Figure 8

source producing 6.4 μR/h at 100 cm distance. The detector map composed of the gamma-ray events for (a) 20 s (300 events), (b) 40 s (600 events), and (c) 69 s (1,000 events). The three detector maps correspond to the images reconstructed by using MLEM (d–f), respectively.
Comparison of reconstructed images of gamma-ray events when exposed to a 137Cs