plane by a 2″2″NaI(Tl) detector having an energy resolution of 8% at 662 keV (BICRON model 2M2/2) equipped with CANBERRA photomultiplier tube base model 802-5. The optimize distance between the source and the scatterer was set to 20 cm and 20 cm between the scatterer to the detector. The spectra were recorded using a CANBERRA PC-based multi-channel analyzer (MCA). The spectrum on the MCA of detector give instance counts for each of 1024 bins divided by voltage. The angle of the scatter detector (θ) was adjusted to produce the different gamma rays energies and acquiring measurements on the MCA. The accuracy of scattered energy was reported in literatures (Limkitjaroenporn et al., 2013,2013).