Terahertz pulse imaging in archaeology

Abstract

The work presented in this paper was performed at the Oriental Institute at the University of Chicago, on objects from their permanent collection: an ancient Egyptian bird mummy and three ancient Sumerian corroded copper-alloy objects. We used a portable, fiber-coupled terahertz (THz) time-domain spectroscopic imaging system, which allowed us to measure specimens in both transmission and reflection geometry, and present time- and frequency-based image modes. The results confirm earlier evidence that THz imaging can provide complementary information to that obtainable from X-ray computed tomography (XRCT) scans of mummies, giving better visualisation of low density regions. In addition, we demonstrated that THz imaging can distinguish mineralized layers in metal artifacts.

Keywords

terahertz (THz) / time-domain imaging / spectroscopy / non-destructive evaluation / archaeology

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Acknowledgements

This work was supported by the European Commission’s Seventh Framework Program CHARISMA (Grant No. 228330) and the Marie Curie Intra-European project TISCH (Grant No. 330442). The authors would also like to thank Charles A. Pelizzari—associate professor and director of medical physics in the Department of Radiation and Cellular Oncology at the University of Chicago—and Christian Wietholt—an application engineer working for visage Imaging, Inc. and developer of the Amira visualization software—for their expertise in X-ray computed tomography and imaging modes.

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2014 Higher Education Press and Springer-Verlag Berlin Heidelberg