## 4 Discussion  
Most shielding plates used in medical institutions are used for shielding X-rays and gamma rays. Because the energy range is fixed, the plates used in medical institutions are observed to correspond to a smaller range than those used in working areas [33].  
Generally, tungsten is mixed with an inorganic compound, such as resin, and processed into the desired shape and thickness. However, maintaining the reproducibility of the shielding performance is challenging. In this study, tungsten plates were used to fabricate shielding plates with different thicknesses and different processing methods. The three shielding plates produced had a thickness of 0.3 mm or less, and the difference in shielding performance between the plates produced via hot and cold rolling was less than 6%, indicating that there was no significant difference. However, it could have an impact on the materials used for small parts or on the production of custom shields.  
In previous studies, the hot-rolling method was reported to reduce the thickness of the tungsten plate. Because this process could increase both durability and density, the shielding rate could also increase [34; 35]. The shielding rate can be increased using a high-density shielding material or by increasing the density of the shield [36].  
The hot and cold rolling methods are carried out at temperatures greater than and less than 1200 \({}^{\circ}\)C, respectively, and can be performed more effectively by preheating [37]. The cost of processing tungsten into a plate is high; however, it is eco-friendly and can be  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline  & & \multicolumn{3}{c}{**Mean of Exposure (\(\mu\)R)**} & \multicolumn{3}{c}{**Shielding Rate (\%)**} \\ \cline{3-8}
**Effective** & **Peak Voltage** & \multirow{2}{*}{**Nothing**} & \multirow{2}{*}{**Hot**} & \multirow{2}{*}{**Coll**} & \multirow{2}{*}{**Hot**} & \multirow{2}{*}{**Coll**} \\
**X-ray Energy** & & & & & & & \\
**(keV)** & & & & & & & \\ \cline{3-8}  & & & & & & & \\ \cline{3-8}  & & & & & & & \\ \hline
24.6 & 40 & 106.90 & 0 & 1.98 & 4.02 & 100 & 98.15 & 96.24 \\
28.7 & 60 & 381.63 & 2.49 & 33.91 & 51.82 & 99.35 & 91.11 & 86.42 \\
32.5 & 80 & 799.70 & 21.49 & 135.07 & 181.70 & 97.35 & 83.11 & 77.28 \\
48.5 & 100 & 1318.33 & 49.23 & 274.33 & 358.90 & 96.27 & 79.19 & 72.78 \\
54.9 & 120 & 1648.33 & 71.37 & 372.10 & 484.77 & 95.67 & 77.43 & 70.59 \\ \hline \hline \end{tabular}
\end{table}
Table 1: Shielding performance according to the shielding plate manufacturing process.  
Figure 6: Comparison of shielding performance between the manufactured thin-film tungsten plate and lead.  
used continuously. In addition, its excellent durability makes it a suitable device for use in medical institutions [38; 39]. The thinner the tungsten plate, the more appropriate it is to use a cold-rolling method with a relatively simple processing technology. However, when the cross-sectional structures of the plates were evaluated, hot rolling was observed to be more appropriate for analyzing laminated structures. In particular, the same difference was observed in the X-ray area, which corresponds to the energy range of the diagnostic area.  
When the shield is manufactured in the form of a sheet or film, voids may be generated in the process of stirring the mixture and shielding material. When the shielding plate is manufactured using the rolling method, the flexibility is lowered; however, the problem of such voids can be resolved. Moreover, tungsten plates can also help mitigate problems, such as hardening, and reduce cracks that occur in the long term [40; 41].  
Tungsten metal processing has limitations in terms of time and economic efficiency. However, the 0.3 mm-thick tungsten plate used in this study showed an excellent shielding performance as a replacement for lead; therefore, it can be considered as an eco-friendly material for use in radiation shielding in the future.