Front Absorber in official ALICE physics coordinate system.

diff --git a/STRUCT/AliABSOv0.cxx b/STRUCT/AliABSOv0.cxx
index b88f2ca..180de0c 100644 (file)
--- a/STRUCT/AliABSOv0.cxx
+++ b/STRUCT/AliABSOv0.cxx
@@ -104,13 +104,13 @@ void AliABSOv0::CreateGeometry()
     fNLayers[0] = 5; 
     fMLayers[0][0]  = kAir;              fZLayers[0][0] = kZAbsStart;
     fMLayers[0][1]  = kC;                fZLayers[0][1] = kZAbsCc;             
-    fMLayers[0][2]  = kConcrete;         fZLayers[0][2] = kZRear-kDRear-dzFe;
-    fMLayers[0][3]  = kSteel;            fZLayers[0][3] = kZRear-kDRear;
+    fMLayers[0][2]  = kConcrete;         fZLayers[0][2] = kZRear - kDRear - dzFe;
+    fMLayers[0][3]  = kSteel;            fZLayers[0][3] = kZRear - kDRear;
     fMLayers[0][4]  = kSteel;            fZLayers[0][4] = kZRear;
 // 2 < theta < 3
     fNLayers[1] = 6; 
 
-    fMLayers[1][0] = kAir          ;      fZLayers[1][0] = fZLayers[0][0]-10.;
+    fMLayers[1][0] = kAir          ;      fZLayers[1][0] = fZLayers[0][0] - 10.;
     fMLayers[1][1] = kAl           ;      fZLayers[1][1] = fZLayers[0][0];
     fMLayers[1][2] = fMLayers[0][1];      fZLayers[1][2] = fZLayers[0][1];
     fMLayers[1][3] = fMLayers[0][2];      fZLayers[1][3] = fZLayers[0][2];
@@ -118,10 +118,9 @@ void AliABSOv0::CreateGeometry()
     fMLayers[1][5] = kNiCuW;              fZLayers[1][5] = fZLayers[0][4];
 //    
 
-    Float_t dTube=0.1;                     // tube thickness
-    Float_t dInsu=0.5;                     // insulation thickness
-    Float_t dEnve=0.1;                     // protective envelope thickness
-    //    Float_t dFree=0.5;                     // clearance thickness
+    Float_t dTube = 0.1;                     // tube thickness
+    Float_t dInsu = 0.5;                     // insulation thickness
+    Float_t dEnve = 0.1;                     // protective envelope thickness
 
 
 // Mother volume and outer shielding: Pb
@@ -129,108 +128,113 @@ void AliABSOv0::CreateGeometry()
   par[1]  = 360.;
   par[2]  = 7.;
     
-  par[3]  = -(kZRear-kZAbsStart)/2.;
-  par[4]  = kRAbs;
-  par[5]  = kZAbsStart * TMath::Tan(kTheta1);
+  par[21] = (kZRear - kZAbsStart) / 2.;
+  par[22] = kRAbs;
+  par[23] = kZAbsStart * TMath::Tan(kTheta1);
 
-  par[6]  = par[3]+(kZNose-kZAbsStart);
-  par[7]  = kRAbs;
-  par[8]  = kZNose * TMath::Tan(kTheta1);
+  par[18] = par[21] - (kZNose - kZAbsStart);
+  par[19] = kRAbs;
+  par[20] = kZNose * TMath::Tan(kTheta1);
 
-  par[9]  = par[3]+(kZConeTPC-kZAbsStart);
-  par[10] = kRAbs;
-  par[11] = par[8] + (par[9] - par[6]) * TMath::Tan(kTheta2);
+  par[15] = par[21] - (kZConeTPC - kZAbsStart);
+  par[16] = kRAbs;
+  par[17] = par[20] - (par[15] - par[18]) * TMath::Tan(kTheta2);
 
-  par[12]  = par[3]+(kZOpen-kZAbsStart);
+  par[12] = par[21]  - (kZOpen - kZAbsStart);
   par[13] = kRAbs;
-  par[14] = par[11] + (par[12] - par[9]) * TMath::Tan(kAccMax);
+  par[14] = par[17] - (par[12] - par[15]) * TMath::Tan(kAccMax);
 
