Neutron autoradiography
The Neutronenautoradiografie is an imaging, non-destructive method, in which the elemental composition of objects by neutron activation and subsequent autoradiography can be determined. This makes neutron autoradiography a variant of neutron activation analysis .
Applications
Using neutron autoradiography, paintings , especially old masters , as well as the phases of creation (sketches, drafts, corrections, painting processes) that are hidden under the final layer of paint can be made visible and the pigments contained therein identified.
principle
The paintings to be examined are irradiated with neutrons , which makes some atomic nuclei of the chemical elements contained in the color pigments weakly radioactive. The characteristic neutron activations of the various elements are shown in the Karlsruhe nuclide map . On average, four out of a trillion (10 12 ) atomic nuclei are converted. After the end of the neutron irradiation, these radioactive atomic nuclei emit α and β radiation , which can be detected with a sensitive X-ray film .
The intensity and half-life of the radioactive decay depends on the chemical elements contained in the color pigments. By applying X-ray films at certain intervals that depend on the half-life of the atomic nuclei, the distribution of the corresponding elements in the color pigments can be mapped. From the films placed one after the other on the painting and the simultaneous energy measurement of the γ-radiation, a comparison with X-ray images , infrared images and microscopic examination of the image area by experts allows conclusions to be drawn about the color layers. The analysis of the emitted γ-radiation then enables the identification of the radiating elements and thus also the pigments.
| Film edition | Running time after
End of activation |
On the movies
detectable elements |
|---|---|---|
| 1st film | 30 minutes to 2.5 hours | manganese |
| 2nd film | 1 day to 2 days | Copper, sodium, potassium |
| 3rd movie | 2.5 days to 6 days | Arsenic, antimony |
| 4. Film | 9 days to 40 days | Phosphorus, mercury, antimony, cobalt |
For example, manganese is found in umber and dark ocher , and copper in malachite , azurite and verdigris . Arsenic is found in smalts and mercury in cinnabar .
In cooperation with the Helmholtz Center Berlin for Materials and Energy , formerly the Hahn-Meitner-Institut Berlin, the Berlin Gemäldegalerie has been able to use neutron autoradiography to examine its complete inventory of Rembrandt images since 1985 . The results have been made available to the Rembrandt Database of the Rembrandt Research Project in The Hague.
With this new scientific method, the man with the gold helmet could be classified as not coming from Rembrandt, but assigned to his circle or a contemporary.
Individual evidence
- ^ Neutron Radiography, Proceedings of the Second World Conference Paris, France, June 16–20, 1986 Editors: John P. Barton, Gérard Farny, Jean-Louis Person, Heinz Röttger, Springer Verlag 1987
- ↑ neutron autoradiography , ColourLex
- ↑ World of Physics: Neutron Autoradiography in Art. ( Memento of the original from July 3, 2013 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ helmholtz-berlin.de: Painting research ( Memento of the original from June 17, 2013 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ Art as Science: Neutron Autoradiography and Painting Analyzes.
- ^ Rembrandt Database
- ↑ C.-O. Fischer, Claudia Laurenze, W. Leuther, K. Slusallek, Autoradiography of Oil Paintings at the Berlin Experimental Reactor (BER II), in Neutron Radiography, Editors: John P. Barton, Gérard Farny, Jean-Louis Person, Heinz Röttger, Proceedings of the Second World Conference Paris, France, June 16-20, 1986, Springer 1987.
- ^ Kaiser Friedrich Museums Association
- ↑ Jan Kelch, ed. The man with the gold helmet, a documentation of the Gemäldegalerie in cooperation with the Rathgen research laboratory SMPK and the Hahn-Meitner-Institut Berlin, Berlin 1986.
