp("USCR",18,"UTS3", xpos, ypos, zpos,0,"ONLY",parCrb,kNparCrb);
-  gMC->Gsposp("USCR",19,"UTS1", xpos,-ypos, zpos,0,"ONLY",parCrb,kNparCrb);
-  gMC->Gsposp("USCR",20,"UTS2", xpos,-ypos, zpos,0,"ONLY",parCrb,kNparCrb);
-  gMC->Gsposp("USCR",21,"UTS3", xpos,-ypos, zpos,0,"ONLY",parCrb,kNparCrb);
+  TVirtualMC::GetMC()->Gsposp("USCR",16,"UTS1", xpos, ypos, zpos,0,"ONLY",parCrb,kNparCrb);
+  TVirtualMC::GetMC()->Gsposp("USCR",17,"UTS2", xpos, ypos, zpos,0,"ONLY",parCrb,kNparCrb);
+  TVirtualMC::GetMC()->Gsposp("USCR",18,"UTS3", xpos, ypos, zpos,0,"ONLY",parCrb,kNparCrb);
+  TVirtualMC::GetMC()->Gsposp("USCR",19,"UTS1", xpos,-ypos, zpos,0,"ONLY",parCrb,kNparCrb);
+  TVirtualMC::GetMC()->Gsposp("USCR",20,"UTS2", xpos,-ypos, zpos,0,"ONLY",parCrb,kNparCrb);
+  TVirtualMC::GetMC()->Gsposp("USCR",21,"UTS3", xpos,-ypos, zpos,0,"ONLY",parCrb,kNparCrb);
   // Top 1 (only in front of PHOS)
   parCrb[0] = 111.48/2.0;
   parCrb[1] = 105.00/2.0;
@@ -1158,8 +1058,8 @@ void AliTRDgeometry::CreateFrame(Int_t *idtmed)
   xpos      =   0.0;
   ypos      =   0.0;
   zpos      = fgkSMpltT/2.0 - fgkSheight/2.0;
-  gMC->Gsposp("USCR",22,"UTS2", xpos, ypos,-zpos,0,"ONLY",parCrb,kNparCrb);
-  gMC->Gsposp("USCR",23,"UTS3", xpos, ypos,-zpos,0,"ONLY",parCrb,kNparCrb);
+  TVirtualMC::GetMC()->Gsposp("USCR",22,"UTS2", xpos, ypos,-zpos,0,"ONLY",parCrb,kNparCrb);
+  TVirtualMC::GetMC()->Gsposp("USCR",23,"UTS3", xpos, ypos,-zpos,0,"ONLY",parCrb,kNparCrb);
   // Top 2 (only in front of PHOS)
   parCrb[0] = 111.48/2.0;
   parCrb[1] =  56.00/2.0;
@@ -1167,10 +1067,10 @@ void AliTRDgeometry::CreateFrame(Int_t *idtmed)
   xpos      =   0.0;
   ypos      =  85.5;
   zpos      = fgkSMpltT/2.0 - fgkSheight/2.0;
-  gMC->Gsposp("USCR",24,"UTS2", xpos, ypos,-zpos,0,"ONLY",parCrb,kNparCrb);
-  gMC->Gsposp("USCR",25,"UTS3", xpos, ypos,-zpos,0,"ONLY",parCrb,kNparCrb);
-  gMC->Gsposp("USCR",26,"UTS2", xpos,-ypos,-zpos,0,"ONLY",parCrb,kNparCrb);
-  gMC->Gsposp("USCR",27,"UTS3", xpos,-ypos,-zpos,0,"ONLY",parCrb,kNparCrb);
+  TVirtualMC::GetMC()->Gsposp("USCR",24,"UTS2", xpos, ypos,-zpos,0,"ONLY",parCrb,kNparCrb);
+  TVirtualMC::GetMC()->Gsposp("USCR",25,"UTS3", xpos, ypos,-zpos,0,"ONLY",parCrb,kNparCrb);
+  TVirtualMC::GetMC()->Gsposp("USCR",26,"UTS2", xpos,-ypos,-zpos,0,"ONLY",parCrb,kNparCrb);
+  TVirtualMC::GetMC()->Gsposp("USCR",27,"UTS3", xpos,-ypos,-zpos,0,"ONLY",parCrb,kNparCrb);
 
   //
   // The chamber support rails
@@ -1194,23 +1094,23 @@ void AliTRDgeometry::CreateFrame(Int_t *idtmed)
   parSRL[ 8] = kSRLwidB /2.0;
   parSRL[ 9] = kSRLwidA /2.0;
   parSRL[10] = 5.0;
-  gMC->Gsvolu("USRL","TRAP",idtmed[1301-1],parSRL,kNparSRL);
+  TVirtualMC::GetMC()->Gsvolu("USRL","TRAP",idtmed[1301-1],parSRL,kNparSRL);
 
   xpos  = 0.0;
   ypos  = 0.0;
   zpos  = 0.0;
   for (ilayer = 1; ilayer < kNlayer; ilayer++) {
-    xpos  = fCwidth[ilayer]/2.0 + kSRLwidA/2.0 + kSRLdst;
+    xpos  = fgkCwidth[ilayer]/2.0 + kSRLwidA/2.0 + kSRLdst;
     ypos  = 0.0;
     zpos  = fgkVrocsm + fgkSMpltT - fgkCalZpos - fgkSheight/2.0  
           + fgkCraH + fgkCdrH - fgkCalH - kSRLhgt/2.0 
           + ilayer * (fgkCH + fgkVspace);
-    gMC->Gspos("USRL",ilayer+1          ,"UTI1", xpos,ypos,zpos,matrix[2],"ONLY");
-    gMC->Gspos("USRL",ilayer+1+  kNlayer,"UTI1",-xpos,ypos,zpos,matrix[3],"ONLY");
-    gMC->Gspos("USRL",ilayer+1+2*kNlayer,"UTI2", xpos,ypos,zpos,matrix[2],"ONLY");
-    gMC->Gspos("USRL",ilayer+1+3*kNlayer,"UTI2",-xpos,ypos,zpos,matrix[3],"ONLY");
-    gMC->Gspos("USRL",ilayer+1+4*kNlayer,"UTI3", xpos,ypos,zpos,matrix[2],"ONLY");
-    gMC->Gspos("USRL",ilayer+1+5*kNlayer,"UTI3",-xpos,ypos,zpos,matrix[3],"ONLY");
+    TVirtualMC::GetMC()->Gspos("USRL",ilayer+1          ,"UTI1", xpos,ypos,zpos,matrix[2],"ONLY");
+    TVirtualMC::GetMC()->Gspos("USRL",ilayer+1+  kNlayer,"UTI1",-xpos,ypos,zpos,matrix[3],"ONLY");
+    TVirtualMC::GetMC()->Gspos("USRL",ilayer+1+2*kNlayer,"UTI2", xpos,ypos,zpos,matrix[2],"ONLY");
+    TVirtualMC::GetMC()->Gspos("USRL",ilayer+1+3*kNlayer,"UTI2",-xpos,ypos,zpos,matrix[3],"ONLY");
+    TVirtualMC::GetMC()->Gspos("USRL",ilayer+1+4*kNlayer,"UTI3", xpos,ypos,zpos,matrix[2],"ONLY");
+    TVirtualMC::GetMC()->Gspos("USRL",ilayer+1+5*kNlayer,"UTI3",-xpos,ypos,zpos,matrix[3],"ONLY");
   }
 
   //
@@ -1236,9 +1136,9 @@ void AliTRDgeometry::CreateFrame(Int_t *idtmed)
   for (ilayer = 0; ilayer < kNlayer; ilayer++) {
 
     // The aluminum of the cross bars
-    parSCB[0] = fCwidth[ilayer]/2.0 + kSRLdst/2.0;
-    sprintf(cTagV,"USF%01d",ilayer);
-    gMC->Gsvolu(cTagV,"BOX ",idtmed[1301-1],parSCB,kNparSCB);
+    parSCB[0] = fgkCwidth[ilayer]/2.0 + kSRLdst/2.0;
+    snprintf(cTagV,kTag,"USF%01d",ilayer);
+    TVirtualMC::GetMC()->Gsvolu(cTagV,"BOX ",idtmed[1301-1],parSCB,kNparSCB);
 
     // The empty regions in the cross bars
     Float_t thkSCB = kSCBthk;
@@ -1247,36 +1147,36 @@ void AliTRDgeometry::CreateFrame(Int_t *idtmed)
     }
     parSCI[2] = parSCB[2] - thkSCB;
     parSCI[0] = parSCB[0]/4.0 - kSCBthk;
-    sprintf(cTagV,"USI%01d",ilayer);
-    gMC->Gsvolu(cTagV,"BOX ",idtmed[1302-1],parSCI,kNparSCI);
+    snprintf(cTagV,kTag,"USI%01d",ilayer);
+    TVirtualMC::GetMC()->Gsvolu(cTagV,"BOX ",idtmed[1302-1],parSCI,kNparSCI);
 
-    sprintf(cTagV,"USI%01d",ilayer);
-    sprintf(cTagM,"USF%01d",ilayer);
+    snprintf(cTagV,kTag,"USI%01d",ilayer);
+    snprintf(cTagM,kTag,"USF%01d",ilayer);
     ypos  = 0.0;
     zpos  = 0.0;
     xpos  =   parSCI[0] + thkSCB/2.0;
-    gMC->Gspos(cTagV,1,cTagM,xpos,ypos,zpos,0,"ONLY");
+    TVirtualMC::GetMC()->Gspos(cTagV,1,cTagM,xpos,ypos,zpos,0,"ONLY");
     xpos  = - parSCI[0] - thkSCB/2.0;
-    gMC->Gspos(cTagV,2,cTagM,xpos,ypos,zpos,0,"ONLY");
+    TVirtualMC::GetMC()->Gspos(cTagV,2,cTagM,xpos,ypos,zpos,0,"ONLY");
     xpos  =   3.0 * parSCI[0] + 1.5 * thkSCB;
-    gMC->Gspos(cTagV,3,cTagM,xpos,ypos,zpos,0,"ONLY");
+    TVirtualMC::GetMC()->Gspos(cTagV,3,cTagM,xpos,ypos,zpos,0,"ONLY");
     xpos  = - 3.0 * parSCI[0] - 1.5 * thkSCB;
-    gMC->Gspos(cTagV,4,cTagM,xpos,ypos,zpos,0,"ONLY");
+    TVirtualMC::GetMC()->Gspos(cTagV,4,cTagM,xpos,ypos,zpos,0,"ONLY");
 
-    sprintf(cTagV,"USF%01d",ilayer);
+    snprintf(cTagV,kTag,"USF%01d",ilayer);
     xpos  = 0.0;
     zpos  = fgkVrocsm + fgkSMpltT + parSCB[2] - fgkSheight/2.0 
           + ilayer * (fgkCH + fgkVspace);
 
-    ypos  =   fClength[ilayer][2]/2.0 + fClength[ilayer][1];
-    gMC->Gspos(cTagV, 1,"UTI1", xpos,ypos,zpos,0,"ONLY");
-    gMC->Gspos(cTagV, 3,"UTI2", xpos,ypos,zpos,0,"ONLY");
-    gMC->Gspos(cTagV, 5,"UTI3", xpos,ypos,zpos,0,"ONLY");
+    ypos  =   fgkClength[ilayer][2]/2.0 + fgkClength[ilayer][1];
+    TVirtualMC::GetMC()->Gspos(cTagV, 1,"UTI1", xpos,ypos,zpos,0,"ONLY");
+    TVirtualMC::GetMC()->Gspos(cTagV, 3,"UTI2", xpos,ypos,zpos,0,"ONLY");
+    TVirtualMC::GetMC()->Gspos(cTagV, 5,"UTI3", xpos,ypos,zpos,0,"ONLY");
 
-    ypos  = - fClength[ilayer][2]/2.0 - fClength[ilayer][1];
-    gMC->Gspos(cTagV, 2,"UTI1", xpos,ypos,zpos,0,"ONLY");
-    gMC->Gspos(cTagV, 4,"UTI2", xpos,ypos,zpos,0,"ONLY");
-    gMC->Gspos(cTagV, 6,"UTI3", xpos,ypos,zpos,0,"ONLY");
+    ypos  = - fgkClength[ilayer][2]/2.0 - fgkClength[ilayer][1];
+    TVirtualMC::GetMC()->Gspos(cTagV, 2,"UTI1", xpos,ypos,zpos,0,"ONLY");
+    TVirtualMC::GetMC()->Gspos(cTagV, 4,"UTI2", xpos,ypos,zpos,0,"ONLY");
+    TVirtualMC::GetMC()->Gspos(cTagV, 6,"UTI3", xpos,ypos,zpos,0,"ONLY");
 
   }
 
@@ -1289,24 +1189,24 @@ void AliTRDgeometry::CreateFrame(Int_t *idtmed)
 
   for (ilayer = 1; ilayer < kNlayer-1; ilayer++) {
 
-    parSCH[0] = fCwidth[ilayer]/2.0;
-    parSCH[1] = (fClength[ilayer+1][2]/2.0 + fClength[ilayer+1][1]
-               - fClength[ilayer  ][2]/2.0 - fClength[ilayer  ][1])/2.0;
+    parSCH[0] = fgkCwidth[ilayer]/2.0;
+    parSCH[1] = (fgkClength[ilayer+1][2]/2.0 + fgkClength[ilayer+1][1]
+               - fgkClength[ilayer  ][2]/2.0 - fgkClength[ilayer  ][1])/2.0;
     parSCH[2] = kSCHhgt/2.0;
 
-    sprintf(cTagV,"USH%01d",ilayer);
-    gMC->Gsvolu(cTagV,"BOX ",idtmed[1301-1],parSCH,kNparSCH);
+    snprintf(cTagV,kTag,"USH%01d",ilayer);
+    TVirtualMC::GetMC()->Gsvolu(cTagV,"BOX ",idtmed[1301-1],parSCH,kNparSCH);
     xpos  = 0.0;
-    ypos  = fClength[ilayer][2]/2.0 + fClength[ilayer][1] + parSCH[1];
+    ypos  = fgkClength[ilayer][2]/2.0 + fgkClength[ilayer][1] + parSCH[1];
     zpos  = fgkVrocsm + fgkSMpltT - kSCHhgt/2.0 - fgkSheight/2.0 
           + (ilayer+1) * (fgkCH + fgkVspace);
-    gMC->Gspos(cTagV,1,"UTI1", xpos,ypos,zpos,0,"ONLY");
-    gMC->Gspos(cTagV,3,"UTI2", xpos,ypos,zpos,0,"ONLY");
-    gMC->Gspos(cTagV,5,"UTI3", xpos,ypos,zpos,0,"ONLY");
+    TVirtualMC::GetMC()->Gspos(cTagV,1,"UTI1", xpos,ypos,zpos,0,"ONLY");
+    TVirtualMC::GetMC()->Gspos(cTagV,3,"UTI2", xpos,ypos,zpos,0,"ONLY");
+    TVirtualMC::GetMC()->Gspos(cTagV,5,"UTI3", xpos,ypos,zpos,0,"ONLY");
     ypos  = -ypos;
-    gMC->Gspos(cTagV,2,"UTI1", xpos,ypos,zpos,0,"ONLY");
-    gMC->Gspos(cTagV,4,"UTI2", xpos,ypos,zpos,0,"ONLY");
-    gMC->Gspos(cTagV,6,"UTI3", xpos,ypos,zpos,0,"ONLY");
+    TVirtualMC::GetMC()->Gspos(cTagV,2,"UTI1", xpos,ypos,zpos,0,"ONLY");
+    TVirtualMC::GetMC()->Gspos(cTagV,4,"UTI2", xpos,ypos,zpos,0,"ONLY");
+    TVirtualMC::GetMC()->Gspos(cTagV,6,"UTI3", xpos,ypos,zpos,0,"ONLY");
 