-  par[15] = par[3]+(kZRear-kDRear-kZAbsStart);
-  par[16] = kRAbs   + (par[15] - par[12]) * TMath::Tan(kThetaOpen1) ;
-  par[17] = par[14] + (par[15] - par[12]) * TMath::Tan(kAccMax);
+  par[9]  = par[21]  - (kZRear - kDRear - kZAbsStart);
+  par[10] = kRAbs   - (par[9] - par[12]) * TMath::Tan(kThetaOpen1) ;
+  par[11] = par[14] - (par[9] - par[12]) * TMath::Tan(kAccMax);
 
-  par[18] = par[3]+(kZRear-kDRear-kZAbsStart);
-  par[19] = (kZRear-kDRear) * TMath::Tan(kAccMin);
-  par[20] = par[14] + (par[18] - par[12]) * TMath::Tan(kAccMax);
+  par[6]  = par[21]  - (kZRear - kDRear - kZAbsStart);
+  par[7]  = (kZRear - kDRear) * TMath::Tan(kAccMin);
+  par[8]  = par[14] - (par[6] - par[12]) * TMath::Tan(kAccMax);
 
-  par[21] = -par[3];
-  par[22] =  kZRear* TMath::Tan(kAccMin);
-  par[23] = par[20] + (par[21] - par[18]) * TMath::Tan(kAccMax);
+  par[3] =  - par[21];
+  par[4] = kZRear  * TMath::Tan(kAccMin);
+  par[5] = par[8] - (par[3] - par[6]) * TMath::Tan(kAccMax);
   gMC->Gsvolu("ABSS", "PCON", idtmed[kPb], par, 24);
-  { // Begin local scope for i
-      for (Int_t i=4; i<18; i+=3) par[i]  = 0;
-  } // End local scope for i
+
+  for (Int_t i = 22; i > 7; i -= 3) par[i]  = 0;
+
   gMC->Gsvolu("ABSM", "PCON", idtmed[kVacuum+40], par, 24);
   gMC->Gspos("ABSS", 1, "ABSM", 0., 0., 0., 0, "ONLY");
 
 //
 // Steel envelope
 //
-  par[4] = par[5] -kDSteel;
-  par[7] = par[8] -kDSteel;
-  par[10]= par[11]-kDSteel;  
-  par[13]= par[14]-kDSteel;  
-  par[16]= par[17]-kDSteel;  
-  par[19]= par[20]-kDSteel;  
-  par[22]= par[23]-kDSteel;  
+  par[4] = par[5]  - kDSteel;
+  par[7] = par[8]  - kDSteel;
+  par[10]= par[11] - kDSteel;  
+  par[13]= par[14] - kDSteel;  
+  par[16]= par[17] - kDSteel;  
+  par[19]= par[20] - kDSteel;  
+  par[22]= par[23] - kDSteel;  
+
   gMC->Gsvolu("ABST", "PCON", idtmed[kSteel], par, 24);
   gMC->Gspos("ABST", 1, "ABSS", 0., 0., 0., 0, "ONLY");
 //
 // Polyethylene shield
 // 
   cpar[0] = (kZRear - kZConeTPC) / 2.;
-  cpar[1] = kZConeTPC * TMath::Tan(kAccMax);
+  cpar[1] = kZRear * TMath::Tan(kAccMax);
   cpar[2] = cpar[1] + kDPoly;
-  cpar[3] = kZRear * TMath::Tan(kAccMax);
+  cpar[3] = kZConeTPC * TMath::Tan(kAccMax);
   cpar[4] = cpar[3] + kDPoly;
+
   gMC->Gsvolu("APOL", "CONE", idtmed[kPolyCH2+40], cpar, 5);
-  dz = (kZRear-kZAbsStart)/2.-cpar[0];
+  dz = - (kZRear - kZAbsStart) / 2. + cpar[0];
   gMC->Gspos("APOL", 1, "ABSS", 0., 0., dz, 0, "ONLY");
 
