GlobalTime Tracking Challenges for Short Reactions of Secondary Particles from Long Half-Life Decay Isotopes

Particles, Track, Event, Run and Biasing
2

This should really just be in the user manual. The way I have done (and seen this done) is in TrackingAction and hopefully works for all radioactive decays in which the first daughter is of interest:

void TrackingAction::PostUserTrackingAction(const G4Track* track)
{

    // Reset global time on first decay (to avoid waiting for half life of first decay)
    if (track->GetParentID() == 0) { // This track belongs to a primary vertex
       
            // ============Setting secondary tracks to zero global time==============
            G4TrackVector* secondaries = fpTrackingManager->GimmeSecondaries();
            size_t nSeco = secondaries->size();

            if (nSeco > 0){
                for(size_t i=0; i < nSeco; i++) {
                    (*secondaries)[i]->SetGlobalTime(0.);
                    }
     }
}

You’ll need to include G4RunManger to get access to fpTrackingManager.