   }
 
@@ -1319,7 +1219,7 @@ void AliTRDgeometry::CreateFrame(Int_t *idtmed)
   parTRD[1]  = 114.00/2.0;
   parTRD[2]  =   1.20/2.0;
   parTRD[3]  =  71.30/2.0;
-  gMC->Gsvolu("USDB","TRD1",idtmed[1301-1],parTRD,kNparTRD);
+  TVirtualMC::GetMC()->Gsvolu("USDB","TRD1",idtmed[1301-1],parTRD,kNparTRD);
   // Empty spaces (air)
   parTRP[ 0] =   1.20/2.0;
   parTRP[ 1] =   0.0;
@@ -1332,11 +1232,11 @@ void AliTRDgeometry::CreateFrame(Int_t *idtmed)
   parTRP[ 8] =  50.60/2.0;
   parTRP[ 9] =   5.00/2.0;
   parTRP[10] =   3.5;
-  gMC->Gsvolu("USD1","TRAP",idtmed[1302-1],parTRP,kNparTRP);
+  TVirtualMC::GetMC()->Gsvolu("USD1","TRAP",idtmed[1302-1],parTRP,kNparTRP);
   xpos       =  18.0;
   ypos       =   0.0;
   zpos       =   27.00/2.0 - 71.3/2.0;
-  gMC->Gspos("USD1",1,"USDB", xpos, ypos, zpos,matrix[2],"ONLY");
+  TVirtualMC::GetMC()->Gspos("USD1",1,"USDB", xpos, ypos, zpos,matrix[2],"ONLY");
   // Empty spaces (air)
   parTRP[ 0] =   1.20/2.0;
   parTRP[ 1] =   0.0;
@@ -1349,20 +1249,20 @@ void AliTRDgeometry::CreateFrame(Int_t *idtmed)
   parTRP[ 8] =   5.00/2.0;
   parTRP[ 9] =  62.10/2.0;
   parTRP[10] =   3.5;
-  gMC->Gsvolu("USD2","TRAP",idtmed[1302-1],parTRP,kNparTRP);
+  TVirtualMC::GetMC()->Gsvolu("USD2","TRAP",idtmed[1302-1],parTRP,kNparTRP);
   xpos       =  21.0;
   ypos       =   0.0;
   zpos       =  71.3/2.0 - 33.0/2.0;
-  gMC->Gspos("USD2",1,"USDB", xpos, ypos, zpos,matrix[2],"ONLY");
+  TVirtualMC::GetMC()->Gspos("USD2",1,"USDB", xpos, ypos, zpos,matrix[2],"ONLY");
   // Empty spaces (air)
   parBOX[ 0] =  22.50/2.0;
   parBOX[ 1] =   1.20/2.0;
   parBOX[ 2] =  70.50/2.0;
-  gMC->Gsvolu("USD3","BOX ",idtmed[1302-1],parBOX,kNparBOX);
+  TVirtualMC::GetMC()->Gsvolu("USD3","BOX ",idtmed[1302-1],parBOX,kNparBOX);
   xpos       = -25.75;
   ypos       =   0.0;
   zpos       =   0.4;
-  gMC->Gspos("USD3",1,"USDB", xpos, ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USD3",1,"USDB", xpos, ypos, zpos,        0,"ONLY");
   // Empty spaces (air)
   parTRP[ 0] =   1.20/2.0;
   parTRP[ 1] =   0.0;
@@ -1375,11 +1275,11 @@ void AliTRDgeometry::CreateFrame(Int_t *idtmed)
   parTRP[ 8] =   5.00/2.0;
   parTRP[ 9] =  65.00/2.0;
   parTRP[10] =  -1.0;
-  gMC->Gsvolu("USD4","TRAP",idtmed[1302-1],parTRP,kNparTRP);
+  TVirtualMC::GetMC()->Gsvolu("USD4","TRAP",idtmed[1302-1],parTRP,kNparTRP);
   xpos       =   2.0;
   ypos       =   0.0;
   zpos       =  -1.6;
-  gMC->Gspos("USD4",1,"USDB", xpos, ypos, zpos,matrix[6],"ONLY");
+  TVirtualMC::GetMC()->Gspos("USD4",1,"USDB", xpos, ypos, zpos,matrix[6],"ONLY");
   // Empty spaces (air)
   parTRP[ 0] =   1.20/2.0;
   parTRP[ 1] =   0.0;
@@ -1392,11 +1292,11 @@ void AliTRDgeometry::CreateFrame(Int_t *idtmed)
   parTRP[ 8] =  63.50/2.0;
   parTRP[ 9] =   5.00/2.0;
   parTRP[10] =  16.0;
-  gMC->Gsvolu("USD5","TRAP",idtmed[1302-1],parTRP,kNparTRP);
+  TVirtualMC::GetMC()->Gsvolu("USD5","TRAP",idtmed[1302-1],parTRP,kNparTRP);
   xpos       =  36.5;
   ypos       =   0.0;
   zpos       =  -1.5;
-  gMC->Gspos("USD5",1,"USDB", xpos, ypos, zpos,matrix[5],"ONLY");
+  TVirtualMC::GetMC()->Gspos("USD5",1,"USDB", xpos, ypos, zpos,matrix[5],"ONLY");
   // Empty spaces (air)
   parTRP[ 0] =   1.20/2.0;
   parTRP[ 1] =   0.0;
@@ -1409,62 +1309,62 @@ void AliTRDgeometry::CreateFrame(Int_t *idtmed)
   parTRP[ 8] =   4.50/2.0;
   parTRP[ 9] =  16.50/2.0;
   parTRP[10] =  -5.0;
-  gMC->Gsvolu("USD6","TRAP",idtmed[1302-1],parTRP,kNparTRP);
+  TVirtualMC::GetMC()->Gsvolu("USD6","TRAP",idtmed[1302-1],parTRP,kNparTRP);
   xpos       = -43.7;
   ypos       =   0.0;
   zpos       =   0.4;
-  gMC->Gspos("USD6",1,"USDB", xpos, ypos, zpos,matrix[2],"ONLY");
+  TVirtualMC::GetMC()->Gspos("USD6",1,"USDB", xpos, ypos, zpos,matrix[2],"ONLY");
   xpos       =   0.0;
-  ypos       =   fClength[5][2]/2.0;
+  ypos       =   fgkClength[5][2]/2.0;
   zpos       =   0.04;
-  gMC->Gspos("USDB",1,"UTI1", xpos, ypos, zpos,        0,"ONLY");
-  gMC->Gspos("USDB",2,"UTI1", xpos,-ypos, zpos,        0,"ONLY");
-  gMC->Gspos("USDB",3,"UTI2", xpos, ypos, zpos,        0,"ONLY");
-  gMC->Gspos("USDB",4,"UTI2", xpos,-ypos, zpos,        0,"ONLY");
-  gMC->Gspos("USDB",5,"UTI3", xpos, ypos, zpos,        0,"ONLY");
-  gMC->Gspos("USDB",6,"UTI3", xpos,-ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USDB",1,"UTI1", xpos, ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USDB",2,"UTI1", xpos,-ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USDB",3,"UTI2", xpos, ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USDB",4,"UTI2", xpos,-ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USDB",5,"UTI3", xpos, ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USDB",6,"UTI3", xpos,-ypos, zpos,        0,"ONLY");
   // Upper bar (aluminum)
   parBOX[0] = 95.00/2.0;
   parBOX[1] =  1.20/2.0;
   parBOX[2] =  3.00/2.0;
-  gMC->Gsvolu("USD7","BOX ",idtmed[1301-1],parBOX,kNparBOX);
+  TVirtualMC::GetMC()->Gsvolu("USD7","BOX ",idtmed[1301-1],parBOX,kNparBOX);
   xpos       =   0.0;
-  ypos       =   fClength[5][2]/2.0;
+  ypos       =   fgkClength[5][2]/2.0;
   zpos       =   fgkSheight/2.0 - fgkSMpltT  - 3.00/2.0;
-  gMC->Gspos("USD7",1,"UTI1", xpos, ypos, zpos,        0,"ONLY");
-  gMC->Gspos("USD7",2,"UTI1", xpos,-ypos, zpos,        0,"ONLY");
-  gMC->Gspos("USD7",3,"UTI2", xpos, ypos, zpos,        0,"ONLY");
-  gMC->Gspos("USD7",4,"UTI2", xpos,-ypos, zpos,        0,"ONLY");
-  gMC->Gspos("USD7",5,"UTI3", xpos, ypos, zpos,        0,"ONLY");
-  gMC->Gspos("USD7",6,"UTI3", xpos,-ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USD7",1,"UTI1", xpos, ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USD7",2,"UTI1", xpos,-ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USD7",3,"UTI2", xpos, ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USD7",4,"UTI2", xpos,-ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USD7",5,"UTI3", xpos, ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USD7",6,"UTI3", xpos,-ypos, zpos,        0,"ONLY");
   // Lower bar (aluminum)
   parBOX[0] = 90.22/2.0;
   parBOX[1] =  1.20/2.0;
   parBOX[2] =  1.74/2.0;
-  gMC->Gsvolu("USD8","BOX ",idtmed[1301-1],parBOX,kNparBOX);
+  TVirtualMC::GetMC()->Gsvolu("USD8","BOX ",idtmed[1301-1],parBOX,kNparBOX);
   xpos       =   0.0;
-  ypos       =   fClength[5][2]/2.0 - 0.1;
+  ypos       =   fgkClength[5][2]/2.0 - 0.1;
   zpos       =  -fgkSheight/2.0 + fgkSMpltT + 2.27;
-  gMC->Gspos("USD8",1,"UTI1", xpos, ypos, zpos,        0,"ONLY");
-  gMC->Gspos("USD8",2,"UTI1", xpos,-ypos, zpos,        0,"ONLY");
-  gMC->Gspos("USD8",3,"UTI2", xpos, ypos, zpos,        0,"ONLY");
-  gMC->Gspos("USD8",4,"UTI2", xpos,-ypos, zpos,        0,"ONLY");
-  gMC->Gspos("USD8",5,"UTI3", xpos, ypos, zpos,        0,"ONLY");
-  gMC->Gspos("USD8",6,"UTI3", xpos,-ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USD8",1,"UTI1", xpos, ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USD8",2,"UTI1", xpos,-ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USD8",3,"UTI2", xpos, ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USD8",4,"UTI2", xpos,-ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USD8",5,"UTI3", xpos, ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USD8",6,"UTI3", xpos,-ypos, zpos,        0,"ONLY");
   // Lower bar (aluminum)
   parBOX[0] = 82.60/2.0;
   parBOX[1] =  1.20/2.0;
   parBOX[2] =  1.40/2.0;
-  gMC->Gsvolu("USD9","BOX ",idtmed[1301-1],parBOX,kNparBOX);
+  TVirtualMC::GetMC()->Gsvolu("USD9","BOX ",idtmed[1301-1],parBOX,kNparBOX);
   xpos       =   0.0;
-  ypos       =   fClength[5][2]/2.0;
+  ypos       =   fgkClength[5][2]/2.0;
   zpos       =  -fgkSheight/2.0 + fgkSMpltT + 1.40/2.0;
-  gMC->Gspos("USD9",1,"UTI1", xpos, ypos, zpos,        0,"ONLY");
-  gMC->Gspos("USD9",2,"UTI1", xpos,-ypos, zpos,        0,"ONLY");
-  gMC->Gspos("USD9",3,"UTI2", xpos, ypos, zpos,        0,"ONLY");
-  gMC->Gspos("USD9",4,"UTI2", xpos,-ypos, zpos,        0,"ONLY");
-  gMC->Gspos("USD9",5,"UTI3", xpos, ypos, zpos,        0,"ONLY");
-  gMC->Gspos("USD9",6,"UTI3", xpos,-ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USD9",1,"UTI1", xpos, ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USD9",2,"UTI1", xpos,-ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USD9",3,"UTI2", xpos, ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USD9",4,"UTI2", xpos,-ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USD9",5,"UTI3", xpos, ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USD9",6,"UTI3", xpos,-ypos, zpos,        0,"ONLY");
   // Front sheet (aluminum)
   parTRP[ 0] =   0.10/2.0;
   parTRP[ 1] =   0.0;
@@ -1477,16 +1377,16 @@ void AliTRDgeometry::CreateFrame(Int_t *idtmed)
   parTRP[ 8] =  31.70/2.0;
   parTRP[ 9] =  44.00/2.0;
   parTRP[10] =  -5.0;
-  gMC->Gsvolu("USDF","TRAP",idtmed[1302-1],parTRP,kNparTRP);
+  TVirtualMC::GetMC()->Gsvolu("USDF","TRAP",idtmed[1302-1],parTRP,kNparTRP);
   xpos       = -32.0;
-  ypos       =   fClength[5][2]/2.0 + 1.20/2.0 + 0.10/2.0;
+  ypos       =   fgkClength[5][2]/2.0 + 1.20/2.0 + 0.10/2.0;
   zpos       =   0.0;
-  gMC->Gspos("USDF",1,"UTI1", xpos, ypos, zpos,matrix[2],"ONLY");
-  gMC->Gspos("USDF",2,"UTI1", xpos,-ypos, zpos,matrix[2],"ONLY");
-  gMC->Gspos("USDF",3,"UTI2", xpos, ypos, zpos,matrix[2],"ONLY");
-  gMC->Gspos("USDF",4,"UTI2", xpos,-ypos, zpos,matrix[2],"ONLY");
-  gMC->Gspos("USDF",5,"UTI3", xpos, ypos, zpos,matrix[2],"ONLY");
-  gMC->Gspos("USDF",6,"UTI3", xpos,-ypos, zpos,matrix[2],"ONLY");
+  TVirtualMC::GetMC()->Gspos("USDF",1,"UTI1", xpos, ypos, zpos,matrix[2],"ONLY");
+  TVirtualMC::GetMC()->Gspos("USDF",2,"UTI1", xpos,-ypos, zpos,matrix[2],"ONLY");
+  TVirtualMC::GetMC()->Gspos("USDF",3,"UTI2", xpos, ypos, zpos,matrix[2],"ONLY");
+  TVirtualMC::GetMC()->Gspos("USDF",4,"UTI2", xpos,-ypos, zpos,matrix[2],"ONLY");
+  TVirtualMC::GetMC()->Gspos("USDF",5,"UTI3", xpos, ypos, zpos,matrix[2],"ONLY");
+  TVirtualMC::GetMC()->Gspos("USDF",6,"UTI3", xpos,-ypos, zpos,matrix[2],"ONLY");
 
   //
   // The flat frame in front of the chambers
@@ -1497,27 +1397,27 @@ void AliTRDgeometry::CreateFrame(Int_t *idtmed)
   parTRD[1]  = 114.00/2.0 - 0.1;
   parTRD[2]  =   1.50/2.0;
   parTRD[3]  =  70.30/2.0;
-  gMC->Gsvolu("USCB","TRD1",idtmed[1301-1],parTRD,kNparTRD);
+  TVirtualMC::GetMC()->Gsvolu("USCB","TRD1",idtmed[1301-1],parTRD,kNparTRD);
   // Empty spaces (air)
   parTRD[0]  =  87.00/2.0;
   parTRD[1]  =  10.00/2.0;
   parTRD[2]  =   1.50/2.0;
   parTRD[3]  =  26.35/2.0;
-  gMC->Gsvolu("USC1","TRD1",idtmed[1302-1],parTRD,kNparTRD);
+  TVirtualMC::GetMC()->Gsvolu("USC1","TRD1",idtmed[1302-1],parTRD,kNparTRD);
   xpos       =  0.0;
   ypos       =  0.0;
   zpos       = 26.35/2.0 - 70.3/2.0;
-  gMC->Gspos("USC1",1,"USCB",xpos,ypos,zpos,0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USC1",1,"USCB",xpos,ypos,zpos,0,"ONLY");
   // Empty spaces (air)
   parTRD[0]  =  10.00/2.0;
   parTRD[1]  = 111.00/2.0;
   parTRD[2]  =   1.50/2.0;
   parTRD[3]  =  35.05/2.0;
-  gMC->Gsvolu("USC2","TRD1",idtmed[1302-1],parTRD,kNparTRD);
+  TVirtualMC::GetMC()->Gsvolu("USC2","TRD1",idtmed[1302-1],parTRD,kNparTRD);
   xpos       =  0.0;
   ypos       =  0.0;
   zpos       = 70.3/2.0 - 35.05/2.0;
-  gMC->Gspos("USC2",1,"USCB",xpos,ypos,zpos,0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USC2",1,"USCB",xpos,ypos,zpos,0,"ONLY");
   // Empty spaces (air)
   parTRP[ 0] =   1.50/2.0;
   parTRP[ 1] =   0.0;
@@ -1530,63 +1430,63 @@ void AliTRDgeometry::CreateFrame(Int_t *idtmed)
   parTRP[ 8] =  63.90/2.0;
   parTRP[ 9] =   8.86/2.0;
   parTRP[10] =  16.0;
-  gMC->Gsvolu("USC3","TRAP",idtmed[1302-1],parTRP,kNparTRP);
+  TVirtualMC::GetMC()->Gsvolu("USC3","TRAP",idtmed[1302-1],parTRP,kNparTRP);
   xpos       = -30.5;
   ypos       =   0.0;
   zpos       =  -2.0;
-  gMC->Gspos("USC3",1,"USCB", xpos, ypos, zpos,matrix[4],"ONLY");
-  gMC->Gspos("USC3",2,"USCB",-xpos, ypos, zpos,matrix[5],"ONLY");
+  TVirtualMC::GetMC()->Gspos("USC3",1,"USCB", xpos, ypos, zpos,matrix[4],"ONLY");
+  TVirtualMC::GetMC()->Gspos("USC3",2,"USCB",-xpos, ypos, zpos,matrix[5],"ONLY");
   xpos       =   0.0;
-  ypos       =   fClength[5][2]/2.0 + fClength[5][1] + fClength[5][0];
+  ypos       =   fgkClength[5][2]/2.0 + fgkClength[5][1] + fgkClength[5][0];
   zpos       =   0.0;
-  gMC->Gspos("USCB",1,"UTI1", xpos, ypos, zpos,        0,"ONLY");
-  gMC->Gspos("USCB",2,"UTI1", xpos,-ypos, zpos,        0,"ONLY");
-  gMC->Gspos("USCB",3,"UTI2", xpos, ypos, zpos,        0,"ONLY");
-  gMC->Gspos("USCB",4,"UTI2", xpos,-ypos, zpos,        0,"ONLY");
-  gMC->Gspos("USCB",5,"UTI3", xpos, ypos, zpos,        0,"ONLY");
-  gMC->Gspos("USCB",6,"UTI3", xpos,-ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USCB",1,"UTI1", xpos, ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USCB",2,"UTI1", xpos,-ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USCB",3,"UTI2", xpos, ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USCB",4,"UTI2", xpos,-ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USCB",5,"UTI3", xpos, ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USCB",6,"UTI3", xpos,-ypos, zpos,        0,"ONLY");
   // Upper bar (aluminum)
   parBOX[0] = 95.00/2.0;
   parBOX[1] =  1.50/2.0;
   parBOX[2] =  3.00/2.0;
-  gMC->Gsvolu("USC4","BOX ",idtmed[1301-1],parBOX,kNparBOX);
+  TVirtualMC::GetMC()->Gsvolu("USC4","BOX ",idtmed[1301-1],parBOX,kNparBOX);
   xpos       =   0.0;
-  ypos       =   fClength[5][2]/2.0 + fClength[5][1] + fClength[5][0];
+  ypos       =   fgkClength[5][2]/2.0 + fgkClength[5][1] + fgkClength[5][0];
   zpos       =   fgkSheight/2.0 - fgkSMpltT - 3.00/2.0;
-  gMC->Gspos("USC4",1,"UTI1", xpos, ypos, zpos,        0,"ONLY");
-  gMC->Gspos("USC4",2,"UTI1", xpos,-ypos, zpos,        0,"ONLY");
-  gMC->Gspos("USC4",3,"UTI2", xpos, ypos, zpos,        0,"ONLY");
-  gMC->Gspos("USC4",4,"UTI2", xpos,-ypos, zpos,        0,"ONLY");
-  gMC->Gspos("USC4",5,"UTI3", xpos, ypos, zpos,        0,"ONLY");
-  gMC->Gspos("USC4",6,"UTI3", xpos,-ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USC4",1,"UTI1", xpos, ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USC4",2,"UTI1", xpos,-ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USC4",3,"UTI2", xpos, ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USC4",4,"UTI2", xpos,-ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USC4",5,"UTI3", xpos, ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USC4",6,"UTI3", xpos,-ypos, zpos,        0,"ONLY");
   // Lower bar (aluminum)
   parBOX[0] = 90.22/2.0;
   parBOX[1] =  1.50/2.0;
   parBOX[2] =  2.00/2.0;
-  gMC->Gsvolu("USC5","BOX ",idtmed[1301-1],parBOX,kNparBOX);
+  TVirtualMC::GetMC()->Gsvolu("USC5","BOX ",idtmed[1301-1],parBOX,kNparBOX);
   xpos       =   0.0;
-  ypos       =   fClength[5][2]/2.0 + fClength[5][1] + fClength[5][0];
+  ypos       =   fgkClength[5][2]/2.0 + fgkClength[5][1] + fgkClength[5][0];
   zpos       =  -fgkSheight/2.0 + fgkSMpltT + 2.60;
-  gMC->Gspos("USC5",1,"UTI1", xpos, ypos, zpos,        0,"ONLY");
-  gMC->Gspos("USC5",2,"UTI1", xpos,-ypos, zpos,        0,"ONLY");
-  gMC->Gspos("USC5",3,"UTI2", xpos, ypos, zpos,        0,"ONLY");
-  gMC->Gspos("USC5",4,"UTI2", xpos,-ypos, zpos,        0,"ONLY");
-  gMC->Gspos("USC5",5,"UTI3", xpos, ypos, zpos,        0,"ONLY");
-  gMC->Gspos("USC5",6,"UTI3", xpos,-ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USC5",1,"UTI1", xpos, ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USC5",2,"UTI1", xpos,-ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USC5",3,"UTI2", xpos, ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USC5",4,"UTI2", xpos,-ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USC5",5,"UTI3", xpos, ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USC5",6,"UTI3", xpos,-ypos, zpos,        0,"ONLY");
   // Lower bar (aluminum)
   parBOX[0] = 82.60/2.0;
   parBOX[1] =  1.50/2.0;
   parBOX[2] =  1.60/2.0;
-  gMC->Gsvolu("USC6","BOX ",idtmed[1301-1],parBOX,kNparBOX);
+  TVirtualMC::GetMC()->Gsvolu("USC6","BOX ",idtmed[1301-1],parBOX,kNparBOX);
   xpos       =   0.0;
-  ypos       =   fClength[5][2]/2.0 + fClength[5][1] + fClength[5][0];
+  ypos       =   fgkClength[5][2]/2.0 + fgkClength[5][1] + fgkClength[5][0];
   zpos       =  -fgkSheight/2.0 + fgkSMpltT + 1.60/2.0;
-  gMC->Gspos("USC6",1,"UTI1", xpos, ypos, zpos,        0,"ONLY");
-  gMC->Gspos("USC6",2,"UTI1", xpos,-ypos, zpos,        0,"ONLY");
-  gMC->Gspos("USC6",3,"UTI2", xpos, ypos, zpos,        0,"ONLY");
-  gMC->Gspos("USC6",4,"UTI2", xpos,-ypos, zpos,        0,"ONLY");
-  gMC->Gspos("USC6",5,"UTI3", xpos, ypos, zpos,        0,"ONLY");
-  gMC->Gspos("USC6",6,"UTI3", xpos,-ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USC6",1,"UTI1", xpos, ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USC6",2,"UTI1", xpos,-ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USC6",3,"UTI2", xpos, ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USC6",4,"UTI2", xpos,-ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USC6",5,"UTI3", xpos, ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USC6",6,"UTI3", xpos,-ypos, zpos,        0,"ONLY");
 
