Message: Problems with Optical Photons [OpAbsorption] Not Logged In (login)
 Next-in-Thread Next-in-Thread
 Next-in-Forum Next-in-Forum

Question Problems with Optical Photons [OpAbsorption] 

Forum: Processes Involving Optical Photons
Date: 11 Mar, 2011
From: Ana <Ana>

Hi, I have a problem with my simulation.

I have created a pet module with scintillation crystal, I know the geometry is ok. I'm working with geant4.9.4.p01. I reated the simulation with a previous version of geant.

In order to use my simulation with the new geant I have changed the PhysicList, because "LowEnergy" packages are no more available. With my new PhysicList, I have no problems with e- and gamma and the scintillation process is ok. So, I obtain optical photons. My problem begin in this point, with this message:

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

   G4VDiscreteProcess::PostStepGetPhysicalInteractionLength [ OpAbsorption]
 Particle type - opticalphoton
   mass:        0[GeV]
   charge:      0[e]
   Direction x: -0.279654, y: -0.61239, z: 0.73944
   Total Momentum = 2.95e-09[GeV]
   Momentum: -8.24978e-10[GeV], y: -1.80655e-09[GeV], z: 2.18135e-09[GeV]
   Total Energy   = 2.95e-09[GeV]
   Kinetic Energy = 2.95e-09[GeV]
 MagneticMoment  [MeV/T]: 0
   ProperTime     = 0[ns]
 in Material  LSO
InteractionLength= 1.79769e+307[cm] 
G4VProcess::SubtractNumberOfInteractionLengthLeft() [OpAbsorption]
 currentInteractionLength = -nan [cm] previousStepSize = 0.652837 [cm]

*** G4Exception : ProcMan
      issued by : G4VProcess::SubtractNumberOfInteractionLengthLeft()
Negative currentInteractionLength for OpAbsorption
*** Event Must Be Aborted 
G4VDiscreteProcess::PostStepGetPhysicalInteractionLength [ OpAbsorption]
 Particle type - opticalphoton
   mass:        0[GeV]
   charge:      0[e]
   Direction x: -0.279654, y: -0.61239, z: 0.73944
   Total Momentum = 2.95e-09[GeV]
   Momentum: -8.24978e-10[GeV], y: -1.80655e-09[GeV], z: 2.18135e-09[GeV]
   Total Energy   = 2.95e-09[GeV]
   Kinetic Energy = 2.95e-09[GeV]
 MagneticMoment  [MeV/T]: 0
   ProperTime     = -nan[ns]
 in Material  OpGrease
InteractionLength= 1.79769e+307[cm] 

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

I let you a part of my PhysicList ->

#include "G4Scintillation.hh"
#include "G4OpAbsorption.hh"
#include "G4OpRayleigh.hh"
#include "G4OpBoundaryProcess.hh"

void IMPPhysicsList::ConstructOp() {

  // this absorption process inside optical media
  G4OpAbsorption* theAbsorptionProcess = new G4OpAbsorption();
  // Rayleigh scattering for optical photons (aerogel radiators)
  G4OpRayleigh*   theRayleighScatteringProcess = new G4OpRayleigh();
  // Boundary process definition Class
  G4OpBoundaryProcess* theBoundaryProcess = new G4OpBoundaryProcess();
  // THE SCINTILLATION PROCESS
  G4Scintillation* theScintProcess = new G4Scintillation("Scintillation");

  theScintProcess->SetTrackSecondariesFirst(true);

  // Chose level 0 (no verbose)

  theAbsorptionProcess         -> SetVerboseLevel(2);
  theRayleighScatteringProcess -> SetVerboseLevel(0);
  theBoundaryProcess           -> SetVerboseLevel(0);

  // Boundary model (UNIFIED OR GLISUR (OLD GEANT3)) For now only GEANT3
  G4OpticalSurfaceModel themodel = unified;
  theBoundaryProcess->SetModel(themodel);

  theParticleIterator->reset();
  while( (*theParticleIterator)() ){
    G4ParticleDefinition* particle = theParticleIterator->value();
    G4ProcessManager* pmanager = particle->GetProcessManager();
    G4String particleName = particle->GetParticleName();

   if (theScintProcess->IsApplicable(*particle)) {

      pmanager->AddProcess(theScintProcess);

      pmanager->SetProcessOrderingToLast(theScintProcess,idxAtRest);

      pmanager->SetProcessOrderingToLast(theScintProcess,idxPostStep);

    }
    if (particleName == "opticalphoton") {
      G4cout << ">>>>>>>>>>>>>> AddDiscreteProcess to OpticalPhoton " << G4endl;
      pmanager->AddDiscreteProcess(theAbsorptionProcess);
      pmanager->AddContinuousProcess(theRayleighScatteringProcess);
      pmanager->AddContinuousProcess(theBoundaryProcess);
    }
  }
}

I need your help. Thanks :)

Inline Depth:
 1 1
 All All
Outline Depth:
 1 1
 2 2
 All All
Add message: (add)

1 Feedback: Re: Problems with Optical Photons [OpAbsorption]   (Gumplinger Peter - 11 Mar, 2011)
(_ None: Re: Problems with Optical Photons [OpAbsorption]   (Ana - 14 Mar, 2011)
1 Feedback: Re: Problems with Optical Photons [OpAbsorption]   (Gumplinger Peter - 15 Mar, 2011)
2 Warning: Re: Problems with Optical Photons [OpAbsorption]   (Gumplinger Peter - 15 Mar, 2011)
1 Sad: Re: Problems with Optical Photons [OpAbsorption]   (Ana - 22 Mar, 2011)
 Add Message Add Message
to: "Problems with Optical Photons [OpAbsorption]"

 Subscribe Subscribe

This site runs SLAC HyperNews version 1.11-slac-98, derived from the original HyperNews