 //
 // Tungsten nose to protect TPC
 // 
   cpar[0] = (kZNose - kZAbsStart) / 2.;
-  cpar[1] = kZAbsStart * TMath::Tan(kAccMax);
-  cpar[2] = kZAbsStart * TMath::Tan(kTheta1)-kDSteel;
-  cpar[3] = kZNose * TMath::Tan(kAccMax);
-  cpar[4] = kZNose * TMath::Tan(kTheta1)-kDSteel;
+  cpar[1] = kZNose * TMath::Tan(kAccMax);
+  cpar[2] = kZNose * TMath::Tan(kTheta1) - kDSteel;
+  cpar[3] = kZAbsStart * TMath::Tan(kAccMax);
+  cpar[4] = kZAbsStart * TMath::Tan(kTheta1) - kDSteel;
+
   gMC->Gsvolu("ANOS", "CONE", idtmed[kW], cpar, 5);
   //
-  dz = -(kZRear-kZAbsStart)/2.+cpar[0];
+  dz =  (kZRear - kZAbsStart) / 2. - cpar[0];
   gMC->Gspos("ANOS", 1, "ABSS", 0., 0., dz, 0, "ONLY");
   //
   // Tungsten inner shield
   //
-  Float_t zW = kZTwoDeg+.1;
-  Float_t dZ = zW+(kZRear-kDRear-zW)/2.;
+  Float_t zW = kZTwoDeg + .1;
+  Float_t dZ = zW + (kZRear - kDRear - zW) / 2.;
   //
   pcpar[0]  = 0.;
   pcpar[1]  = 360.;
   pcpar[2]  = 3.;
-  pcpar[3]  = zW-dZ;
-  pcpar[4]  = kRAbs;
-  pcpar[5]  = zW * TMath::Tan(kAccMin);
-  pcpar[6]  = kZOpen-dZ;
+  pcpar[9]  = - (zW - dZ);
+  pcpar[10] = kRAbs;
+  pcpar[11] = zW * TMath::Tan(kAccMin);
+  pcpar[6]  = - (kZOpen - dZ);
   pcpar[7]  = kRAbs;
   pcpar[8]  = kZOpen * TMath::Tan(kAccMin);
-  pcpar[9]  = kZRear-kDRear-dZ;
-  pcpar[10] = kRAbs+(kZRear-kDRear-kZOpen) * TMath::Tan(kThetaOpen1);
-  pcpar[11] = (kZRear-kDRear) * TMath::Tan(kAccMin);
+  pcpar[3]  = - (kZRear - kDRear - dZ);
+  pcpar[4]  = kRAbs + (kZRear - kDRear - kZOpen) * TMath::Tan(kThetaOpen1);
+  pcpar[5]  = (kZRear - kDRear) * TMath::Tan(kAccMin);
   
   gMC->Gsvolu("AWIN", "PCON", idtmed[kNiCuW+40], pcpar, 12);
-  dz=(zW+kZRear-kDRear)/2-(kZAbsStart+kZRear)/2.;
+  dz = -(zW + kZRear - kDRear) / 2 + (kZAbsStart + kZRear) / 2.;
   gMC->Gspos("AWIN", 1, "ABSS", 0., 0., dz, 0, "ONLY");
 //
 // First part replaced by Carbon  
 //
   cpar[0] = (200.-zW)/2.;
+
   cpar[1] = kRAbs;
-  cpar[2] = pcpar[5];
+  cpar[2] = 200. * TMath::Tan(kAccMin);
   cpar[3] = kRAbs;
-  cpar[4] = 200. * TMath::Tan(kAccMin);
+  cpar[4] = pcpar[11];
+
   gMC->Gsvolu("ACNO", "CONE", idtmed[kC], cpar, 5);
-  dz = zW-dZ+cpar[0];
+  dz = - (zW - dZ+cpar[0]);
   gMC->Gspos("ACNO", 1, "AWIN", 0., 0., dz, 0, "ONLY");
 
