示例#1
0
void AliITSMaterialsTGeo(TString gfile="geometry.root"){
  // Macro to print out the ITS material definitions as found
  // in the TGeo geometry file.

  // retrives geometry 
  if(!gGeoManager) gGeoManager = new TGeoManager();
  TGeoManager::Import(gfile.Data());
  if (!gGeoManager) {
    cout<<"geometry not found\n";
    return;
  } // end if

  TList *medlist=gGeoManager->GetListOfMedia();
  TGeoMedium *med;
  TGeoMaterial *mat;
  Int_t imed,nmed,i;
  printf("imed  Id       Med_Name             Mat_Name       ");
  for(i=0;i<20;i++) printf("   par[%2d]   ",i);
  printf("\n");
  imed=0;
  do{
    med = (TGeoMedium*)(medlist->At(imed));
    if(!med) continue;
    /*if((((med->GetName())[0]=='I')&& // Only ITS.
        ((med->GetName())[1]=='T')&&
        ((med->GetName())[2]=='S')&&
	((med->GetName())[3]=='_')))*/{
    mat = med->GetMaterial();
    if(mat)
      printf("%4d %4d %30s %30s",imed,med->GetId(),med->GetName(),mat->GetName());
    else
      printf("%4d %4d %30s %30s",imed,med->GetId(),med->GetName(),"No Material");
    for(i=0;i<20;i++) printf(" %12g",med->GetParam(i));
    printf("\n");
    imed++;
    }
  }while(med!=medlist->Last());
}
/**
 * Calculate effective radiation length traversed by particle traveling between two points
 * along straight line.
 * 
 * Calculation is done according to the eq. (27.23)
 * @see http://pdg.lbl.gov/2006/reviews/passagerpp.pdf
 * 
 * @param globalPosStart starting point in the global coordinate system
 * @param globalPosFinish ending point in the global coordinate system
 * @param skipBoundaryVolumes if true subtract rad length of the volumes containing start and finish points
 * 
 * @return radiation length in units of X0
 */
float EUTelGeometryTelescopeGeoDescription::findRadLengthIntegral( const double globalPosStart[], const double globalPosFinish[], bool skipBoundaryPonitsVolumes ) {

    streamlog_out(DEBUG1) << "EUTelGeometryTelescopeGeoDescription::findRadLengthIntegral()" << std::endl;
    
    float rad = 0.;        // integral of radiation length in units of X0
    
    const double mm2cm = 0.1;
    
    /* TGeo uses cm and grams as internal units e.g. in radiation length and density. Telescope/LCIO uses mm. Therefore this routine is full of 
     annoying conversion factors */    
    
    const double stepLenght2 = ( globalPosFinish[0] - globalPosStart[0] )*( globalPosFinish[0] - globalPosStart[0] ) +
                               ( globalPosFinish[1] - globalPosStart[1] )*( globalPosFinish[1] - globalPosStart[1] ) +
                               ( globalPosFinish[2] - globalPosStart[2] )*( globalPosFinish[2] - globalPosStart[2] );
    
    const double stepLenght  = TMath::Sqrt( stepLenght2 );

    // don't need conversion factor to for calculation of directions
    const double xp  = ( globalPosFinish[0] - globalPosStart[0] )/stepLenght;
    const double yp  = ( globalPosFinish[1] - globalPosStart[1] )/stepLenght;
    const double zp  = ( globalPosFinish[2] - globalPosStart[2] )/stepLenght;

    streamlog_out(DEBUG0) << "Start point (x,y,z):" << globalPosStart[0] << "," << globalPosStart[1] << "," << globalPosStart[2] << std::endl;
    streamlog_out(DEBUG0) << "Finish point (x,y,z):" << globalPosFinish[0] << "," << globalPosFinish[1] << "," << globalPosFinish[2] << std::endl;
    streamlog_out(DEBUG0) << "Direction (nx,ny,nz):" << xp << "," << yp << "," << zp << std::endl;
    
    double snext;
    double pt[3], loc[3];
    double epsil = 1.E-7;
    double lastrad = 0.;
    int ismall       = 0;
    int nbound       = 0;
    float length     = 0.;
    TGeoMedium *med;
    TGeoShape *shape;
    