   //
   // The long corner ledges
@@ -1613,28 +1513,28 @@ void AliTRDgeometry::CreateFrame(Int_t *idtmed)
   parSCL[0]  = kSCLthkUa /2.0;
   parSCL[1]  = fgkSlength/2.0;
   parSCL[2]  = kSCLwidUa /2.0;
-  gMC->Gsvolu("USL1","BOX ",idtmed[1301-1],parSCL,kNparSCL);
+  TVirtualMC::GetMC()->Gsvolu("USL1","BOX ",idtmed[1301-1],parSCL,kNparSCL);
   xpos  =   fgkSwidth2/2.0 - fgkSMpltT - kSCLposxUa;
   ypos  =   0.0;
   zpos  =   fgkSheight/2.0 - fgkSMpltT - kSCLposzUa;
-  gMC->Gspos("USL1",1,"UTI1", xpos,ypos,zpos,matrix[0],"ONLY");
+  TVirtualMC::GetMC()->Gspos("USL1",1,"UTI1", xpos,ypos,zpos,matrix[0],"ONLY");
   xpos  = -xpos;
-  gMC->Gspos("USL1",2,"UTI1", xpos,ypos,zpos,matrix[1],"ONLY");
+  TVirtualMC::GetMC()->Gspos("USL1",2,"UTI1", xpos,ypos,zpos,matrix[1],"ONLY");
   // Horizontal
   parSCL[0]  = kSCLwidUb /2.0;
   parSCL[1]  = fgkSlength/2.0;
   parSCL[2]  = kSCLthkUb /2.0;
-  gMC->Gsvolu("USL2","BOX ",idtmed[1301-1],parSCL,kNparSCL);
+  TVirtualMC::GetMC()->Gsvolu("USL2","BOX ",idtmed[1301-1],parSCL,kNparSCL);
   xpos  =   fgkSwidth2/2.0 - fgkSMpltT - kSCLposxUb;
   ypos  =   0.0;
   zpos  =   fgkSheight/2.0 - fgkSMpltT - kSCLposzUb; 
-  gMC->Gspos("USL2",1,"UTI1", xpos,ypos,zpos,        0,"ONLY");
-  gMC->Gspos("USL2",3,"UTI2", xpos,ypos,zpos,        0,"ONLY");
-  gMC->Gspos("USL2",5,"UTI3", xpos,ypos,zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USL2",1,"UTI1", xpos,ypos,zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USL2",3,"UTI2", xpos,ypos,zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USL2",5,"UTI3", xpos,ypos,zpos,        0,"ONLY");
   xpos  = -xpos;
-  gMC->Gspos("USL2",2,"UTI1", xpos,ypos,zpos,        0,"ONLY");
-  gMC->Gspos("USL2",4,"UTI2", xpos,ypos,zpos,        0,"ONLY");
-  gMC->Gspos("USL2",6,"UTI3", xpos,ypos,zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USL2",2,"UTI1", xpos,ypos,zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USL2",4,"UTI2", xpos,ypos,zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USL2",6,"UTI3", xpos,ypos,zpos,        0,"ONLY");
 
   // Lower ledges 
   // Thickness of the corner ledges
@@ -1661,32 +1561,32 @@ void AliTRDgeometry::CreateFrame(Int_t *idtmed)
   parSCLb[ 8] = kSCLthkLb /2.0;
   parSCLb[ 9] = kSCLthkLa /2.0;
   parSCLb[10] = 5.0;
-  gMC->Gsvolu("USL3","TRAP",idtmed[1301-1],parSCLb,kNparSCLb);
+  TVirtualMC::GetMC()->Gsvolu("USL3","TRAP",idtmed[1301-1],parSCLb,kNparSCLb);
   xpos  =   fgkSwidth1/2.0 - fgkSMpltT - kSCLposxLa;
   ypos  =   0.0;
   zpos  = - fgkSheight/2.0 + fgkSMpltT + kSCLposzLa;
-  gMC->Gspos("USL3",1,"UTI1", xpos,ypos,zpos,matrix[2],"ONLY");
-  gMC->Gspos("USL3",3,"UTI2", xpos,ypos,zpos,matrix[2],"ONLY");
-  gMC->Gspos("USL3",5,"UTI3", xpos,ypos,zpos,matrix[2],"ONLY");
+  TVirtualMC::GetMC()->Gspos("USL3",1,"UTI1", xpos,ypos,zpos,matrix[2],"ONLY");
+  TVirtualMC::GetMC()->Gspos("USL3",3,"UTI2", xpos,ypos,zpos,matrix[2],"ONLY");
+  TVirtualMC::GetMC()->Gspos("USL3",5,"UTI3", xpos,ypos,zpos,matrix[2],"ONLY");
   xpos  = -xpos;
-  gMC->Gspos("USL3",2,"UTI1", xpos,ypos,zpos,matrix[3],"ONLY");
-  gMC->Gspos("USL3",4,"UTI2", xpos,ypos,zpos,matrix[3],"ONLY");
-  gMC->Gspos("USL3",6,"UTI3", xpos,ypos,zpos,matrix[3],"ONLY");
+  TVirtualMC::GetMC()->Gspos("USL3",2,"UTI1", xpos,ypos,zpos,matrix[3],"ONLY");
+  TVirtualMC::GetMC()->Gspos("USL3",4,"UTI2", xpos,ypos,zpos,matrix[3],"ONLY");
+  TVirtualMC::GetMC()->Gspos("USL3",6,"UTI3", xpos,ypos,zpos,matrix[3],"ONLY");
   // Horizontal part
   parSCL[0]  = kSCLwidLb /2.0;
   parSCL[1]  = fgkSlength/2.0;
   parSCL[2]  = kSCLthkLb /2.0;
-  gMC->Gsvolu("USL4","BOX ",idtmed[1301-1],parSCL,kNparSCL);
+  TVirtualMC::GetMC()->Gsvolu("USL4","BOX ",idtmed[1301-1],parSCL,kNparSCL);
   xpos  =   fgkSwidth1/2.0 - fgkSMpltT - kSCLposxLb;
   ypos  =   0.0;
   zpos  = - fgkSheight/2.0 + fgkSMpltT + kSCLposzLb;
-  gMC->Gspos("USL4",1,"UTI1", xpos,ypos,zpos,        0,"ONLY");
-  gMC->Gspos("USL4",3,"UTI2", xpos,ypos,zpos,        0,"ONLY");
-  gMC->Gspos("USL4",5,"UTI3", xpos,ypos,zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USL4",1,"UTI1", xpos,ypos,zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USL4",3,"UTI2", xpos,ypos,zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USL4",5,"UTI3", xpos,ypos,zpos,        0,"ONLY");
   xpos  = -xpos;
-  gMC->Gspos("USL4",2,"UTI1", xpos,ypos,zpos,        0,"ONLY");
-  gMC->Gspos("USL4",4,"UTI2", xpos,ypos,zpos,        0,"ONLY");
-  gMC->Gspos("USL4",6,"UTI3", xpos,ypos,zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USL4",2,"UTI1", xpos,ypos,zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USL4",4,"UTI2", xpos,ypos,zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("USL4",6,"UTI3", xpos,ypos,zpos,        0,"ONLY");
 
   //
   // Aluminum plates in the front part of the super modules
@@ -1698,26 +1598,26 @@ void AliTRDgeometry::CreateFrame(Int_t *idtmed)
   parTrd[1] = fgkSwidth2/2.0 - 2.5;
   parTrd[2] = fgkSMpltT /2.0;
   parTrd[3] = fgkSheight/2.0 - 1.0;
-  gMC->Gsvolu("UTA1","TRD1",idtmed[1301-1],parTrd,kNparTrd);
+  TVirtualMC::GetMC()->Gsvolu("UTA1","TRD1",idtmed[1301-1],parTrd,kNparTrd);
   xpos      =  0.0;
   ypos      =  fgkSMpltT/2.0 - fgkFlength/2.0;
   zpos      = -0.5;
-  gMC->Gspos("UTA1",1,"UTF1",xpos, ypos,zpos,        0,"ONLY");
-  gMC->Gspos("UTA1",2,"UTF2",xpos,-ypos,zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTA1",1,"UTF1",xpos, ypos,zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTA1",2,"UTF2",xpos,-ypos,zpos,        0,"ONLY");
 
   const Int_t kNparPlt = 3;
   Float_t parPlt[kNparPlt];
   parPlt[0] =  0.0;
   parPlt[1] =  0.0;
   parPlt[2] =  0.0;
-  gMC->Gsvolu("UTA2","BOX ",idtmed[1301-1],parPlt,0);
+  TVirtualMC::GetMC()->Gsvolu("UTA2","BOX ",idtmed[1301-1],parPlt,0);
   xpos      =  0.0;
   ypos      =  0.0;
   zpos      =  fgkSheight/2.0 - fgkSMpltT/2.0;
   parPlt[0] = fgkSwidth2/2.0 - 0.2;
   parPlt[1] = fgkFlength/2.0;
   parPlt[2] = fgkSMpltT /2.0;
-  gMC->Gsposp("UTA2",1,"UTF2",xpos,ypos,zpos
+  TVirtualMC::GetMC()->Gsposp("UTA2",1,"UTF2",xpos,ypos,zpos
                     ,        0,"ONLY",parPlt,kNparPlt);
   xpos      = (fgkSwidth1 + fgkSwidth2)/4.0 - fgkSMpltT/2.0 - 0.0016;
   ypos      =  0.0;
@@ -1725,21 +1625,21 @@ void AliTRDgeometry::CreateFrame(Int_t *idtmed)
   parPlt[0] = fgkSMpltT /2.0;
   parPlt[1] = fgkFlength/2.0;
   parPlt[2] = fgkSheight/2.0;
-  gMC->Gsposp("UTA2",2,"UTF2", xpos,ypos,zpos
+  TVirtualMC::GetMC()->Gsposp("UTA2",2,"UTF2", xpos,ypos,zpos
                     ,matrix[0],"ONLY",parPlt,kNparPlt);
-  gMC->Gsposp("UTA2",3,"UTF2",-xpos,ypos,zpos
+  TVirtualMC::GetMC()->Gsposp("UTA2",3,"UTF2",-xpos,ypos,zpos
                     ,matrix[1],"ONLY",parPlt,kNparPlt);
 
   // Additional aluminum bar
   parBOX[0] = 80.0/2.0;
   parBOX[1] =  1.0/2.0;
   parBOX[2] = 10.0/2.0;
-  gMC->Gsvolu("UTA3","BOX ",idtmed[1301-1],parBOX,kNparBOX);
+  TVirtualMC::GetMC()->Gsvolu("UTA3","BOX ",idtmed[1301-1],parBOX,kNparBOX);
   xpos      =  0.0;
   ypos      =  1.0/2.0 + fgkSMpltT - fgkFlength/2.0;
   zpos      =  fgkSheight/2.0 - 1.5 - 10.0/2.0;
-  gMC->Gspos("UTA3",1,"UTF1", xpos, ypos, zpos,        0,"ONLY");
-  gMC->Gspos("UTA3",2,"UTF2", xpos,-ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTA3",1,"UTF1", xpos, ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTA3",2,"UTF2", xpos,-ypos, zpos,        0,"ONLY");
 
 }
 
@@ -1770,7 +1670,8 @@ void AliTRDgeometry::CreateServices(Int_t *idtmed)
   Float_t ypos  = 0.0;
   Float_t zpos  = 0.0;
 
-  Char_t  cTagV[100];
+  const Int_t kTag = 100;
+  Char_t  cTagV[kTag];
 
   const Int_t kNparBox  = 3;
   Float_t parBox[kNparBox];
@@ -1789,16 +1690,16 @@ void AliTRDgeometry::CreateServices(Int_t *idtmed)
   // The rotation matrices
   const Int_t kNmatrix = 10;
   Int_t   matrix[kNmatrix];
-  gMC->Matrix(matrix[0], 100.0,   0.0,  90.0,  90.0,  10.0,   0.0); // rotation around y-axis
-  gMC->Matrix(matrix[1],  80.0,   0.0,  90.0,  90.0,  10.0, 180.0); // rotation around y-axis
-  gMC->Matrix(matrix[2],   0.0,   0.0,  90.0,  90.0,  90.0,   0.0);
-  gMC->Matrix(matrix[3], 180.0,   0.0,  90.0,  90.0,  90.0, 180.0);
-  gMC->Matrix(matrix[4],  90.0,   0.0,   0.0,   0.0,  90.0,  90.0);
-  gMC->Matrix(matrix[5], 100.0,   0.0,  90.0, 270.0,  10.0,   0.0);
-  gMC->Matrix(matrix[6],  80.0,   0.0,  90.0, 270.0,  10.0, 180.0);
-  gMC->Matrix(matrix[7],  90.0,  10.0,  90.0, 100.0,   0.0,   0.0); // rotation around z-axis
-  gMC->Matrix(matrix[8],  90.0, 350.0,  90.0,  80.0,   0.0,   0.0); // rotation around z-axis
-  gMC->Matrix(matrix[9],  90.0,  90.0,  90.0, 180.0,   0.0,   0.0); // rotation around z-axis
+  TVirtualMC::GetMC()->Matrix(matrix[0], 100.0,   0.0,  90.0,  90.0,  10.0,   0.0); // rotation around y-axis
+  TVirtualMC::GetMC()->Matrix(matrix[1],  80.0,   0.0,  90.0,  90.0,  10.0, 180.0); // rotation around y-axis
+  TVirtualMC::GetMC()->Matrix(matrix[2],   0.0,   0.0,  90.0,  90.0,  90.0,   0.0);
+  TVirtualMC::GetMC()->Matrix(matrix[3], 180.0,   0.0,  90.0,  90.0,  90.0, 180.0);
+  TVirtualMC::GetMC()->Matrix(matrix[4],  90.0,   0.0,   0.0,   0.0,  90.0,  90.0);
+  TVirtualMC::GetMC()->Matrix(matrix[5], 100.0,   0.0,  90.0, 270.0,  10.0,   0.0);
+  TVirtualMC::GetMC()->Matrix(matrix[6],  80.0,   0.0,  90.0, 270.0,  10.0, 180.0);
+  TVirtualMC::GetMC()->Matrix(matrix[7],  90.0,  10.0,  90.0, 100.0,   0.0,   0.0); // rotation around z-axis
+  TVirtualMC::GetMC()->Matrix(matrix[8],  90.0, 350.0,  90.0,  80.0,   0.0,   0.0); // rotation around z-axis
+  TVirtualMC::GetMC()->Matrix(matrix[9],  90.0,  90.0,  90.0, 180.0,   0.0,   0.0); // rotation around z-axis
     
