The field of view of a scintillator pair for cosmic rays
  Particles in an extended air shower (EAS), initiated by a cosmic ray primary, lead to two nearly simultaneous detections in a scintillator pair. The angle of the EAS and the axis through both scintillators can be reconstructed using the time difference of the detections and the distance between the scintillators. The acceptances of a scintillator along the axis through the scintillators and perpendicularly on this axis follow the same distribution in theory. Using a data set with two perpendicular detector pairs this theory is verified. The distribution of possible origins of cosmic ray primaries, and the resulting EAS, can thus be described using the perpendicular distribution for a given time difference. 
N.G. Schultheiss
astro-ph.IM