 /*  
@@ -248,53 +252,55 @@ void AliABSOv0::CreateGeometry()
   //
   //     Inner tracking region
   //
-  //     mother volume: Cu
   //
   //
   pcpar[0]  = 0.;
   pcpar[1]  = 360.;
   pcpar[2]  = 3.;
-  pcpar[3]  = -(kZRear-kZAbsStart)/2.;
-  pcpar[4]  = kRAbs;
-  pcpar[5]  = kZAbsStart * TMath::Tan(kAccMax);
-  pcpar[6]  = pcpar[3]+(kZTwoDeg-kZAbsStart);
+  pcpar[9]  = (kZRear - kZAbsStart) / 2.;
+  pcpar[10] = kRAbs;
+  pcpar[11] = kZAbsStart * TMath::Tan(kAccMax);
+  pcpar[6]  = pcpar[9] - (kZTwoDeg - kZAbsStart);
   pcpar[7]  = kRAbs;
   pcpar[8]  = kZTwoDeg * TMath::Tan(kAccMax);
-  pcpar[9]  = -pcpar[3];
-  pcpar[10] = kZRear * TMath::Tan(kAccMin);
-  pcpar[11] = kZRear * TMath::Tan(kAccMax);
+  pcpar[3]  = - pcpar[9];
+  pcpar[4]  = kZRear * TMath::Tan(kAccMin);
+  pcpar[5]  = kZRear * TMath::Tan(kAccMax);
   gMC->Gsvolu("AITR", "PCON", idtmed[fMLayers[0][4]], pcpar, 12);
   //
   // special Pb medium for last 5 cm of Pb
-  Float_t zr=kZRear-2.-0.001;
+  Float_t zr = kZRear - 2. - 0.001;
   cpar[0] = 1.0;
-  cpar[1] = zr * TMath::Tan(kThetaR);
-  cpar[2] = zr * TMath::Tan(kAccMax);
-  cpar[3] = cpar[1] + TMath::Tan(kThetaR) * 2;
-  cpar[4] = cpar[2] + TMath::Tan(kAccMax) * 2;
+  cpar[3] = zr * TMath::Tan(kThetaR);
+  cpar[4] = zr * TMath::Tan(kAccMax);
+  cpar[1] = cpar[3] + TMath::Tan(kThetaR) * 2;
+  cpar[2] = cpar[4] + TMath::Tan(kAccMax) * 2;
+  
   gMC->Gsvolu("ARPB", "CONE", idtmed[fMLayers[0][4]], cpar, 5);
-  dz=(kZRear-kZAbsStart)/2.-cpar[0]-0.001;
+  dz= - (kZRear - kZAbsStart) / 2. + cpar[0] - 0.001;
   gMC->Gspos("ARPB", 1, "AITR", 0., 0., dz, 0, "ONLY");
   //
   //     concrete cone: concrete 
   //
-  pcpar[9]  = pcpar[3]+(kZRear-kDRear-kZAbsStart);
-  pcpar[10] = (kZRear-kDRear) * TMath::Tan(kAccMin);
-  pcpar[11] = (kZRear-kDRear) * TMath::Tan(kAccMax);
+  pcpar[3]  = pcpar[9] - (kZRear - kDRear - kZAbsStart);
+  pcpar[4] = (kZRear-kDRear) * TMath::Tan(kAccMin);
+  pcpar[5] = (kZRear-kDRear) * TMath::Tan(kAccMax);
   gMC->Gsvolu("ACON", "PCON", idtmed[fMLayers[0][2]+40], pcpar, 12);
   gMC->Gspos("ACON", 1, "AITR", 0., 0., 0., 0, "ONLY");
 //
 //    Fe Cone 
 //
-  zr = kZRear-kDRear-dzFe;
-  cpar[0]  = dzFe/2.;
-  cpar[1] = zr * TMath::Tan(kAccMin);
-  cpar[2] = zr * TMath::Tan(kAccMax);
-  cpar[3] = cpar[1] + TMath::Tan(kAccMin) * dzFe;
-  cpar[4] = cpar[2] + TMath::Tan(kAccMax) * dzFe;
+  zr = kZRear - kDRear - dzFe;
+
+  cpar[0] = dzFe/2.;
+  cpar[3] = zr * TMath::Tan(kAccMin);
+  cpar[4] = zr * TMath::Tan(kAccMax);
+  cpar[1] = cpar[3] + TMath::Tan(kAccMin) * dzFe;
+  cpar[2] = cpar[4] + TMath::Tan(kAccMax) * dzFe;
+
   gMC->Gsvolu("ACFE", "CONE",idtmed[fMLayers[0][3]], cpar, 5);
 
-  dz = (kZRear-kZAbsStart)/2.-kDRear-dzFe/2.;
+  dz = - (kZRear - kZAbsStart) / 2. + kDRear + dzFe / 2.;
 
   gMC->Gspos("ACFE", 1, "ACON", 0., 0., dz, 0, "ONLY");
 
