X-ray analysis of cultural heritage at museums by using portable instruments

We have been developing a portable powder diffractometer and XRF spectrometer since 2001 jointly with two X-ray makers: i.e., Institute of X-ray Technologies Co. Ltd. and OURSTEX Co. Ltd., respectively. The instruments were brought to several museums as well as many archeological sites in Egypt, Turkey, Italy, etc. to characterize the cultural heritage and the results were reflected on their improvement. The instruments thus developed are suitable for on site analyses with enough sensitivity, accuracy, and durability. The latest version of our diffractometer (weight 15 kg) adopted Si-PIN as a detector, which enable us to obtain EDX spectrum of the sample as well as a good powder diffraction pattern with low background. The XRF spectrometer (25 kg) is equipped with SDD detector and monochromatic/white X-ray sources. Recently the Be window of the detector was replaced with MOXTEK AP3 polymer window and vacuum sample chamber was introduced to quantify Na and Mg. The instruments were brought to Archaeological Museum in Zadar, Croatia, Okayama Orient Museum and MIHO Museum in Japan. The samples are glass, pottery, metallic and stone objects dated from second millennium B.C. to modern. We have chemically characterized 109 Roman glass artifacts excavated at a Roman necropolis found in Zadar, and classified based on decolorants, impurity and vessel types. We have studied glass, faience, pottery and metal collections at the Orient Museum. The results include identification of cassiterite in glazed Islamic pottery. At MIHO museum, stone objects from China and Middle East were characterized by the diffractometer. The analyses were made as joint projects with S. Gluscevic (Archaeological Museum), R. Shikaku (Orient Museum), Y. Azuma and Y. Kuwabara (MIHO Museum). (author)