FIGURE 1.
FIGURE 1.
This figure shows 3 γ-rays being emitted from a point source at top of figure. γ-ray labeled “Good Detection” passes right through collimator hole and will be properly localized directly below point source. γ-ray labeled “Stopped by septa” hits septa and interacts, presumably by photoelectric effect, in septum and thus does not reach scintillation crystal.However, γ-ray labeled “Septal Penetration Bad Detection” passes through septum, reaching scintillation crystal at wrong location, not directly below point source. Probability for septal penetration depends on energy of incident γ-ray and thickness of septum. d = hole diameter; L = hole length; t = thickness of interhole septa.