   //
   // The cooling arterias
@@ -1818,24 +1719,24 @@ void AliTRDgeometry::CreateServices(Int_t *idtmed)
   parCOL[0] = 0.0;
   parCOL[1] = 0.0;
   parCOL[2] = 0.0;
-  gMC->Gsvolu("UTC1","BOX ",idtmed[1308-1],parCOL,0);
-  gMC->Gsvolu("UTC3","BOX ",idtmed[1308-1],parCOL,0);
+  TVirtualMC::GetMC()->Gsvolu("UTC1","BOX ",idtmed[1308-1],parCOL,0);
+  TVirtualMC::GetMC()->Gsvolu("UTC3","BOX ",idtmed[1308-1],parCOL,0);
   parCOL[0] =  kCOLwid/2.0 - kCOLthk;
   parCOL[1] = -1.0;
   parCOL[2] =  kCOLhgt/2.0 - kCOLthk;
-  gMC->Gsvolu("UTC2","BOX ",idtmed[1314-1],parCOL,kNparCOL);
-  gMC->Gsvolu("UTC4","BOX ",idtmed[1314-1],parCOL,kNparCOL);
+  TVirtualMC::GetMC()->Gsvolu("UTC2","BOX ",idtmed[1314-1],parCOL,kNparCOL);
+  TVirtualMC::GetMC()->Gsvolu("UTC4","BOX ",idtmed[1314-1],parCOL,kNparCOL);
 
   xpos  = 0.0;
   ypos  = 0.0;
   zpos  = 0.0;
-  gMC->Gspos("UTC2",1,"UTC1", xpos,ypos,zpos,0,"ONLY");
-  gMC->Gspos("UTC4",1,"UTC3", xpos,ypos,zpos,0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTC2",1,"UTC1", xpos,ypos,zpos,0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTC4",1,"UTC3", xpos,ypos,zpos,0,"ONLY");
 
   for (ilayer = 1; ilayer < kNlayer; ilayer++) { 
 
     // Along the chambers
-    xpos      = fCwidth[ilayer]/2.0 + kCOLwid/2.0 + kCOLposx;
+    xpos      = fgkCwidth[ilayer]/2.0 + kCOLwid/2.0 + kCOLposx;
     ypos      = 0.0;
     zpos      = fgkVrocsm + fgkSMpltT - fgkCalZpos 
               + kCOLhgt/2.0 - fgkSheight/2.0 + kCOLposz 
@@ -1843,21 +1744,21 @@ void AliTRDgeometry::CreateServices(Int_t *idtmed)
     parCOL[0] = kCOLwid   /2.0;
     parCOL[1] = fgkSlength/2.0;
     parCOL[2] = kCOLhgt   /2.0;
-    gMC->Gsposp("UTC1",ilayer          ,"UTI1", xpos,ypos,zpos
+    TVirtualMC::GetMC()->Gsposp("UTC1",ilayer          ,"UTI1", xpos,ypos,zpos
                       ,matrix[0],"ONLY",parCOL,kNparCOL);
-    gMC->Gsposp("UTC1",ilayer+  kNlayer,"UTI1",-xpos,ypos,zpos
+    TVirtualMC::GetMC()->Gsposp("UTC1",ilayer+  kNlayer,"UTI1",-xpos,ypos,zpos
                       ,matrix[1],"ONLY",parCOL,kNparCOL);
-    gMC->Gsposp("UTC1",ilayer+6*kNlayer,"UTI2", xpos,ypos,zpos
+    TVirtualMC::GetMC()->Gsposp("UTC1",ilayer+6*kNlayer,"UTI2", xpos,ypos,zpos
                       ,matrix[0],"ONLY",parCOL,kNparCOL);
-    gMC->Gsposp("UTC1",ilayer+7*kNlayer,"UTI2",-xpos,ypos,zpos
+    TVirtualMC::GetMC()->Gsposp("UTC1",ilayer+7*kNlayer,"UTI2",-xpos,ypos,zpos
                       ,matrix[1],"ONLY",parCOL,kNparCOL);
-    gMC->Gsposp("UTC1",ilayer+8*kNlayer ,"UTI3", xpos,ypos,zpos
+    TVirtualMC::GetMC()->Gsposp("UTC1",ilayer+8*kNlayer ,"UTI3", xpos,ypos,zpos
                       ,matrix[0],"ONLY",parCOL,kNparCOL);
-    gMC->Gsposp("UTC1",ilayer+9*kNlayer,"UTI3",-xpos,ypos,zpos
+    TVirtualMC::GetMC()->Gsposp("UTC1",ilayer+9*kNlayer,"UTI3",-xpos,ypos,zpos
                       ,matrix[1],"ONLY",parCOL,kNparCOL);
 
     // Front of supermodules
-    xpos      = fCwidth[ilayer]/2.0 + kCOLwid/2.0 + kCOLposx;
+    xpos      = fgkCwidth[ilayer]/2.0 + kCOLwid/2.0 + kCOLposx;
     ypos      = 0.0;
     zpos      = fgkVrocsm + fgkSMpltT - fgkCalZpos 
               + kCOLhgt/2.0 - fgkSheight/2.0 + kCOLposz 
@@ -1865,13 +1766,13 @@ void AliTRDgeometry::CreateServices(Int_t *idtmed)
     parCOL[0] = kCOLwid   /2.0;
     parCOL[1] = fgkFlength/2.0;
     parCOL[2] = kCOLhgt   /2.0;
-    gMC->Gsposp("UTC3",ilayer+2*kNlayer,"UTF1", xpos,ypos,zpos
+    TVirtualMC::GetMC()->Gsposp("UTC3",ilayer+2*kNlayer,"UTF1", xpos,ypos,zpos
                       ,matrix[0],"ONLY",parCOL,kNparCOL);
-    gMC->Gsposp("UTC3",ilayer+3*kNlayer,"UTF1",-xpos,ypos,zpos
+    TVirtualMC::GetMC()->Gsposp("UTC3",ilayer+3*kNlayer,"UTF1",-xpos,ypos,zpos
                       ,matrix[1],"ONLY",parCOL,kNparCOL);
-    gMC->Gsposp("UTC3",ilayer+4*kNlayer,"UTF2", xpos,ypos,zpos
+    TVirtualMC::GetMC()->Gsposp("UTC3",ilayer+4*kNlayer,"UTF2", xpos,ypos,zpos
                       ,matrix[0],"ONLY",parCOL,kNparCOL);
-    gMC->Gsposp("UTC3",ilayer+5*kNlayer,"UTF2",-xpos,ypos,zpos
+    TVirtualMC::GetMC()->Gsposp("UTC3",ilayer+5*kNlayer,"UTF2",-xpos,ypos,zpos
                       ,matrix[1],"ONLY",parCOL,kNparCOL);
 
   }
@@ -1879,7 +1780,7 @@ void AliTRDgeometry::CreateServices(Int_t *idtmed)
   for (ilayer = 1; ilayer < kNlayer; ilayer++) { 
 
     // In baby frame
-    xpos      = fCwidth[ilayer]/2.0 + kCOLwid/2.0 + kCOLposx - 2.5;
+    xpos      = fgkCwidth[ilayer]/2.0 + kCOLwid/2.0 + kCOLposx - 2.5;
     ypos      = kBBSdz/2.0 - kBBMdz/2.0;
     zpos      = fgkVrocsm + fgkSMpltT - fgkCalZpos 
               + kCOLhgt/2.0 - fgkSheight/2.0 + kCOLposz 
@@ -1887,9 +1788,9 @@ void AliTRDgeometry::CreateServices(Int_t *idtmed)
     parCOL[0] = kCOLwid/2.0;
     parCOL[1] = kBBSdz /2.0;
     parCOL[2] = kCOLhgt/2.0;
-    gMC->Gsposp("UTC3",ilayer+6*kNlayer,"BBTRD", xpos, ypos, zpos
+    TVirtualMC::GetMC()->Gsposp("UTC3",ilayer+6*kNlayer,"BBTRD", xpos, ypos, zpos
                       ,matrix[0],"ONLY",parCOL,kNparCOL);
-    gMC->Gsposp("UTC3",ilayer+7*kNlayer,"BBTRD",-xpos, ypos, zpos
+    TVirtualMC::GetMC()->Gsposp("UTC3",ilayer+7*kNlayer,"BBTRD",-xpos, ypos, zpos
                       ,matrix[1],"ONLY",parCOL,kNparCOL);
 
   }
@@ -1897,7 +1798,7 @@ void AliTRDgeometry::CreateServices(Int_t *idtmed)
   for (ilayer = 1; ilayer < kNlayer; ilayer++) { 
 
     // In back frame
-    xpos      = fCwidth[ilayer]/2.0 + kCOLwid/2.0 + kCOLposx - 0.3;
+    xpos      = fgkCwidth[ilayer]/2.0 + kCOLwid/2.0 + kCOLposx - 0.3;
     ypos      = -kBFSdz/2.0 + kBFMdz/2.0;
     zpos      = fgkVrocsm + fgkSMpltT - fgkCalZpos 
               + kCOLhgt/2.0 - fgkSheight/2.0 + kCOLposz 
@@ -1905,69 +1806,69 @@ void AliTRDgeometry::CreateServices(Int_t *idtmed)
     parCOL[0] = kCOLwid/2.0;
     parCOL[1] = kBFSdz /2.0;
     parCOL[2] = kCOLhgt/2.0;
-    gMC->Gsposp("UTC3",ilayer+6*kNlayer,"BFTRD", xpos,ypos,zpos
+    TVirtualMC::GetMC()->Gsposp("UTC3",ilayer+6*kNlayer,"BFTRD", xpos,ypos,zpos
                       ,matrix[0],"ONLY",parCOL,kNparCOL);
-    gMC->Gsposp("UTC3",ilayer+7*kNlayer,"BFTRD",-xpos,ypos,zpos
+    TVirtualMC::GetMC()->Gsposp("UTC3",ilayer+7*kNlayer,"BFTRD",-xpos,ypos,zpos
                       ,matrix[1],"ONLY",parCOL,kNparCOL);
 
   }
 
   // The upper most layer
   // Along the chambers
-  xpos      = fCwidth[5]/2.0 - kCOLhgt/2.0 - 1.3;
+  xpos      = fgkCwidth[5]/2.0 - kCOLhgt/2.0 - 1.3;
   ypos      = 0.0;
   zpos      = fgkSheight/2.0 - fgkSMpltT - 0.4 - kCOLwid/2.0; 
   parCOL[0] = kCOLwid   /2.0;
   parCOL[1] = fgkSlength/2.0;
   parCOL[2] = kCOLhgt   /2.0;
-  gMC->Gsposp("UTC1",6          ,"UTI1", xpos,ypos,zpos
+  TVirtualMC::GetMC()->Gsposp("UTC1",6          ,"UTI1", xpos,ypos,zpos
                     ,matrix[3],"ONLY",parCOL,kNparCOL);
-  gMC->Gsposp("UTC1",6+  kNlayer,"UTI1",-xpos,ypos,zpos
+  TVirtualMC::GetMC()->Gsposp("UTC1",6+  kNlayer,"UTI1",-xpos,ypos,zpos
                     ,matrix[3],"ONLY",parCOL,kNparCOL);
-  gMC->Gsposp("UTC1",6+6*kNlayer,"UTI2", xpos,ypos,zpos
+  TVirtualMC::GetMC()->Gsposp("UTC1",6+6*kNlayer,"UTI2", xpos,ypos,zpos
                     ,matrix[3],"ONLY",parCOL,kNparCOL);
-  gMC->Gsposp("UTC1",6+7*kNlayer,"UTI2",-xpos,ypos,zpos
+  TVirtualMC::GetMC()->Gsposp("UTC1",6+7*kNlayer,"UTI2",-xpos,ypos,zpos
                     ,matrix[3],"ONLY",parCOL,kNparCOL);
-  gMC->Gsposp("UTC1",6+8*kNlayer,"UTI3", xpos,ypos,zpos
+  TVirtualMC::GetMC()->Gsposp("UTC1",6+8*kNlayer,"UTI3", xpos,ypos,zpos
                     ,matrix[3],"ONLY",parCOL,kNparCOL);
-  gMC->Gsposp("UTC1",6+9*kNlayer,"UTI3",-xpos,ypos,zpos
+  TVirtualMC::GetMC()->Gsposp("UTC1",6+9*kNlayer,"UTI3",-xpos,ypos,zpos
                     ,matrix[3],"ONLY",parCOL,kNparCOL);
   // Front of supermodules
-  xpos      = fCwidth[5]/2.0 - kCOLhgt/2.0 - 1.3;
+  xpos      = fgkCwidth[5]/2.0 - kCOLhgt/2.0 - 1.3;
   ypos      = 0.0;
   zpos      = fgkSheight/2.0 - fgkSMpltT - 0.4 - kCOLwid/2.0; 
   parCOL[0] = kCOLwid   /2.0;
   parCOL[1] = fgkFlength/2.0;
   parCOL[2] = kCOLhgt   /2.0;
-  gMC->Gsposp("UTC3",6+2*kNlayer,"UTF1", xpos,ypos,zpos
+  TVirtualMC::GetMC()->Gsposp("UTC3",6+2*kNlayer,"UTF1", xpos,ypos,zpos
                     ,matrix[3],"ONLY",parCOL,kNparCOL);
-  gMC->Gsposp("UTC3",6+3*kNlayer,"UTF1",-xpos,ypos,zpos
+  TVirtualMC::GetMC()->Gsposp("UTC3",6+3*kNlayer,"UTF1",-xpos,ypos,zpos
                     ,matrix[3],"ONLY",parCOL,kNparCOL);
-  gMC->Gsposp("UTC3",6+4*kNlayer,"UTF2", xpos,ypos,zpos
+  TVirtualMC::GetMC()->Gsposp("UTC3",6+4*kNlayer,"UTF2", xpos,ypos,zpos
                     ,matrix[3],"ONLY",parCOL,kNparCOL);
-  gMC->Gsposp("UTC3",6+5*kNlayer,"UTF2",-xpos,ypos,zpos
+  TVirtualMC::GetMC()->Gsposp("UTC3",6+5*kNlayer,"UTF2",-xpos,ypos,zpos
                     ,matrix[3],"ONLY",parCOL,kNparCOL);
   // In baby frame
-  xpos      = fCwidth[5]/2.0 - kCOLhgt/2.0 - 3.1;
+  xpos      = fgkCwidth[5]/2.0 - kCOLhgt/2.0 - 3.1;
   ypos      = kBBSdz/2.0 - kBBMdz/2.0;
   zpos      = fgkSheight/2.0 - fgkSMpltT - 0.4 - kCOLwid/2.0; 
   parCOL[0] = kCOLwid/2.0;
   parCOL[1] = kBBSdz /2.0;
   parCOL[2] = kCOLhgt/2.0;
-  gMC->Gsposp("UTC3",6+6*kNlayer,"BBTRD", xpos, ypos, zpos
+  TVirtualMC::GetMC()->Gsposp("UTC3",6+6*kNlayer,"BBTRD", xpos, ypos, zpos
                     ,matrix[3],"ONLY",parCOL,kNparCOL);
-  gMC->Gsposp("UTC3",6+7*kNlayer,"BBTRD",-xpos, ypos, zpos
+  TVirtualMC::GetMC()->Gsposp("UTC3",6+7*kNlayer,"BBTRD",-xpos, ypos, zpos
                     ,matrix[3],"ONLY",parCOL,kNparCOL);
   // In back frame
-  xpos      = fCwidth[5]/2.0 - kCOLhgt/2.0 - 1.3;
+  xpos      = fgkCwidth[5]/2.0 - kCOLhgt/2.0 - 1.3;
   ypos      = -kBFSdz/2.0 + kBFMdz/2.0;
   zpos      = fgkSheight/2.0 - fgkSMpltT - 0.4 - kCOLwid/2.0; 
   parCOL[0] = kCOLwid/2.0;
   parCOL[1] = kBFSdz /2.0;
   parCOL[2] = kCOLhgt/2.0;
-  gMC->Gsposp("UTC3",6+6*kNlayer,"BFTRD", xpos,ypos,zpos
+  TVirtualMC::GetMC()->Gsposp("UTC3",6+6*kNlayer,"BFTRD", xpos,ypos,zpos
                     ,matrix[3],"ONLY",parCOL,kNparCOL);
-  gMC->Gsposp("UTC3",6+7*kNlayer,"BFTRD",-xpos,ypos,zpos
+  TVirtualMC::GetMC()->Gsposp("UTC3",6+7*kNlayer,"BFTRD",-xpos,ypos,zpos
                     ,matrix[3],"ONLY",parCOL,kNparCOL);
 
