Angle of landing for a particle

Particles, Track, Event, Run and Biasing
1

Hi
For a particle that is emitted from a source and moves in a straight path to reach a surface, how can we have the angle of landing of that particle with respect to the vertical axis

1 Like
2

You can add this computation in the SteppingAction, by taking the particle momentum vector at the pre-step point when the step is touching the target surface.

3

here you could find inspiration: geant4/G4PSFlatSurfaceFlux.cc at v11.0.3 · Geant4/geant4 · GitHub