Morphological and microstructural characterization of an ancient Chola bronze statuette by neutron based non-invasive techniques.

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Francesco Cantini, Sara Creange, Yueer Li, Lambert van Eijck, and 3 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-3706226/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 28 Feb, 2024 Read the published version in Archaeological and Anthropological Sciences → Version 1 posted 7 You are reading this latest preprint version Abstract The evolution of metallurgy is a fundamental aspect related to the knowledge of the technological level of ancient civilizations, for which the information was mostly part of an oral tradition. The ancient, preserved artefacts are the only keepers of this long gone knowledge. Most advanced non-invasive techniques provide us the key to access it. Neutron techniques are nowadays the only available approach for revealing, non-destructively and with good spatial resolution, the morphological and micro-structural properties within the whole volume of densely composed artefacts such as bronze statues. Application of neutron methods allows us to learn about ancient artefacts manufacturing methods and to study at a very detailed level the current conservation status in their different parts. As part of a research project dedicated to the study of ancient Asian bronzes led by the Rijksmuseum Metal Conservation Department, four statues from the Rijksmuseum Asian collection were analysed using non-invasive neutron techniques. In this work, we present the investigation of a South Indian bronze statuette depicting Shiva in the form of Chandrasekhara (AK-MAK-1291, c. 1000-1200 A.D.) by means of white beam tomography, energy selective neutron imaging (performed on CONRAD-2 at HZB, DE, and on FISH at TU-Delft, NL) and neutron diffraction (on ENGIN-X at ISIS, UK). The application of neutron imaging revealed the inner structure of the statue and allowed us to investigate the conservation state and potential cracking on the surface and in the bulk, to understand the interconnection of the different sections of the statue and to obtain clues about the manufacturing processes. These morphological and microstructural results were employed to guide neutron diffraction analyses that allowed us to precisely characterize compositional differences, the presence of dendrites and columnar growth peak structures related to casting. This work is a complete non-invasive analytical investigation on an archaeological bronze artefact, providing outstanding results: from a quantitative analysis of the composition and microstructure to an in-depth morphological analysis capable of unveiling details on the ancient casting methods of the statue. Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 1. Introduction The study and the preservation of historical artefacts are grounded upon the intimate knowledge of the constituent materials and the understanding of their manufacturing methods. It is essential to have diagnostic tools capable of providing the highest amount of information with a minimum of invasiveness. The Rijksmuseum Metals conservation department initiated the technical study of a South Indian bronze Chandrasekhara (“the moon-crested one”, hereafter referred to as Shiva, AK-MAK-1291, c. 1000–1200 A.D.) along with three other bronzes from India and Southeast Asia. The date, estimated on stylistic grounds, falls within the Chola Dynasty in South India (Srinivasan, 2006 ). During this period a bronze casting industry developed in the region of the Keviri river, specializing in solid-cast bronzes up to several meters tall, of a scale and quality unmatched in the rest of the world (Dehejia, 2021 ). Casting was closely linked with religious ritual, and the methods were to a certain extent codified in religious texts and passed down through generations of bronze-casting families. Descendants of the Chola casters still produce bronzes largely following the ancient methods (Levy, et al., 2007 ). This provides a unique opportunity to examine features found in ancient statues with reference to current local casting practice and ritual casting described in ancient texts. The Shiva (Fig. 1 ) is a four-armed figure standing on a pedestal and backed by a flaming halo (Fig. 1 ); it is owned by the Royal Society of the Friends of Asian Art (VVAK) and housed in the Rijksmuseum in Amsterdam. The statuette at 40 cm and 4.9 kg is not particularly large for a Chola bronze and was made by means of the direct lost wax casting technique. According to initial visual assessments and knowledge of current casting practice in South India (Levy, et al., 2007 ), it is assumed the Shiva could be cast in three separate parts that are then mechanically joined: the figure, the pedestal which consists of a rectangular base topped with a circular double lotus flower, and a flaming halo inserted into brackets at the side of the pedestal. No bulk analysis of the alloy composition had been performed prior to this work; the statue was believed to have comparable composition to typologically similar sculptures, with an alloy of nearly pure copper (Craddock & Hook, 2007 ; Werner, 1972 ). A different alloy is believed to have been used for the arched structure, the so-called halo. The Shiva figurine is decorated with bas-relief jewellery including bracelets, necklaces, earrings, and a ribbon. The necklace ends with a pendant which, under visual inspection, appears very dark and is suspected to be a precious metal. Preliminary surface analysis by X-Ray Fluorescence (XRF) is difficult because of the presence of corrosion and soil. The surface appears mainly light green in colour, probably due to the presence of anhydrous copper sulphate, copper carbonates and copper-based silicate concretions. Below the pedestal, we can observe azurite, malachite, and cuprite. Based on qualitative XRF measurements (Olympus handheld and comparisons with other published Chola bronzes) (Craddock & Hook, 2007 ; Srinivasan, 1999 ), the main alloy is supposed to be mostly copper with the addition of tin and lead. Common X-ray non-invasive diagnostic techniques for characterizing metals, such as X-ray diffraction and imaging do not allow microstructural analysis and do not possess high power penetration in thick materials consisting of heavy elements. For this reason, optical microscopy techniques have traditionally been used - e.g., metallography - which are however highly invasive, requiring a substantial withdrawal of material from the sample. The use of neutron as an investigation probe for metallic artefacts has made it possible to have non-invasive microstructural analytical techniques. Unlike X-rays, the use of neutron allows to discern between metals with similar atomic numbers, because of large differences in the cross section among metals and a good penetration into materials, even with a thickness of several centimetres. The quality and quantity of information that can be achieved with Neutron Diffraction and Imaging techniques can provide, further supported by the interdisciplinary contribution in data interpretation, information ranging from structural and microstructural description to the analysis of the state of conservation of the artefact up to the technological process involved in its manufacturing. The thorough characterization of this statue required a multi-analytical approach, organized in three different experimental campaigns (Neutron Imaging, Neutron Diffraction and Neutron Activation Analysis) at three international facilities (2016, Helmholtz Zentrum Berlin, DE; 2019, ISIS neutron and muon source, UK; 2022, Reactor Institute TU Delft, Delft, NL). Neutron Imaging (NI) analysis allows for morphological and microstructural results that reveal clues related to the casting process and the relationship among the various constituent parts of the statue (the pedestal, the halo and the Shiva figurine). Both White Beam Neutron Tomography (WB-NT) and Energy Selective Neutron Radiography (ES-NR) were exploited to achieve a complete morphological characterization as well as information about the casting techniques involved in the manufacturing of this artefact. Time of Flight-Neutron Diffraction analysis (ToF-ND) driven by Neutron Imaging (NI) results was used primarily for the alloy characterization and to study precise areas of the statue aiming to better understand some morphological features highlighted by tomography reconstruction. Further insights, which became necessary following the data analysis of the first two experimental campaigns, were achieved by means of Thermal WB-NT followed by Neutron Activation Analysis (NAA). The goal of this work was to analyse the phase and elemental composition, to investigate the presence of specific mineral phases related to corrosionto investigate the structural stability, to verify that the sculpture is a solid cast, to determine the number of separately cast parts and investigate what type of joint was used between the various parts (e.g., mechanical joint or by applying soldering medium). Moreover, one of our goals was to exploit morphological and microstructural analysis to provide clues about the casting process such as the orientation of the mould during casting. 2. Methods To be able to answer the afore-mentioned questions, several neutron methods were applied. NI allows to investigate the interior of bulk metals in a completely non-invasive way without any pre-treatment of the statuette. Likewise, ToF-ND and NAA are both non-invasive methods and can be used to investigate the interior of such bulk objects. 2.1 Neutron imaging White Beam Neutron Tomography (WB-NT) of the entire statue was performed using the cold-neutron beamline CONRAD-2 (Kardjilov, et al., 2014 ). At the same beamline, Energy-Selective Neutron Radiography (ES-NR) was also performed to visualize the crystallinity variations over the statue. The cold WB-NT was later complemented with thermal WB-NT at the FISH beamline (Zhou, et al., 2018). WB-NT yields the 3-dimensional entire structure of the statue, very similar to CT scans used in hospitals. The 3D computer model can then be used to explore the interior of the object through the variations in grey value of the images in (virtual) computed slicing of the 3D model in any direction. With a sub-millimetre spatial resolution, it renders microstructural details of the bronze casting and is an essential tool for investigating the manufacturing methods and determining the conservation state. In the case of bronze, the thickness of the metal, the presence of fractures, gaps and defects, and the presence of porosity can be investigated (Lehmann, et al., 2010 ; Grazzi, et al., 2018; Schulz, et al., 2023 ; Salvemini, et al., 2023). 2.1.1 Cold Neutron Tomography (NT) The entire statue was investigated with NT using the cold neutron beamline CONRAD-2 of the BERII 10 MW research reactor at Helmholtz Zentrum Berlin (HZB) in Berlin, Germany. The instrumental resolution was set by using a scintillator screen of 200µm thickness and a pinhole that sets the beam divergence to L/D = 250, yielding a neutron flux of 10 7 cm − 2 s − 1 . Because the statue is larger than the neutron beam Field of View (FoV), the tomography was performed by collecting transmission images for 500 angular positions of the portion in the neutron beam, for 2 vertical positions of the statue. We also acquired 10 Dark Current (DC) images and 10 Open Beam (OB) images. In order to remove high intensity pixels generated by scintillator defect or by gamma particle the whole data set was pre-treated exploiting noise filter Remove Outliers by ImageJ software (Rasband, 2011 ; Rueden, et al., 2017). DC images were subtracted from both the raw radiographic stack and the OB image, to minimise thermal noise contribution. Then the stack was divided respect to the median value of the Open Beam images to normalise neutron beam intensity fluctuation. The two resulting projection data sets were stitched together, and the 3D model was reconstructed using the Filtered Back Projection algorithm of the Octopus Reconstruction software package (Dierick, et al., 2004 ). During the reconstruction routine, a polynomial ring filter was applied as well as the rotation axis correction and tilt correction. Notwithstanding the data reduction and filtering procedure the final slices are affected by some reconstruction artefacts. More details are reported in the Supplementary material S1 . Nonetheless, this types of reconstruction artefacts are easily recognizable, and it was therefore possible to carry out consciously the morphological and microstructural analysis of the Imaging data. The 3D volume reconstruction, segmentation and rendering were obtained using 3D Slicer 4.11 (Fedorov, et al., 2012). 2.1.2 Thermal Neutron Tomography (NT) Additional NT was performed at the FISH beam line of the research reactor at TU Delft, The Netherlands (Zhou, et al., 2018). Highly attenuating materials are visualized in higher detail by thermal neutrons than cold neutrons, as the beam hardening artefacts are less severe due to the spectral properties of the thermal neutron beamline. The stacked neutron guide of FISH provides a thermal neutron beam with a wavelength band centered on 1.59 Å (van Well, et al., 1991 ), c.f. the cold spectrum of CONRAD. In addition, the setup has slightly better L/D ratios of 325 and 277 in horizontal and vertical directions respectively, yielding a slightly improved spatial resolution of the reconstructed 3D model. Because of the limited field of view (FOV) of the beamline, measurement of the shoulder and neck volume was performed using 3 horizontal positions of the statue in the beam, extending the FOV from 80 × 140 mm 2 to 210 × 140 mm 2 , including 10 mm side by side superimposition area to correctly perform stitching. For the experiment, we used a 200 µm thick 6 LiF/ZnS scintillator yielding a 3D spatial resolution of approximately 400 µm. The data were converted to a 3D model using the same software as for the CONRAD data set. 2.1.3 Energy Selective Neutron Radiography Scan The wide neutron energy range of the CONRAD-2 beamline allows to inspect the microstructural properties of the statue. Energy-selective radiography is based on the acquisition of a series of neutron transmission images, where each image is generated by transmitted monochromatic neutron beam. This condition is achieved by using a double crystal monochromator, able to select a specific wavelength by maintaining the beam parallel to the pre-filtered conditions (Salvemini & Grazzi, 2012 ; Josic, et al., 2011 ). By performing a wavelength radiography scan, the contrast of the transmission image in crystalline areas of the sample, changes due to the so-called Bragg cut-off. In fact, for each crystalline phase in the bronze, depending on its lattice arrangement, there are characteristic neutron wavelengths at which the beam transmission suddenly increases for a tiny increase of the wavelength. From the analysis of the series of transmission images, one can infer useful details about phase distribution and relative concentration. Moreover, if there are discrepancies in the crystallographic domains microstructure with respect to the standard features of a polycrystalline material (homogeneous composition, large size grains, isotropic orientation distribution, regular rounded shape) the Bragg-edge imaging set will provide specific different attenuation coefficients. The data set of 31 transmission images were collected at wavelength steps of 0.05 Å from 3.0 to 4.5 Å. The experimental setup parameters for all neutron techniques used in this work are described below in Table 1 . Table 1 Neutron imaging experimental configuration parameter for the three experimental session. *Energy Selective Scan requires static sample that can be placed much closer to the detector, increasing the resolution. NEUTRON IMAGING Experimental Configuration Parameter White Beam Neutron Tomography @ CONRAD-2 Energy Selective Scan @ CONRAD-2 White Beam Neutron Tomography @ FISH Neutron Beam peak value ~ 0.4 nm ~ 0.4 nm 0.159 nm Field of view 300x300 mm 2 300x300 mm 2 240 × 140 mm 2 Scintillator 6 LiF/ZnS, t:200 µm 6 LiF/ZnS, t:200 µm 6 LiF/ZnS, t:200 µm Spatial resolution ~ 480 µm ~ 230 µm* ~ 400 µm L/D 250 250 H:325; V:277 #projections / radiograms 500 31 500 Acquisition time: 15 sec 200 sec 15 sec Rotation axis to scintillator distance 15 cm 6 cm 15 cm Beam modifier DCM – Double crystal monochromator ((Δλ/λ = 3%). Wavelength interval 3.0–15 Å 3.0–4.5 Å 0.7–4.1 Å Wavelength step 0.05 Å 2.2 Neutron Diffraction (ND) ND allows studying the atomic scale crystalline structure of the bulk of the statue, non-invasively. Rietveld refinement allows to obtain quantitative phase analysis and then the relative concentration of the different structural arrangement of the sample components. Moreover, by performing ToF-ND on the ENGIN-X beamline of the ISIS Neutron and Muon Source, Didcot, UK, and exploiting the high resolution collimation devices, such crystalline structures can be determined for specifically selected sub-volumes within the statue. Rietveld analysis of the ToF-ND data makes possible to obtain information of the binary concentration of copper and tin in bronze (single phase alloy for Sn wt% less than 10%), lead concentration, presence and amount of non-metal mineralization phases, presence, and distribution of residual strain, intra-granular microstructural strain, domain size and grain orientation texture index. Experimental data were collected for a selection of 21 sub-volumes of 2x2x2 mm 2 , using a neutron wavelength band of 0.5–6 Å and 2 detector banks positioned at +/-90° (2θ) scattering angle. Data Analysis was carried out exploiting Rietveld Refinement Method using GSAS software (Toby, 2001 ; Von Dreele & Larson, 2004 ), that allows for phase characterization. Quantitative phase analysis and elemental composition were obtained exploiting of calibration curves published by Grazzi et al, 2010 (Grazzi, et al., 2010 ). 