    // Get starting node
    gGeoManager->InitTrack( globalPosStart[0]/*mm*/, globalPosStart[1]/*mm*/, globalPosStart[2]/*mm*/, xp, yp, zp );
    TGeoNode *nextnode = gGeoManager->GetCurrentNode( );
    
    double currentStep = stepLenght /*mm*/;
    // Loop over all, encountered during the propagation, volumes 
    while ( nextnode ) {
        med = NULL;
        
	// Check if current point is inside silicon sensor. Radiation length of silicon sensors is accounted in thin scatterers of GBL.
        bool isBoundaryVolume = false;
        if ( gGeoManager->IsSameLocation( globalPosStart[0], globalPosStart[1], globalPosStart[2] ) ||
             gGeoManager->IsSameLocation( globalPosFinish[0], globalPosFinish[1], globalPosFinish[2] ) ) isBoundaryVolume = true;
        
        if ( nextnode ) med = nextnode->GetVolume()->GetMedium();
        else return 0.;
        
        shape = nextnode->GetVolume()->GetShape();
        
        // make a step to the next intersection point
        if ( currentStep > 1.e-9 /*mm*/ ) nextnode = gGeoManager->FindNextBoundaryAndStep( currentStep /*mm*/ );
        else return rad;
        
        snext  = gGeoManager->GetStep() /*mm*/;
        
        // Small steps treatment
        if ( snext < 1.e-8 /*mm*/ ) {
            ismall++;
            
            // Terminate calculation if too many small steps done
            if ( ismall > 3 ) {
                streamlog_out( WARNING1 ) << "ERROR: Small steps in: " << gGeoManager->GetPath() << " shape=" << shape->ClassName() << endl;
                return rad;
            }

            // increase step size (epsilon) and advance along the particle direction
            memcpy( pt, gGeoManager->GetCurrentPoint(), 3 * sizeof (double) );
            const double *dir = gGeoManager->GetCurrentDirection();
            for ( Int_t i = 0; i < 3; i++ ) pt[i] += epsil * dir[i];
            snext = epsil;
            length += snext;
            
            // Ignore start and finish volumes if required
            if ( skipBoundaryPonitsVolumes && isBoundaryVolume ) {
                rad += 0.;
            } else {
                rad += lastrad*snext;
            }
            
            gGeoManager->CdTop( );
            nextnode = gGeoManager->FindNode( pt[0], pt[1], pt[2] );    // Check if particle is crossed the boundary
            if ( gGeoManager->IsOutside() ) return rad;                 // leave if not
            TGeoMatrix *mat = gGeoManager->GetCurrentMatrix();          
            mat->MasterToLocal( pt, loc );
            if ( !gGeoManager->GetCurrentVolume()->Contains( loc ) ) {
                gGeoManager->CdUp();
                nextnode = gGeoManager->GetCurrentNode();               // move to new volume
            }
            continue;
        } else {
            ismall = 0;
        }
        
        // Normal steps case
        nbound++;
        length += snext;
        currentStep -= snext;
        if ( med ) {
            double radlen = med->GetMaterial()->GetRadLen() /*cm*/;
            if ( radlen > 1.e-9 && radlen < 1.e10 ) {
                
                lastrad = 1. / radlen * mm2cm;
                
                // Ignore start and finish volumes if required
                if ( skipBoundaryPonitsVolumes && isBoundaryVolume ) {
                    rad += 0.;
                } else {
                    rad += lastrad*snext;
                }
                
            } else {
                lastrad = 0.;
            }
            streamlog_out( DEBUG0 ) << "STEP #" << nbound << std::endl;
            streamlog_out( DEBUG0 ) << "   step[mm]=" << snext << "   length[mm]=" << length
                    << " rad[X0]=" << snext * mm2cm / radlen << " " << med->GetName( ) 
                    << " rho[g/cm^3]=" << med->GetMaterial()->GetDensity() <<" radlen[cm]=" << radlen << " Boundary:" << (isBoundaryVolume?"yes":"no")
		    << std::endl;
        }
    }
    
    streamlog_out(DEBUG1) << "--------EUTelGeometryTelescopeGeoDescription::findRadLengthIntegral()--------" << std::endl;
    
    return rad;
}