A technology developed by CERN to create detectors capable of counting and tracking particles also used by ESA in space missions found a very different application in the art field. InsightART, a company opened in Prague, in the Czech Republic, in ESA’s Business Incubation Center (BIC), adapted a chip based on that technology called Timepix to a device to find fake artworks and incorrectly attributed.
This family of detectors was created by CERN to be used while operating the Large Hadron Collider (LHC), currently the largest particle accelerator in the world. The need was to have a detector with sufficient sensitivity and dynamic field to trace the products of the experiments conducted. Thanks to the potential shown for applications other than particle physics, Medipix chips were created in the 1990s, now up to Medipix4, useful in fields such as astrophysics but also for some medical exams. A variant is the Timepix family, used in various experiments on the International Space Station, in an instrument of ESA’s Proba-V space probe and in other applications in different fields.
The Timepix chip uses a 256 x 256 pixel silicon sensor. Each pixel has an area of about 55 square micrometres, about half the thickness of a human hair, processes radiation and sends signals autonomously, capturing very high levels of detail. This type of sensitivity has become useful to examine artworks with an equipment much smaller than the huge synchrotrons that in the past were the only ones that could perform certain types of examinations and in a much deeper way than a normal X-ray analysis, as they can offer a separate image of each layer of pigment.
InsightART was opened to conduct much more detailed X-ray scans than normal ones by exploiting the potential of the Timepix chips. They allow to detect differences in materials showing contrasts that are impossible to detect with normal tests by measuring the different wavelengths of X-rays measured in the different layers. A full scan takes between 10 minutes and 2 hours, depending on the type and size of the work. The results allow for example to understand if the work was modified and even if it’s a fake.
The top image (courtesy InsightART) shows an example of analysis made possible thanks to InsightART. A painting called “The Crau with a View of Montmajour” has been studied for three years by the restorer Jiri Lauterkranc to try to understand if it was possible to attribute it to Vincent Van Gogh. A number of analyzes were used by InsightART which in the image are:
- The painting signed Vincent and possibly a Vincent Van Gogh, oil on canvas
- Material-sensitive X-ray radiography showing lead-dominated pigments
- Material-sensitive X-ray radiography, showing pigments dominated by zinc, chromium and cadmium
- X-ray black and white radiography
- Material-sensitive X-ray radiography of the painting showing a drawing of a female nude in the lower layers of the painting
The discovery of the drawing of a female nude added the possibility of making a comparison with the style of other drawings by Vincent Van Gogh. After all these studies, Jiri Lauterkranc became convinced that the painting was indeed made by the great painter and sent the evidence collected to the Van Gogh Foundation for final verifications.
The analysis of the various layers of pigments can also be applied to statues to obtain more information that can help to understand how many layers of pigments there are and therefore possible changes made over time. Josef Uher, cofounder of InsightART, explained that 50% of artworks could be fake or incorrectly attributed. More in-depth examinations can offer help to experts, in this case with an application of a technology created for completely different purposes.