2.3 Neutron Activation Analysis (NAA) NAA was used to non-destructively determine the elemental composition of the pendant, below the corrosion layer. It is based on spectroscopy of gamma photons emitted by radioactive isotopes (Greenberg, et al., 2011 ). The radioactivity is generated during neutron irradiation and decays through photon emission with isotope-specific energy and time constant. By analysing the gamma spectrum, a quantitative elemental composition is determined, if the attenuation of neutrons and gamma photons inside the object is accounted for. The neutron irradiation was performed at the FISH beamline, which provides a neutron flux density of 6.5x10 6 n cm − 2 s − 1 . Gamma spectroscopy was done using a detector system consisting of a HPGe crystal of 26.9% relative efficiency and a DSPEC multichannel analyser providing 8192 channels spectra with energy ranging from 200keV to 3600 keV. The Shiva’s chest area was irradiated at the FISH beamline for 22.5 h to ensure that sufficient numbers of Au and Ag atoms (potential components of the pendant) would be activated to obtain a measurement uncertainty less than 1%. Activation gamma spectra were measured 6 days after irradiation; the distance from the detector surface to the pendant surface was 3 cm. 3. Results and discussions In this section, the results will be presented and discussed, they are not organized according to the used analytical techniques, but according to the type of information they can provide: the morphological / microstructural study of the artefact, the composition of the alloy, the “reconstruction” of the manufacturing method used to produce the statuette. 3.1 General morphological description The WB-NT reconstruction confirms that both the figurine and the halo are solid cast. The pedestal is revealed to be a complex hollow structure (Fig. 2 ). The housing for the halo pins on the side of the square base allows for a mechanical connection: the use of a small amount of hard solder material (Giumlia-Mair, 2012 ; Azéma, et al., 2017) for this joint cannot be completely ruled out, as there are some points of interconnection between the pins and the wall of the brackets. The contact points in some cases can be identified as earthy concretions showing a lower grey value than the metal, while in specific points the presence of material sharing the same grey tone as the metal is evident. Mineralization phases are certainly present in the interstices left in the pin housing (see Supplementary material S2 ). Despite some reconstruction artefacts, such as shadowing effects, the alloy appears homogeneous for the pedestal, the Shiva figurine, and the halo; in fact, the three sections of the statue have relatively similar composition as reported by the ToF-ND compositional analysis (see paragraph 3.2 Alloy Characterization) Fig. 9 and Table 2 ). In the Shiva figurine, widespread ubiquitous porosity can be observed (Fig. 3 ): the pores have a rather varied size distribution ranging in size of several hundred µm (500–1000 µm Ø). Considering the spatial resolution limit for cold NT of 480 µm, it seems that neither the halo nor the pedestal is affected by strong porosity. The statuette is in a good state of conservation considering that it is an archaeological artefact, both from a structural point of view and from the corrosion of the alloy. In the whole artefact, there are no significant fractures except for a single 16 mm long crack inside the belly of the statue, which is likely due to shrinkage of the metal during cooling and does not seem to affect the structural stability of the object. Hydrogen is present in several mineralization phases and strongly interacts with the neutron, resulting particularly bright in the tomographic images. This allows us to obtain both surface and bulk mapping of the corroded areas. As can be seen in Fig. 3 , the presence of mineralized phases is limited to the surface and, in particular, associated with residues of concretions trapped in the undercuts, or in the areas of the figurine richer in finely decorated details. The same situation can be observed for the pedestal, where the most attenuating phases are identified in the junction between the halo pins and the brackets (for more detailed images, please refer to Supplementary material S2 ). ToF-ND phase analysis allowed us to identify and quantify some of the main copper alloy alteration products (see Fig. 4 for the inspection locations of ToF-ND analysis). Cuprite is present in low concentrations exceeding 1 wt% only in two analysed measurement areas; nantokite, which can be an indication of active corrosion, is present in only 4 areas of the 21 investigated ranging from 0.1–0.9 wt%. Other phases suggesting active corrosion such as paratacamite and atacamite were not found. Consequently, it seems that the bulk of the statue is not affected by active corrosion. Chalcocite has not been identified: the undetectability of this phase does not exclude its presence in quantities below the detection limit (0.1 wt%) for the ToF-ND analysis. 3.2 The pedestal As described in the Introduction, the pedestal is a hollow form consisting of a square base surmounted by a semi-dome structure representing the lotus flower, from which Shiva emerges. There are many examples of statuettes of the similar typology, and many are described in the literature from an archaeological/artistic point of view, but technical studies are rare, especially of the pedestals (some known examples are described in (Craddock & Hook, 2007 ) and (Dehejia, 2021 ). Often the pedestal is described as a single piece, either mechanically mounted or cast as one with the figurine of the deity. The tomographic reconstruction highlighted some discontinuities at the height of the upper level of the square base from which "the lotus flower" originates (Fig. 5 ); these are thickenings of a few millimetres that follow the circumference of the base of the lotus flower. However, this observation is not sufficient to hypothesize that the two parts were cast separately and then assembled, indeed the discontinuities could be attributed to a joint created during the preparation of the wax model of the statuette. The protrusions of wax inside the pedestal, if not removed, could have been faithfully transferred to the mould and finally to the cast bronze (wax on wax joint). However, as seen in figures (5–7), the square base has four inward extensions directly underneath the plane supporting the lotus pedestal. The sagittal and normal sections show that these supports do not always connect perfectly with the semi-dome structure of the lotus flower but appear to directly support the top plate of the square base (Fig. 8 ) (see also the pedestal assembly hypothesis in Supplementary material S3 , Fig. S6-S8). This could support the hypothesis that the square base was cast independently from the lotus flower which could instead have been cast as a whole with the underlying plate acting as a lid for the underlying base. The two parts could have been joined by welding, and the lid with the lotus flower could have rested perfectly on the four supports. In support of this hypothesis, there are at least four examples of statuettes of the Chola period, in the collection of the Thanjavur Museum which do not have a square base but have the lotus flower connected directly to a rectangular plate (Dehejia, 2021 ). Other examples of a lotus flower cast separately from a square base can be found as well (Slaczka, et al., 2019 ; Dehejia, 2021 ). WB-NT also allowed us to study the connection system between the Shiva figurine and the pedestal. The feet of the Shiva figurine end in a round flat structure which serves as a base. The statue and the circular footplate were cast together; indeed, no solder lines are visible here. The round footplate has a finer and more compact crystalline grain, probably due to the intense cold mechanical work undergone to fit the housing into the base. To confirm that this footplate was cast together with Shiva, the microstructure at the interface between the foot and the round plate was observed. In Fig. 6 (A) and 6(B) two details of the normal section of the left foot are shown: the first image is a tomographic projection, the second a 3D reconstruction. We observe the presence of two phases: the darker one can be attributed to dendrites with higher tin content. These dendritic structures are more than 500 µm in length on average and up to 2 mm across the interface extending from the foot to the base. The solidification process of the molten alloy begins in contact with the colder walls of the mould, where a thin layer of crystals is formed, while the dendritic branches, richer in copper (the first component to solidify), propagate inwards. Subsequently, the Sn-rich branches will grow as last elements, on the dendritic structures of the first solidified volume (Scott, 1991 ). The presence of dendrites across the interface supports the hypothesis that the footplate and feet were cast together rather than soldered. Moreover, the size of these microstructural features suggests that the cooling of the melt was slow enough to allow the formation of elongated dendritic like crystals hundreds of micrometres in size. The footplate, as seen in the axial projections in Fig. 6 or in detail in Fig. 7 (see also Fig. S9 in Supplementary material S3 ), rest on the four supports within the lotus flower. The assembly appears to have occurred mechanically by placing the figurine on supports within the flower and then by cold hammering to allow part of the edge to be folded back stabilizing the figurine to the pedestal (Craddock & Hook, 2007 ). This method is a common practice in modern-day South Indian workshops. In Fig. 8 , we show the 3D segmentation of the three sections of the statuette and a possible representation of the assembly process. 3.2 Alloy characterization In order to characterize the different portions of the artefact, looking for confirmation of what the WB-NT data suggest, neutron diffraction measurements were performed at multiple locations within the statuette, each location with a gauge volume of 5 mm x 2 mm x 2 mm. Starting from an accurate determination of the lattice parameter of the Face Centered Cubic (FCC) copper alloy crystalline structure (alpha phase) it was possible to obtain the quantitative analysis of the alloy. In fact, bronze is a substitutional alloy with tin replacing some of the copper atoms, and the lattice parameter of the alloy increases as a function of tin amount with respect to the pure copper value (3.6147 Å). The tin concentration of each sample was estimated by calculating the equivalent tin content as a function of lattice parameter. The equivalent binary Cu-Sn alloy composition was determined using the calibration curves published by Grazzi et al, 2010 (Grazzi, et al., 2010 ). The results of the ToF-ND analyses are summarized in Fig. 9 and Table 2 . The bronze alloy of the entire artefact is characterized by a low tin content between 2.4–4.6 wt %, and by a lead concentration that varies widely from 2.9 wt% to 12% wt. Since lead isn't a copper alloying agent (miscibility of 0.1 wt %) and because it is the last element to solidify in a Cu-Sn and Pb system, it is forced to occupy inter-grain positions left by the solidification of the Cu-Sn alloy. Therefore, lead is present in isolated spheroidal accumulations inhomogeneously distributed within the cast metal. Furthermore, its inhomogeneity may also depend on the preparation of the alloy in the crucible (Cantini, et al., 2023; Oudbashi, et al., 2020; Hughes, et al., 1982 ). For this reason, the various portions of the statue were compared, mainly considering the differences in tin concentration, to later evaluate the differences in lead content. The halo, certainly cast separately, has an alloy with an average equivalent tin content of 4.6 wt%. The base and the Shiva figurine have very similar alloys (Tables 2 and 3 ). It is interesting to note that the base has an average Pb content of 3.3 wt%, lower than the other sections of the statuette. This could be attributed to a conscious choice to use a more fluid alloy with a lower melting point to carry out the solid cast: with these characteristics the alloy could have finely filled the details of the moulds of the most valuable portions of the artefact: Shiva figurine and its flaming halo. Table 2 ToF-ND. Concentration (% wt) of the main elements present in the alloy as derived from Rietveld refinement. The column on the right records the weight percentage content of the equivalent tin in monophasic binary alloy with copper, for each sample. Measurement area SAMPLE Cu (wt%) Er. Sn (wt%) Er. Pb (wt%) Er. Sn (wt%) Binary Er. PEDESTAL 1 93.8 0.1 2.6 0.1 3.6 0.5 2.7 0.1 2 94.1 0.1 2.9 0.1 3 0.9 3.0 0.1 3 93.5 0.1 2.8 0.1 3.7 0.5 2.9 0.1 4 94.6 0.1 2.5 0.1 2.9 0.4 2.6 0.1 RIGHT LEG 5 88.2 0.1 3 0.1 8.8 1.4 3.3 0.1 6 92.2 0.1 2.5 0.1 5.3 1.1 2.6 0.1 7 86.1 0.1 2.7 0.1 11.2 1.6 3.0 0.1 HEAD 8 94.1 0.2 3 0.2 2.9 1.3 3.1 0.2 9 90.6 0.1 3.1 0.1 6.3 0.7 3.3 0.1 10 90.6 0.1 3.4 0.1 6 0.6 3.6 0.1 11 89.8 0.1 3 0.1 7.2 1.2 3.2 0.1 12 89.7 0.1 3.2 0.1 7.1 0.7 3.4 0.1 HALO 13 88.1 0.1 4.2 0.1 7.7 0.5 4.6 0.1 14 87.7 0.1 4.2 0.1 8.1 0.5 4.6 0.1 15 87.5 0.1 4.1 0.1 8.4 0.4 4.5 0.1 16 83.8 0.1 4.2 0.1 12 0.9 4.8 0.1 HEAD (flower, nape) 17 90.6 0.1 3.2 0.1 6.2 1.1 3.4 0.1 18 88.1 0.1 2.9 0.1 9 1 3.2 0.1 RIGHT ARM 19 88.7 0.1 2.8 0.1 8.5 0.9 3.1 0.1 20 93.5 0.1 3 0.1 3.5 0.9 3.1 0.1 21 91.8 0.1 2.9 0.1 5.3 0.5 3.1 0.1 Table 3 ToF-ND Alloy composition results. Average content (wt%) Average concentration (wt%) Statuette section Sn (wt%) St. dev Pb (wt%) St. dev Sn (wt%) Binary St.dev SHIVA FIGURINE 3.0 0.2 6.7 2.3 3.2 0.2 PEDESTAL ( Square ) 2.7 0.2 3.3 0.4 2.8 0.2 PEDESTAL ( Lotus ) 2.7 0.2 3.3 0.6 2.8 0.2 HALO 4.2 0.1 9.1 2.0 4.6 0.1 3.3 The pendant The figurine of Shiva wears a necklace with a small pendant which, according to visual inspection, could be made of silver (now tarnished) possibly alloyed with gold (Fig. 10 ). From the tomographic images, this decorative element stands out with a very high attenuation coefficient (the grey value is 3 times the value of the body) confirming such hypothesis since both silver and gold have a high neutron absorption cross-section ( Ag σ scatt = 5 barn; σ abs = 63 barn; Au σ scatt = 8 barn; σ abs = 99 barn). This assumption is supported by the neutron diffraction analysis, which confirms that its main constituent is Ag or Au (lattice parameter compatible with Ag-Cu or Au-Cu alloy. However, the diffraction method alone, based on lattice parameter determination as discriminating factor was not sufficient to univocally discern the composition. By performing NAA, the elemental composition of the pendant has been determined, yielding the Au and Ag concentration. The composition of the pendant has been determined, taking into account the inhomogeneity of the neutron beam and a correction for neutron self-shielding and gamma self-attenuation (Greenberg, et al., 2011 ) by simplifying the shape shown in Fig. 10 C as a “box” of the same volume. The result shows that the pendant is made of a mixture of Au and Ag with a mass ratio of 1/46 (from a manufacturing practical point of view it can be considered silver). The ToF-ND phase analysis of the pendant sample volume (point n°8) is characterized by the presence of bronze phase (alpha 1) at 36.3 wt% and by a second major phase at 63.2 wt%. The presence of phase alpha 1 of the bronze is explained as the gauge volume used for the measurements was 5mm x 2mm x 2mm and covered a volume that includes both the pendant and the surrounding bronze. In fact, phase alpha 1 has the same composition as the other points on the body of the Shiva figurine. The other phase is instead representative of the pendant and potentially it is a mixture of Ag-Cu-Au. It is not possible to reach such a lattice parameter value considering an Ag-Au mixture, since the lowest lattice parameter of this alloy is 10% higher than the one obtained. It is then necessary to include copper in the alloy and, because the Ag/Au ratio derived from NAA is 46:1, the Au contribution can be considered negligible. Considering, then, the Ag-Cu alloy (Cu cannot be measured within the pendant using NAA data), it is possible to obtain the measured lattice parameter only by performing quenching within a mould (due to its small size the casting of the pendant can be considered a spontaneous quenching) since, at equilibrium, the maximum copper value hosted in silver is much lower (max 3 at%) providing a higher lattice parameter value. The resulting composition as derived from Pearson (Pearson, 1958 ) and references within is 95.02 wt% ±0.02 and Cu 4.98 wt% ±0.02 (confirming again as silver from a practical point of view). 