@@ -303,67 +309,69 @@ void AliABSOv0::CreateGeometry()
   //
   //     carbon cone: carbon
   //
-  pcpar[9]  = pcpar[3]+(kZAbsCc-kZAbsStart);
-  pcpar[10]  = kZAbsCc * TMath::Tan(kAccMin);
-  pcpar[11]  = kZAbsCc * TMath::Tan(kAccMax);
+  pcpar[3]   = pcpar[9] - (kZAbsCc - kZAbsStart);
+  pcpar[4]   = kZAbsCc * TMath::Tan(kAccMin);
+  pcpar[5]   = kZAbsCc * TMath::Tan(kAccMax);
   gMC->Gsvolu("ACAR", "PCON", idtmed[fMLayers[0][1]+40], pcpar, 12);
   gMC->Gspos("ACAR", 1, "ACON", 0., 0., 0., 0, "ONLY");
  //
  //     carbon cone outer region
  //
   cpar[0]  = 10.;
-  cpar[1]  = kRAbs;
-  cpar[2]  = kZAbsStart* TMath::Tan(kAccMax);
   cpar[3]  = kRAbs;
-  cpar[4]  = cpar[2]+2. * cpar[0] * TMath::Tan(kAccMax);
+  cpar[4]  = kZAbsStart * TMath::Tan(kAccMax);
+  cpar[1]  = kRAbs;
+  cpar[2]  = cpar[4] + 2. * cpar[0] * TMath::Tan(kAccMax);
 
   gMC->Gsvolu("ACAO", "CONE", idtmed[fMLayers[0][1]], cpar, 5);
-  dz=-(kZRear-kZAbsStart)/2.+cpar[0];
+  dz= (kZRear-kZAbsStart) / 2. - cpar[0];
   gMC->Gspos("ACAO", 1, "ACAR", 0., 0., dz, 0, "ONLY");
   //
   //     inner W shield
-  Float_t epsi=0.;
-  Float_t repsi=1.;
+  Float_t epsi  = 0.;
+  Float_t repsi = 1.;
   
