# Gamma Ray Shielding Properties of Yb\({}^{3+}\)-Doped Calcium Borotellurite Glasses
## 3 Results and Discussion
It describes the thickness at which the attenuator will reduce the radiation to half of its initial intensity. The HVL as a function of the density of the TeBYbX glasses is exhibited in Figure 8. From Figure 8, it is clear that the HVL of the chosen samples has a downward trend as the density of the glasses increases. This tendency in the HVL implies that among the TeBYbX glasses, TeBYb5, the sample with the highest content of TeO\({}_{2}\) as well as the greatest density, is the most efficient at shielding the photons, whereas TeBYb1, the sample with the lowest content of TeO\({}_{2}\) and lowest density, is the least efficient at shielding the photons. We can explain the previous relationship between the HVL and the density of the \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Sample Code** & **TeO\({}_{2}\)** & **B\({}_{2}\)O\({}_{3}\)** & **CaO** & **CaF\({}_{2}\)** & **Yb\({}_{2}\)O\({}_{3}\)** & **Density (g/cm\({}^{3}\))** \\ \hline TeBYb1 & 10 & 54 & 25.5 & 10 & 0.5 & 3.08 \\ \hline TeBYb2 & 16 & 50.4 & 23.1 & 10 & 0.5 & 3.25 \\ \hline TeBYb3 & 22 & 46.8 & 20.7 & 10 & 0.5 & 3.43 \\ \hline TeBYb4 & 31 & 41.4 & 17.1 & 10 & 0.5 & 3.71 \\ \hline TeBYb5 & 54 & 27.6 & 7.9 & 10 & 0.5 & 4.46 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Samples’ codes, composition (mol%) for the TeBYb-X glasses. Figure 7: The effective atomic number for the TeBYbX glasses. TeBYbX glasses according to the following: when the gamma photons pass through the low density glass, there is a space between the atoms, hence the probability of photon-glass atom interaction is relatively small, and thus it is much easier for the photons to pass through the glass, therefore we need to increase the thickness of the sample to attenuate the 50% of the initial photons, so the HVL for the low density materials is high. In contrast, the probability of the photons interacting with the high density glass is high, and thus the penetration of the photons through the glass decreased, and this reduced the HVL for the high density glass samples. Moreover, as seen in Figure 8, the HVL varied between 1.796 and 1.009 cm at 0.284 MeV and increased to 5.791 cm (for TeBYb1) and 4.068 cm (for TeBYb5) at 2.506 MeV. The previous results imply that, as the energy increases from 0.284 to 2.506 MeV, the attenuation by the TeBYbX glasses decreases. This can also be understood from the types of radiation-matter interaction; as we go from low to high energy, the probability of the photoelectric effect decreases and the probability of Compton scattering increases [37]. For the chosen calcium borotellurite glasses (TeBYbX), we determined the tenth value layer for the samples with lowest and highest TeO\({}_{2}\) contents, namely TeBYb1 and TeBYb5, then we calculated the ratio between the TVL for the TeBYb1 and TeBYb5 glasses (\(\rm{TVL_{TeBYb1}}/\rm{TVL_{TeBYb5}}\)). The results are presented in Figure 9. The aim of this figure is to understand the influence of the 10 and 54 mol% of TeO\({}_{2}\) on the thickness of the TeBYbX samples that can attenuate the gamma rays. By examining the data presented in Figure 9, one can easily understand that TeBYb1 has a higher TVL than TeBYb5, because the ratio is almost larger than 1. The \(\rm{TVL_{TeBYb1}}/\rm{TVL_{TeBYb5}}\) decreases with the increasing energy; it starts with maximum value of 1.78 at 0.284 MeV, then reduces quickly with a further  
Figure 8: The half value layer (cm) as a function of the density of the TeBYbX glasses. increase in energy. The \(\rm TVL_{\rm TEBYb1}/TVL_{\rm TEBYb5}\) at 0.347 and 0.511 MeV are 1.64 and 1.61. We can conclude from this figure that increasing the amount of \(\rm TeO_{2}\) from 10 to 54 mol\(\%\) in the selected calcium borotellurite glasses (TeBYbX) leads to a decrease in the TVL by a factor of 1.48 (on average). This findings agrees with the obtained findings in the \(\rm\mu\) and \(\rm Z_{\rm eff}\) figures.