3.6 Casting techniques Tomography data analysis also allows some details about the manufacturing method of the artefact to be inferred. WB-NT undoubtedly shows that the statue was made in three distinct castings, using the direct lost wax technique: the Shiva statuette was cast together with the round footplate under his feet, while the base and the halo were cast independently. We tried to verify the sprue positions suggested by the literature (Craddock, 2015 ). According to the traditional South Indian statuette casting technique, the gate system is built in the wax model, at the back of the statue. The main sprues can be located between the shoulder blades or directly in the nape. The mould is then typically buried in a casting pit (Craddock, 2015 ; Levy, et al., 2007 ). As far as the mould position of the Shiva figurine is concerned, based on distribution of the pores, it is probable that the legs were oriented upwards, with the round base lying underfoot as a feeder. This is compatible with the reconstructions proposed in the literature (Craddock, 2015 ), showing a slightly tilted figurine, face down. The analysis of the set of monochromatic radiographies in the wavelength range between λ = 4.05 Å and λ = 4.20 Å, crossing the (111) Bragg reflection of the Cu-Sn face centered cubic alpha phase shows the presence of anisotropic oligocrystals (mm /sub mm scale) which are constituted by single crystal grains oriented in different spatial directions. This phenomenon is present in the whole artefact: the Shiva figurine, the pedestal, and the halo (Fig. 11 a-e) (see also Supplementary material S5 for full size images). They appear as dark spots and the phenomenon is related to a strong coherent scattering effect removing neutrons from the primary beam. Oligo-crystals can certainly be attributed to the bronze microstructure since they are no longer visible in radiographs taken at wavelengths over the (111) family of copper lattice planes (FCC), where the scattering effect of such a phase contributes no more to the attenuation (Su, et al., 2021 ). The uneven distribution of single crystal spots shown by ES -NR results for the Halo (Fig. 12 ), together with neutron diffraction results (lead distribution (Fig S.21 in Supplementary material S6 ) and related documentation of current production of bronze statuary in Tamil Nadu, allows us to formulate a hypothesis on the position of the Halo mould during casting. The presence of such oligo-crystals, and dendrites suggests that the entire statuette has undergone a carefully controlled slow cooling. This is in agreement with the custom of placing the mould underground as is still done in the casting tradition of Tamil Nadu (Craddock & Hook, 2007 ; Levy, et al., 2007 ). Figure 13 (A) shows that the presence of large size crystallites interests the entire development of the halo, but their size abruptly decreases at the height of the left forearm. Moreover, it seems that the decrease of the crystals size appears to follow a certain angle. The size of the grains is inversely related to the speed of the solidification process; small crystals implies that part of the halo must have cooled down faster. Based on the models described in the literature, and on the traditional techniques used in contemporary South Indian workshops (Fig. 13 (B)), a casting model for the Halo is proposed (Fig. 13 (C)): the mould was placed in the ground, tilted both towards the front (with the top of the arch pointing down), and sideways, with the left-side sprue only partially buried, thus exposing only that area of the mould to more rapid cooling. 4. Conclusions This work demonstrates how non-invasive analysis can yield quantitative and qualitative physical properties of the interior of large solid cast bronzes. The investigation of the Shiva statuette (AK-MAK 1291) from the Rijksmuseum Asian Collection using different neutron-based techniques allowed us to inspect the bulk composition and conservation state and to reveal crucial details of manufacturing process. The ability to study the bulk of the statue, beyond the surface concretions and corrosion layers, allows investigation of the uncorroded bulk metal at length scales down to a few hundred micrometres. Some of the main results concern the exploitation of: local composition discrepancies which support hypotheses about casting techniques; the presence of oligo-crystals in the body of the statue and in a large portion of the halo, suggesting the orientation of the mould and its cooling rate; the presence and distribution of inner porosity to evaluate the orientation of the mould during the casting; the identification of a special alloy used for the pendant inlay. Bronze artistic/archaeological artefacts fabricated by means of direct lost wax casting are unique and irreproducible objects. Therefore, even if this type of statuette has been studied from an archaeological and stylistic point of view, only a technological study of the individual artefact can shed light on the methods actually used to make it. In this work it was possible to provide a morphological and microstructural characterization of the entire statuette, describe the state of conservation of the bulk of the artefact, and to identify and quantify the main mineralization phases. Although it is a solid cast statue, the WB-NT allowed us to visualize fine several microstructural details, for instance dendrites, which allow us to confirm that the Shiva figurine was cast as a whole with the flattened round plate under his feet. The morphological analysis through the study of the axial, sagittal and normal tomographic stacks, also exploiting non orthogonal reslicing, allowed us to obtain information on the assembly of the pedestal. Furthermore, the quantitative analysis of the bronze alloy was obtained by means of ToF-ND: by combining the results of the WB-NT, NAA and ToF-ND, the composition of the pendant of the necklace was also obtained. Moreover, some clues concerning the casting method were obtained, for example the ES-NR scan showed the presence in the structure of grain oligocrystals. The size and ubiquitous distribution of these single crystals would not have been possible without careful cooling of the mould after casting. The cooling must have been slow enough to allow these crystals to grow to millimetres-scale size. Furthermore, the abrupt decrease in the size of the grains on the left side of the halo allowed us to propose a reconstruction of the position of the mould during casting. It is important to underline that all results were obtained in a completely non-invasive way. Declarations Competing interest: None of the authors have competing interests as defined by Springer, or other interests that could be perceived as influencing the findings and/or discussion reported in this article. Funding: No funding was used to support the research described in this manuscript. Author Contribution F.G., F. C. and S.C. conceptualization, F.C. original draft writing and figures preparation; N.K., F.C., F.G. and S.C., WB-NT and ESNI data acquisition (at HZB); L.v.E., Y.L., S. C., WB-NT and NAA data acquisition (at TU-Delft); S. K., F.C., F.G. and S.C., ToF-ND data acquisition (at ISIS); F.C. and F.G., WB-NT and ESNI data curation; Y.L. and L.v.E., NAA data curation; F.G., and F.C. ToF-ND data curation; F.C., F.G., L.v.E., Y.L. and S.C. editing; All authors reviewed the manuscript. References Azéma, A. et al., 2017. Pour une meilleure compréhension du procédé de soudage de la grande statuaire antique en bronze: analyses et modélisation expérimentale. Technè. La science au service de l’histoire de l’art et de la préservation des biens culturels, p. 73–83. Cantini, F. et al., 2023. The Vittoria Alata from Brescia: a combined neutron techniques and SEM-EDS approach to the study of the alloy of a bronze Roman statue. Journal of Archaeological Science: Reports, 51(104112), pp. 1-17. Craddock, P. & Hook, D., 2007. The Bronze Industries of South India: A Continuing Tradition?. Washington DC: Freer Gallery of Art. Craddock, P. T., 2015. The metal casting traditions of South Asia: continuity and innovation. Indian Journal of History of Science, 1(50), pp. 55-82. Dehejia, V., 2021. The Thief Who Stole My Heart: The Material Life of Sacred Bronzes from Chola India. s.l.:Princeton University Press. Dierick, M., Masschaele, B. & Van Hoorebeke, L., 2004. 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Salvemini, F. et al., 2023. An insight into a Shang dynasty bronze vessel by nuclear techniques. Applied Sciences, 13(3), p. 1549. Schulz, M., Lehmann, E. & Losk, A., 2023. Neutron Imaging. In: O. Akira, et al. eds. Non-Destructive Material Characterization Methods. I ed. s.l.:s.n., pp. 209-214. Scott, D. A., 1991. Metallography and microstructure of ancient and historic metals. s.l.:Getty Conservation Centre, Los Angeles. Slaczka, A., Creange, S. & Van Bennekom, J., 2019. Nataraja informed through text and technique: A study of the monumental indian bronze at the Rijksmuseum. The Rijksmuseum Bulletin, 67(1), pp. 5-29.. Srinivasan, S., 1999. Preliminary insights into the provenance of South Indian copper alloys and images using a holistic approach of comparisons of their lead isotopes and chemical composition with slags and ores. Archaeopress. Srinivasan, S., 2006. The art and science of Chola bronzes. Orientations, 37(8), pp. 46-54. Su, Y., Oikawa, K. & Shinohara, T., 2021. 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Supplementary Files SupplementaryMaterials.docx Cite Share Download PDF Status: Published Journal Publication published 28 Feb, 2024 Read the published version in Archaeological and Anthropological Sciences → Version 1 posted Editorial decision: Revision requested 20 Jan, 2024 Reviews received at journal 17 Jan, 2024 Reviewers agreed at journal 30 Dec, 2023 Reviewers invited by journal 28 Dec, 2023 Editor assigned by journal 07 Dec, 2023 Submission checks completed at journal 06 Dec, 2023 First submitted to journal 04 Dec, 2023 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-3706226","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":256622249,"identity":"07e3071d-14cf-4f47-9da7-1774dd7f03e6","order_by":0,"name":"Francesco Cantini","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAvklEQVRIiWNgGAWjYBAC9gYwJcHABmIl2AAZhLTwHACRCUCVIFZCGpBBSA9UC8giEJEGxAS1MDA//Fz4wyKPT/KN2YMHCRYMfPINhLSwGUvPSJAoZpPOMTdISCDCYfZATdI8CRKJbdI5ZhKJP4jxCwMP82+wFskzZhJE2QLUwgaxRYKHWC3MbGbWPGlALTxpZSAtPGxsCQS0sDc/vs1jU5c4v/3wNskfCXVy8s0HCFjDjOHSUTAKRsEoGAWUAwAZ2SyG1HNeNgAAAABJRU5ErkJggg==","orcid":"","institution":"Università degli Studi di Firenze (UNIFI)","correspondingAuthor":true,"submittingAuthor":false,"prefix":"","firstName":"Francesco","middleName":"","lastName":"Cantini","suffix":""},{"id":256622250,"identity":"5fb52411-c414-4ce9-a508-884767349c43","order_by":1,"name":"Sara Creange","email":"","orcid":"","institution":"Rijksmuseum","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Sara","middleName":"","lastName":"Creange","suffix":""},{"id":256622251,"identity":"f687fa8f-fc1c-4a39-90fc-52ecfb386162","order_by":2,"name":"Yueer Li","email":"","orcid":"","institution":"Technische Universiteit Delft (TU-Delft)","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Yueer","middleName":"","lastName":"Li","suffix":""},{"id":256622252,"identity":"55fbd1d4-7c2f-4561-9325-13c9fb045009","order_by":3,"name":"Lambert van Eijck","email":"","orcid":"","institution":"Technische Universiteit Delft (TU-Delft)","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Lambert","middleName":"van","lastName":"Eijck","suffix":""},{"id":256622253,"identity":"ed3cded8-1c7c-46d2-8350-60217a51dd4e","order_by":4,"name":"Nikolay Kardjilov","email":"","orcid":"","institution":"Helmholtz-Zentrum Berlin (HZB)","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Nikolay","middleName":"","lastName":"Kardjilov","suffix":""},{"id":256622254,"identity":"b0247e1d-8ae8-4300-b3b8-54c520e8a905","order_by":5,"name":"Saurabh Kabra","email":"","orcid":"","institution":"ISIS Neutron and Muon facility, STFC-UKRI","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Saurabh","middleName":"","lastName":"Kabra","suffix":""},{"id":256622255,"identity":"accc958c-76cd-41be-81a0-59e68798faac","order_by":6,"name":"Francesco Grazzi","email":"","orcid":"","institution":"Consiglio Nazionale delle Ricerche, Istituto di Fisica Applicata Nello Carrara (CNR-IFAC)","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Francesco","middleName":"","lastName":"Grazzi","suffix":""}],"badges":[],"createdAt":"2023-12-04 15:59:19","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-3706226/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-3706226/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s12520-024-01948-z","type":"published","date":"2024-02-28T15:01:20+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":47814898,"identity":"995f235b-0785-47f0-b364-ea3589599e25","added_by":"auto","created_at":"2023-12-07 19:46:48","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":2233677,"visible":true,"origin":"","legend":"\u003cp\u003eThe Shiva bronze statuette (AK-MAK-1291). Views of the artefact: front (\u003cstrong\u003eA\u003c/strong\u003e), left side (\u003cstrong\u003eB\u003c/strong\u003e), verso (\u003cstrong\u003eC\u003c/strong\u003e), right side (\u003cstrong\u003eD\u003c/strong\u003e).\u003c/p\u003e","description":"","filename":"floatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-3706226/v1/affcb639fbaa0095070aaf87.png"},{"id":47814899,"identity":"e78ab25d-4a12-4a16-b8dd-8cbe81bd2afa","added_by":"auto","created_at":"2023-12-07 19:46:48","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":822655,"visible":true,"origin":"","legend":"\u003cp\u003eShiva (AK-MAK-1291). Neutron Tomography projections. Normal slices (zx); Sagittal slices (yz); axial slices (xy).