Studies of Coins of Medieval Volga Bulgaria by Neutron Diffraction and Tomography

Phase Composition and Its Spatial Distribution in Antique Copper Coins: Neutron Tomography and Diffraction Studies

“…The results of the chemical composition obtained from the surface of coins may differ from the distribution of chemical components in the entire coin volume [ 12 , 14 ]. The neutron diffraction method provides a non-destructive structural diagnostic with high penetration inside a volume of coins.…”

“…Currently, coins are being intensely investigated by means of non-destructive physical methods, such as traditional techniques like metallography or X-ray diffraction [ 1 , 3 , 9 ]. In this context, we should also mention the neutron radiography [ 10 , 11 , 12 ] and neutron diffraction [ 12 , 13 , 14 ] methods as relatively modern structural non-destructive experimental approaches [ 1 , 15 , 16 ]. The fundamental difference in nature of neutron interaction with matter compared to X-rays provides additional benefits to neutron methods, including sensitivity to light elements, a notable difference in contrast between isotopes and high penetration effect through metals or heavy elements.…”

“…The fundamental difference in nature of neutron interaction with matter compared to X-rays provides additional benefits to neutron methods, including sensitivity to light elements, a notable difference in contrast between isotopes and high penetration effect through metals or heavy elements. Neutron imaging and scattering methods are successful in separating the components of coin alloys with neighboring elements: iron and nickel, copper and zinc [ 17 ], copper and silver [ 12 , 14 ], copper and lead [ 18 ]. Moreover, neutron structural methods were applied to determine the bulk composition hidden by corrosion [ 11 , 14 ] for coin identification [ 11 ], for the reconstruction of coinage technologies and sources of mining materials for coins [ 19 ] and for the description of coins’ degradation like internal corrosion tracks [ 11 , 20 ] and deterioration areas [ 18 , 21 ].…”

Archaeometallurgical Analysis of the Provincial Silver Coinage of Judah: More on the Chaîne Opératoire of the Minting Process

“…The patina of ancient objects made of silver alloys may contain Ag 2 O, Ag 2 S, and/or AgCl, which can result in uncertainties concerning the obtained elemental data [ 9 ]. Therefore, the detected chemical composition obtained from the surface of the coin can be fundamentally different from the chemical composition over the entire volume of the coin [ 23 ]. Moreover, even when bulk material composition of ancient silver coins is obtained by destructive testing methods, there may be uncertainties concerning elemental analysis results that assume homogenous elemental distribution, which is often incorrect [ 21 ].…”

Non-destructive structural studies of coins from the Uzundara Fortress using X-ray diffraction and neutron tomography

“…Currently, active experimental research is being conducted on the coins discovered during excavations using both traditional research methods and modern methods of non-destructive structural diagnostics [9][10][11][12][13]. Such structural methods include the X-ray diffraction method [14,15], which makes it possible to obtain information about the phase composition of the investigated object, and the neutron imaging methods, which allows to obtain the spatial distribution of phase components in the volume of the studied coins [13,14,[16][17][18]. The neutron tomography method, due to the features of the neutron beam interaction while passing through the elements of the investigated object with different chemical compositions, thickness and density, makes it possible to obtain detailed information about the internal structure of metal coins [16,19] with a spatial resolution at the micron level [20], as well as to obtain a virtual three-dimensional model of the coin for further analysis.…”