   //
@@ -1986,13 +1887,13 @@ void AliTRDgeometry::CreateServices(Int_t *idtmed)
   parPWR[0] = 0.0;
   parPWR[1] = 0.0;
   parPWR[2] = 0.0;
-  gMC->Gsvolu("UTP1","BOX ",idtmed[1325-1],parPWR,0);
-  gMC->Gsvolu("UTP3","BOX ",idtmed[1325-1],parPWR,0);
+  TVirtualMC::GetMC()->Gsvolu("UTP1","BOX ",idtmed[1325-1],parPWR,0);
+  TVirtualMC::GetMC()->Gsvolu("UTP3","BOX ",idtmed[1325-1],parPWR,0);
   
   for (ilayer = 1; ilayer < kNlayer; ilayer++) { 
 
     // Along the chambers
-    xpos      = fCwidth[ilayer]/2.0 + kPWRwid/2.0 + kPWRposx;
+    xpos      = fgkCwidth[ilayer]/2.0 + kPWRwid/2.0 + kPWRposx;
     ypos      = 0.0;
     zpos      = fgkVrocsm + fgkSMpltT - fgkCalZpos 
               + kPWRhgtA/2.0 - fgkSheight/2.0 + kPWRposz 
@@ -2000,21 +1901,21 @@ void AliTRDgeometry::CreateServices(Int_t *idtmed)
     parPWR[0] = kPWRwid   /2.0;
     parPWR[1] = fgkSlength/2.0;
     parPWR[2] = kPWRhgtA  /2.0;
-    gMC->Gsposp("UTP1",ilayer          ,"UTI1", xpos,ypos,zpos
+    TVirtualMC::GetMC()->Gsposp("UTP1",ilayer          ,"UTI1", xpos,ypos,zpos
                       ,matrix[0],"ONLY",parPWR,kNparPWR);
-    gMC->Gsposp("UTP1",ilayer+  kNlayer,"UTI1",-xpos,ypos,zpos
+    TVirtualMC::GetMC()->Gsposp("UTP1",ilayer+  kNlayer,"UTI1",-xpos,ypos,zpos
                       ,matrix[1],"ONLY",parPWR,kNparPWR);
-    gMC->Gsposp("UTP1",ilayer+6*kNlayer,"UTI2", xpos,ypos,zpos
+    TVirtualMC::GetMC()->Gsposp("UTP1",ilayer+6*kNlayer,"UTI2", xpos,ypos,zpos
                       ,matrix[0],"ONLY",parPWR,kNparPWR);
-    gMC->Gsposp("UTP1",ilayer+7*kNlayer,"UTI2",-xpos,ypos,zpos
+    TVirtualMC::GetMC()->Gsposp("UTP1",ilayer+7*kNlayer,"UTI2",-xpos,ypos,zpos
                       ,matrix[1],"ONLY",parPWR,kNparPWR);
-    gMC->Gsposp("UTP1",ilayer+8*kNlayer,"UTI3", xpos,ypos,zpos
+    TVirtualMC::GetMC()->Gsposp("UTP1",ilayer+8*kNlayer,"UTI3", xpos,ypos,zpos
                       ,matrix[0],"ONLY",parPWR,kNparPWR);
-    gMC->Gsposp("UTP1",ilayer+9*kNlayer,"UTI3",-xpos,ypos,zpos
+    TVirtualMC::GetMC()->Gsposp("UTP1",ilayer+9*kNlayer,"UTI3",-xpos,ypos,zpos
                       ,matrix[1],"ONLY",parPWR,kNparPWR);
 
     // Front of supermodule
-    xpos      = fCwidth[ilayer]/2.0 + kPWRwid/2.0 + kPWRposx;
+    xpos      = fgkCwidth[ilayer]/2.0 + kPWRwid/2.0 + kPWRposx;
     ypos      = 0.0;
     zpos      = fgkVrocsm + fgkSMpltT - fgkCalZpos 
               + kPWRhgtA/2.0 - fgkSheight/2.0 + kPWRposz 
@@ -2022,13 +1923,13 @@ void AliTRDgeometry::CreateServices(Int_t *idtmed)
     parPWR[0] = kPWRwid   /2.0;
     parPWR[1] = fgkFlength/2.0;
     parPWR[2] = kPWRhgtA  /2.0;
-    gMC->Gsposp("UTP3",ilayer+2*kNlayer,"UTF1", xpos,ypos,zpos
+    TVirtualMC::GetMC()->Gsposp("UTP3",ilayer+2*kNlayer,"UTF1", xpos,ypos,zpos
                       ,matrix[0],"ONLY",parPWR,kNparPWR);
-    gMC->Gsposp("UTP3",ilayer+3*kNlayer,"UTF1",-xpos,ypos,zpos
+    TVirtualMC::GetMC()->Gsposp("UTP3",ilayer+3*kNlayer,"UTF1",-xpos,ypos,zpos
                       ,matrix[1],"ONLY",parPWR,kNparPWR);
-    gMC->Gsposp("UTP3",ilayer+4*kNlayer,"UTF2", xpos,ypos,zpos
+    TVirtualMC::GetMC()->Gsposp("UTP3",ilayer+4*kNlayer,"UTF2", xpos,ypos,zpos
                       ,matrix[0],"ONLY",parPWR,kNparPWR);
-    gMC->Gsposp("UTP3",ilayer+5*kNlayer,"UTF2",-xpos,ypos,zpos
+    TVirtualMC::GetMC()->Gsposp("UTP3",ilayer+5*kNlayer,"UTF2",-xpos,ypos,zpos
                       ,matrix[1],"ONLY",parPWR,kNparPWR);
 
   }
@@ -2036,7 +1937,7 @@ void AliTRDgeometry::CreateServices(Int_t *idtmed)
   for (ilayer = 1; ilayer < kNlayer; ilayer++) { 
 
     // In baby frame
-    xpos      = fCwidth[ilayer]/2.0 + kPWRwid/2.0 + kPWRposx - 2.5;
+    xpos      = fgkCwidth[ilayer]/2.0 + kPWRwid/2.0 + kPWRposx - 2.5;
     ypos      = kBBSdz/2.0 - kBBMdz/2.0;
     zpos      = fgkVrocsm + fgkSMpltT - fgkCalZpos 
               + kPWRhgtB/2.0 - fgkSheight/2.0 + kPWRposz 
@@ -2044,9 +1945,9 @@ void AliTRDgeometry::CreateServices(Int_t *idtmed)
     parPWR[0] = kPWRwid /2.0;
     parPWR[1] = kBBSdz  /2.0;
     parPWR[2] = kPWRhgtB/2.0;
-    gMC->Gsposp("UTP3",ilayer+6*kNlayer,"BBTRD", xpos, ypos, zpos
+    TVirtualMC::GetMC()->Gsposp("UTP3",ilayer+6*kNlayer,"BBTRD", xpos, ypos, zpos
                       ,matrix[0],"ONLY",parPWR,kNparPWR);
-    gMC->Gsposp("UTP3",ilayer+7*kNlayer,"BBTRD",-xpos, ypos, zpos
+    TVirtualMC::GetMC()->Gsposp("UTP3",ilayer+7*kNlayer,"BBTRD",-xpos, ypos, zpos
                       ,matrix[1],"ONLY",parPWR,kNparPWR);
 
   }
@@ -2054,7 +1955,7 @@ void AliTRDgeometry::CreateServices(Int_t *idtmed)
   for (ilayer = 1; ilayer < kNlayer; ilayer++) { 
 
     // In back frame
-    xpos      = fCwidth[ilayer]/2.0 + kPWRwid/2.0 + kPWRposx - 0.3;
+    xpos      = fgkCwidth[ilayer]/2.0 + kPWRwid/2.0 + kPWRposx - 0.3;
     ypos      = -kBFSdz/2.0 + kBFMdz/2.0;
     zpos      = fgkVrocsm + fgkSMpltT - fgkCalZpos 
               + kPWRhgtB/2.0 - fgkSheight/2.0 + kPWRposz 
@@ -2062,69 +1963,69 @@ void AliTRDgeometry::CreateServices(Int_t *idtmed)
     parPWR[0] = kPWRwid /2.0;
     parPWR[1] = kBFSdz  /2.0;
     parPWR[2] = kPWRhgtB/2.0;
-    gMC->Gsposp("UTP3",ilayer+8*kNlayer,"BFTRD", xpos,ypos,zpos
+    TVirtualMC::GetMC()->Gsposp("UTP3",ilayer+8*kNlayer,"BFTRD", xpos,ypos,zpos
                       ,matrix[0],"ONLY",parPWR,kNparPWR);
-    gMC->Gsposp("UTP3",ilayer+9*kNlayer,"BFTRD",-xpos,ypos,zpos
+    TVirtualMC::GetMC()->Gsposp("UTP3",ilayer+9*kNlayer,"BFTRD",-xpos,ypos,zpos
                       ,matrix[1],"ONLY",parPWR,kNparPWR);
 
   }
 
   // The upper most layer
   // Along the chambers
-  xpos      = fCwidth[5]/2.0 + kPWRhgtB/2.0 - 1.3;
+  xpos      = fgkCwidth[5]/2.0 + kPWRhgtB/2.0 - 1.3;
   ypos      = 0.0;
   zpos      = fgkSheight/2.0 - fgkSMpltT - 0.6 - kPWRwid/2.0; 
   parPWR[0] = kPWRwid   /2.0;
   parPWR[1] = fgkSlength/2.0;
   parPWR[2] = kPWRhgtB  /2.0 ;
-  gMC->Gsposp("UTP1",6          ,"UTI1", xpos,ypos,zpos
+  TVirtualMC::GetMC()->Gsposp("UTP1",6          ,"UTI1", xpos,ypos,zpos
                     ,matrix[3],"ONLY",parPWR,kNparPWR);
-  gMC->Gsposp("UTP1",6+  kNlayer,"UTI1",-xpos,ypos,zpos
+  TVirtualMC::GetMC()->Gsposp("UTP1",6+  kNlayer,"UTI1",-xpos,ypos,zpos
                     ,matrix[3],"ONLY",parPWR,kNparPWR);
-  gMC->Gsposp("UTP1",6+6*kNlayer,"UTI2", xpos,ypos,zpos
+  TVirtualMC::GetMC()->Gsposp("UTP1",6+6*kNlayer,"UTI2", xpos,ypos,zpos
                     ,matrix[3],"ONLY",parPWR,kNparPWR);
-  gMC->Gsposp("UTP1",6+7*kNlayer,"UTI2",-xpos,ypos,zpos
+  TVirtualMC::GetMC()->Gsposp("UTP1",6+7*kNlayer,"UTI2",-xpos,ypos,zpos
                     ,matrix[3],"ONLY",parPWR,kNparPWR);
-  gMC->Gsposp("UTP1",6+8*kNlayer,"UTI3", xpos,ypos,zpos
+  TVirtualMC::GetMC()->Gsposp("UTP1",6+8*kNlayer,"UTI3", xpos,ypos,zpos
                     ,matrix[3],"ONLY",parPWR,kNparPWR);
-  gMC->Gsposp("UTP1",6+9*kNlayer,"UTI3",-xpos,ypos,zpos
+  TVirtualMC::GetMC()->Gsposp("UTP1",6+9*kNlayer,"UTI3",-xpos,ypos,zpos
                     ,matrix[3],"ONLY",parPWR,kNparPWR);
   // Front of supermodules
-  xpos      = fCwidth[5]/2.0 + kPWRhgtB/2.0 - 1.3;
+  xpos      = fgkCwidth[5]/2.0 + kPWRhgtB/2.0 - 1.3;
   ypos      = 0.0;
   zpos      = fgkSheight/2.0 - fgkSMpltT - 0.6 - kPWRwid/2.0; 
   parPWR[0] = kPWRwid   /2.0;
   parPWR[1] = fgkFlength/2.0;
   parPWR[2] = kPWRhgtB  /2.0;
-  gMC->Gsposp("UTP3",6+2*kNlayer,"UTF1", xpos,ypos,zpos
+  TVirtualMC::GetMC()->Gsposp("UTP3",6+2*kNlayer,"UTF1", xpos,ypos,zpos
                     ,matrix[3],"ONLY",parPWR,kNparPWR);
-  gMC->Gsposp("UTP3",6+3*kNlayer,"UTF1",-xpos,ypos,zpos
+  TVirtualMC::GetMC()->Gsposp("UTP3",6+3*kNlayer,"UTF1",-xpos,ypos,zpos
                     ,matrix[3],"ONLY",parPWR,kNparPWR);
-  gMC->Gsposp("UTP3",6+4*kNlayer,"UTF2", xpos,ypos,zpos
+  TVirtualMC::GetMC()->Gsposp("UTP3",6+4*kNlayer,"UTF2", xpos,ypos,zpos
                     ,matrix[3],"ONLY",parPWR,kNparPWR);
-  gMC->Gsposp("UTP3",6+5*kNlayer,"UTF2",-xpos,ypos,zpos
+  TVirtualMC::GetMC()->Gsposp("UTP3",6+5*kNlayer,"UTF2",-xpos,ypos,zpos
                     ,matrix[3],"ONLY",parPWR,kNparPWR);
   // In baby frame
-  xpos      = fCwidth[5]/2.0 + kPWRhgtB/2.0 - 3.0;
+  xpos      = fgkCwidth[5]/2.0 + kPWRhgtB/2.0 - 3.0;
   ypos      = kBBSdz/2.0 - kBBMdz/2.0;
   zpos      = fgkSheight/2.0 - fgkSMpltT - 0.6 - kPWRwid/2.0; 
   parPWR[0] = kPWRwid /2.0;
   parPWR[1] = kBBSdz  /2.0;
   parPWR[2] = kPWRhgtB/2.0;
-  gMC->Gsposp("UTP3",6+6*kNlayer,"BBTRD", xpos, ypos, zpos
+  TVirtualMC::GetMC()->Gsposp("UTP3",6+6*kNlayer,"BBTRD", xpos, ypos, zpos
                     ,matrix[3],"ONLY",parPWR,kNparPWR);
-  gMC->Gsposp("UTP3",6+7*kNlayer,"BBTRD",-xpos, ypos, zpos
+  TVirtualMC::GetMC()->Gsposp("UTP3",6+7*kNlayer,"BBTRD",-xpos, ypos, zpos
                     ,matrix[3],"ONLY",parPWR,kNparPWR);
   // In back frame
-  xpos      = fCwidth[5]/2.0 + kPWRhgtB/2.0 - 1.3;
+  xpos      = fgkCwidth[5]/2.0 + kPWRhgtB/2.0 - 1.3;
   ypos      = -kBFSdz/2.0 + kBFMdz/2.0;
   zpos      = fgkSheight/2.0 - fgkSMpltT - 0.6 - kPWRwid/2.0; 
   parPWR[0] = kPWRwid /2.0;
   parPWR[1] = kBFSdz  /2.0;
   parPWR[2] = kPWRhgtB/2.0;
-  gMC->Gsposp("UTP3",6+8*kNlayer,"BFTRD", xpos,ypos,zpos
+  TVirtualMC::GetMC()->Gsposp("UTP3",6+8*kNlayer,"BFTRD", xpos,ypos,zpos
                     ,matrix[3],"ONLY",parPWR,kNparPWR);
-  gMC->Gsposp("UTP3",6+9*kNlayer,"BFTRD",-xpos,ypos,zpos
+  TVirtualMC::GetMC()->Gsposp("UTP3",6+9*kNlayer,"BFTRD",-xpos,ypos,zpos
                     ,matrix[3],"ONLY",parPWR,kNparPWR);
 
   //
@@ -2134,23 +2035,23 @@ void AliTRDgeometry::CreateServices(Int_t *idtmed)
 
   parTube[0] = 0.0;
   parTube[1] = 2.2/2.0;
-  parTube[2] = fClength[5][2]/2.0 - fgkHspace/2.0;
-  gMC->Gsvolu("UTG1","TUBE",idtmed[1308-1],parTube,kNparTube);
+  parTube[2] = fgkClength[5][2]/2.0 - fgkHspace/2.0;
+  TVirtualMC::GetMC()->Gsvolu("UTG1","TUBE",idtmed[1308-1],parTube,kNparTube);
   parTube[0] = 0.0;
   parTube[1] = 2.1/2.0;
-  parTube[2] = fClength[5][2]/2.0 - fgkHspace/2.0;
-  gMC->Gsvolu("UTG2","TUBE",idtmed[1309-1],parTube,kNparTube);
+  parTube[2] = fgkClength[5][2]/2.0 - fgkHspace/2.0;
+  TVirtualMC::GetMC()->Gsvolu("UTG2","TUBE",idtmed[1309-1],parTube,kNparTube);
   xpos  = 0.0;
   ypos  = 0.0;
   zpos  = 0.0;
-  gMC->Gspos("UTG2",1,"UTG1",xpos,ypos,zpos,0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTG2",1,"UTG1",xpos,ypos,zpos,0,"ONLY");
   for (ilayer = 0; ilayer < kNlayer; ilayer++) { 
-    xpos      = fCwidth[ilayer]/2.0 + kCOLwid/2.0 - 1.5;
+    xpos      = fgkCwidth[ilayer]/2.0 + kCOLwid/2.0 - 1.5;
     ypos      = 0.0;
     zpos      = fgkVrocsm + fgkSMpltT + kCOLhgt/2.0 - fgkSheight/2.0 + 5.0 
               + ilayer * (fgkCH + fgkVspace);
-    gMC->Gspos("UTG1",1+ilayer,"UTI3", xpos, ypos, zpos,matrix[4],"ONLY");
-    gMC->Gspos("UTG1",7+ilayer,"UTI3",-xpos, ypos, zpos,matrix[4],"ONLY");
+    TVirtualMC::GetMC()->Gspos("UTG1",1+ilayer,"UTI3", xpos, ypos, zpos,matrix[4],"ONLY");
+    TVirtualMC::GetMC()->Gspos("UTG1",7+ilayer,"UTI3",-xpos, ypos, zpos,matrix[4],"ONLY");
   }
 
   //
@@ -2165,11 +2066,11 @@ void AliTRDgeometry::CreateServices(Int_t *idtmed)
 
       Int_t iDet = GetDetectorSec(ilayer,istack);
 
-      sprintf(cTagV,"UU%02d",iDet);
-      parServ[0] = fCwidth[ilayer]         /2.0;
-      parServ[1] = fClength[ilayer][istack]/2.0 - fgkHspace/2.0;
+      snprintf(cTagV,kTag,"UU%02d",iDet);
+      parServ[0] = fgkCwidth[ilayer]         /2.0;
+      parServ[1] = fgkClength[ilayer][istack]/2.0 - fgkHspace/2.0;
       parServ[2] = fgkCsvH                 /2.0;
-      gMC->Gsvolu(cTagV,"BOX",idtmed[1302-1],parServ,kNparServ);
+      TVirtualMC::GetMC()->Gsvolu(cTagV,"BOX",idtmed[1302-1],parServ,kNparServ);
 