\u003c/p\u003e","description":"","filename":"floatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-3706226/v1/71d8d03675101e5950fe8a99.png"},{"id":47814337,"identity":"d2262b59-0228-41b8-bc00-dc2a6d573da2","added_by":"auto","created_at":"2023-12-07 19:38:49","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":816851,"visible":true,"origin":"","legend":"\u003cp\u003eShiva (AK-MAK-1291). Neutron Tomography normal slices of the Shiva figurine body showing morphological features: (\u003cstrong\u003eA\u003c/strong\u003e) close up details of high attenuating phases, rich in hydrogen, thickening in the superficial interstices and in the undercuts of the earrings; (\u003cstrong\u003eB\u003c/strong\u003e) a cavity, which can be interpreted as an internal fracture or a shrinkage void, present in the belly of the figurine; (\u003cstrong\u003eC\u003c/strong\u003e) Porosity ubiquitously present in Shiva's body. Gases are present within the mould before casting and furthermore develop during heating. Often the gases are able to escape through vents in the mould; otherwise, they are absorbed into the mould material or trapped in the bulk of the metal, resulting in porosity.\u003c/p\u003e","description":"","filename":"floatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-3706226/v1/5d982eedee4b5bea8b9d0658.png"},{"id":47814329,"identity":"8a3d4d2f-a8c6-4969-bbdd-a2a22a7f2d96","added_by":"auto","created_at":"2023-12-07 19:38:48","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":553957,"visible":true,"origin":"","legend":"\u003cp\u003eToF-ND mineralization phase analysis. The numbered measuring points are depicted on the 3D visualization of the reconstruction model. The concentration of each phase is reported in %wt.\u003c/p\u003e","description":"","filename":"floatimage4.png","url":"https://assets-eu.researchsquare.com/files/rs-3706226/v1/e0178bbeeb0a7937b626045e.png"},{"id":47814900,"identity":"87a486f7-c04f-4b27-a8ee-d5412af9ca9f","added_by":"auto","created_at":"2023-12-07 19:46:49","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":366470,"visible":true,"origin":"","legend":"\u003cp\u003eShiva (AK-MAK-1291). Pedestal. Neutron Tomography. Axial (xy) Projections.\u003c/p\u003e","description":"","filename":"floatimage5.png","url":"https://assets-eu.researchsquare.com/files/rs-3706226/v1/02ab8f467fbecdd763b3fa08.png"},{"id":47814331,"identity":"73b07784-5e0c-4a63-8f6c-e76b4d5dd98c","added_by":"auto","created_at":"2023-12-07 19:38:48","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":532662,"visible":true,"origin":"","legend":"\u003cp\u003eShiva (AK-MAK-1291) - pedestal details. Neutron tomography and reconstruction of the three-dimensional model. The magnification at the top right shows some dendrites that cross the round plate ending in the feet of the statue.\u003c/p\u003e","description":"","filename":"floatimage6.png","url":"https://assets-eu.researchsquare.com/files/rs-3706226/v1/ed41cdddbd527f72d5687374.png"},{"id":47814336,"identity":"9b27c96a-bb21-4cfe-a945-8e0035054d15","added_by":"auto","created_at":"2023-12-07 19:38:49","extension":"png","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":600145,"visible":true,"origin":"","legend":"\u003cp\u003eShiva (AK-MAK-1291) - pedestal joint details.\u003c/p\u003e","description":"","filename":"floatimage7.png","url":"https://assets-eu.researchsquare.com/files/rs-3706226/v1/3e7c8efa5e3375a5b10709c0.png"},{"id":47814990,"identity":"c8109819-4677-47db-99f3-1dbc4f68c4a7","added_by":"auto","created_at":"2023-12-07 19:54:49","extension":"png","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":1364555,"visible":true,"origin":"","legend":"\u003cp\u003eShiva statuette assembly of the presumed independently cast portions. 1) Hard soldering; 2) mechanical joint; 3) mechanical joint and/or hard soldering.\u003c/p\u003e","description":"","filename":"floatimage8.png","url":"https://assets-eu.researchsquare.com/files/rs-3706226/v1/d371cbf64181ee8306e33b07.png"},{"id":47814333,"identity":"a9e01809-efaf-4390-b8b2-2c10c2a9d87b","added_by":"auto","created_at":"2023-12-07 19:38:49","extension":"png","order_by":9,"title":"Figure 9","display":"","copyAsset":false,"role":"figure","size":146579,"visible":true,"origin":"","legend":"\u003cp\u003eToF-ND Alloy composition result. On the left in the figure the measurement areas positions are shown; on the right in the diagram the distribution of the lead vs tin content (wt%) is reported (for more details see Supplementary material \u003cstrong\u003eS4\u003c/strong\u003e).\u003c/p\u003e","description":"","filename":"9.png","url":"https://assets-eu.researchsquare.com/files/rs-3706226/v1/33073423e1bd438b9beef981.png"},{"id":47814335,"identity":"fc77862d-55a9-4b36-8728-cf068092a1ba","added_by":"auto","created_at":"2023-12-07 19:38:49","extension":"png","order_by":10,"title":"Figure 10","display":"","copyAsset":false,"role":"figure","size":1132688,"visible":true,"origin":"","legend":"\u003cp\u003e(\u003cstrong\u003eA\u003c/strong\u003e) Axial slice of neutron tomography model of the Shiva’s pendant from the FISH data; (\u003cstrong\u003eB\u003c/strong\u003e) Neutron tomography slice close-up detail. (\u003cstrong\u003eC\u003c/strong\u003e) 3D model of the Shiva’s pendant as used for NAA quantitative composition correction and volume calculation (\u003cstrong\u003eD\u003c/strong\u003e) Pendant position in the 3D Volume reconstruction model.\u003c/p\u003e","description":"","filename":"floatimage10.png","url":"https://assets-eu.researchsquare.com/files/rs-3706226/v1/b6a844064a830db64939895b.png"},{"id":47814991,"identity":"ac7c499d-8088-457d-b1b5-06e102fc543c","added_by":"auto","created_at":"2023-12-07 19:54:49","extension":"png","order_by":11,"title":"Figure 11","display":"","copyAsset":false,"role":"figure","size":1213488,"visible":true,"origin":"","legend":"\u003cp\u003eShiva (AK-MAK-1291) – Selected monochromatic image at 3.55 Å neutron wavelength, obtained during Energy Selective Neutron Radiography scan (for more details see Supplementary material \u003cstrong\u003eS5\u003c/strong\u003e).\u003c/p\u003e","description":"","filename":"floatimage11.png","url":"https://assets-eu.researchsquare.com/files/rs-3706226/v1/a03b6a7495baa83df441ef34.png"},{"id":47814901,"identity":"4afd7155-79f0-4c87-bef1-3e0d406a5a56","added_by":"auto","created_at":"2023-12-07 19:46:49","extension":"png","order_by":12,"title":"Figure 12","display":"","copyAsset":false,"role":"figure","size":532114,"visible":true,"origin":"","legend":"\u003cp\u003eShiva (AK-MAK-1291) - oligocrystals grain size. \u003cstrong\u003eA)\u003c/strong\u003e position of the 14 areas analysed on the halo. Within each area, the diameter of three grains was measured. In the table \u003cstrong\u003eB)\u003c/strong\u003e the average value of the oligo-crystal size is compared with the metal thickness of the relative section of the halo. \u003cstrong\u003eC)\u003c/strong\u003e Halo grain size distribution in the different part of the halo.\u003c/p\u003e","description":"","filename":"floatimage12.png","url":"https://assets-eu.researchsquare.com/files/rs-3706226/v1/f728e943c79a15ff00b1a9a8.png"},{"id":47814339,"identity":"20cccb41-cfba-4f48-b1f4-0cfef0cd73d3","added_by":"auto","created_at":"2023-12-07 19:38:49","extension":"png","order_by":13,"title":"Figure 13","display":"","copyAsset":false,"role":"figure","size":1620430,"visible":true,"origin":"","legend":"\u003cp\u003eShiva (AK-MAK-1291) - Hypothesis of positioning of the mould for casting the “Halo”: \u003cstrong\u003e(A) \u003c/strong\u003e– in blue the \"Halo\" area probably subjected to slower cooling; \u003cstrong\u003e\u0026nbsp;(B) \u003c/strong\u003e- clay moulds for decorative elements left to dry in a traditional Tamil Nadu artisan “workshop” (credit courtesy of Rijksmuseum) ; \u003cstrong\u003e(C)–\u003c/strong\u003e diagram of a possible arrangement of the mould in the ground. The mould was likely inclined with the top of the arch facing downwards (a) and rotated with one of the sprues raised above ground level so as to expose a small part of the halo (b) to fast cooling.\u003c/p\u003e","description":"","filename":"floatimage13.png","url":"https://assets-eu.researchsquare.com/files/rs-3706226/v1/375bd37a3c60db5fa37d0092.png"},{"id":51958530,"identity":"c97e6a9f-8d69-43ab-8336-d8ae6d725230","added_by":"auto","created_at":"2024-03-04 15:17:09","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":5068218,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-3706226/v1/0e3e828d-9826-4833-9e62-79aec9310680.pdf"},{"id":47814343,"identity":"3a3705a4-8276-4411-bec9-ef18120186f3","added_by":"auto","created_at":"2023-12-07 19:38:49","extension":"docx","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":10883085,"visible":true,"origin":"","legend":"","description":"","filename":"SupplementaryMaterials.docx","url":"https://assets-eu.researchsquare.com/files/rs-3706226/v1/3ce57af66048c6f50d2705e5.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Morphological and microstructural characterization of an ancient Chola bronze statuette by neutron based non-invasive techniques.","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003eThe study and the preservation of historical artefacts are grounded upon the intimate knowledge of the constituent materials and the understanding of their manufacturing methods. It is essential to have diagnostic tools capable of providing the highest amount of information with a minimum of invasiveness.\u003c/p\u003e \u003cp\u003eThe Rijksmuseum Metals conservation department initiated the technical study of a South Indian bronze \u003cem\u003eChandrasekhara\u003c/em\u003e (\u0026ldquo;the moon-crested one\u0026rdquo;, hereafter referred to as Shiva, AK-MAK-1291, c. 1000\u0026ndash;1200 A.D.) along with three other bronzes from India and Southeast Asia. The date, estimated on stylistic grounds, falls within the Chola Dynasty in South India (Srinivasan, \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e2006\u003c/span\u003e). During this period a bronze casting industry developed in the region of the Keviri river, specializing in solid-cast bronzes up to several meters tall, of a scale and quality unmatched in the rest of the world (Dehejia, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). Casting was closely linked with religious ritual, and the methods were to a certain extent codified in religious texts and passed down through generations of bronze-casting families. Descendants of the Chola casters still produce bronzes largely following the ancient methods (Levy, et al., \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e2007\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThis provides a unique opportunity to examine features found in ancient statues with reference to current local casting practice and ritual casting described in ancient texts.\u003c/p\u003e \u003cp\u003eThe Shiva (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e) is a four-armed figure standing on a pedestal and backed by a flaming halo (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e); it is owned by the Royal Society of the Friends of Asian Art (VVAK) and housed in the Rijksmuseum in Amsterdam. The statuette at 40 cm and 4.9 kg is not particularly large for a Chola bronze and was made by means of the direct lost wax casting technique. According to initial visual assessments and knowledge of current casting practice in South India (Levy, et al., \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e2007\u003c/span\u003e), it is assumed the Shiva could be cast in three separate parts that are then mechanically joined: the figure, the pedestal which consists of a rectangular base topped with a circular double lotus flower, and a flaming halo inserted into brackets at the side of the pedestal. No bulk analysis of the alloy composition had been performed prior to this work; the statue was believed to have comparable composition to typologically similar sculptures, with an alloy of nearly pure copper (Craddock \u0026amp; Hook, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e2007\u003c/span\u003e; Werner, \u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e1972\u003c/span\u003e). A different alloy is believed to have been used for the arched structure, the so-called halo. The Shiva figurine is decorated with bas-relief jewellery including bracelets, necklaces, earrings, and a ribbon. The necklace ends with a pendant which, under visual inspection, appears very dark and is suspected to be a precious metal.\u003c/p\u003e \u003cp\u003ePreliminary surface analysis by X-Ray Fluorescence (XRF) is difficult because of the presence of corrosion and soil. The surface appears mainly light green in colour, probably due to the presence of anhydrous copper sulphate, copper carbonates and copper-based silicate concretions. Below the pedestal, we can observe azurite, malachite, and cuprite. Based on qualitative XRF measurements (Olympus handheld and comparisons with other published Chola bronzes) (Craddock \u0026amp; Hook, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e2007\u003c/span\u003e; Srinivasan, \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e1999\u003c/span\u003e), the main alloy is supposed to be mostly copper with the addition of tin and lead.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eCommon X-ray non-invasive diagnostic techniques for characterizing metals, such as X-ray diffraction and imaging do not allow microstructural analysis and do not possess high power penetration in thick materials consisting of heavy elements. For this reason, optical microscopy techniques have traditionally been used - e.g., metallography - which are however highly invasive, requiring a substantial withdrawal of material from the sample. The use of neutron as an investigation probe for metallic artefacts has made it possible to have non-invasive microstructural analytical techniques. Unlike X-rays, the use of neutron allows to discern between metals with similar atomic numbers, because of large differences in the cross section among metals and a good penetration into materials, even with a thickness of several centimetres.\u003c/p\u003e \u003cp\u003eThe quality and quantity of information that can be achieved with Neutron Diffraction and Imaging techniques can provide, further supported by the interdisciplinary contribution in data interpretation, information ranging from structural and microstructural description to the analysis of the state of conservation of the artefact up to the technological process involved in its manufacturing.\u003c/p\u003e \u003cp\u003eThe thorough characterization of this statue required a multi-analytical approach, organized in three different experimental campaigns (Neutron Imaging, Neutron Diffraction and Neutron Activation Analysis) at three international facilities (2016, Helmholtz Zentrum Berlin, DE; 2019, ISIS neutron and muon source, UK; 2022, Reactor Institute TU Delft, Delft, NL).\u003c/p\u003e \u003cp\u003eNeutron Imaging (NI) analysis allows for morphological and microstructural results that reveal clues related to the casting process and the relationship among the various constituent parts of the statue (the pedestal, the halo and the Shiva figurine). Both White Beam Neutron Tomography (WB-NT) and Energy Selective Neutron Radiography (ES-NR) were exploited to achieve a complete morphological characterization as well as information about the casting techniques involved in the manufacturing of this artefact. Time of Flight-Neutron Diffraction analysis (ToF-ND) driven by Neutron Imaging (NI) results was used primarily for the alloy characterization and to study precise areas of the statue aiming to better understand some morphological features highlighted by tomography reconstruction. Further insights, which became necessary following the data analysis of the first two experimental campaigns, were achieved by means of Thermal WB-NT followed by Neutron Activation Analysis (NAA).