## 3 Application to Cultural Heritage Science
### Elemental Analysis of Bronze Artefacts  
Copper and bronze were used extensively through time, leaving us with a wealth of cultural objects that are just waiting to be studied. Over the last years, some bronze artefacts were analysed by means of muon spectroscopy. In [PERSON] et al. [36], a Chinese bronze mirror (Seiun-Kyo) was measured. The mirror was measured with a momentum of 22 MeV/c. From the data analysis, results showed it composed of a ternary alloy (copper, \begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Sample**} & \multirow{2}{*}{**Element**} & \multicolumn{2}{c}{**Muonic X-ray**} & \multicolumn{1}{c}{**X-ray Fluorescence**} \\  & & **Measurement [wt.\%]** & **[wt.\%]** \\ \hline \multirow{3}{*}{Tempo-Tsuho (Edo)} & Cu & 77.7 \(\pm\) 1.6 & 77.77 \(\pm\) 0.01 \\  & Sn & 12.5 \(\pm\) 1.5 & 14.45 \(\pm\) 0.54 \\  & Pb & 9.8 \(\pm\) 1.5 & 7.79 \(\pm\) 0.16 \\ \hline \multirow{3}{*}{Tempo-Tshuo (Mito)} & Cu & 69.0 \(\pm\) 1.9 & 73.64 \(\pm\) 0.01 \\  & Sn & 9.9 \(\pm\) 1.3 & 12.18 \(\pm\) 0.41 \\ \cline{1-1}  & Pb & 21.1 \(\pm\) 2.6 & 14.17 \(\pm\) 0.12 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Elemental composition of the two coins in wt.%. The real coin is the Tempo-Tsuho (Edo), while the counterfeit is the Tempo-Tsuho (Mito). Results are compared with XRF. Data was taken and adapted from [36]. Figure 8: Gold variation within the sample thickness. Reprinted with permission from “Nondestructive Elemental Depth-Profiling Analysis by Muonic X-ray Measurement”. [PERSON], [PERSON], [PERSON], [PERSON], [PERSON], [PERSON], [PERSON], [PERSON], [PERSON], [PERSON], [PERSON], [PERSON], [PERSON], [PERSON]. 2015, Analytical Chemistry, Vol. 87, pp. 4597–4600, Ref. [21] Copyright (2015) American Chemical Society. tin and lead) with smaller amounts of other elements. To perform elemental composition, three specific peaks were chosen: 115 keV for copper, 159 keV for tin and 233 keV for lead. The elemental composition of the mirror was found to be 71.8% copper, 22.1% tin and 6.1% of lead. Figure 9: Spectra of Tiberius (**a**) and Julian (**b**) measured coins. Gold is present in both coins with a double peak at 400 keV and 406 keV and a gamma peak at 355 keV. As mentioned before, the surface (yellow) is representative of the interior (red). Reprinted with permission from Ref [37] © 2021, Elsevier Ltd. Similarly, in [PERSON] et al. [23] and [PERSON] et al. ([38], forthcoming), Nuragic \"votive\" ships were characterized. Particularly, in Marcucci, two voting ships coming from the tomb of the \"Tre Navicelle\" were irradiated at Port 4 of the RIKEN-RAL facility. Votive ships are a unique production of the Sardinian metallurgy and in this work, the elemental composition was investigated. From the data analysis, results show the hull of the two samples to be composed of a ternary alloy (copper, tin, lead), with a lower concentration of tin in the head and the mast, balanced by a higher concentration of lead. For sample n.6779 (Figure 10a, points A, D, E) the average composition is: copper 76.4 \(\pm\) 0.3 wt.%, tin 12.2 \(\pm\) 0.2 wt.% and lead 11.5 \(\pm\) 0.3 wt.%. While for sample n.6780 (Figure 10b, points A, D, E), the average composition is: copper 77.4 \(\pm\) 0.5 wt.%, tin 10.7 \(\pm\) 0.3 wt.%, and lead 11.8\(\pm\) 0.5 wt.%. The variation between the composition of the head and the mast, compared to the hull, is used to make assumptions about the manufacturing technique. Here, the authors suggest that the boats were made by a two-step casting process: the first part involved the hull, while the head and the mast were added in a second phase. These two pieces were intentionally made with a different alloy, rich in lead, as reported in Figure 11; a high amount of lead, indeed, helps with the casting of complex details, since the fluidity of the alloy is increased.