Geometric Sensitivity of a Pinhole Collimator

Figure 1

Perspective View of the Knife-edge Pinhole Collimator. A point source at 𝑧=ℎ and angle 𝜃 emits a photon that intersects the 𝑧=0 plane at (𝜌cos𝛽,𝜌sin𝛽,0) with an incident angle 𝜃_𝑎. The acceptance angle of the collimator is 𝛼 and the diameter of the aperture is 𝑑. Δ𝐿 is the path length of the photon in the attenuating medium. Reproduced from [3] with permission ( 2001 IEEE).