\u003c/p\u003e \u003cp\u003eThe goal of this work was to analyse the phase and elemental composition, to investigate the presence of specific mineral phases related to corrosionto investigate the structural stability, to verify that the sculpture is a solid cast, to determine the number of separately cast parts and investigate what type of joint was used between the various parts (e.g., mechanical joint or by applying soldering medium). Moreover, one of our goals was to exploit morphological and microstructural analysis to provide clues about the casting process such as the orientation of the mould during casting.\u003c/p\u003e"},{"header":"2. Methods","content":"\u003cp\u003eTo be able to answer the afore-mentioned questions, several neutron methods were applied. NI allows to investigate the interior of bulk metals in a completely non-invasive way without any pre-treatment of the statuette. Likewise, ToF-ND and NAA are both non-invasive methods and can be used to investigate the interior of such bulk objects.\u003c/p\u003e\n\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\n\u003ch2\u003e2.1 Neutron imaging\u003c/h2\u003e\n\u003cp\u003eWhite Beam Neutron Tomography (WB-NT) of the entire statue was performed using the cold-neutron beamline CONRAD-2 (Kardjilov, et al., \u003cspan class=\"CitationRef\"\u003e2014\u003c/span\u003e). At the same beamline, Energy-Selective Neutron Radiography (ES-NR) was also performed to visualize the crystallinity variations over the statue. The cold WB-NT was later complemented with thermal WB-NT at the FISH beamline (Zhou, et al., 2018).\u003c/p\u003e\n\u003cdiv class=\"BlockQuote\"\u003e\n\u003cp\u003eWB-NT yields the 3-dimensional entire structure of the statue, very similar to CT scans used in hospitals. The 3D computer model can then be used to explore the interior of the object through the variations in grey value of the images in (virtual) computed slicing of the 3D model in any direction. With a sub-millimetre spatial resolution, it renders microstructural details of the bronze casting and is an essential tool for investigating the manufacturing methods and determining the conservation state. In the case of bronze, the thickness of the metal, the presence of fractures, gaps and defects, and the presence of porosity can be investigated (Lehmann, et al., \u003cspan class=\"CitationRef\"\u003e2010\u003c/span\u003e; Grazzi, et al., 2018; Schulz, et al., \u003cspan class=\"CitationRef\"\u003e2023\u003c/span\u003e; Salvemini, et al., 2023).\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec4\" class=\"Section3\"\u003e\n\u003ch2\u003e2.1.1 Cold Neutron Tomography (NT)\u003c/h2\u003e\n\u003cp\u003eThe entire statue was investigated with NT using the cold neutron beamline CONRAD-2 of the BERII 10 MW research reactor at Helmholtz Zentrum Berlin (HZB) in Berlin, Germany. The instrumental resolution was set by using a scintillator screen of 200\u0026micro;m thickness and a pinhole that sets the beam divergence to L/D\u0026thinsp;=\u0026thinsp;250, yielding a neutron flux of 10\u003csup\u003e7\u003c/sup\u003e cm\u003csup\u003e\u0026minus;\u0026thinsp;2\u003c/sup\u003es\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e. Because the statue is larger than the neutron beam Field of View (FoV), the tomography was performed by collecting transmission images for 500 angular positions of the portion in the neutron beam, for 2 vertical positions of the statue. We also acquired 10 Dark Current (DC) images and 10 Open Beam (OB) images. In order to remove high intensity pixels generated by scintillator defect or by gamma particle the whole data set was pre-treated exploiting noise filter Remove Outliers by ImageJ software (Rasband, \u003cspan class=\"CitationRef\"\u003e2011\u003c/span\u003e; Rueden, et al., 2017). DC images were subtracted from both the raw radiographic stack and the OB image, to minimise thermal noise contribution. Then the stack was divided respect to the median value of the Open Beam images to normalise neutron beam intensity fluctuation. The two resulting projection data sets were stitched together, and the 3D model was reconstructed using the Filtered Back Projection algorithm of the Octopus Reconstruction software package (Dierick, et al., \u003cspan class=\"CitationRef\"\u003e2004\u003c/span\u003e). During the reconstruction routine, a polynomial ring filter was applied as well as the rotation axis correction and tilt correction. Notwithstanding the data reduction and filtering procedure the final slices are affected by some reconstruction artefacts. More details are reported in the \u003cem\u003eSupplementary material\u003c/em\u003e \u003cstrong\u003eS1\u003c/strong\u003e. Nonetheless, this types of reconstruction artefacts are easily recognizable, and it was therefore possible to carry out consciously the morphological and microstructural analysis of the Imaging data. The 3D volume reconstruction, segmentation and rendering were obtained using 3D Slicer 4.11 (Fedorov, et al., 2012).\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec5\" class=\"Section3\"\u003e\n\u003ch2\u003e2.1.2 Thermal Neutron Tomography (NT)\u003c/h2\u003e\n\u003cp\u003eAdditional NT was performed at the FISH beam line of the research reactor at TU Delft, The Netherlands (Zhou, et al., 2018). Highly attenuating materials are visualized in higher detail by thermal neutrons than cold neutrons, as the beam hardening artefacts are less severe due to the spectral properties of the thermal neutron beamline. The stacked neutron guide of FISH provides a thermal neutron beam with a wavelength band centered on 1.59 \u0026Aring; (van Well, et al., \u003cspan class=\"CitationRef\"\u003e1991\u003c/span\u003e), c.f. the cold spectrum of CONRAD. In addition, the setup has slightly better L/D ratios of 325 and 277 in horizontal and vertical directions respectively, yielding a slightly improved spatial resolution of the reconstructed 3D model. Because of the limited field of view (FOV) of the beamline, measurement of the shoulder and neck volume was performed using 3 horizontal positions of the statue in the beam, extending the FOV from 80 \u0026times; 140 mm\u003csup\u003e2\u003c/sup\u003e to 210 \u0026times; 140 mm\u003csup\u003e2\u003c/sup\u003e, including 10 mm side by side superimposition area to correctly perform stitching. For the experiment, we used a 200 \u0026micro;m thick \u003csup\u003e6\u003c/sup\u003eLiF/ZnS scintillator yielding a 3D spatial resolution of approximately 400 \u0026micro;m. The data were converted to a 3D model using the same software as for the CONRAD data set.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec6\" class=\"Section3\"\u003e\n\u003ch2\u003e2.1.3 Energy Selective Neutron Radiography Scan\u003c/h2\u003e\n\u003cp\u003eThe wide neutron energy range of the CONRAD-2 beamline allows to inspect the microstructural properties of the statue. Energy-selective radiography is based on the acquisition of a series of neutron transmission images, where each image is generated by transmitted monochromatic neutron beam. This condition is achieved by using a double crystal monochromator, able to select a specific wavelength by maintaining the beam parallel to the pre-filtered conditions (Salvemini \u0026amp; Grazzi, \u003cspan class=\"CitationRef\"\u003e2012\u003c/span\u003e; Josic, et al., \u003cspan class=\"CitationRef\"\u003e2011\u003c/span\u003e). By performing a wavelength radiography scan, the contrast of the transmission image in crystalline areas of the sample, changes due to the so-called Bragg cut-off. In fact, for each crystalline phase in the bronze, depending on its lattice arrangement, there are characteristic neutron wavelengths at which the beam transmission suddenly increases for a tiny increase of the wavelength. From the analysis of the series of transmission images, one can infer useful details about phase distribution and relative concentration. Moreover, if there are discrepancies in the crystallographic domains microstructure with respect to the standard features of a polycrystalline material (homogeneous composition, large size grains, isotropic orientation distribution, regular rounded shape) the Bragg-edge imaging set will provide specific different attenuation coefficients. The data set of 31 transmission images were collected at wavelength steps of 0.05 \u0026Aring; from 3.0 to 4.5 \u0026Aring;. The experimental setup parameters for all neutron techniques used in this work are described below in Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e\n\u003cdiv class=\"gridtable\"\u003e\n\u003ctable id=\"Tab1\" border=\"1\"\u003e\u003ccaption\u003e\n\u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\n\u003cdiv class=\"CaptionContent\"\u003e\n\u003cp\u003eNeutron imaging experimental configuration parameter for the three experimental session. *Energy Selective Scan requires static sample that can be placed much closer to the detector, increasing the resolution.\u003c/p\u003e\n\u003c/div\u003e\n\u003c/caption\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth colspan=\"4\" align=\"left\"\u003e\n\u003cp\u003eNEUTRON IMAGING Experimental Configuration\u003c/p\u003e\n\u003c/th\u003e\n\u003c/tr\u003e\n\u003c/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003eParameter\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003eWhite Beam Neutron Tomography @ CONRAD-2\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003eEnergy Selective Scan @ CONRAD-2\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003eWhite Beam Neutron Tomography @ FISH\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eNeutron Beam peak value\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e~\u0026thinsp;0.4 nm\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e~\u0026thinsp;0.4 nm\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.159 nm\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eField of view\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e300x300 mm\u003csup\u003e2\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e300x300 mm\u003csup\u003e2\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e240 \u0026times; 140 mm\u003csup\u003e2\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eScintillator\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003csup\u003e6\u003c/sup\u003eLiF/ZnS, t:200 \u0026micro;m\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003csup\u003e6\u003c/sup\u003eLiF/ZnS, t:200 \u0026micro;m\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003csup\u003e6\u003c/sup\u003eLiF/ZnS, t:200 \u0026micro;m\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eSpatial resolution\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e~\u0026thinsp;480 \u0026micro;m\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e~\u0026thinsp;230 \u0026micro;m*\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e~\u0026thinsp;400 \u0026micro;m\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eL/D\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e250\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e250\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eH:325; V:277\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e#projections / radiograms\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e500\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e31\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e500\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eAcquisition time:\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e15 sec\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e200 sec\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e15 sec\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eRotation axis to scintillator distance\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e15 cm\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e6 cm\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e15 cm\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eBeam modifier\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eDCM \u0026ndash; Double crystal monochromator ((\u0026Delta;\u0026lambda;/\u0026lambda;\u0026thinsp;=\u0026thinsp;3%).\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eWavelength interval\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e3.0\u0026ndash;15 \u0026Aring;\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e3.0\u0026ndash;4.5 \u0026Aring;\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.7\u0026ndash;4.1 \u0026Aring;\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eWavelength step\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.05 \u0026Aring;\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n\u003c/div\u003e\n\u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec7\" class=\"Section2\"\u003e\n\u003ch2\u003e2.2 Neutron Diffraction (ND)\u003c/h2\u003e\n\u003cdiv class=\"BlockQuote\"\u003e\n\u003cp\u003eND allows studying the atomic scale crystalline structure of the bulk of the statue, non-invasively. Rietveld refinement allows to obtain quantitative phase analysis and then the relative concentration of the different structural arrangement of the sample components. Moreover, by performing ToF-ND on the ENGIN-X beamline of the ISIS Neutron and Muon Source, Didcot, UK, and exploiting the high resolution collimation devices, such crystalline structures can be determined for specifically selected sub-volumes within the statue. Rietveld analysis of the ToF-ND data makes possible to obtain information of the binary concentration of copper and tin in bronze (single phase alloy for Sn wt% less than 10%), lead concentration, presence and amount of non-metal mineralization phases, presence, and distribution of residual strain, intra-granular microstructural strain, domain size and grain orientation texture index. Experimental data were collected for a selection of 21 sub-volumes of 2x2x2 mm\u003csup\u003e2\u003c/sup\u003e, using a neutron wavelength band of 0.5\u0026ndash;6 \u0026Aring; and 2 detector banks positioned at +/-90\u0026deg; (2\u0026theta;) scattering angle. Data Analysis was carried out exploiting Rietveld Refinement Method using GSAS software (Toby, \u003cspan class=\"CitationRef\"\u003e2001\u003c/span\u003e; Von Dreele \u0026amp; Larson, \u003cspan class=\"CitationRef\"\u003e2004\u003c/span\u003e), that allows for phase characterization. Quantitative phase analysis and elemental composition were obtained exploiting of calibration curves published by Grazzi et al, \u003cspan class=\"CitationRef\"\u003e2010\u003c/span\u003e (Grazzi, et al., \u003cspan class=\"CitationRef\"\u003e2010\u003c/span\u003e).\u003c/p\u003e\n\u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e\n\u003ch2\u003e2.3 Neutron Activation Analysis (NAA)\u003c/h2\u003e\n\u003cp\u003eNAA was used to non-destructively determine the elemental composition of the pendant, below the corrosion layer. It is based on spectroscopy of gamma photons emitted by radioactive isotopes (Greenberg, et al., \u003cspan class=\"CitationRef\"\u003e2011\u003c/span\u003e). The radioactivity is generated during neutron irradiation and decays through photon emission with isotope-specific energy and time constant. By analysing the gamma spectrum, a quantitative elemental composition is determined, if the attenuation of neutrons and gamma photons inside the object is accounted for.\u003c/p\u003e\n\u003cp\u003eThe neutron irradiation was performed at the FISH beamline, which provides a neutron flux density of 6.5x10\u003csup\u003e6\u003c/sup\u003e n cm\u003csup\u003e\u0026minus;\u0026thinsp;2\u003c/sup\u003e s\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e. Gamma spectroscopy was done using a detector system consisting of a HPGe crystal of 26.9% relative efficiency and a DSPEC multichannel analyser providing 8192 channels spectra with energy ranging from 200keV to 3600 keV. The Shiva\u0026rsquo;s chest area was irradiated at the FISH beamline for 22.5 h to ensure that sufficient numbers of Au and Ag atoms (potential components of the pendant) would be activated to obtain a measurement uncertainty less than 1%. Activation gamma spectra were measured 6 days after irradiation; the distance from the detector surface to the pendant surface was 3 cm.