Decay time of excited states may not be transferred to emitted photon

[jvavrek]

I haven't tested this yet, but I don't think the decay time of the excited state is ever sampled to provide an emission time for the new photon. Most lifetimes are very short (1-100 fs) but it could be interesting to include that correction, likely involving the following lines in G4NRF.cc:

G4DynamicParticle* aGamma = new G4DynamicParticle(G4Gamma::Gamma(), emitted_gamma_direction, E_gamma);
aParticleChange.AddSecondary(aGamma);

Something like (pseudocode):

aGamma->SetProperTime(current_time + G4RandExponential(-pLevel->Lifetime()));

maybe?