     }
   }
@@ -2182,17 +2083,17 @@ void AliTRDgeometry::CreateServices(Int_t *idtmed)
   parTube[0] =  0.0;
   parTube[1] =  0.0;
   parTube[2] =  0.0;
-  gMC->Gsvolu("UTCP","TUBE",idtmed[1324-1],parTube,0);
+  TVirtualMC::GetMC()->Gsvolu("UTCP","TUBE",idtmed[1324-1],parTube,0);
   // The cooling water
   parTube[0] =  0.0;
   parTube[1] =  0.2/2.0;
   parTube[2] = -1.0;
-  gMC->Gsvolu("UTCH","TUBE",idtmed[1314-1],parTube,kNparTube);
+  TVirtualMC::GetMC()->Gsvolu("UTCH","TUBE",idtmed[1314-1],parTube,kNparTube);
   // Water inside the cooling pipe
   xpos = 0.0;
   ypos = 0.0;
   zpos = 0.0;
-  gMC->Gspos("UTCH",1,"UTCP",xpos,ypos,zpos,0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTCH",1,"UTCP",xpos,ypos,zpos,0,"ONLY");
 
   // Position the cooling pipes in the mother volume
   for (istack = 0; istack < kNstack; istack++) {
@@ -2202,17 +2103,17 @@ void AliTRDgeometry::CreateServices(Int_t *idtmed)
       Int_t   nMCMrow = GetRowMax(ilayer,istack,0);
       Float_t ySize   = (GetChamberLength(ilayer,istack) - 2.0*fgkRpadW) 
                       / ((Float_t) nMCMrow);
-      sprintf(cTagV,"UU%02d",iDet);
+      snprintf(cTagV,kTag,"UU%02d",iDet);
       for (Int_t iMCMrow = 0; iMCMrow < nMCMrow; iMCMrow++) {
         xpos   = 0.0;
         ypos   = (0.5 + iMCMrow) * ySize 
-               - fClength[ilayer][istack]/2.0 + fgkHspace/2.0;
+               - fgkClength[ilayer][istack]/2.0 + fgkHspace/2.0;
         zpos   = 0.0 + 0.742/2.0;                 
        // The cooling pipes
         parTube[0] = 0.0;
         parTube[1] = 0.3/2.0; // Thickness of the cooling pipes
-        parTube[2] = fCwidth[ilayer]/2.0;
-        gMC->Gsposp("UTCP",iCopy+iMCMrow,cTagV,xpos,ypos,zpos
+        parTube[2] = fgkCwidth[ilayer]/2.0;
+        TVirtualMC::GetMC()->Gsposp("UTCP",iCopy+iMCMrow,cTagV,xpos,ypos,zpos
                           ,matrix[2],"ONLY",parTube,kNparTube);
       }
     }
@@ -2226,7 +2127,7 @@ void AliTRDgeometry::CreateServices(Int_t *idtmed)
   parTube[0] = 0.0;
   parTube[1] = 0.0;
   parTube[2] = 0.0;
-  gMC->Gsvolu("UTPL","TUBE",idtmed[1305-1],parTube,0);
+  TVirtualMC::GetMC()->Gsvolu("UTPL","TUBE",idtmed[1305-1],parTube,0);
 
   // Position the power lines in the mother volume
   for (istack = 0; istack < kNstack; istack++) {
@@ -2236,16 +2137,16 @@ void AliTRDgeometry::CreateServices(Int_t *idtmed)
       Int_t   nMCMrow = GetRowMax(ilayer,istack,0);
       Float_t ySize   = (GetChamberLength(ilayer,istack) - 2.0*fgkRpadW) 
                       / ((Float_t) nMCMrow);
-      sprintf(cTagV,"UU%02d",iDet);
+      snprintf(cTagV,kTag,"UU%02d",iDet);
       for (Int_t iMCMrow = 0; iMCMrow < nMCMrow; iMCMrow++) {
         xpos       = 0.0;
         ypos       = (0.5 + iMCMrow) * ySize - 1.0 
-                   - fClength[ilayer][istack]/2.0 + fgkHspace/2.0;
+                   - fgkClength[ilayer][istack]/2.0 + fgkHspace/2.0;
         zpos       = -0.4 + 0.742/2.0;
         parTube[0] = 0.0;
         parTube[1] = 0.2/2.0; // Thickness of the power lines
-        parTube[2] = fCwidth[ilayer]/2.0;
-        gMC->Gsposp("UTPL",iCopy+iMCMrow,cTagV,xpos,ypos,zpos
+        parTube[2] = fgkCwidth[ilayer]/2.0;
+        TVirtualMC::GetMC()->Gsposp("UTPL",iCopy+iMCMrow,cTagV,xpos,ypos,zpos
                           ,matrix[2],"ONLY",parTube,kNparTube);
       }
     }
@@ -2270,40 +2171,40 @@ void AliTRDgeometry::CreateServices(Int_t *idtmed)
   parMCM[0] = kMCMx   /2.0;
   parMCM[1] = kMCMy   /2.0;
   parMCM[2] = kMCMz   /2.0;
-  gMC->Gsvolu("UMCM","BOX",idtmed[1302-1],parMCM,kNparMCM);
+  TVirtualMC::GetMC()->Gsvolu("UMCM","BOX",idtmed[1302-1],parMCM,kNparMCM);
 
   // The MCM carrier G10 layer
   parMCM[0] = kMCMx   /2.0;
   parMCM[1] = kMCMy   /2.0;
   parMCM[2] = kMCMpcTh/2.0;
-  gMC->Gsvolu("UMC1","BOX",idtmed[1319-1],parMCM,kNparMCM);
+  TVirtualMC::GetMC()->Gsvolu("UMC1","BOX",idtmed[1319-1],parMCM,kNparMCM);
   // The MCM carrier Cu layer
   parMCM[0] = kMCMx   /2.0;
   parMCM[1] = kMCMy   /2.0;
   parMCM[2] = kMCMcuTh/2.0;
-  gMC->Gsvolu("UMC2","BOX",idtmed[1318-1],parMCM,kNparMCM);
+  TVirtualMC::GetMC()->Gsvolu("UMC2","BOX",idtmed[1318-1],parMCM,kNparMCM);
   // The silicon of the chips
   parMCM[0] = kMCMx   /2.0;
   parMCM[1] = kMCMy   /2.0;
   parMCM[2] = kMCMsiTh/2.0;
-  gMC->Gsvolu("UMC3","BOX",idtmed[1320-1],parMCM,kNparMCM);
+  TVirtualMC::GetMC()->Gsvolu("UMC3","BOX",idtmed[1320-1],parMCM,kNparMCM);
   // The aluminum of the cooling plates
   parMCM[0] = kMCMx   /2.0;
   parMCM[1] = kMCMy   /2.0;
   parMCM[2] = kMCMcoTh/2.0;
-  gMC->Gsvolu("UMC4","BOX",idtmed[1324-1],parMCM,kNparMCM);
+  TVirtualMC::GetMC()->Gsvolu("UMC4","BOX",idtmed[1324-1],parMCM,kNparMCM);
 
   // Put the MCM material inside the MCM mother volume
   xpos  =  0.0;
   ypos  =  0.0;
   zpos  = -kMCMz   /2.0 + kMCMpcTh/2.0;
-  gMC->Gspos("UMC1",1,"UMCM",xpos,ypos,zpos,0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("UMC1",1,"UMCM",xpos,ypos,zpos,0,"ONLY");
   zpos +=  kMCMpcTh/2.0 + kMCMcuTh/2.0;
-  gMC->Gspos("UMC2",1,"UMCM",xpos,ypos,zpos,0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("UMC2",1,"UMCM",xpos,ypos,zpos,0,"ONLY");
   zpos +=  kMCMcuTh/2.0 + kMCMsiTh/2.0;
-  gMC->Gspos("UMC3",1,"UMCM",xpos,ypos,zpos,0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("UMC3",1,"UMCM",xpos,ypos,zpos,0,"ONLY");
   zpos +=  kMCMsiTh/2.0 + kMCMcoTh/2.0;
-  gMC->Gspos("UMC4",1,"UMCM",xpos,ypos,zpos,0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("UMC4",1,"UMCM",xpos,ypos,zpos,0,"ONLY");
 
   // Position the MCMs in the mother volume
   for (istack = 0; istack < kNstack; istack++) {
@@ -2317,30 +2218,30 @@ void AliTRDgeometry::CreateServices(Int_t *idtmed)
       Float_t xSize   = (GetChamberWidth(ilayer)         - 2.0*fgkCpadW)
                       / ((Float_t) nMCMcol + 6);             // Introduce 6 gaps
       Int_t   iMCM[8] = {  1,  2,  3,  5,  8,  9, 10, 12 };  // 0..7 MCM + 6 gap structure
-      sprintf(cTagV,"UU%02d",iDet);
+      snprintf(cTagV,kTag,"UU%02d",iDet);
       for (Int_t iMCMrow = 0; iMCMrow < nMCMrow; iMCMrow++) {
         for (Int_t iMCMcol = 0; iMCMcol < nMCMcol; iMCMcol++) {
           xpos      = (0.5 + iMCM[iMCMcol]) * xSize + 1.0
-                    - fCwidth[ilayer]/2.0;
+                    - fgkCwidth[ilayer]/2.0;
           ypos      = (0.5 + iMCMrow) * ySize + 1.0
-                    - fClength[ilayer][istack]/2.0 + fgkHspace/2.0;
+                    - fgkClength[ilayer][istack]/2.0 + fgkHspace/2.0;
           zpos      = -0.4 + 0.742/2.0;
-          gMC->Gspos("UMCM",iCopy+iMCMrow*10+iMCMcol,cTagV
+          TVirtualMC::GetMC()->Gspos("UMCM",iCopy+iMCMrow*10+iMCMcol,cTagV
                            ,xpos,ypos,zpos,0,"ONLY");
          // Add two additional smaller cooling pipes on top of the MCMs
          // to mimic the meandering structure
           xpos      = (0.5 + iMCM[iMCMcol]) * xSize + 1.0
-                    - fCwidth[ilayer]/2.0;
+                    - fgkCwidth[ilayer]/2.0;
           ypos      = (0.5 + iMCMrow) * ySize
-                    - fClength[ilayer][istack]/2.0 + fgkHspace/2.0;
+                    - fgkClength[ilayer][istack]/2.0 + fgkHspace/2.0;
           zpos      = 0.0 + 0.742/2.0;                 
           parTube[0] = 0.0;
           parTube[1] = 0.3/2.0; // Thickness of the cooling pipes
           parTube[2] = kMCMx/2.0;
-          gMC->Gsposp("UTCP",iCopy+iMCMrow*10+iMCMcol+ 50,cTagV
+          TVirtualMC::GetMC()->Gsposp("UTCP",iCopy+iMCMrow*10+iMCMcol+ 50,cTagV
                             ,xpos,ypos+1.0,zpos
                             ,matrix[2],"ONLY",parTube,kNparTube);
-          gMC->Gsposp("UTCP",iCopy+iMCMrow*10+iMCMcol+500,cTagV
+          TVirtualMC::GetMC()->Gsposp("UTCP",iCopy+iMCMrow*10+iMCMcol+500,cTagV
                             ,xpos,ypos+2.0,zpos
                             ,matrix[2],"ONLY",parTube,kNparTube);
 
@@ -2368,45 +2269,45 @@ void AliTRDgeometry::CreateServices(Int_t *idtmed)
   parDCS[0] = kDCSx   /2.0;
   parDCS[1] = kDCSy   /2.0;
   parDCS[2] = kDCSz   /2.0;
-  gMC->Gsvolu("UDCS","BOX",idtmed[1302-1],parDCS,kNparDCS);
+  TVirtualMC::GetMC()->Gsvolu("UDCS","BOX",idtmed[1302-1],parDCS,kNparDCS);
 
   // The DCS carrier G10 layer
   parDCS[0] = kDCSx   /2.0;
   parDCS[1] = kDCSy   /2.0;
   parDCS[2] = kDCSpcTh/2.0;
-  gMC->Gsvolu("UDC1","BOX",idtmed[1319-1],parDCS,kNparDCS);
+  TVirtualMC::GetMC()->Gsvolu("UDC1","BOX",idtmed[1319-1],parDCS,kNparDCS);
   // The DCS carrier Cu layer
   parDCS[0] = kDCSx   /2.0;
   parDCS[1] = kDCSy   /2.0;
   parDCS[2] = kDCScuTh/2.0;
-  gMC->Gsvolu("UDC2","BOX",idtmed[1318-1],parDCS,kNparDCS);
+  TVirtualMC::GetMC()->Gsvolu("UDC2","BOX",idtmed[1318-1],parDCS,kNparDCS);
   // The aluminum of the cooling plates
   parDCS[0] = 5.0     /2.0;
   parDCS[1] = 5.0     /2.0;
   parDCS[2] = kDCScoTh/2.0;
-  gMC->Gsvolu("UDC3","BOX",idtmed[1324-1],parDCS,kNparDCS);
+  TVirtualMC::GetMC()->Gsvolu("UDC3","BOX",idtmed[1324-1],parDCS,kNparDCS);
 
   // Put the DCS material inside the DCS mother volume
   xpos  =  0.0;
   ypos  =  0.0;
   zpos  = -kDCSz   /2.0 + kDCSpcTh/2.0;
-  gMC->Gspos("UDC1",1,"UDCS",xpos,ypos,zpos,0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("UDC1",1,"UDCS",xpos,ypos,zpos,0,"ONLY");
   zpos +=  kDCSpcTh/2.0 + kDCScuTh/2.0;
-  gMC->Gspos("UDC2",1,"UDCS",xpos,ypos,zpos,0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("UDC2",1,"UDCS",xpos,ypos,zpos,0,"ONLY");
   zpos +=  kDCScuTh/2.0 + kDCScoTh/2.0;
-  gMC->Gspos("UDC3",1,"UDCS",xpos,ypos,zpos,0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("UDC3",1,"UDCS",xpos,ypos,zpos,0,"ONLY");
 
   // Put the DCS board in the chamber services mother volume
   for (istack = 0; istack < kNstack; istack++) {
     for (ilayer = 0; ilayer < kNlayer; ilayer++) {
       Int_t   iDet    = GetDetectorSec(ilayer,istack);
       Int_t   iCopy   = iDet + 1;
-      xpos =  fCwidth[ilayer]/2.0 - 1.9 * (GetChamberLength(ilayer,istack) - 2.0*fgkRpadW) 
+      xpos =  fgkCwidth[ilayer]/2.0 - 1.9 * (GetChamberLength(ilayer,istack) - 2.0*fgkRpadW) 
                                         / ((Float_t) GetRowMax(ilayer,istack,0));
-      ypos =  0.05 * fClength[ilayer][istack];
+      ypos =  0.05 * fgkClength[ilayer][istack];
       zpos =  kDCSz/2.0 - fgkCsvH/2.0;
-      sprintf(cTagV,"UU%02d",iDet);
-      gMC->Gspos("UDCS",iCopy,cTagV,xpos,ypos,zpos,0,"ONLY");
+      snprintf(cTagV,kTag,"UU%02d",iDet);
+      TVirtualMC::GetMC()->Gspos("UDCS",iCopy,cTagV,xpos,ypos,zpos,0,"ONLY");
     }
   }
 
@@ -2428,51 +2329,51 @@ void AliTRDgeometry::CreateServices(Int_t *idtmed)
   parORI[0] = kORIx   /2.0;
   parORI[1] = kORIy   /2.0;
   parORI[2] = kORIz   /2.0;
-  gMC->Gsvolu("UORI","BOX",idtmed[1302-1],parORI,kNparORI);
+  TVirtualMC::GetMC()->Gsvolu("UORI","BOX",idtmed[1302-1],parORI,kNparORI);
 
   // The ORI carrier G10 layer
   parORI[0] = kORIx   /2.0;
   parORI[1] = kORIy   /2.0;
   parORI[2] = kORIpcTh/2.0;
-  gMC->Gsvolu("UOR1","BOX",idtmed[1319-1],parORI,kNparORI);
+  TVirtualMC::GetMC()->Gsvolu("UOR1","BOX",idtmed[1319-1],parORI,kNparORI);
   // The ORI carrier Cu layer
   parORI[0] = kORIx   /2.0;
   parORI[1] = kORIy   /2.0;
   parORI[2] = kORIcuTh/2.0;
-  gMC->Gsvolu("UOR2","BOX",idtmed[1318-1],parORI,kNparORI);
+  TVirtualMC::GetMC()->Gsvolu("UOR2","BOX",idtmed[1318-1],parORI,kNparORI);
   // The aluminum of the cooling plates
   parORI[0] = kORIx   /2.0;
   parORI[1] = kORIy   /2.0;
   parORI[2] = kORIcoTh/2.0;
-  gMC->Gsvolu("UOR3","BOX",idtmed[1324-1],parORI,kNparORI);
+  TVirtualMC::GetMC()->Gsvolu("UOR3","BOX",idtmed[1324-1],parORI,kNparORI);
 
   // Put the ORI material inside the ORI mother volume
   xpos  =  0.0;
   ypos  =  0.0;
   zpos  = -kORIz   /2.0 + kORIpcTh/2.0;
-  gMC->Gspos("UOR1",1,"UORI",xpos,ypos,zpos,0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("UOR1",1,"UORI",xpos,ypos,zpos,0,"ONLY");
   zpos +=  kORIpcTh/2.0 + kORIcuTh/2.0;
-  gMC->Gspos("UOR2",1,"UORI",xpos,ypos,zpos,0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("UOR2",1,"UORI",xpos,ypos,zpos,0,"ONLY");
   zpos +=  kORIcuTh/2.0 + kORIcoTh/2.0;
-  gMC->Gspos("UOR3",1,"UORI",xpos,ypos,zpos,0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("UOR3",1,"UORI",xpos,ypos,zpos,0,"ONLY");
 
