SPring-8, the large synchrotron radiation facility

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Analysis of Ancient Artworks Using SPring-8 (Press Release)

Release Date
18 Dec, 2013
  • BL08W (High Energy Inelastic Scattering)
– Shedding light on Origin of Sassanian Glassware -

Okayama Orient Museum
Japan Synchrotron Radiation Research Institute (JASRI)
Tokyo University of Science

Despite it is well known Sasanian glass*1 in the Shosoin Tresure Repository, such as Hakururi no wan , a facet cut glass bowl, Ruri no Tsuki, a blue glass goblet, there is no clear definition of Sasanian glass. Fluorescent X-ray analysis*2, by which trace elements contained in glassware are detected, is effective in identifying the method, date and place of manufacture of the glassware. This is because most of the trace elements contained in the glassware are heavy elements such as rare-earth elements, the contents of which largely differ depending on the area where the raw materials were obtained. The highly sensitive detection of heavy elements using high-energy X-rays gives a clue to the origin, namely, the place and date of manufacture, of the glassware.

SPring-8*3 is a high-energy synchrotron radiation source that produces high-energy X-rays and enables highly sensitive measurement of all elements including uranium. Using the high-energy X-rays of SPring-8, Ryuji Shikaku (assistant chief curator) of the Okayama Orient Museum (Director, Toshiaki Otsuka), Izumi Nakai (professor) and Yoshinari Abe (assistant professor) of the Tokyo University of Science (Chairman of the Board of Directors, Shigeru Nakane), and Naoto Yagi (coordinator), Yoshiharu Sakurai (group leader) and Masayoshi Ito (research scientist) of JASRI (President, Yoshiharu Doi) developed a technique for analyzing glassware in a nondestructive manner. This new technique enables the measurement of valuable archaeological materials and museum pieces without damaging them and will be applied to the cultural research of ancient glassware in the future.

The Okayama Orient Museum provided the materials examined in this research. The featured materials were the glassware including sherds, manufactured during the Sassanian dynasty in the period from 226 to 651 AD. The analysis at SPring-8 revealed that a large amount of heavy elements, such as rare-earth elements, is contained in the “Bowl with Pinched Decoration”, which is identified as early Sassanian glassware manufactured from the 3rd to 4th centuries on the basis of typological features. On the other hand, only a small amount of heavy elements is contained in the “Circular Facetted Bowl”, which is identified as late Sassanian glassware manufactured during the 6th to 7th centuries. Such a compositional difference reflects the difference in the raw materials of these vessels. The results of this experiment show the possibility of estimating the date of manufacture of Sassanian glassware in a nondestructive manner.

In this research, the state-of-the-art technique of synchrotron radiation analysis was used to deepen the understanding of the Shosoin Treasures, namely, to solve the mysteries of cultural assets. The results of this research make the significance and usefulness of synchrotron radiation science understandable and realistic to everyone and show that the utilization of synchrotron radiation supports a wide range of academic research. The achievements will be presented at academic conferences. In addition, many artworks and archaeological artifacts that belong to our museums will be examined and better understood using not only the fluorescent X-ray analysis but also the high-resolution X-ray imaging and high-precision X-ray diffraction at SPring-8.

<<Figures>>

Fig. 1 Measurement at SPring-8 BL08W beamline
Fig. 1 Measurement at SPring-8 BL08W beamline

Fig. 2 Measured values for two types of glass vessel with different typological features
Fig. 2 Measured values for two types of glass vessel with different typological features

Fig. 3 Measured values and literature values
Fig. 3 Measured values and literature values

<<Glossary>>
*1 Sassanian glass
Sasanian glass is the Glassware manufactured between 3rd century to 7th century. in the Mesopotamia- Iran area that was ruled by Sasanian Empire. The details of the glassware have remained unclarified because of the following reasons. Some Sasanian sites in the central Iraq, the political center of Sasanian empire, were excavated before WWII with old excavation method, those were published only interim reports until now. In addition, All the museum pieces said to be from Northern Iran were acquired from the art market in 1960’s, those were lost archaeological informations. The origins of which are unclear. Sassanian glassware was strongly influenced by Roman glassware, which was manufactured in the area around the Mediterranean Sea in the same period, and it is difficult to distinguish between these two types of glassware from only the shape of the vessels and the manufacturing and decorating techniques.

*2 Fluorescent X-ray analysis
When elements are irradiated with X-rays, the electrons in the inner shells of the atoms of elements are expelled out, creating holes that are filled by electrons from the outer shells. Fluorescent X-rays are generated by the transition of electrons from the outer to inner shells. Their wavelength corresponds to the energy difference between the inner and outer shells. Because the energy difference between the inner and outer shells is specific to each element, the energy of fluorescent X-rays is also specific to each element. Thus, the types of elements that constitute a sample can be determined by experimentally measuring the energy of the fluorescent X-rays. The concentration of the target element can be determined by measuring the intensity of the fluorescent X-rays. Each element emits high-energy (K) and low-energy (L) fluorescent X-rays specific to each element.

*3 SPring-8
A large synchrotron radiation facility that generates the highest-quality synchrotron radiation, located in Hyogo prefecture, Japan. Owned by Riken, and operated by JASRI. The nickname SPring-8 is short for Super Photon ring-8 GeV. Synchrotron radiation refers to the strong and highly oriented electron magnetic waves generated when the orbit of electrons, accelerated to a near-light speed, is bent by magnetic field. Applications of the synchrotron radiation produced by SPring-8 includes nanotechnology, biotechnology and industrial use.


For more information, please contact:
  Assistant chief curator. Ryuji Shikaku (Okayama Orient Museum)
    E-mail : mail1