# Itarare Group Sandstone as a Sustainable Alternative Material for Photon Radiation Shielding
## 3 Results  
The results of the elemental analysis (Table 1) indicate that the AR4 sample contained the highest amount of silicon oxide (SiO\({}_{2}\)). In contrast, the RMPS sample contained the lowest amount, with a difference of approximately 1.1 times between them. For aluminum oxide (Al\({}_{2}\)O\({}_{3}\)), the highest amounts were found in sample AR1 and the lowest in sample AR4, with a difference of approximately 1.2 times between them. For iron oxide (Fe\({}_{2}\)O\({}_{3}\)), the highest quantities were found in the RMPS sample, while the lowest quantity was found in the RMPP sample, with a difference of approximately 1.7 times between them. The other oxides (K\({}_{2}\)O, SO\({}_{3}\), TiO\({}_{2}\)) had concentrations of less than 2%. It is also worth mentioning that other oxides were found, but their concentrations were very low. For this reason, we decided not to present their concentrations, as their contributions to the shielding parameters are negligible. The mass attenuation coefficient for the lowest photon energy (0.015 MeV) was highest for RMPS (c. 7.3 cm\({}^{2}\)/g) and lowest for AR2 (c. 6.6 cm\({}^{2}\)/g) (Figure 3a). For the energy of 0.1 MeV (Figure 3b), RMPS (c. 0.174 cm\({}^{2}\)/g) showed the highest MAC, while the lowest was found for AR2 (c. 0.171 cm\({}^{2}\)/g). For photons with an energy of 1.0 MeV (Figure 3c), MAC values ranged from c. 0.0632 cm\({}^{2}\)/g (AR1, RMPS, RMPP) to c. 0.0633 cm\({}^{2}\)/g (AR2, RMPP, AR4). At the highest photon energy analyzed (10 MeV) (Figure 3d), the values found were c. 0.0226 cm\({}^{2}\)/g for samples AR1 and AR2 and c. 0.0227 cm\({}^{2}\)/g for the others. The deviations (error bars) observed for the lower photon energies in MAC are primarily attributed to variations in the oxide composition between repetitions for each rock sample studied. The differences in the deviations for the different energies are associated with the different effects (photoelectric absorption, incoherent scattering, and pair production) of photon attenuation  
The LAC for the lowest photon energy (0.015 MeV) exhibited the greatest value for RMPS (c. 11.6 cm\({}^{-1}\)) and the least for AR2 (c. 10.4 cm\({}^{-1}\)) (Figure 4a). For the energy of 0.1 MeV (Figure 4b), the RMPS (c. 0.273 cm\({}^{-1}\)) demonstrated the highest LAC, while the lowest was observed for AR1 (c. 0.268 cm\({}^{-1}\)). For photons with an energy of 1.0 MeV (Figure 4c), all samples exhibited the same value of c. 0.099 cm\({}^{-1}\). At the highest photon energy examined (10 MeV) (Figure 4d), only sample AR1 exhibited a value of c. 0.035 cm\({}^{-1}\), whereas the remaining samples showed a value of c. 0.036 cm\({}^{-1}\). The lowest and highest MFP values for the lowest photon energy were observed in RMPS (c. 0.087 cm) and AR2 (c. 0.096 cm) (Figure 5a), respectively. For the energy of 0.1 MeV (Figure 5b), the lowest MFP value was found for RMPS (c. 3.67 cm), while the highest was found for AR1 (c. 3.73 cm). For the 1 MeV photons (Figure 5c), the AR2 samples (c. 10.06 cm) showed the lowest MFP values, and the RMPS samples (c. 10.07 cm) had the highest. For the highest photon energy studied (10 MeV) (Figure 5d), the lowest MFP values were found for RMPS (c. 28.01 cm) and the highest for AR1 (c. 28.15 cm). Figure 4: Linear attenuation coefficient (LAC) of the different rock samples (AR1, AR2, RMPS, RMPI, RMP, AR4) for the following photon energies: (**a**) 0.015 MeV, (**b**) 0.1 MeV, (**c**) 1 MeV, and (**d**) 10 MeV. The bars represent the standard deviation from the mean. The HVL (Figure 6) followed the same trend as the MFP. This result was expected, as both parameters are inversely proportional to LAC. The lowest and highest HVL values for the lowest photon energy were observed in RMPS (c. 0.060 cm) and AR2 (0.067 cm), respectively (Figure 6a). For the energy of 0.1 MeV (Figure 6b), RMPS showed the lowest HVL value (c. 2.54 cm), while AR1 showed the highest (c. 2.58 cm).