{
  // Gem disk geometry parameters
  //-----------------------------
  const Double_t  kDisk1InnerRadius    = 3.15;   // (cm) //from EMC TDR
  const Double_t  kDisk2InnerRadius    = 3.30;   // (cm) //?
  const Double_t  kDisk3InnerRadius    = 3.45;   // (cm) //?
  const Double_t  kDisk4InnerRadius    = 3.60;   // (cm) //?

  const Double_t  kDisk1OuterRadius    = 8.7;   // (cm) //from EMC TDR
  const Double_t  kDisk2OuterRadius    = 9.1;   // (cm) //?
  const Double_t  kDisk3OuterRadius    = 9.5;   // (cm) //from EMC TDR
  const Double_t  kDisk4OuterRadius    = 9.9;   // (cm) //from EMC TDR

  const Double_t  kDisk1ZPosition = 1070.0;   // (cm) //from EMC TDR
  const Double_t  kDisk2ZPosition = 1120.0;   // (cm) //from EMC TDR
  const Double_t  kDisk3ZPosition = 1170.0;   // (cm) //from EMC TDR
  const Double_t  kDisk4ZPosition = 1220.0;   // (cm) //from EMC TDR

  const Double_t  kHalfFoilThickness  = 0.0075; // Thickness of sensitive foil (cm)


  //--------------------------------------------------------------------
  gROOT->Macro("$VMCWORKDIR/gconfig/rootlogon.C");
  
  // Load this libraries
  gSystem->Load("libGeoBase");
  gSystem->Load("libParBase");
  gSystem->Load("libBase");
  gSystem->Load("libPndData");
  gSystem->Load("libPassive");
  
  TString outfile= "geo/MATZE_LUMI_150mum.root";
  TFile* fi = new TFile(outfile,"RECREATE");  
  
  FairGeoLoader* geoLoad = new FairGeoLoader("TGeo","FairGeoLoader");
  FairGeoInterface *geoFace = geoLoad->getGeoInterface();
  geoFace->setMediaFile("../../geometry/media_pnd.geo");
  geoFace->readMedia();
  geoFace->print();

  FairGeoMedia *Media =  geoFace->getMedia();
  FairGeoBuilder *geobuild=geoLoad->getGeoBuilder();

  FairGeoMedium *CbmMediumAir  = Media->getMedium("air");
  FairGeoMedium *CbmMediumPWO = Media->getMedium("PWO");
  FairGeoMedium *CbmMediumCarbon  = Media->getMedium("carbon");
  FairGeoMedium *CbmMediumAluminium = Media->getMedium("aluminium");
  FairGeoMedium *CbmMediumGermanium = Media->getMedium("silicon");
  
  Int_t nmed=geobuild->createMedium(CbmMediumAir);
  nmed=geobuild->createMedium(CbmMediumPWO);
  nmed=geobuild->createMedium(CbmMediumCarbon);
  nmed=geobuild->createMedium(CbmMediumAluminium);
  nmed=geobuild->createMedium(CbmMediumGermanium);

  TGeoManager* gGeoMan = (TGeoManager*)gROOT->FindObject("FAIRGeom");

  TGeoVolume *top = new TGeoVolumeAssembly("Gem");
                    
  gGeoMan->SetTopVolume(top);
  

TGeoShape *Disk1Shape = new TGeoTube("disk1shape",kDisk1InnerRadius,kDisk1OuterRadius,kHalfFoilThickness);
TGeoShape *Disk2Shape = new TGeoTube("disk2shape",kDisk2InnerRadius,kDisk2OuterRadius,kHalfFoilThickness);
TGeoShape *Disk3Shape = new TGeoTube("disk3shape",kDisk3InnerRadius,kDisk3OuterRadius,kHalfFoilThickness);
TGeoShape *Disk4Shape = new TGeoTube("disk4shape",kDisk4InnerRadius,kDisk3OuterRadius,kHalfFoilThickness);

TGeoVolume* Disk1Vol = new TGeoVolume("LumActiveRect1",Disk1Shape,gGeoMan->GetMedium("silicon"));
TGeoVolume* Disk2Vol = new TGeoVolume("LumActiveRect2",Disk2Shape,gGeoMan->GetMedium("silicon"));
TGeoVolume* Disk3Vol = new TGeoVolume("LumActiveRect3",Disk3Shape,gGeoMan->GetMedium("silicon"));
TGeoVolume* Disk4Vol = new TGeoVolume("LumActiveRect4",Disk4Shape,gGeoMan->GetMedium("silicon"));

TGeoTranslation* trt1 = new TGeoTranslation(0.,0.,kDisk1ZPosition);
TGeoTranslation* trt2 = new TGeoTranslation(0.,0.,kDisk2ZPosition);
TGeoTranslation* trt3 = new TGeoTranslation(0.,0.,kDisk3ZPosition);
TGeoTranslation* trt4 = new TGeoTranslation(0.,0.,kDisk4ZPosition);

TGeoRotation* dummyrot = new TGeoRotation();

TGeoCombiTrans* trc1= new TGeoCombiTrans(*trt1,*dummyrot); 
trc1->SetName("LumActiveRect1");
trc1->RegisterYourself();

TGeoCombiTrans* trc2= new TGeoCombiTrans(*trt2,*dummyrot); 
trc2->SetName("LumActiveRect2");
trc2->RegisterYourself();

TGeoCombiTrans* trc3= new TGeoCombiTrans(*trt3,*dummyrot); 
trc3->SetName("LumActiveRect3");
trc3->RegisterYourself();

TGeoCombiTrans* trc4= new TGeoCombiTrans(*trt4,*dummyrot); 
trc4->SetName("LumActiveRect4");
trc4->RegisterYourself();


TGeoVolumeAssembly* SubunitVol = new TGeoVolumeAssembly("Lumi_Strip_Disks");
SubunitVol->AddNode(Disk1Vol,0,trc1);
SubunitVol->AddNode(Disk2Vol,0,trc2);
SubunitVol->AddNode(Disk3Vol,0,trc3);
SubunitVol->AddNode(Disk4Vol,0,trc4);


top->AddNode(SubunitVol,0,new TGeoCombiTrans());

  gGeoMan->CloseGeometry();
  top->Write();
  fi->Close();
//   gGeoManager->Export(outfile);
  top->Draw("ogl");
}