\u003c/p\u003e\n\u003c/div\u003e"},{"header":"3. Results and discussions","content":"\u003cp\u003eIn this section, the results will be presented and discussed, they are not organized according to the used analytical techniques, but according to the type of information they can provide: the morphological / microstructural study of the artefact, the composition of the alloy, the \u0026ldquo;reconstruction\u0026rdquo; of the manufacturing method used to produce the statuette.\u003c/p\u003e\n\u003cdiv id=\"Sec10\" class=\"Section2\"\u003e\n\u003ch2\u003e3.1 General morphological description\u003c/h2\u003e\n\u003cp\u003eThe WB-NT reconstruction confirms that both the figurine and the halo are solid cast. The pedestal is revealed to be a complex hollow structure (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e). The housing for the halo pins on the side of the square base allows for a mechanical connection: the use of a small amount of hard solder material (Giumlia-Mair, \u003cspan class=\"CitationRef\"\u003e2012\u003c/span\u003e; Az\u0026eacute;ma, et al., 2017) for this joint cannot be completely ruled out, as there are some points of interconnection between the pins and the wall of the brackets. The contact points in some cases can be identified as earthy concretions showing a lower grey value than the metal, while in specific points the presence of material sharing the same grey tone as the metal is evident. Mineralization phases are certainly present in the interstices left in the pin housing (see \u003cem\u003eSupplementary material\u003c/em\u003e \u003cstrong\u003eS2\u003c/strong\u003e).\u003c/p\u003e\n\u003cp\u003eDespite some reconstruction artefacts, such as shadowing effects, the alloy appears homogeneous for the pedestal, the Shiva figurine, and the halo; in fact, the three sections of the statue have relatively similar composition as reported by the ToF-ND compositional analysis (see paragraph 3.2 Alloy Characterization) Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e9\u003c/span\u003e and Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e). In the Shiva figurine, widespread ubiquitous porosity can be observed (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e): the pores have a rather varied size distribution ranging in size of several hundred \u0026micro;m (500\u0026ndash;1000 \u0026micro;m \u0026Oslash;). Considering the spatial resolution limit for cold NT of 480 \u0026micro;m, it seems that neither the halo nor the pedestal is affected by strong porosity.\u003c/p\u003e\n\u003cp\u003eThe statuette is in a good state of conservation considering that it is an archaeological artefact, both from a structural point of view and from the corrosion of the alloy. In the whole artefact, there are no significant fractures except for a single 16 mm long crack inside the belly of the statue, which is likely due to shrinkage of the metal during cooling and does not seem to affect the structural stability of the object.\u003c/p\u003e\n\u003cp\u003eHydrogen is present in several mineralization phases and strongly interacts with the neutron, resulting particularly bright in the tomographic images. This allows us to obtain both surface and bulk mapping of the corroded areas. As can be seen in Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e, the presence of mineralized phases is limited to the surface and, in particular, associated with residues of concretions trapped in the undercuts, or in the areas of the figurine richer in finely decorated details.\u003c/p\u003e\n\u003cp\u003eThe same situation can be observed for the pedestal, where the most attenuating phases are identified in the junction between the halo pins and the brackets (for more detailed images, please refer to \u003cem\u003eSupplementary material\u003c/em\u003e \u003cstrong\u003eS2\u003c/strong\u003e). ToF-ND phase analysis allowed us to identify and quantify some of the main copper alloy alteration products (see Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e4\u003c/span\u003e for the inspection locations of ToF-ND analysis). Cuprite is present in low concentrations exceeding 1 wt% only in two analysed measurement areas; nantokite, which can be an indication of active corrosion, is present in only 4 areas of the 21 investigated ranging from 0.1\u0026ndash;0.9 wt%. Other phases suggesting active corrosion such as paratacamite and atacamite were not found. Consequently, it seems that the bulk of the statue is not affected by active corrosion.\u003c/p\u003e\n\u003cp\u003eChalcocite has not been identified: the undetectability of this phase does not exclude its presence in quantities below the detection limit (0.1 wt%) for the ToF-ND analysis.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e\n\u003ch2\u003e3.2 The pedestal\u003c/h2\u003e\n\u003cp\u003eAs described in the Introduction, the pedestal is a hollow form consisting of a square base surmounted by a semi-dome structure representing the lotus flower, from which Shiva emerges. There are many examples of statuettes of the similar typology, and many are described in the literature from an archaeological/artistic point of view, but technical studies are rare, especially of the pedestals (some known examples are described in (Craddock \u0026amp; Hook, \u003cspan class=\"CitationRef\"\u003e2007\u003c/span\u003e) and (Dehejia, \u003cspan class=\"CitationRef\"\u003e2021\u003c/span\u003e). Often the pedestal is described as a single piece, either mechanically mounted or cast as one with the figurine of the deity. The tomographic reconstruction highlighted some discontinuities at the height of the upper level of the square base from which \"the lotus flower\" originates (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e5\u003c/span\u003e); these are thickenings of a few millimetres that follow the circumference of the base of the lotus flower. However, this observation is not sufficient to hypothesize that the two parts were cast separately and then assembled, indeed the discontinuities could be attributed to a joint created during the preparation of the wax model of the statuette. The protrusions of wax inside the pedestal, if not removed, could have been faithfully transferred to the mould and finally to the cast bronze (wax on wax joint).\u003c/p\u003e\n\u003cp\u003eHowever, as seen in figures (5\u0026ndash;7), the square base has four inward extensions directly underneath the plane supporting the lotus pedestal. The sagittal and normal sections show that these supports do not always connect perfectly with the semi-dome structure of the lotus flower but appear to directly support the top plate of the square base (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e8\u003c/span\u003e) (see also the pedestal assembly hypothesis in \u003cem\u003eSupplementary material\u003c/em\u003e \u003cstrong\u003eS3\u003c/strong\u003e, Fig. S6-S8). This could support the hypothesis that the square base was cast independently from the lotus flower which could instead have been cast as a whole with the underlying plate acting as a lid for the underlying base. The two parts could have been joined by welding, and the lid with the lotus flower could have rested perfectly on the four supports. In support of this hypothesis, there are at least four examples of statuettes of the Chola period, in the collection of the Thanjavur Museum which do not have a square base but have the lotus flower connected directly to a rectangular plate (Dehejia, \u003cspan class=\"CitationRef\"\u003e2021\u003c/span\u003e). Other examples of a lotus flower cast separately from a square base can be found as well (Slaczka, et al., \u003cspan class=\"CitationRef\"\u003e2019\u003c/span\u003e; Dehejia, \u003cspan class=\"CitationRef\"\u003e2021\u003c/span\u003e).\u003c/p\u003e\n\u003cp\u003eWB-NT also allowed us to study the connection system between the Shiva figurine and the pedestal. The feet of the Shiva figurine end in a round flat structure which serves as a base. The statue and the circular footplate were cast together; indeed, no solder lines are visible here. The round footplate has a finer and more compact crystalline grain, probably due to the intense cold mechanical work undergone to fit the housing into the base.\u003c/p\u003e\n\u003cp\u003eTo confirm that this footplate was cast together with Shiva, the microstructure at the interface between the foot and the round plate was observed. In Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e6\u003c/span\u003e(A) and 6(B) two details of the normal section of the left foot are shown: the first image is a tomographic projection, the second a 3D reconstruction. We observe the presence of two phases: the darker one can be attributed to dendrites with higher tin content. These dendritic structures are more than 500 \u0026micro;m in length on average and up to 2 mm across the interface extending from the foot to the base.\u003c/p\u003e\n\u003cp\u003eThe solidification process of the molten alloy begins in contact with the colder walls of the mould, where a thin layer of crystals is formed, while the dendritic branches, richer in copper (the first component to solidify), propagate inwards. Subsequently, the Sn-rich branches will grow as last elements, on the dendritic structures of the first solidified volume (Scott, \u003cspan class=\"CitationRef\"\u003e1991\u003c/span\u003e). The presence of dendrites across the interface supports the hypothesis that the footplate and feet were cast together rather than soldered. Moreover, the size of these microstructural features suggests that the cooling of the melt was slow enough to allow the formation of elongated dendritic like crystals hundreds of micrometres in size.\u003c/p\u003e\n\u003cp\u003eThe footplate, as seen in the axial projections in Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e6\u003c/span\u003e or in detail in Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e7\u003c/span\u003e (see also Fig. S9 in \u003cem\u003eSupplementary material\u003c/em\u003e \u003cstrong\u003eS3\u003c/strong\u003e), rest on the four supports within the lotus flower. The assembly appears to have occurred mechanically by placing the figurine on supports within the flower and then by cold hammering to allow part of the edge to be folded back stabilizing the figurine to the pedestal (Craddock \u0026amp; Hook, \u003cspan class=\"CitationRef\"\u003e2007\u003c/span\u003e). This method is a common practice in modern-day South Indian workshops.\u003c/p\u003e\n\u003cp\u003eIn Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e8\u003c/span\u003e, we show the 3D segmentation of the three sections of the statuette and a possible representation of the assembly process.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec12\" class=\"Section2\"\u003e\n\u003ch2\u003e3.2 Alloy characterization\u003c/h2\u003e\n\u003cp\u003eIn order to characterize the different portions of the artefact, looking for confirmation of what the WB-NT data suggest, neutron diffraction measurements were performed at multiple locations within the statuette, each location with a gauge volume of 5 mm x 2 mm x 2 mm.\u003c/p\u003e\n\u003cp\u003eStarting from an accurate determination of the lattice parameter of the Face Centered Cubic (FCC) copper alloy crystalline structure (alpha phase) it was possible to obtain the quantitative analysis of the alloy. In fact, bronze is a substitutional alloy with tin replacing some of the copper atoms, and the lattice parameter of the alloy increases as a function of tin amount with respect to the pure copper value (3.6147 \u0026Aring;). The tin concentration of each sample was estimated by calculating the equivalent tin content as a function of lattice parameter. The equivalent binary Cu-Sn alloy composition was determined using the calibration curves published by Grazzi et al, \u003cspan class=\"CitationRef\"\u003e2010\u003c/span\u003e (Grazzi, et al., \u003cspan class=\"CitationRef\"\u003e2010\u003c/span\u003e).\u003c/p\u003e\n\u003cp\u003eThe results of the ToF-ND analyses are summarized in Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e9\u003c/span\u003e and Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e. The bronze alloy of the entire artefact is characterized by a low tin content between 2.4\u0026ndash;4.6 wt %, and by a lead concentration that varies widely from 2.9 wt% to 12% wt.\u003c/p\u003e\n\u003cp\u003eSince lead isn't a copper alloying agent (miscibility of 0.1 wt %) and because it is the last element to solidify in a Cu-Sn and Pb system, it is forced to occupy inter-grain positions left by the solidification of the Cu-Sn alloy. Therefore, lead is present in isolated spheroidal accumulations inhomogeneously distributed within the cast metal. Furthermore, its inhomogeneity may also depend on the preparation of the alloy in the crucible (Cantini, et al., 2023; Oudbashi, et al., 2020; Hughes, et al., \u003cspan class=\"CitationRef\"\u003e1982\u003c/span\u003e). For this reason, the various portions of the statue were compared, mainly considering the differences in tin concentration, to later evaluate the differences in lead content.\u003c/p\u003e\n\u003cp\u003eThe halo, certainly cast separately, has an alloy with an average equivalent tin content of 4.6 wt%. The base and the Shiva figurine have very similar alloys (Tables\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e and \u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e). It is interesting to note that the base has an average Pb content of 3.3 wt%, lower than the other sections of the statuette. This could be attributed to a conscious choice to use a more fluid alloy with a lower melting point to carry out the solid cast: with these characteristics the alloy could have finely filled the details of the moulds of the most valuable portions of the artefact: Shiva figurine and its flaming halo.\u003c/p\u003e\n\u003cdiv class=\"gridtable\"\u003e\n\u003ctable id=\"Tab2\" border=\"1\"\u003e\u003ccaption\u003e\n\u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\n\u003cdiv class=\"CaptionContent\"\u003e\n\u003cp\u003eToF-ND. Concentration (% wt) of the main elements present in the alloy as derived from Rietveld refinement. The column on the right records the weight percentage content of the equivalent tin in monophasic binary alloy with copper, for each sample.\u003c/p\u003e\n\u003c/div\u003e\n\u003c/caption\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eMeasurement area\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eSAMPLE\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eCu (wt%)\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003eEr.\u003c/em\u003e\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eSn (wt%)\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003eEr.\u003c/em\u003e\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003ePb (wt%)\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003eEr.\u003c/em\u003e\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eSn (wt%) Binary\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003eEr.