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Question the velocity is greater than c_light Velocity: inf 

Forum: Processes Involving Optical Photons
Date: 23 Feb, 2016
From: Nadia NAD <Nadia NAD>

Hello everyone,

I have been working on modeling a scintillator on Geant4 9.4 version, everything works fine and there is a consistency between the measured spectrum and the calculated one on Geant4 9.4.

Recently, I upgraded to Geant4 10.1 and I get the following error:

G4ParticleChange::CheckIt    : the velocity is greater than c_light  !!
Velocity: inf
-------- EEEE ------- G4Exception-START -------- EEEE -------
*** G4Exception : TRACK003
      issued by : G4ParticleChange::CheckIt
momentum, energy, and/or time was illegal
*** Event Must Be Aborted ***
-------- EEEE -------- G4Exception-END --------- EEEE -------

      -----------------------------------------------
        G4ParticleChange Information  
      -----------------------------------------------
        # of 2ndaries       :                    0
      -----------------------------------------------
        Energy Deposit (MeV):                    0
        Non-ionizing Energy Deposit (MeV):                    0
        Track Status        :                Alive
        True Path Length (mm) :                 72.2
        Stepping Control      :                    0
    Last Step In the voulme  : 
        Mass (GeV)   :                    0
        Charge (eplus)   :                    0
        MagneticMoment   :                    0
                :  =                    0*[e hbar]/[2 m]
        Position - x (mm)   :                 -593
        Position - y (mm)   :                  250
        Position - z (mm)   :                  232
        Time (ns)           :                 0.38
        Proper Time (ns)    :                    0
        Momentum Direct - x :              -0.0227
        Momentum Direct - y :                0.975
        Momentum Direct - z :               -0.219
        Kinetic Energy (MeV):             3.03e-06
        Velocity  (/c):                  inf
        Polarization - x    :                0.996
        Polarization - y    :               0.0401
        Polarization - z    :               0.0754

Here the parameters that I used for the scintillator:

// ------------ Generate & Add Material Properties Table ------------
//
                const G4int nEntries = 15;

                G4double PhotonEnergy[nEntries] =
                          { 2.407*eV, 2.495*eV, 2.533*eV, 2.570*eV,
                            2.609*eV, 2.651*eV, 2.698*eV, 2.738*eV,
                            2.785*eV, 2.832*eV, 2.882*eV, 2.928*eV,
                            2.980*eV, 3.041*eV, 3.092*eV };
                //
                // Scintillateur
                //                  
                G4double RefractiveIndex1[nEntries] =
                          { 1.58, 1.58,  1.58, 1.58,  
                            1.58,  1.58, 1.58,  1.58, 
                            1.58, 1.58, 1.58,   1.58, 
                            1.58, 1.58, 1.58 };

                G4double Absorption1[nEntries] =
                          { 3.8*m, 3.8*m, 3.8*m, 3.8*m, 
                            3.8*m, 3.8*m, 3.8*m, 3.8*m, 
                            3.8*m, 3.8*m, 3.8*m, 3.8*m,
                            3.8*m, 3.8*m, 3.8*m };

   G4double ScintilFast[nEntries] =
             { 0.000 , 0.065 , 0.098 , 0.152 ,
                                        0.217 , 0.348 , 0.435 , 0.5 ,
                                        0.641 , 0.696 , 0.957 , 0.967 ,
                                        0.565 , 0.163 ,0.000 };

                // Scintillateur

                  myMPT1 = new G4MaterialPropertiesTable();
                  myMPT1->AddProperty("RINDEX",       PhotonEnergy, RefractiveIndex1,nEntries);
                  myMPT1->AddProperty("ABSLENGTH",    PhotonEnergy, Absorption1,     nEntries);
                  myMPT1->AddProperty("FASTCOMPONENT",PhotonEnergy, ScintilFast,     nEntries);

                  myMPT1->AddConstProperty("SCINTILLATIONYIELD",m_scintyield*1./MeV);
                  myMPT1->AddConstProperty("RESOLUTIONSCALE",m_sigmascint);
                  myMPT1->AddConstProperty("FASTTIMECONSTANT", 2.1*ns);
                  myMPT1->AddConstProperty("YIELDRATIO",1);

                  Scintillateur->SetMaterialPropertiesTable(myMPT1);

                  // Set the Birks Constant for the  scintillator

                  Scintillateur->GetIonisation()->SetBirksConstant(0.094*mm/MeV);

                G4OpticalSurface* OpscintillateurSurfaceh = new G4OpticalSurface("scintillateurSurfaceh");
                OpscintillateurSurfaceh->SetType(dielectric_dielectric);
                OpscintillateurSurfaceh->SetFinish(polished);
                OpscintillateurSurfaceh->SetModel(unified);
//                                                               
  G4LogicalBorderSurface* scintillateurSurfaceh = 
                                 new G4LogicalBorderSurface("scintillateurSurfaceh",
                                 scin_haut_phys,expHall_phys,OpscintillateurSurfaceh);
// Cathode
  G4OpticalSurface* OpcathodeSurfaceh = new G4OpticalSurface("cathodeSurfaceh");
  OpcathodeSurfaceh->SetType(dielectric_dielectric);
  OpcathodeSurfaceh->SetFinish(polished);
  OpcathodeSurfaceh->SetModel(unified);
//                                     
  G4LogicalBorderSurface* cathodeSurfaceh = 
                  new G4LogicalBorderSurface("cathodeSurfaceh", scin_haut_phys, cathode_haut_phys,OpcathodeSurfaceh);

Any help is welcome,

Thanks in advance.

Nadia.

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1 Feedback: Re: the velocity is greater than c_light Velocity: inf   (Gumplinger Peter - 26 Feb, 2016)
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