-  zr=kZRear-(kDRear-epsi);
-  cpar[0] = (kDRear-epsi)/2.;
-  cpar[1] = zr * TMath::Tan(kAccMin);
-  cpar[2] = zr * TMath::Tan(kThetaR*repsi);
-  cpar[3] = cpar[1] + TMath::Tan(kAccMin) * (kDRear-epsi);
-  cpar[4] = cpar[2] + TMath::Tan(kThetaR*repsi) * (kDRear-epsi);
+  zr = kZRear - (kDRear - epsi);
+  cpar[0] = (kDRear - epsi) / 2.;
+  cpar[3] = zr * TMath::Tan(kAccMin);
+  cpar[4] = zr * TMath::Tan(kThetaR * repsi);
+  cpar[1] = cpar[3] + TMath::Tan(kAccMin) * (kDRear - epsi);
+  cpar[2] = cpar[4] + TMath::Tan(kThetaR * repsi) * (kDRear - epsi);
+
   gMC->Gsvolu("ARW0", "CONE", idtmed[fMLayers[1][4]+40], cpar, 5);
-  dz=(kZRear-kZAbsStart)/2.-cpar[0];
+  dz= - (kZRear - kZAbsStart) / 2. + cpar[0];
   gMC->Gspos("ARW0", 1, "AITR", 0., 0., dz, 0, "ONLY");
   //
   // special W medium for last 5 cm of W
-  zr=kZRear-5;
+  zr = kZRear - 5;
   cpar[0] = 2.5;
-  cpar[1] = zr * TMath::Tan(kAccMin);
-  cpar[2] = zr * TMath::Tan(kThetaR*repsi);
-  cpar[3] = cpar[1] + TMath::Tan(kAccMin) * 5.;
-  cpar[4] = cpar[2] + TMath::Tan(kThetaR*repsi) * 5.;
+  cpar[3] = zr * TMath::Tan(kAccMin);
+  cpar[4] = zr * TMath::Tan(kThetaR * repsi);
+  cpar[1] = cpar[3] + TMath::Tan(kAccMin) * 5.;
+  cpar[2] = cpar[4] + TMath::Tan(kThetaR*repsi) * 5.;
+
   gMC->Gsvolu("ARW1", "CONE", idtmed[fMLayers[1][4]+20], cpar, 5);
-  dz=(kDRear-epsi)/2.-cpar[0];
+  dz = - (kDRear-epsi) / 2. + cpar[0];
   gMC->Gspos("ARW1", 1, "ARW0", 0., 0., dz, 0, "ONLY");
   //
   // Cu
-  Float_t drMin=TMath::Tan(kThetaR) * 5;
-  Float_t drMax=TMath::Tan(kAccMax) * 5;
+  Float_t drMin = TMath::Tan(kThetaR) * 5;
+  Float_t drMax = TMath::Tan(kAccMax) * 5;
   gMC->Gsvolu("ARPE", "CONE", idtmed[fMLayers[0][4]], cpar, 0);
-  cpar[0]=2.5;
-  { // Begin local scope for i
-      for (Int_t i=0; i<3; i++) {
-         zr=kZRear-kDRear+5+i*10.;
-         cpar[1] = zr * TMath::Tan(kThetaR);
-         cpar[2] = zr * TMath::Tan(kAccMax);
-         cpar[3] = cpar[1] + drMin;
-         cpar[4] = cpar[2] + drMax;
-         dz=(kZRear-kZAbsStart)/2.-cpar[0]-5.-(2-i)*10;
-         gMC->Gsposp("ARPE", i+1, "AITR", 0., 0., dz, 0, "ONLY",cpar,5);
-      }
-  } // End local scope for i
+  cpar[0] = 2.5;
+
+  for (Int_t i = 0; i < 3; i++) {
+      zr = kZRear - kDRear + 5 + i * 10.;
+      cpar[3] = zr * TMath::Tan(kThetaR);
+      cpar[4] = zr * TMath::Tan(kAccMax);
+      cpar[1] = cpar[3] + drMin;
+      cpar[2] = cpar[4] + drMax;
+      dz = - (kZRear - kZAbsStart) / 2. + cpar[0] + 5. + (2 - i)*10;
+      gMC->Gsposp("ARPE", i+1, "AITR", 0., 0., dz, 0, "ONLY",cpar,5);
+  }
+
   gMC->Gspos("AITR", 1, "ABSS", 0., 0., 0., 0, "ONLY");        
-  dz = (kZRear-kZAbsStart)/2.+kZAbsStart;
+  dz = - (kZRear - kZAbsStart) / 2. - kZAbsStart;
   gMC->Gspos("ABSM", 1, "ALIC", 0., 0., dz, 0, "ONLY");        
 //
 //
@@ -373,44 +381,45 @@ void AliABSOv0::CreateGeometry()
 //
 //
 // cylindrical piece
-  tpar0[2]=(kZOpen-kZAbsStart)/2;
-  tpar0[0]=kRVacu;
-  tpar0[1]=kRVacu+dTube+dInsu+dEnve;
+  tpar0[2] = (kZOpen-kZAbsStart)/2;
+  tpar0[0] = kRVacu;
+  tpar0[1] = kRVacu + dTube + dInsu + dEnve;
   gMC->Gsvolu("AV11", "TUBE", idtmed[kSteel+40], tpar0, 3);
 //
 // insulation
 
-  tpar[2]=tpar0[2];
-  tpar[0]=kRVacu+dTube;
-  tpar[1]=tpar[0]+dInsu;
+  tpar[2] = tpar0[2];
+  tpar[0] = kRVacu  + dTube;
+  tpar[1] = tpar[0] + dInsu;
   gMC->Gsvolu("AI11", "TUBE", idtmed[kInsulation+40], tpar, 3);
   gMC->Gspos("AI11", 1, "AV11", 0., 0., 0., 0, "ONLY"); 
 //
-  dz=-(kZRear-kZAbsStart)/2.+tpar0[2];
+  dz = (kZRear - kZAbsStart) / 2. - tpar0[2];
   gMC->Gspos("AV11", 1, "ABSM", 0., 0., dz, 0, "ONLY"); 
 //
 // conical piece
 
-  cpar0[0]=(kZRear-kDRear-kZOpen)/2;
-  cpar0[1]= kRVacu-0.05;
-  cpar0[2]= kRVacu+dTube+dInsu+dEnve;
-  Float_t dR=2.*cpar0[0]*TMath::Tan(kThetaOpen1);
-  cpar0[3]=cpar0[1]+dR;
-  cpar0[4]=cpar0[2]+dR;
+  cpar0[0] = (kZRear - kDRear - kZOpen) / 2.;
+  cpar0[3] = kRVacu - 0.05;
+  cpar0[4] = kRVacu + dTube + dInsu + dEnve;
+  Float_t dR = 2. * cpar0[0] * TMath::Tan(kThetaOpen1);
+  cpar0[1]=cpar0[3] + dR;
+  cpar0[2]=cpar0[4] + dR;
   gMC->Gsvolu("AV21", "CONE", idtmed[kSteel+40], cpar0, 5);
-  dTube+=0.05;
+  dTube += 0.05;
 
