# Itarare Group Sandstone as a Sustainable Alternative Material for Photon Radiation Shielding
## 3 Results
For 1 MeV photons (Figure 6c), the RMPS samples (c. 6.98 cm) had the highest HVL values, and the AR2 samples (c. 6.97 cm) had the lowest. For the highest studied photon energy (10 MeV) (Figure 6d), the lowest HVL values were found for the RMPS samples (c. 19.41 cm), and the highest values were found for the AR1 samples (c. 19.51 cm). Figure 5: Mean free path (MFP) of the different rock samples 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 tenth-value layer (Figure 7) followed the same trend as HVL and MFP due to its dependence on LAC. When we analyze the lowest photon energy studied (0.015 MeV) (Figure 7a), we observe that the lowest TVL was obtained for RMPS (c. 0.20 cm), while the highest was obtained for AR2 (c. 0.22 cm), respectively. With the increment in photon energy (Figure 7b), the lowest and the highest TVL were found for RMPS (c. 8.45 cm) and AR1 (c. 8.58 cm). For the photon energy of 1 MeV (Figure 7c), the RMPS samples had the highest TVL (c. 23.20 cm), while the lowest was noted for the AR2 samples (c. 23.16 cm). For the highest photon energy studied (Figure 7d), similar to the findings of the previous two energies, RMPS (c. 64.5 cm) presented the lowest TVL and AR1 (c. 64.8 cm) the highest, respectively. Figure 6: Half-value layer (HVL) of the different rock samples (AR1, AR2, RMPS, RMPI, RMPP, 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 EBF (Figure 8) exhibited similar behavior across different photon energies for the rock samples. The lowest values were found at the lowest (<0.1 MeV) and highest (>1 MeV) photon energies. The most significant differences were observed in the region between 0.1 and 1 MeV for the various MFP values. The increase in MFP led to an increase in EBF. This parameter was practically unaffected for 1 MFP. When comparing samples, the highest EBF values were found for AR2 (Figure 8b) with maximum values (peaks) of c. 2.3 (1 MFP), c. 38 (10 MFP), c. 140 (20 MFP), c. 316 (30 MFP), and c. 568 (40 MFP). The lowest values were seen for RMPS (Figure 8c), with maximum values of c. 2.5 (1 MFP), c. 33 (10 MFP), c. 107 (20 MFP), c. 227 (30 MFP), and c. 398 (40 MFP). Figure 7: Tenth-value layer (TVL) of the different rock samples (AR1, AR2, RMPS, RMPI, RMPP, 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 EABF (Figure 9) also showed similar behavior across different photon energies for the rock samples. The lowest values were found at the lowest (<0.1 MeV) and highest (>1 MeV) photon energies, respectively. The most significant differences were observed in the region between 0.1 and 1 MeV for the different MFP values. With the increase in MFP, there was an increase in EABF, with this parameter being practically insensitive for 1 and 10 MFP. When comparing samples, the highest EBF values were found for AR2 (Figure 9b),  
Figure 8: Energy buildup factor (EBF) of the different rock samples: (**a**) AR1, (**b**) AR2, (**c**) RMPS, (**d**) RMPI, (**e**) RMPP, and (**f**) AR4. The bars represent the standard deviation from the mean. with maximum values (peaks) of c. 2.6 (1 MFP), c. 51 (10 MFP), c. 191 (20 MFP), c. 437 (30 MFP), and c. 791 (40 MFP). The lowest values were observed for RMPS (Figure 9c), with maximum values of c. 2.6 (1 MFP), c. 51 (10 MFP), c. 190 (20 MFP), c. 435 (30 MFP), and c. 787 (40 MFP). To analyze the impact of the chemical  
EABF values selected for the correlation were those obtained at the peak (maximum value) in the incoherent scattering domain region (between 0.1 and 1 MeV). High to very high negative correlations were observed between EBF and the contents of Fe\({}_{2}\)O\({}_{3}\) and K\({}_{2}\)O, ranging from \(-0.75\) to \(-0.66\) and \(-0.83\) to \(-0.68\), respectively.