\u003c/em\u003e\u003c/p\u003e\n\u003c/th\u003e\n\u003c/tr\u003e\n\u003c/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd rowspan=\"4\" align=\"left\"\u003e\n\u003cp\u003ePEDESTAL\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e1\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e93.8\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u003cem\u003e0.1\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e2.6\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u003cem\u003e0.1\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e3.6\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003e0.5\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e2.7\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.1\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e2\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e94.1\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u003cem\u003e0.1\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e2.9\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u003cem\u003e0.1\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e3\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003e0.9\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e3.0\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.1\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e3\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e93.5\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u003cem\u003e0.1\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e2.8\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u003cem\u003e0.1\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e3.7\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003e0.5\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e2.9\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.1\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e4\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e94.6\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u003cem\u003e0.1\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e2.5\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u003cem\u003e0.1\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e2.9\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003e0.4\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e2.6\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.1\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd rowspan=\"3\" align=\"left\"\u003e\n\u003cp\u003eRIGHT LEG\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e5\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e88.2\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u003cem\u003e0.1\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e3\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u003cem\u003e0.1\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e8.8\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003e1.4\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e3.3\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.1\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e6\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e92.2\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u003cem\u003e0.1\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e2.5\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u003cem\u003e0.1\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e5.3\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003e1.1\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e2.6\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.1\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e7\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e86.1\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u003cem\u003e0.1\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e2.7\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u003cem\u003e0.1\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e11.2\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003e1.6\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e3.0\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.1\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd rowspan=\"5\" align=\"left\"\u003e\n\u003cp\u003eHEAD\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e8\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e94.1\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u003cem\u003e0.2\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e3\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u003cem\u003e0.2\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e2.9\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003e1.3\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e3.1\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.2\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e9\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e90.6\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u003cem\u003e0.1\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e3.1\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u003cem\u003e0.1\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e6.3\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003e0.7\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e3.3\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.1\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e10\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e90.6\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u003cem\u003e0.1\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e3.4\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u003cem\u003e0.1\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e6\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003e0.6\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e3.6\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.1\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e11\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e89.8\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u003cem\u003e0.1\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e3\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u003cem\u003e0.1\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e7.2\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003e1.2\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e3.2\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.1\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e12\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e89.7\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u003cem\u003e0.1\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e3.2\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u003cem\u003e0.1\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e7.1\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003e0.7\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e3.4\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.1\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd rowspan=\"4\" align=\"left\"\u003e\n\u003cp\u003eHALO\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e13\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e88.1\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u003cem\u003e0.1\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e4.2\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u003cem\u003e0.1\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e7.7\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003e0.5\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e4.6\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.1\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e14\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e87.7\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u003cem\u003e0.1\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e4.2\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u003cem\u003e0.1\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e8.1\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003e0.5\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e4.6\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.1\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e15\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e87.5\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u003cem\u003e0.1\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e4.1\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u003cem\u003e0.1\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e8.4\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003e0.4\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e4.5\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.1\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e16\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e83.8\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u003cem\u003e0.1\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e4.2\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u003cem\u003e0.1\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e12\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003e0.9\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e4.8\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.1\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eHEAD (flower, nape)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e17\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e90.6\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u003cem\u003e0.1\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e3.2\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u003cem\u003e0.1\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e6.2\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003e1.1\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e3.4\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.1\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e18\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e88.1\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u003cem\u003e0.1\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e2.9\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u003cem\u003e0.1\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e9\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003e1\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e3.2\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.1\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd rowspan=\"3\" align=\"left\"\u003e\n\u003cp\u003eRIGHT ARM\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e19\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e88.7\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u003cem\u003e0.1\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e2.8\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u003cem\u003e0.1\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e8.5\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003e0.9\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e3.1\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.1\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e20\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e93.5\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u003cem\u003e0.1\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e3\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u003cem\u003e0.1\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e3.5\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003e0.9\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e3.1\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.1\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e21\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e91.8\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u003cem\u003e0.1\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e2.9\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u003cem\u003e0.1\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e5.3\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003e0.5\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e3.1\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.1\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n\u003c/div\u003e\n\u003cdiv class=\"gridtable\"\u003e\n\u003cdiv class=\"colspec\" align=\"left\"\u003e\u0026nbsp;\u003c/div\u003e\n\u003ctable id=\"Tab3\" border=\"1\"\u003e\u003ccaption\u003e\n\u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e\n\u003cdiv class=\"CaptionContent\"\u003e\n\u003cp\u003eToF-ND Alloy composition results. Average content (wt%)\u003c/p\u003e\n\u003c/div\u003e\n\u003c/caption\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth colspan=\"7\" align=\"left\"\u003e\n\u003cp\u003eAverage concentration (wt%)\u003c/p\u003e\n\u003c/th\u003e\n\u003c/tr\u003e\n\u003c/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cstrong\u003eStatuette section\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eSn (wt%)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003eSt. dev\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003ePb (wt%)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003eSt. dev\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eSn (wt%) Binary\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003eSt.dev\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eSHIVA FIGURINE\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e3.0\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003e0.2\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e6.7\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003e2.3\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e3.2\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003e0.2\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003ePEDESTAL (\u003cem\u003eSquare\u003c/em\u003e)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e2.7\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003e0.2\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e3.3\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003e0.4\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e2.8\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003e0.2\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003ePEDESTAL (\u003cem\u003eLotus\u003c/em\u003e)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e2.7\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003e0.2\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e3.3\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003e0.6\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e2.8\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003e0.2\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eHALO\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e4.2\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003e0.1\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e9.1\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003e2.0\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e4.6\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003e0.1\u003c/em\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n\u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec13\" class=\"Section2\"\u003e\n\u003ch2\u003e3.3 The pendant\u003c/h2\u003e\n\u003cp\u003eThe figurine of Shiva wears a necklace with a small pendant which, according to visual inspection, could be made of silver (now tarnished) possibly alloyed with gold (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e10\u003c/span\u003e). From the tomographic images, this decorative element stands out with a very high attenuation coefficient (the grey value is 3 times the value of the body) confirming such hypothesis since both silver and gold have a high neutron absorption cross-section (\u003cem\u003eAg\u003c/em\u003e \u0026sigma;\u003csub\u003escatt\u003c/sub\u003e\u0026thinsp;=\u0026thinsp;5 barn; \u0026sigma;\u003csub\u003eabs\u003c/sub\u003e\u0026thinsp;=\u0026thinsp;63 barn; \u003cem\u003eAu\u003c/em\u003e \u0026sigma;\u003csub\u003escatt\u003c/sub\u003e\u0026thinsp;=\u0026thinsp;8 barn; \u0026sigma;\u003csub\u003eabs\u003c/sub\u003e\u0026thinsp;=\u0026thinsp;99 barn).\u003c/p\u003e\n\u003cp\u003eThis assumption is supported by the neutron diffraction analysis, which confirms that its main constituent is Ag or Au (lattice parameter compatible with Ag-Cu or Au-Cu alloy. However, the diffraction method alone, based on lattice parameter determination as discriminating factor was not sufficient to univocally discern the composition. By performing NAA, the elemental composition of the pendant has been determined, yielding the Au and Ag concentration. The composition of the pendant has been determined, taking into account the inhomogeneity of the neutron beam and a correction for neutron self-shielding and gamma self-attenuation (Greenberg, et al., \u003cspan class=\"CitationRef\"\u003e2011\u003c/span\u003e) by simplifying the shape shown in Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e10\u003c/span\u003eC as a \u0026ldquo;box\u0026rdquo; of the same volume. The result shows that the pendant is made of a mixture of Au and Ag with a mass ratio of 1/46 (from a manufacturing practical point of view it can be considered silver).