Synchrotron Radiation and Cultural Heritage

So many of the conversations I have about synchrotron radiation focus on the future— on the ways in which cutting-edge research at facilities is revolutionizing science around the globe. But the extraordinary impact of our field also enables us to better understand our past, as beautifully explained with this issue’s focus on synchrotron radiation and cultural heritage. At the European Synchrotron Radiation Facility in Grenoble, the Extremely Brilliant Source (EBS) upgrade, as well as instrumental developments at new and strongly refurbished beamlines, are enabling groundbreaking capabilities in the study of natural and cultural heritage objects and materials. The BM18 beamline allows researchers to image larger and heavier samples at higher resolution and with a more efficient use of phase contrast imaging than anywhere in the world. The refurbished BM23 and ID24 XAS complex is also facilitating developments in the study of historical materials, especially for the characterization of diluted, complex, and heterogeneous materials. Two complementary XRPD-based techniques are increasingly being used by the cultural heritage community: high angular resolution X-ray powder diffraction (HR-XRPD) and micro X-ray powder diffraction (μXRPD) mapping. These two techniques were recently successfully combined to reveal different lead white qualities in old Masters paintings, as well as to identify a very unusual lead compound, plumbonacrite, in Rembrandt’s impastos. At Synchrotron SOLEIL, the application of synchrotron radiation to the study of heritage materials has been a focus from day one. The research at this facility is broadly concentrated into three categories: deciphering fossilization processes and the search for ancient biomolecules, understanding ancient societies and elaboration techniques, and determining alteration processes and developing conservation strategies. Using complementary tools and taking advantage of the tunability of the synchrotron source, scientists have been able to utilize advanced imaging techniques (especially in 3 D) to reveal unprecedented details of fossil shape, composition, and preservation of species. Especially fascinating is the use of synchrotron infrared spectroscopy to investigate varnish layers of Stradivari violins. In these experiments, the high spatial resolution of the synchrotron-IR beam allowed investigators to directly probe and identify the chemical composition of the different varnish layers and to compare them with hypotheses and traditional views, building much deeper understanding of the history of one of the world’s greatest instruments. In this issue, you’ll also find reports from the SRI 2021 meeting on synchrotron radiation instrumentation (held this year) and updates from a workshop focusing on the current landscape of state-of-the-art metrology needs for semiconductor manufacturing and associated challenges for the future of microelectronics. While these meetings were held virtually, they send a reassuring message that new techniques and research are continuing to fuel exceptional progress. This blending of past, present, and future is very much in the forefront of this issue of Synchrotron Radiation News. These articles demonstrate the truth of Albert Einstein’s famous quote: “The distinction between past, present, and future is only a stubbornly persistent illusion.” n