It has long been thought that the “Madonna and Child”, a painting from a private collection in Prague, was not created by Raphael himself. Property of the popes and then part of Napoleon's war treasure, the painting changed hands several times before arriving in the Czech Republic in the 1930s.
But the painting has now been attributed to Raphael by a group of independent experts. One of the technologies that provided them with the information was a robotized and color X-ray scanner using CERN-designed chips and transferred to a Czech start-up company.
Why it's interesting. On the art market, the number of fakes or paintings attributed to the wrong artist is estimated to be between 30 and 50 per cent. In a report published in 2014, the Fine Arts Expert Institute of Geneva even estimated that over 50 per cent of the works of art it examined were either fakes or misattributed.
The technology. Since 1999, the Medipix Collaborations, bringing together 17 research institutes around CERN, has been developing new photon detectors for particle imaging. As part of Medipix 2, in 2006, it developed Timepix, a detector that combines an electronic analysis chip with a silicon X-ray sensor that charges photons.
In essence, this detector is capable of analyzing the different energy levels of each photon that has passed through the analyzed object from the X-ray source in order to transform them into electronic signals. Instead of assigning gray levels like classical X-rays, this scanner can detect different colors corresponding to the different materials, like the pigments of a painting.
The transfer of technology. Timepix chip technology is used in a wide range of applications such as the analysis of airplane wings, tubes, mining cores... It is also embedded in the International Space Station for analysing cosmic radiation. Two years ago, it enabled the first 3D and color reconstruction of a living person’s wrist.
Most of these applications are developed by CERN's partner and licensee companies, such as the New Zealand company Mars BioIngeenering in medical imaging and the Czech company Advacam in geology, medical research and art.
In 2015, Advacam created the start-up Insightart to develop color X-ray imaging applications in the analysis of art objects, like Van Gogh's drawings and Munch's paintings.
Robotics. Insightart has created a robot called RToo. It has two robotic arms, with an X-ray emitter on one side and a Timepix detector on the other in order to scan fairly large objects. The “Madonna and Child” measures two meters by two.
The Raphael project. During three days, Insightart scanned the painting of the “Madonna and Child” to obtain 11 very high definition images (245 megapixels with a resolution of 50 microns) taken at different X-ray wavelengths. This allowed new maps of the elementary composition of the painting to be drawn up.
According to Aurélie Pezous, Head of Knowledge transfer at CERN:
"It allows us to see the brushstrokes and to reconstruct the way the work was created.”
Combined with more information, such as archives and letters, it allows experts to authenticate the painting. According to the founder of Insightart, Josef Uher:
"It is obvious that the painting was carefully designed by Raphael himself with a clear vision of its final form. The results of the various analyses confirm that the work was painted by Raphael personally, without the help of his studio assistants and apprentices".
The rest. CERN technology should soon be used to analyze another painting by Raphael: “The Holy Family of Francis I” presented at the Louvre.