Figure 4.
Incoherent scattering event in a two-plane Compton camera. The cone surface contains the possible incidence directions (any generatrix) of the initial photon (γ). It interacts with the scatterer plane and deposits an energy Ls. The scattered photon (γ′) releases the rest of the energy La in the absorber. The line connecting both interaction points (in orange) is the propagation direction of γ′. This defines the axis (directrix) of the aforementioned cone, with half-opening (scattering) angle θ and vertex at the scatter point.