   // Put the ORI board in the chamber services mother volume
   for (istack = 0; istack < kNstack; istack++) {
     for (ilayer = 0; ilayer < kNlayer; ilayer++) {
       Int_t   iDet    = GetDetectorSec(ilayer,istack);
       Int_t   iCopy   = iDet + 1;
-      xpos =  fCwidth[ilayer]/2.0 - 1.92 * (GetChamberLength(ilayer,istack) - 2.0*fgkRpadW) 
+      xpos =  fgkCwidth[ilayer]/2.0 - 1.92 * (GetChamberLength(ilayer,istack) - 2.0*fgkRpadW) 
                                         / ((Float_t) GetRowMax(ilayer,istack,0));
       ypos = -16.0;
       zpos =  kORIz/2.0 - fgkCsvH/2.0;
-      sprintf(cTagV,"UU%02d",iDet);
-      gMC->Gspos("UORI",iCopy      ,cTagV,xpos,ypos,zpos,0,"ONLY");
-      xpos = -fCwidth[ilayer]/2.0 + 3.8 * (GetChamberLength(ilayer,istack) - 2.0*fgkRpadW) 
+      snprintf(cTagV,kTag,"UU%02d",iDet);
+      TVirtualMC::GetMC()->Gspos("UORI",iCopy      ,cTagV,xpos,ypos,zpos,0,"ONLY");
+      xpos = -fgkCwidth[ilayer]/2.0 + 3.8 * (GetChamberLength(ilayer,istack) - 2.0*fgkRpadW) 
                                         / ((Float_t) GetRowMax(ilayer,istack,0));
       ypos = -16.0;
       zpos =  kORIz/2.0 - fgkCsvH/2.0;
-      sprintf(cTagV,"UU%02d",iDet);
-      gMC->Gspos("UORI",iCopy+kNdet,cTagV,xpos,ypos,zpos,0,"ONLY");
+      snprintf(cTagV,kTag,"UU%02d",iDet);
+      TVirtualMC::GetMC()->Gspos("UORI",iCopy+kNdet,cTagV,xpos,ypos,zpos,0,"ONLY");
     }
   }
 
@@ -2484,37 +2385,37 @@ void AliTRDgeometry::CreateServices(Int_t *idtmed)
   parTube[0] = 0.0;
   parTube[1] = 0.0;
   parTube[2] = 0.0;
-  gMC->Gsvolu("UTG3","TUBE",idtmed[1308-1],parTube,0);
+  TVirtualMC::GetMC()->Gsvolu("UTG3","TUBE",idtmed[1308-1],parTube,0);
   // The gas inside the in-/outlet pipes (Xe)
   parTube[0] =  0.0;
   parTube[1] =  1.2/2.0;
   parTube[2] = -1.0;
-  gMC->Gsvolu("UTG4","TUBE",idtmed[1309-1],parTube,kNparTube);
+  TVirtualMC::GetMC()->Gsvolu("UTG4","TUBE",idtmed[1309-1],parTube,kNparTube);
   xpos = 0.0;
   ypos = 0.0;
   zpos = 0.0;
-  gMC->Gspos("UTG4",1,"UTG3",xpos,ypos,zpos,0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTG4",1,"UTG3",xpos,ypos,zpos,0,"ONLY");
   for (ilayer = 0; ilayer < kNlayer-1; ilayer++) { 
     xpos       = 0.0;
-    ypos       = fClength[ilayer][2]/2.0 
-               + fClength[ilayer][1] 
-               + fClength[ilayer][0];
+    ypos       = fgkClength[ilayer][2]/2.0 
+               + fgkClength[ilayer][1] 
+               + fgkClength[ilayer][0];
     zpos       = 9.0 - fgkSheight/2.0
                + ilayer * (fgkCH + fgkVspace);
     parTube[0] = 0.0;
     parTube[1] = 1.5/2.0;
-    parTube[2] = fCwidth[ilayer]/2.0 - 2.5;
-    gMC->Gsposp("UTG3",ilayer+1          ,"UTI1", xpos, ypos, zpos
+    parTube[2] = fgkCwidth[ilayer]/2.0 - 2.5;
+    TVirtualMC::GetMC()->Gsposp("UTG3",ilayer+1          ,"UTI1", xpos, ypos, zpos
                       ,matrix[2],"ONLY",parTube,kNparTube);
-    gMC->Gsposp("UTG3",ilayer+1+1*kNlayer,"UTI1", xpos,-ypos, zpos
+    TVirtualMC::GetMC()->Gsposp("UTG3",ilayer+1+1*kNlayer,"UTI1", xpos,-ypos, zpos
                       ,matrix[2],"ONLY",parTube,kNparTube);
-    gMC->Gsposp("UTG3",ilayer+1+2*kNlayer,"UTI2", xpos, ypos, zpos
+    TVirtualMC::GetMC()->Gsposp("UTG3",ilayer+1+2*kNlayer,"UTI2", xpos, ypos, zpos
                       ,matrix[2],"ONLY",parTube,kNparTube);
-    gMC->Gsposp("UTG3",ilayer+1+3*kNlayer,"UTI2", xpos,-ypos, zpos
+    TVirtualMC::GetMC()->Gsposp("UTG3",ilayer+1+3*kNlayer,"UTI2", xpos,-ypos, zpos
                       ,matrix[2],"ONLY",parTube,kNparTube);
-    gMC->Gsposp("UTG3",ilayer+1+4*kNlayer,"UTI3", xpos, ypos, zpos
+    TVirtualMC::GetMC()->Gsposp("UTG3",ilayer+1+4*kNlayer,"UTI3", xpos, ypos, zpos
                       ,matrix[2],"ONLY",parTube,kNparTube);
-    gMC->Gsposp("UTG3",ilayer+1+5*kNlayer,"UTI3", xpos,-ypos, zpos
+    TVirtualMC::GetMC()->Gsposp("UTG3",ilayer+1+5*kNlayer,"UTI3", xpos,-ypos, zpos
                       ,matrix[2],"ONLY",parTube,kNparTube);
   }
 
@@ -2522,129 +2423,129 @@ void AliTRDgeometry::CreateServices(Int_t *idtmed)
   parBox[0] = 14.50/2.0;
   parBox[1] =  4.52/2.0;
   parBox[2] =  5.00/2.0;
-  gMC->Gsvolu("UTGD","BOX ",idtmed[1308-1],parBox,kNparBox);
+  TVirtualMC::GetMC()->Gsvolu("UTGD","BOX ",idtmed[1308-1],parBox,kNparBox);
   parBox[0] = 14.50/2.0;
   parBox[1] =  4.00/2.0;
   parBox[2] =  4.40/2.0;
-  gMC->Gsvolu("UTGI","BOX ",idtmed[1309-1],parBox,kNparBox);
+  TVirtualMC::GetMC()->Gsvolu("UTGI","BOX ",idtmed[1309-1],parBox,kNparBox);
   parTube[0] = 0.0;
   parTube[1] = 4.0/2.0;
   parTube[2] = 8.0/2.0;
-  gMC->Gsvolu("UTGT","TUBE",idtmed[1308-1],parTube,kNparTube);
+  TVirtualMC::GetMC()->Gsvolu("UTGT","TUBE",idtmed[1308-1],parTube,kNparTube);
   parTube[0] = 0.0;
   parTube[1] = 3.4/2.0;
   parTube[2] = 8.0/2.0;
-  gMC->Gsvolu("UTGG","TUBE",idtmed[1309-1],parTube,kNparTube);
+  TVirtualMC::GetMC()->Gsvolu("UTGG","TUBE",idtmed[1309-1],parTube,kNparTube);
   xpos = 0.0;
   ypos = 0.0;
   zpos = 0.0;
-  gMC->Gspos("UTGI",1,"UTGD",xpos,ypos,zpos,        0,"ONLY");
-  gMC->Gspos("UTGG",1,"UTGT",xpos,ypos,zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTGI",1,"UTGD",xpos,ypos,zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTGG",1,"UTGT",xpos,ypos,zpos,        0,"ONLY");
   xpos = 0.0;
   ypos = 0.0;
   zpos = 0.0;
-  gMC->Gspos("UTGD",1,"UTF1",xpos,ypos,zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTGD",1,"UTF1",xpos,ypos,zpos,        0,"ONLY");
   xpos =  -3.0;
   ypos =   0.0;
   zpos =   6.5;
-  gMC->Gspos("UTGT",1,"UTF1",xpos,ypos,zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTGT",1,"UTF1",xpos,ypos,zpos,        0,"ONLY");
   xpos = -11.25;
   ypos =   0.0;
   zpos =   0.5;
-  gMC->Gspos("UTGT",3,"UTF1",xpos,ypos,zpos,matrix[2],"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTGT",3,"UTF1",xpos,ypos,zpos,matrix[2],"ONLY");
   xpos =  11.25;
   ypos =   0.0;
   zpos =   0.5;
-  gMC->Gspos("UTGT",5,"UTF1",xpos,ypos,zpos,matrix[2],"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTGT",5,"UTF1",xpos,ypos,zpos,matrix[2],"ONLY");
 
   // Cooling manifolds
   parBox[0]  =  5.0/2.0;
   parBox[1]  = 23.0/2.0;
   parBox[2]  = 70.0/2.0;
-  gMC->Gsvolu("UTCM","BOX ",idtmed[1302-1],parBox,kNparBox);
+  TVirtualMC::GetMC()->Gsvolu("UTCM","BOX ",idtmed[1302-1],parBox,kNparBox);
   parBox[0]  =  5.0/2.0;
   parBox[1]  =  5.0/2.0;
   parBox[2]  = 70.0/2.0;
-  gMC->Gsvolu("UTCA","BOX ",idtmed[1308-1],parBox,kNparBox);
+  TVirtualMC::GetMC()->Gsvolu("UTCA","BOX ",idtmed[1308-1],parBox,kNparBox);
   parBox[0]  =  5.0/2.0 - 0.3;
   parBox[1]  =  5.0/2.0 - 0.3;
   parBox[2]  = 70.0/2.0 - 0.3;
-  gMC->Gsvolu("UTCW","BOX ",idtmed[1314-1],parBox,kNparBox);
+  TVirtualMC::GetMC()->Gsvolu("UTCW","BOX ",idtmed[1314-1],parBox,kNparBox);
   xpos       =  0.0;
   ypos       =  0.0;
   zpos       =  0.0;
-  gMC->Gspos("UTCW",1,"UTCA", xpos, ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTCW",1,"UTCA", xpos, ypos, zpos,        0,"ONLY");
   xpos       =  0.0;
   ypos       =  5.0/2.0 - 23.0/2.0;
   zpos       =  0.0;
-  gMC->Gspos("UTCA",1,"UTCM", xpos, ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTCA",1,"UTCM", xpos, ypos, zpos,        0,"ONLY");
   parTube[0] =  0.0;
   parTube[1] =  3.0/2.0;
   parTube[2] = 18.0/2.0;
-  gMC->Gsvolu("UTCO","TUBE",idtmed[1308-1],parTube,kNparTube);
+  TVirtualMC::GetMC()->Gsvolu("UTCO","TUBE",idtmed[1308-1],parTube,kNparTube);
   parTube[0] =  0.0;
   parTube[1] =  3.0/2.0 - 0.3;
   parTube[2] = 18.0/2.0;
-  gMC->Gsvolu("UTCL","TUBE",idtmed[1314-1],parTube,kNparTube);
+  TVirtualMC::GetMC()->Gsvolu("UTCL","TUBE",idtmed[1314-1],parTube,kNparTube);
   xpos       =  0.0;
   ypos       =  0.0;
   zpos       =  0.0;
-  gMC->Gspos("UTCL",1,"UTCO", xpos, ypos, zpos,        0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTCL",1,"UTCO", xpos, ypos, zpos,        0,"ONLY");
   xpos       =  0.0;
   ypos       =  2.5;
   zpos       = -70.0/2.0 + 7.0;
-  gMC->Gspos("UTCO",1,"UTCM", xpos, ypos, zpos,matrix[4],"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTCO",1,"UTCM", xpos, ypos, zpos,matrix[4],"ONLY");
   zpos      +=  7.0;
-  gMC->Gspos("UTCO",2,"UTCM", xpos, ypos, zpos,matrix[4],"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTCO",2,"UTCM", xpos, ypos, zpos,matrix[4],"ONLY");
   zpos      +=  7.0;
-  gMC->Gspos("UTCO",3,"UTCM", xpos, ypos, zpos,matrix[4],"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTCO",3,"UTCM", xpos, ypos, zpos,matrix[4],"ONLY");
   zpos      +=  7.0;
-  gMC->Gspos("UTCO",4,"UTCM", xpos, ypos, zpos,matrix[4],"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTCO",4,"UTCM", xpos, ypos, zpos,matrix[4],"ONLY");
   zpos      +=  7.0;
-  gMC->Gspos("UTCO",5,"UTCM", xpos, ypos, zpos,matrix[4],"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTCO",5,"UTCM", xpos, ypos, zpos,matrix[4],"ONLY");
   zpos      +=  7.0;
-  gMC->Gspos("UTCO",6,"UTCM", xpos, ypos, zpos,matrix[4],"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTCO",6,"UTCM", xpos, ypos, zpos,matrix[4],"ONLY");
   zpos      +=  7.0;
-  gMC->Gspos("UTCO",7,"UTCM", xpos, ypos, zpos,matrix[4],"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTCO",7,"UTCM", xpos, ypos, zpos,matrix[4],"ONLY");
   zpos      +=  7.0;
-  gMC->Gspos("UTCO",8,"UTCM", xpos, ypos, zpos,matrix[4],"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTCO",8,"UTCM", xpos, ypos, zpos,matrix[4],"ONLY");
 
   xpos = 40.0;
   ypos =  fgkFlength/2.0 - 23.0/2.0;
   zpos =  0.0;
-  gMC->Gspos("UTCM",1,"UTF1", xpos, ypos, zpos,matrix[0],"ONLY");
-  gMC->Gspos("UTCM",2,"UTF1",-xpos, ypos, zpos,matrix[1],"ONLY");
-  gMC->Gspos("UTCM",3,"UTF2", xpos,-ypos, zpos,matrix[5],"ONLY");
-  gMC->Gspos("UTCM",4,"UTF2",-xpos,-ypos, zpos,matrix[6],"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTCM",1,"UTF1", xpos, ypos, zpos,matrix[0],"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTCM",2,"UTF1",-xpos, ypos, zpos,matrix[1],"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTCM",3,"UTF2", xpos,-ypos, zpos,matrix[5],"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTCM",4,"UTF2",-xpos,-ypos, zpos,matrix[6],"ONLY");
 
   // Power connection boards (Cu)
   parBox[0] =  0.5/2.0;
   parBox[1] = 15.0/2.0;
   parBox[2] =  7.0/2.0;
-  gMC->Gsvolu("UTPC","BOX ",idtmed[1325-1],parBox,kNparBox);
+  TVirtualMC::GetMC()->Gsvolu("UTPC","BOX ",idtmed[1325-1],parBox,kNparBox);
   for (ilayer = 0; ilayer < kNlayer-1; ilayer++) { 
-    xpos      = fCwidth[ilayer]/2.0 + kPWRwid/2.0;
+    xpos      = fgkCwidth[ilayer]/2.0 + kPWRwid/2.0;
     ypos      = 0.0;
     zpos      = fgkVrocsm + fgkSMpltT + kPWRhgtA/2.0 - fgkSheight/2.0 + kPWRposz 
               + (ilayer+1) * (fgkCH + fgkVspace);
-    gMC->Gspos("UTPC",ilayer        ,"UTF1", xpos,ypos,zpos,matrix[0],"ONLY");
-    gMC->Gspos("UTPC",ilayer+kNlayer,"UTF1",-xpos,ypos,zpos,matrix[1],"ONLY");
+    TVirtualMC::GetMC()->Gspos("UTPC",ilayer        ,"UTF1", xpos,ypos,zpos,matrix[0],"ONLY");
+    TVirtualMC::GetMC()->Gspos("UTPC",ilayer+kNlayer,"UTF1",-xpos,ypos,zpos,matrix[1],"ONLY");
   }
-  xpos      = fCwidth[5]/2.0 + kPWRhgtA/2.0 - 2.0;
+  xpos      = fgkCwidth[5]/2.0 + kPWRhgtA/2.0 - 2.0;
   ypos      = 0.0;
   zpos      = fgkSheight/2.0 - fgkSMpltT - 2.0; 
-  gMC->Gspos("UTPC",5        ,"UTF1", xpos,ypos,zpos,matrix[3],"ONLY");
-  gMC->Gspos("UTPC",5+kNlayer,"UTF1",-xpos,ypos,zpos,matrix[3],"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTPC",5        ,"UTF1", xpos,ypos,zpos,matrix[3],"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTPC",5+kNlayer,"UTF1",-xpos,ypos,zpos,matrix[3],"ONLY");
 
   // Power connection panel (Al)
   parBox[0] = 60.0/2.0;
   parBox[1] = 10.0/2.0;
   parBox[2] =  3.0/2.0;
-  gMC->Gsvolu("UTPP","BOX ",idtmed[1301-1],parBox,kNparBox);
+  TVirtualMC::GetMC()->Gsvolu("UTPP","BOX ",idtmed[1301-1],parBox,kNparBox);
   xpos      =  0.0;
   ypos      =  0.0;
   zpos      = 18.0;
-  gMC->Gspos("UTPP",1,"UTF1", xpos,ypos,zpos,0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTPP",1,"UTF1", xpos,ypos,zpos,0,"ONLY");
 
