Study of the degradation of papyrus from Ancient Egypt using XRD-laminography

The objective of this proposal is to gain insight into the degradation processes taking place at the surface of illustrated papyrus from Ancient Egypt. We are investigating a series of illustrated papyrus from Champollion’s private collection, showing scenes from the Book of the Dead. Through X-ray diffraction experiments at ID22, we identified several compounds resulting from a degradation process, especially at the interface between yellow As-based and green Cu-based regions, resulting in the formation of a series of mixed As/Cu compounds. To better understand the reaction pathway leading to the formation of these degradation phases, we intend to perform X-ray diffraction mapping using a laminography approach, a technique well-suited to the 3D mapping of flat samples. In such a way, the 3D organisation of the different painted layers and degradation compounds will be retrieved in a non-invasive way.

本研究提案旨在深入解析古埃及彩绘纸莎草表面所发生的劣化过程。本次研究对象为商博良（Champollion）私人收藏的一批彩绘纸莎草，其上绘有《死者之书》中的相关场景。我们依托ID22光束线开展X射线衍射（X-ray diffraction）实验，已检测到多类由劣化过程产生的化合物，尤其在黄色含砷（As）区域与绿色含铜（Cu）区域的界面处，生成了一系列砷铜混合化合物。为更清晰地阐明此类劣化相的形成反应路径，我们计划采用分层成像（laminography）技术开展X射线衍射测绘，该技术十分适配扁平样品的三维测绘工作。通过该方案，我们将以非侵入式的方式还原不同彩绘层与劣化化合物的三维空间分布结构。