## 3 Results and Discussion
Moreover, from Figure 5 we can easily see that the LAC for the Pb-SX glasses were in reducing order from 20 keV to 80 keV. For instance, for a fix composition (e.g., 30 PbO-5 MoO\({}_{3}\)-5 Li\({}_{2}\)O-40B\({}_{2}\)O\({}_{3}\)), the LAC takes the following values: 229.89 cm\({}^{-1}\) at 20 keV, 38.36 cm\({}^{-1}\) at 40 keV, 13.53 cm\({}^{-1}\) at 40 keV, and 6.63 cm\({}^{-1}\) at 80 keV. It is evident that there is high LAC for the glasses at 20 keV and these are accepted results as the photoelectric absorption dominates at such low energies. It can be concluded that the chosen glasses with high concentration of PbO must be selected for shielding aims when the radiations to be attenuated have average energy values between 20 and 80 keV. The effective atomic number (EAN) were plotted versus energy in Figure 6. From this figure we can understand the relationship between the EAN and the PbO content of the investigated samples in this study. Apparently, as the PbO content increases the EAN of the chosen glasses also increases. The replacement of the B\({}_{2}\)O\({}_{3}\) by PbO is the reason for this trend in the EAN, since the atomic number of B is much less than that of Pb. The glass with a low amount of B\({}_{2}\)O\({}_{3}\) and higher amount of PbO has high EAN in comparison with the glass with a high amount of B\({}_{2}\)O\({}_{3}\). The outcome of the EAN data suggests that Pb-SX samples will perform optimally in shielding the radiation with energy of 20-80 keV when using a high amount of PbO. Additionally, we can see that the EAN has the maximum values of 73.55-76.67 at 20 keV, whereas the lowest values occurred  
Figure 3: Total photoelectric cross section of molybdenum (\(Z=42\)) element by three different libraries with distinct K-absorption edge energies. at 80 keV and varied between 53.63 and 63.39. The EAN decreases when increasing the energy from 20 to 80 keV implying that the shielding performance of the Pb-SX glasses becomes worse when increasing the energy. Figure 4: The MAC for the Pb-SX glasses at four energies (20, 40, 60 and 80 keV). Figure 5: \(Cont.\)  
Figure 5: The LAC for the Pb-SX glasses at (**a**) four energies 20, 40, 60 and 80 keV and (**b**) at 40, 60 and 80 keV (In order to show the values at the three energies more clearly). Figure 6: The EAN for the Pb-SX glasses at four energies (20, 40, 60 and 80 keV). The half-value layer (HVL) were graphed in Figure 7. At all four energies, the HVL values followed the trend of Pb-S1 \(>\) Pb-S2 \(>\) Pb-S3 \(>\) Pb-S4 \(>\) Pb-S5. These results demonstrate that the Pb-S1 glass has the greatest HVL at all the tested energies, while Pb-S5 has the least. This trend is due to the greater PbO content of the Pb-S5 glass (50 mol%) compared to the Pb-S1 glass (30 mol%), causing an increase in density which correlates with a decrease in HVL. Pb-S5 is the most space-efficient radiation shield. The figure also reveals the correlation between energy and HVL. When observing any glass at increasing energy, the HVL values can be seen to greatly increase. The HVL of the Pb-S2 glasses increases from 0.003 cm to 0.015 cm, 0.044 cm, and 0.089 cm for energies of 20, 40, 60, and 80 keV, respectively. However, it should be observed that the HVL of Pb-S1 can be seen to increase at a much greater rate than the HVL of Pb-S5, for instance, which signifies that even though the HVL of Pb-S5 increases with increasing energy, the rate of the increase is much smaller, or the ability of the glass to absorb radiation becomes increasingly better at higher energies. The advantage of the Pb-S5 glass at greater energies is demonstrated in Figure 8, where the tenth-value layer, or TVL, of the glasses are illustrated against incoming photon energy. The differences between the two parameters signifies that TVL will logically be greater than HVL, but the values are still trying to be minimized. Similar to HVL, the TVL values increase when increasing the energy. The TVL of the Pb-S3 glass increases from 0.007 cm at 20 keV to 0.044 cm at 40 keV, 0.125 cm at 60 keV, and 0.257 cm at 80 keV.