\u003c/p\u003e\n\u003cp\u003eThe ToF-ND phase analysis of the pendant sample volume (point n\u0026deg;8) is characterized by the presence of bronze phase (alpha 1) at 36.3 wt% and by a second major phase at 63.2 wt%. The presence of phase alpha 1 of the bronze is explained as the gauge volume used for the measurements was 5mm x 2mm x 2mm and covered a volume that includes both the pendant and the surrounding bronze. In fact, phase alpha 1 has the same composition as the other points on the body of the Shiva figurine. The other phase is instead representative of the pendant and potentially it is a mixture of Ag-Cu-Au. It is not possible to reach such a lattice parameter value considering an Ag-Au mixture, since the lowest lattice parameter of this alloy is 10% higher than the one obtained. It is then necessary to include copper in the alloy and, because the Ag/Au ratio derived from NAA is 46:1, the Au contribution can be considered negligible. Considering, then, the Ag-Cu alloy (Cu cannot be measured within the pendant using NAA data), it is possible to obtain the measured lattice parameter only by performing quenching within a mould (due to its small size the casting of the pendant can be considered a spontaneous quenching) since, at equilibrium, the maximum copper value hosted in silver is much lower (max 3 at%) providing a higher lattice parameter value. The resulting composition as derived from Pearson (Pearson, \u003cspan class=\"CitationRef\"\u003e1958\u003c/span\u003e) and references within is 95.02 wt% \u0026plusmn;0.02 and Cu 4.98 wt% \u0026plusmn;0.02 (confirming again as silver from a practical point of view).\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec14\" class=\"Section2\"\u003e\n\u003ch2\u003e3.6 Casting techniques\u003c/h2\u003e\n\u003cp\u003eTomography data analysis also allows some details about the manufacturing method of the artefact to be inferred.\u003c/p\u003e\n\u003cp\u003eWB-NT undoubtedly shows that the statue was made in three distinct castings, using the direct lost wax technique: the Shiva statuette was cast together with the round footplate under his feet, while the base and the halo were cast independently. We tried to verify the sprue positions suggested by the literature (Craddock, \u003cspan class=\"CitationRef\"\u003e2015\u003c/span\u003e). According to the traditional South Indian statuette casting technique, the gate system is built in the wax model, at the back of the statue. The main sprues can be located between the shoulder blades or directly in the nape. The mould is then typically buried in a casting pit (Craddock, \u003cspan class=\"CitationRef\"\u003e2015\u003c/span\u003e; Levy, et al., \u003cspan class=\"CitationRef\"\u003e2007\u003c/span\u003e). As far as the mould position of the Shiva figurine is concerned, based on distribution of the pores, it is probable that the legs were oriented upwards, with the round base lying underfoot as a feeder. This is compatible with the reconstructions proposed in the literature (Craddock, \u003cspan class=\"CitationRef\"\u003e2015\u003c/span\u003e), showing a slightly tilted figurine, face down.\u003c/p\u003e\n\u003cp\u003eThe analysis of the set of monochromatic radiographies in the wavelength range between \u0026lambda;\u0026thinsp;=\u0026thinsp;4.05 \u0026Aring; and \u0026lambda;\u0026thinsp;=\u0026thinsp;4.20 \u0026Aring;, crossing the (111) Bragg reflection of the Cu-Sn face centered cubic alpha phase shows the presence of anisotropic oligocrystals (mm /sub mm scale) which are constituted by single crystal grains oriented in different spatial directions. This phenomenon is present in the whole artefact: the Shiva figurine, the pedestal, and the halo (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e11\u003c/span\u003ea-e) (see also \u003cem\u003eSupplementary material\u003c/em\u003e \u003cstrong\u003eS5\u003c/strong\u003e for full size images). They appear as dark spots and the phenomenon is related to a strong coherent scattering effect removing neutrons from the primary beam. Oligo-crystals can certainly be attributed to the bronze microstructure since they are no longer visible in radiographs taken at wavelengths over the (111) family of copper lattice planes (FCC), where the scattering effect of such a phase contributes no more to the attenuation (Su, et al., \u003cspan class=\"CitationRef\"\u003e2021\u003c/span\u003e).\u003c/p\u003e\n\u003cp\u003eThe uneven distribution of single crystal spots shown by ES -NR results for the Halo (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e12\u003c/span\u003e), together with neutron diffraction results (lead distribution (Fig S.21 in \u003cem\u003eSupplementary material\u003c/em\u003e \u003cstrong\u003eS6\u003c/strong\u003e) and related documentation of current production of bronze statuary in Tamil Nadu, allows us to formulate a hypothesis on the position of the Halo mould during casting.\u003c/p\u003e\n\u003cp\u003eThe presence of such oligo-crystals, and dendrites suggests that the entire statuette has undergone a carefully controlled slow cooling. This is in agreement with the custom of placing the mould underground as is still done in the casting tradition of Tamil Nadu (Craddock \u0026amp; Hook, \u003cspan class=\"CitationRef\"\u003e2007\u003c/span\u003e; Levy, et al., \u003cspan class=\"CitationRef\"\u003e2007\u003c/span\u003e).\u003c/p\u003e\n\u003cp\u003eFigure \u003cspan class=\"InternalRef\"\u003e13\u003c/span\u003e (A) shows that the presence of large size crystallites interests the entire development of the halo, but their size abruptly decreases at the height of the left forearm. Moreover, it seems that the decrease of the crystals size appears to follow a certain angle. The size of the grains is inversely related to the speed of the solidification process; small crystals implies that part of the halo must have cooled down faster. Based on the models described in the literature, and on the traditional techniques used in contemporary South Indian workshops (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e13\u003c/span\u003e (B)), a casting model for the Halo is proposed (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e13\u003c/span\u003e (C)): the mould was placed in the ground, tilted both towards the front (with the top of the arch pointing down), and sideways, with the left-side sprue only partially buried, thus exposing only that area of the mould to more rapid cooling.\u003c/p\u003e\n\u003c/div\u003e"},{"header":"4. Conclusions","content":"\u003cp\u003eThis work demonstrates how non-invasive analysis can yield quantitative and qualitative physical properties of the interior of large solid cast bronzes. The investigation of the Shiva statuette (AK-MAK 1291) from the Rijksmuseum Asian Collection using different neutron-based techniques allowed us to inspect the bulk composition and conservation state and to reveal crucial details of manufacturing process. The ability to study the bulk of the statue, beyond the surface concretions and corrosion layers, allows investigation of the uncorroded bulk metal at length scales down to a few hundred micrometres.\u003c/p\u003e \u003cp\u003eSome of the main results concern the exploitation of:\u003c/p\u003e \u003cp\u003e \u003cul\u003e \u003cli\u003e \u003cp\u003elocal composition discrepancies which support hypotheses about casting techniques;\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003ethe presence of oligo-crystals in the body of the statue and in a large portion of the halo, suggesting the orientation of the mould and its cooling rate;\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003ethe presence and distribution of inner porosity to evaluate the orientation of the mould during the casting;\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003ethe identification of a special alloy used for the pendant inlay.\u003c/p\u003e \u003c/li\u003e \u003c/ul\u003e \u003c/p\u003e \u003cp\u003eBronze artistic/archaeological artefacts fabricated by means of direct lost wax casting are unique and irreproducible objects. Therefore, even if this type of statuette has been studied from an archaeological and stylistic point of view, only a technological study of the individual artefact can shed light on the methods actually used to make it. In this work it was possible to provide a morphological and microstructural characterization of the entire statuette, describe the state of conservation of the bulk of the artefact, and to identify and quantify the main mineralization phases. Although it is a solid cast statue, the WB-NT allowed us to visualize fine several microstructural details, for instance dendrites, which allow us to confirm that the Shiva figurine was cast as a whole with the flattened round plate under his feet. The morphological analysis through the study of the axial, sagittal and normal tomographic stacks, also exploiting non orthogonal reslicing, allowed us to obtain information on the assembly of the pedestal. Furthermore, the quantitative analysis of the bronze alloy was obtained by means of ToF-ND: by combining the results of the WB-NT, NAA and ToF-ND, the composition of the pendant of the necklace was also obtained.\u003c/p\u003e \u003cp\u003eMoreover, some clues concerning the casting method were obtained, for example the ES-NR scan showed the presence in the structure of grain oligocrystals. The size and ubiquitous distribution of these single crystals would not have been possible without careful cooling of the mould after casting. The cooling must have been slow enough to allow these crystals to grow to millimetres-scale size. Furthermore, the abrupt decrease in the size of the grains on the left side of the halo allowed us to propose a reconstruction of the position of the mould during casting. It is important to underline that all results were obtained in a completely non-invasive way.\u003c/p\u003e"},{"header":"Declarations","content":" \u003ch2\u003eCompeting interest:\u003c/h2\u003e \u003cp\u003eNone of the authors have competing interests as defined by Springer, or other interests that could be perceived as influencing the findings and/or discussion reported in this article.\u003c/p\u003e \u003ch2\u003eFunding:\u003c/h2\u003e \u003cp\u003eNo funding was used to support the research described in this manuscript.\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eF.G., F. C. and S.C. conceptualization, F.C. original draft writing and figures preparation; N.K., F.C., F.G. and S.C., WB-NT and ESNI data acquisition (at HZB); L.v.E., Y.L., S. C., WB-NT and NAA data acquisition (at TU-Delft); S. K., F.C., F.G. and S.C., ToF-ND data acquisition (at ISIS); F.C. and F.G., WB-NT and ESNI data curation; Y.L. and L.v.E., NAA data curation; F.G., and F.C. ToF-ND data curation; F.C., F.G., L.v.E., Y.L. and S.C. editing; All authors reviewed the manuscript.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eAz\u0026eacute;ma, A. et al., 2017. Pour une meilleure compr\u0026eacute;hension du proc\u0026eacute;d\u0026eacute; de soudage de la grande statuaire antique en bronze: analyses et mod\u0026eacute;lisation exp\u0026eacute;rimentale. \u003cem\u003eTechn\u0026egrave;. La science au service de l\u0026rsquo;histoire de l\u0026rsquo;art et de la pr\u0026eacute;servation des biens culturels, \u003c/em\u003ep. 73\u0026ndash;83.\u003c/li\u003e\n\u003cli\u003eCantini, F. et al., 2023. 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FISH: A thermal neutron imaging station at HOR Delft. \u003cem\u003eJournal of Archaeological Science: Reports, \u003c/em\u003e20(.), pp. 369-373.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"archaeological-and-anthropological-sciences","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"aasc","sideBox":"Learn more about [Archaeological and Anthropological Sciences](http://link.springer.com/journal/12517)","snPcode":"12520","submissionUrl":"https://submission.nature.com/new-submission/12520/3","title":"Archaeological and Anthropological Sciences","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-3706226/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-3706226/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThe evolution of metallurgy is a fundamental aspect related to the knowledge of the technological level of ancient civilizations, for which the information was mostly part of an oral tradition. The ancient, preserved artefacts are the only keepers of this long gone knowledge. Most advanced non-invasive techniques provide us the key to access it. Neutron techniques are nowadays the only available approach for revealing, non-destructively and with good spatial resolution, the morphological and micro-structural properties within the whole volume of densely composed artefacts such as bronze statues. Application of neutron methods allows us to learn about ancient artefacts manufacturing methods and to study at a very detailed level the current conservation status in their different parts. As part of a research project dedicated to the study of ancient Asian bronzes led by the Rijksmuseum Metal Conservation Department, four statues from the Rijksmuseum Asian collection were analysed using non-invasive neutron techniques. In this work, we present the investigation of a South Indian bronze statuette depicting Shiva in the form of Chandrasekhara (AK-MAK-1291, c. 1000-1200 A.D.) by means of white beam tomography, energy selective neutron imaging (performed on CONRAD-2 at HZB, DE, and on FISH at TU-Delft, NL) and neutron diffraction (on ENGIN-X at ISIS, UK). The application of neutron imaging revealed the inner structure of the statue and allowed us to investigate the conservation state and potential cracking on the surface and in the bulk, to understand the interconnection of the different sections of the statue and to obtain clues about the manufacturing processes. These morphological and microstructural results were employed to guide neutron diffraction analyses that allowed us to precisely characterize compositional differences, the presence of dendrites and columnar growth peak structures related to casting. This work is a complete non-invasive analytical investigation on an archaeological bronze artefact, providing outstanding results: from a quantitative analysis of the composition and microstructure to an in-depth morphological analysis capable of unveiling details on the ancient casting methods of the statue.\u003c/p\u003e","manuscriptTitle":"Morphological and microstructural characterization of an ancient Chola bronze statuette by neutron based non-invasive techniques.","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2023-12-07 19:38:43","doi":"10.21203/rs.3.rs-3706226/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2024-01-20T22:25:26+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-01-17T06:43:03+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"9fcf2a02-a076-478c-9a08-061c663e1205","date":"2023-12-30T16:28:45+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2023-12-28T16:12:27+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2023-12-07T13:44:41+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2023-12-06T06:13:27+00:00","index":"","fulltext":""},{"type":"submitted","content":"Archaeological and Anthropological Sciences","date":"2023-12-04T15:50:24+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"archaeological-and-anthropological-sciences","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"aasc","sideBox":"Learn more about [Archaeological and Anthropological Sciences](http://link.springer.com/journal/12517)","snPcode":"12520","submissionUrl":"https://submission.nature.com/new-submission/12520/3","title":"Archaeological and Anthropological Sciences","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"be3af73a-ff91-49f1-9922-d46fa85dde3c","owner":[],"postedDate":"December 7th, 2023","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2024-03-04T15:11:47+00:00","versionOfRecord":{"articleIdentity":"rs-3706226","link":"https://doi.org/10.1007/s12520-024-01948-z","journal":{"identity":"archaeological-and-anthropological-sciences","isVorOnly":false,"title":"Archaeological and Anthropological Sciences"},"publishedOn":"2024-02-28 15:01:20","publishedOnDateReadable":"February 28th, 2024"},"versionCreatedAt":"2023-12-07 19:38:43","video":"","vorDoi":"10.1007/s12520-024-01948-z","vorDoiUrl":"https://doi.org/10.1007/s12520-024-01948-z","workflowStages":[]},"version":"v1","identity":"rs-3706226","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-3706226","identity":"rs-3706226","version":["v1"]},"buildId":"FbvkV6FR0MCFSLy54lSbu","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}