Force decay in a plane

Hello everyone,

I am simulating the two-body decay of Po210 with:

G4int A = 210, Z = 84; // 210Po
G4ParticleDefinition* ion = G4IonTable::GetIonTable()->GetIon(Z,A);

I would like to force the two-body decay to occur only in the Y-Z plane.

I guess I could use G4RadioactiveDecay::SetDecayDirection(), but I am not sure:

  1. At which stage I can access G4RadioactiveDecay (e.g., steppingAction, eventAction::BeginOfEventAction)
  2. How do I actually retrieve the G4RadioactiveDecay object.