Figure 3.

Simulated absorbed weight distribution of a single target inside the 3-D volume was summed in the y direction and projected to the x-z plane. (a) The background photon group (BG) consists of photons that do not enter the target. (b) The target group (TG) consists of photons that enter the target. (c) The upper target group (UTG) includes the photons entering the upper half target only, when the target is separated into the upper half and the bottom half. (d) The upper and bottom target group (UBTG) includes the photons that reach the bottom half target when the target is separated into two parts.