Retrieving images from tarnished daguerreotypes using X-ray fluorescence imaging with an X-ray micro beam with tunable energy

Authors

Tsun-Kong Sham
Y. Zou Finfrock
Qunfeng Xiao
Renfei Feng
Sarah Bassnett, Western UniversityFollow

Document Type

Article

Publication Date

5-2024

Volume

67

Journal

Journal of Cultural Heritage

URL with Digital Object Identifier

https://doi.org/10.1016/j.culher.2024.02.003

Abstract

We report recent observations using a synchrotron X-ray micro-beam to retrieve images from tarnished 19th century daguerreotypes. We confirm that high quality image can always be retrieved from tarnished plates using Hg Lα XRF as long as the bulk of the image particles and their distribution remains intact. We also report results from using tunable tender X-rays (2 - 7 keV) to conduct imaging in high vacuum at energy above the Ag L-edge and the Hg M-edge, extracting images using Ag Lα and Hg Mα, respectively among others (e.g., S to track corrosion). Images obtained with the surface sensitive total electron yield (TEY) and the bulk sensitive fluorescence yield (FLY) as well as corresponding micro-XANES are reported. Flux tolerance to high intensity X-beam is also explored. These results and their implications for cultural heritage research are discussed.

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