 //
 // insulation
-  cpar[0]=cpar0[0];
-  cpar[1]=cpar0[1]+dTube;
-  cpar[2]=cpar0[1]+dTube+dInsu;
-  cpar[3]=cpar0[3]+dTube;
-  cpar[4]=cpar0[3]+dTube+dInsu;
+  cpar[0] = cpar0[0];
+  cpar[1] = cpar0[1] + dTube;
+  cpar[2] = cpar0[1] + dTube + dInsu;
+  cpar[3] = cpar0[3] + dTube;
+  cpar[4] = cpar0[3] + dTube + dInsu;
+
   gMC->Gsvolu("AI21", "CONE", idtmed[kInsulation+40], cpar, 5);
   gMC->Gspos("AI21", 1, "AV21", 0., 0., 0., 0, "ONLY"); 
   
-  dz=(kZRear-kZAbsStart)/2.-cpar0[0]-kDRear;
+  dz = - (kZRear - kZAbsStart) / 2. + cpar0[0] + kDRear;
   gMC->Gspos("AV21", 1, "ABSM", 0., 0., dz, 0, "ONLY"); 
 //
 // Support cone 
@@ -420,19 +429,19 @@ void AliABSOv0::CreateGeometry()
   par[2]  =   8.0;
   par[3]  =   4.0;
     
-  par[4]  = kZRear;
+  par[4]  = - kZRear;
   par[5]  = 100.;
   par[6]  = 180.;
   
-  par[7]  = kZRear+20.;
+  par[7]  = - kZRear - 20.;
   par[8]  = 100.;
   par[9]  = 180.;
 
-  par[10] = kZRear+20.;
+  par[10] = - kZRear - 20.;
   par[11] = 178.;
   par[12] = 180.;
 
-  par[13] = 600.;
+  par[13] = - 600.;
   par[14] = 178.;
   par[15] = 180.;
   
@@ -441,25 +450,25 @@ void AliABSOv0::CreateGeometry()
   gMC->Gspos("ASSS", 1, "ALIC", 0., 0., 0., 0, "ONLY");
 
   Float_t trap[11];
-  trap[ 0] = (530.-170.)/2.;
+  trap[ 0] = (530. - 170.) / 2.;
   trap[ 2] = 0.;
   trap[ 3] = 2.; 
-  trap[ 4] = (600.-(kZRear+2.))/2.;;
+  trap[ 4] = (600. - (kZRear + 2.)) / 2.;;
   trap[ 5] = trap[4];
   trap[ 6] = 0.;
   trap[ 7] = 2.;
   trap[ 8] = 5.;
   trap[ 9] = 5.;
   trap[10] = 0.;
-  trap[ 1] = -TMath::ATan((trap[4]-trap[8])/2./trap[0])*180./TMath::Pi();
+  trap[ 1] = -TMath::ATan((trap[4] - trap[8]) / 2. / trap[0]) * 180. / TMath::Pi();
   AliMatrix(idrotm[1600], 180., 0., 90., 0., 90., 90.);
   AliMatrix(idrotm[1601], 180., 0., 90., 0., 90., 270.);
   gMC->Gsvolu("ASST", "TRAP", idtmed[kSteel], trap, 11);
   dz = (600.+kZRear+2.)/2.+(trap[4]-trap[8])/2.;
-  //  Float_t dy =  170.+trap[0];
+  Float_t dy =  170.+trap[0];
   
-//  gMC->Gspos("ASST", 1, "ALIC", 0.,  dy, dz, idrotm[1600], "ONLY");
-//  gMC->Gspos("ASST", 2, "ALIC", 0., -dy, dz, idrotm[1601], "ONLY");
+//  gMC->Gspos("ASST", 1, "ALIC", 0.,  dy, - dz, idrotm[1600], "ONLY");
+//  gMC->Gspos("ASST", 2, "ALIC", 0., -dy, - dz, idrotm[1601], "ONLY");
 }
 
 //_____________________________________________________________________________