   //
   // Electronics boxes
@@ -2654,68 +2555,68 @@ void AliTRDgeometry::CreateServices(Int_t *idtmed)
   parBox[0] = 60.0/2.0;
   parBox[1] = 10.0/2.0;
   parBox[2] =  6.0/2.0;
-  gMC->Gsvolu("UTE1","BOX ",idtmed[1308-1],parBox,kNparBox);
+  TVirtualMC::GetMC()->Gsvolu("UTE1","BOX ",idtmed[1308-1],parBox,kNparBox);
   // Interior (air)
   parBox[0] = parBox[0] - 0.5;
   parBox[1] = parBox[1] - 0.5;
   parBox[2] = parBox[2] - 0.5;
-  gMC->Gsvolu("UTE2","BOX ",idtmed[1302-1],parBox,kNparBox);
+  TVirtualMC::GetMC()->Gsvolu("UTE2","BOX ",idtmed[1302-1],parBox,kNparBox);
   xpos      = 0.0;
   ypos      = 0.0;
   zpos      = 0.0;
-  gMC->Gspos("UTE2",1,"UTE1",xpos,ypos,zpos,0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTE2",1,"UTE1",xpos,ypos,zpos,0,"ONLY");
   xpos      = 0.0;
   ypos      =  fgkSlength/2.0 - 10.0/2.0 - 3.0;
   zpos      = -fgkSheight/2.0 +  6.0/2.0 + 1.0;
-  gMC->Gspos("UTE1",1,"UTI1", xpos,ypos,zpos,0,"ONLY");
-  gMC->Gspos("UTE1",2,"UTI2", xpos,ypos,zpos,0,"ONLY");
-  gMC->Gspos("UTE1",3,"UTI3", xpos,ypos,zpos,0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTE1",1,"UTI1", xpos,ypos,zpos,0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTE1",2,"UTI2", xpos,ypos,zpos,0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTE1",3,"UTI3", xpos,ypos,zpos,0,"ONLY");
 
   // Casing (INOX)
   parBox[0] = 50.0/2.0;
   parBox[1] = 15.0/2.0;
   parBox[2] = 20.0/2.0;
-  gMC->Gsvolu("UTE3","BOX ",idtmed[1308-1],parBox,kNparBox);
+  TVirtualMC::GetMC()->Gsvolu("UTE3","BOX ",idtmed[1308-1],parBox,kNparBox);
   // Interior (air)
   parBox[0] = parBox[0] - 0.5;
   parBox[1] = parBox[1] - 0.5;
   parBox[2] = parBox[2] - 0.5;
-  gMC->Gsvolu("UTE4","BOX ",idtmed[1302-1],parBox,kNparBox);
+  TVirtualMC::GetMC()->Gsvolu("UTE4","BOX ",idtmed[1302-1],parBox,kNparBox);
   xpos      = 0.0;
   ypos      = 0.0;
   zpos      = 0.0;
-  gMC->Gspos("UTE4",1,"UTE3",xpos,ypos,zpos,0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTE4",1,"UTE3",xpos,ypos,zpos,0,"ONLY");
   xpos      = 0.0;
   ypos      = -fgkSlength/2.0 + 15.0/2.0 + 3.0;
   zpos      = -fgkSheight/2.0 + 20.0/2.0 + 1.0;
-  gMC->Gspos("UTE3",1,"UTI1", xpos,ypos,zpos,0,"ONLY");
-  gMC->Gspos("UTE3",2,"UTI2", xpos,ypos,zpos,0,"ONLY");
-  gMC->Gspos("UTE3",3,"UTI3", xpos,ypos,zpos,0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTE3",1,"UTI1", xpos,ypos,zpos,0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTE3",2,"UTI2", xpos,ypos,zpos,0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTE3",3,"UTI3", xpos,ypos,zpos,0,"ONLY");
 
   // Casing (INOX)
   parBox[0] = 20.0/2.0;
   parBox[1] =  7.0/2.0;
   parBox[2] = 20.0/2.0;
-  gMC->Gsvolu("UTE5","BOX ",idtmed[1308-1],parBox,kNparBox);
+  TVirtualMC::GetMC()->Gsvolu("UTE5","BOX ",idtmed[1308-1],parBox,kNparBox);
   // Interior (air)
   parBox[0] = parBox[0] - 0.5;
   parBox[1] = parBox[1] - 0.5;
   parBox[2] = parBox[2] - 0.5;
-  gMC->Gsvolu("UTE6","BOX ",idtmed[1302-1],parBox,kNparBox);
+  TVirtualMC::GetMC()->Gsvolu("UTE6","BOX ",idtmed[1302-1],parBox,kNparBox);
   xpos      = 0.0;
   ypos      = 0.0;
   zpos      = 0.0;
-  gMC->Gspos("UTE6",1,"UTE5",xpos,ypos,zpos,0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTE6",1,"UTE5",xpos,ypos,zpos,0,"ONLY");
   xpos      = 20.0;
   ypos      = -fgkSlength/2.0 +  7.0/2.0 + 3.0;
   zpos      = 0.0;
-  gMC->Gspos("UTE5",1,"UTI1", xpos,ypos,zpos,0,"ONLY");
-  gMC->Gspos("UTE5",2,"UTI2", xpos,ypos,zpos,0,"ONLY");
-  gMC->Gspos("UTE5",3,"UTI3", xpos,ypos,zpos,0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTE5",1,"UTI1", xpos,ypos,zpos,0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTE5",2,"UTI2", xpos,ypos,zpos,0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTE5",3,"UTI3", xpos,ypos,zpos,0,"ONLY");
   xpos      = -xpos;
-  gMC->Gspos("UTE5",4,"UTI1", xpos,ypos,zpos,0,"ONLY");
-  gMC->Gspos("UTE5",5,"UTI2", xpos,ypos,zpos,0,"ONLY");
-  gMC->Gspos("UTE5",6,"UTI3", xpos,ypos,zpos,0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTE5",4,"UTI1", xpos,ypos,zpos,0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTE5",5,"UTI2", xpos,ypos,zpos,0,"ONLY");
+  TVirtualMC::GetMC()->Gspos("UTE5",6,"UTI3", xpos,ypos,zpos,0,"ONLY");
 
 }
 
@@ -2727,8 +2628,9 @@ void AliTRDgeometry::AssembleChamber(Int_t ilayer, Int_t istack)
   // alignable volume of a single readout chamber
   //
 
-  Char_t  cTagM[100];
-  Char_t  cTagV[100];
+  const Int_t kTag = 100;
+  Char_t  cTagV[kTag];
+  Char_t  cTagM[kTag];
 
   Double_t xpos = 0.0;
   Double_t ypos = 0.0;
@@ -2737,7 +2639,7 @@ void AliTRDgeometry::AssembleChamber(Int_t ilayer, Int_t istack)
   Int_t idet = GetDetectorSec(ilayer,istack);
 
   // Create the assembly for a given ROC
-  sprintf(cTagM,"UT%02d",idet);
+  snprintf(cTagM,kTag,"UT%02d",idet);
   TGeoVolume *roc = new TGeoVolumeAssembly(cTagM);
 
   // Add the lower part of the chamber (aluminum frame),
@@ -2745,24 +2647,24 @@ void AliTRDgeometry::AssembleChamber(Int_t ilayer, Int_t istack)
   xpos = 0.0;
   ypos = 0.0;
   zpos = fgkCraH/2.0 + fgkCdrH/2.0 - fgkCHsv/2.0;
-  sprintf(cTagV,"UA%02d",idet);
+  snprintf(cTagV,kTag,"UA%02d",idet);
   TGeoVolume *rocA = gGeoManager->GetVolume(cTagV);
   roc->AddNode(rocA,1,new TGeoTranslation(xpos,ypos,zpos));
 
   // Add the additional aluminum ledges
-  xpos = fCwidth[ilayer]/2.0 + fgkCalWmod/2.0;
+  xpos = fgkCwidth[ilayer]/2.0 + fgkCalWmod/2.0;
   ypos = 0.0;
   zpos = fgkCraH + fgkCdrH - fgkCalZpos - fgkCalHmod/2.0 - fgkCHsv/2.0;
-  sprintf(cTagV,"UZ%02d",idet);
+  snprintf(cTagV,kTag,"UZ%02d",idet);
   TGeoVolume *rocZ = gGeoManager->GetVolume(cTagV);
   roc->AddNode(rocZ,1,new TGeoTranslation( xpos,ypos,zpos));
   roc->AddNode(rocZ,2,new TGeoTranslation(-xpos,ypos,zpos));
 
   // Add the additional wacosit ledges
-  xpos = fCwidth[ilayer]/2.0 + fgkCwsW/2.0;
+  xpos = fgkCwidth[ilayer]/2.0 + fgkCwsW/2.0;
   ypos = 0.0;
   zpos = fgkCraH + fgkCdrH - fgkCwsH/2.0 - fgkCHsv/2.0;
-  sprintf(cTagV,"UP%02d",idet);
+  snprintf(cTagV,kTag,"UP%02d",idet);
   TGeoVolume *rocP = gGeoManager->GetVolume(cTagV);
   roc->AddNode(rocP,1,new TGeoTranslation( xpos,ypos,zpos));
   roc->AddNode(rocP,2,new TGeoTranslation(-xpos,ypos,zpos));
@@ -2772,7 +2674,7 @@ void AliTRDgeometry::AssembleChamber(Int_t ilayer, Int_t istack)
   xpos = 0.0;
   ypos = 0.0;
   zpos = fgkCamH/2.0 + fgkCraH + fgkCdrH - fgkCHsv/2.0;
-  sprintf(cTagV,"UD%02d",idet);
+  snprintf(cTagV,kTag,"UD%02d",idet);
   TGeoVolume *rocD = gGeoManager->GetVolume(cTagV);
   roc->AddNode(rocD,1,new TGeoTranslation(xpos,ypos,zpos));
 
@@ -2781,7 +2683,7 @@ void AliTRDgeometry::AssembleChamber(Int_t ilayer, Int_t istack)
   xpos = 0.0;
   ypos = 0.0;
   zpos = fgkCroH/2.0 + fgkCamH + fgkCraH + fgkCdrH - fgkCHsv/2.0;
-  sprintf(cTagV,"UF%02d",idet);
+  snprintf(cTagV,kTag,"UF%02d",idet);
   TGeoVolume *rocF = gGeoManager->GetVolume(cTagV);
   roc->AddNode(rocF,1,new TGeoTranslation(xpos,ypos,zpos));
 
@@ -2789,18 +2691,18 @@ void AliTRDgeometry::AssembleChamber(Int_t ilayer, Int_t istack)
   xpos = 0.0;
   ypos = 0.0;
   zpos = fgkCsvH/2.0 + fgkCroH + fgkCamH + fgkCraH + fgkCdrH - fgkCHsv/2.0;
-  sprintf(cTagV,"UU%02d",idet);
+  snprintf(cTagV,kTag,"UU%02d",idet);
   TGeoVolume *rocU = gGeoManager->GetVolume(cTagV);
   roc->AddNode(rocU,1,new TGeoTranslation(xpos,ypos,zpos));
 
   // Place the ROC assembly into the super modules
   xpos = 0.0;
   ypos = 0.0;
-  ypos  = fClength[ilayer][0] + fClength[ilayer][1] + fClength[ilayer][2]/2.0;
+  ypos  = fgkClength[ilayer][0] + fgkClength[ilayer][1] + fgkClength[ilayer][2]/2.0;
   for (Int_t ic = 0; ic < istack; ic++) {
-    ypos -= fClength[ilayer][ic];
+    ypos -= fgkClength[ilayer][ic];
   }
-  ypos -= fClength[ilayer][istack]/2.0;
+  ypos -= fgkClength[ilayer][istack]/2.0;
   zpos  = fgkVrocsm + fgkSMpltT + fgkCHsv/2.0 - fgkSheight/2.0
         + ilayer * (fgkCH + fgkVspace);
   TGeoVolume *sm1 = gGeoManager->GetVolume("UTI1");
@@ -2825,10 +2727,11 @@ Bool_t AliTRDgeometry::RotateBack(Int_t det
   // coordinates <loc> into the coordinates of the ALICE restframe <glb>.
   //
 
-  Int_t sector = GetSector(det);
+  Int_t   sector = GetSector(det);
+  Float_t phi = 2.0 * TMath::Pi() /  (Float_t) fgkNsector * ((Float_t) sector + 0.5);
 
-  glb[0] = loc[0] * fRotB11[sector] - loc[1] * fRotB12[sector];
-  glb[1] = loc[0] * fRotB21[sector] + loc[1] * fRotB22[sector];
+  glb[0] = loc[0] * TMath::Cos(phi) - loc[1] * TMath::Sin(phi);
+  glb[1] = loc[0] * TMath::Sin(phi) + loc[1] * TMath::Cos(phi);
   glb[2] = loc[2];
 
   return kTRUE;
@@ -2892,8 +2795,8 @@ Int_t AliTRDgeometry::GetStack(Double_t z, Int_t layer)
       (layer >= fgkNlayer)) return -1;
        
   Int_t    istck = fgkNstack;
-  Double_t zmin;
-  Double_t zmax;
+  Double_t zmin  = 0.0;
+  Double_t zmax  = 0.0;
 
   do {
     istck--;
@@ -2928,12 +2831,12 @@ AliTRDpadPlane *AliTRDgeometry::GetPadPlane(Int_t layer, Int_t stack)
   // Returns the pad plane for a given plane <pl> and stack <st> number
   //
 
-  if (!fPadPlaneArray) {
+  if (!fgPadPlaneArray) {
     CreatePadPlaneArray();
   }
 
   Int_t ipp = GetDetectorSec(layer,stack);
-  return ((AliTRDpadPlane *) fPadPlaneArray->At(ipp));
+  return ((AliTRDpadPlane *) fgPadPlaneArray->At(ipp));
 
 }
 
@@ -2993,6 +2896,9 @@ Bool_t AliTRDgeometry::CreateClusterMatrixArray()
     return kFALSE;
   }
 
+  if(fgClusterMatrixArray)
+    return kTRUE;
+
   TString volPath;
   TString vpStr   = "ALIC_1/B077_1/BSEGMO";
   TString vpApp1  = "_1/BTRD";
@@ -3001,7 +2907,7 @@ Bool_t AliTRDgeometry::CreateClusterMatrixArray()
   TString vpApp3b = "/UTR2_1/UTS2_1/UTI2_1";
   TString vpApp3c = "/UTR3_1/UTS3_1/UTI3_1";
 
-  fClusterMatrixArray = new TObjArray(kNdet);
+  fgClusterMatrixArray = new TObjArray(kNdet);
   AliAlignObjParams o;
 
   for (Int_t iLayer = AliGeomManager::kTRD1; iLayer <= AliGeomManager::kTRD6; iLayer++) {
@@ -3022,6 +2928,7 @@ Bool_t AliTRDgeometry::CreateClusterMatrixArray()
       case 13:
       case 14:
       case 15:
+        // Check for holes in from of PHOS
         if (istack == 2) {
           continue;
        }
@@ -3038,12 +2945,6 @@ Bool_t AliTRDgeometry::CreateClusterMatrixArray()
        continue;
       }
 
-      // Check for holes in from of PHOS
-      if (((isector == 13) || (isector == 14) || (isector == 15)) && 
-          (istack == 2)) {
-        continue; 
-      }
-
       UShort_t     volid   = AliGeomManager::LayerToVolUID(iLayer,iModule);
       const char  *symname = AliGeomManager::SymName(volid);
       TGeoPNEntry *pne     = gGeoManager->GetAlignableEntry(symname);
@@ -3055,11 +2956,11 @@ Bool_t AliTRDgeometry::CreateClusterMatrixArray()
        continue;
       }
       if (!strstr(path,"ALIC")) {
-        AliDebug(1,Form("Not a valid path: %s\n",path));
+        AliDebugClass(1,Form("Not a valid path: %s\n",path));
         continue;
       }
       if (!gGeoManager->cd(path)) {
-        AliError(Form("Cannot go to path: %s\n",path));
+        AliErrorClass(Form("Cannot go to path: %s\n",path));
         continue;
       }
       TGeoHMatrix *m         = gGeoManager->GetCurrentMatrix();
@@ -3078,7 +2979,7 @@ Bool_t AliTRDgeometry::CreateClusterMatrixArray()
       rotSector.RotateZ(sectorAngle);
       rotMatrix.MultiplyLeft(&rotSector.Inverse());
 
-      fClusterMatrixArray->AddAt(new TGeoHMatrix(rotMatrix),lid);       
+      fgClusterMatrixArray->AddAt(new TGeoHMatrix(rotMatrix),lid);       
 
     }    
   }
@@ -3088,15 +2989,27 @@ Bool_t AliTRDgeometry::CreateClusterMatrixArray()
 }
 
 //_____________________________________________________________________________
-Bool_t AliTRDgeometry::ChamberInGeometry(Int_t det)
+TGeoHMatrix *AliTRDgeometry::GetClusterMatrix(Int_t det)
 {
   //
-  // Checks whether the given detector is part of the current geometry
+  // Returns the cluster transformation matrix for a given detector
   //
 
-  if (!fClusterMatrixArray) {
-    CreateClusterMatrixArray();
+  if (!fgClusterMatrixArray) {
+    if (!CreateClusterMatrixArray()) {
+      return NULL;
+    }
   }  
+  return (TGeoHMatrix *) fgClusterMatrixArray->At(det);
+
+}
+
+//_____________________________________________________________________________
+Bool_t AliTRDgeometry::ChamberInGeometry(Int_t det)
+{
+  //
+  // Checks whether the given detector is part of the current geometry
+  //
 
   if (!GetClusterMatrix(det)) {
     return kFALSE;
@@ -3138,7 +3051,7 @@ Bool_t AliTRDgeometry::IsOnBoundary(Int_t det, Float_t y, Float_t z, Float_t eps
   if ((stk <          0) || 
       (stk >= fgkNstack)) return kTRUE;
 
-  AliTRDpadPlane *pp = (AliTRDpadPlane*) fPadPlaneArray->At(GetDetectorSec(ly, stk));
+  AliTRDpadPlane *pp = (AliTRDpadPlane*) fgPadPlaneArray->At(GetDetectorSec(ly, stk));
   if(!pp) return kTRUE;
 
   Double_t max  = pp->GetRow0();