Synchrotron X-ray Mapping of Xenon Sorption in Carbon Ink on Papyrus

X-ray imaging of hidden carbon-based inks on organic substrates remains an unsolved problem for the recovery of text from written artifacts. Collections that cannot be read without severe textual fragmentation or physical destruction include the Herculaneum papyri and mummy cartonnage, as well as isolated book scroll discoveries. Here, we propose the use of xenon sorption in regions of increased carbon concentration to differentiate ink from substrate in the X-ray imaging of these objects. A mock-up sample was placed in an aluminum vessel and exposed to xenon atmospheres at pressures up to 10 bar. Using the BESSY II synchrotron light source, we acquired a series of images to demonstrate the visibility of xenon uptake in ink particles as well as its subsequent desorption from the sample.