Protecting Cultural Heritage
Editorial review 2026
Ancient objects have suffered the ravages of time: “Buried underground, stuck in mud, exposed to weather conditions, attacked by insects or microorganisms, these sometimes modest objects that awaken our interest require ingenuity, meticulousness and patience in order to bring them back to life in their original form”.
Gamma irradiation provides a way to preserve certain cultural heritage objects. Irradiation with gamma rays allows not only the disinfection of these objects, but also their consolidation. It is possible to stop the causes of deterioration and strengthen, through impregnation, the structure of the most damaged pieces.
Irradiation of ethnographic material
View through a window of the Art-Nucléart irradiation chamber. The cobalt-60 source rods can be seen. The window is made of lead-containing glass. Lead glass is thick enough to absorb the gamma rays from cobalt-60, allowing the operation to be observed safely. Gauges monitor the amount of irradiation received by the objects as well as their temperature and, if necessary, allow the position of the source to be modified remotely.
© CEA/Art-Nucléart
This technique is used for the conservation of cultural heritage objects in the fields of art, ethnology and archaeology. Gamma rays harden certain families of plastic materials through polymerization. The hardening occurs directly on site. This phenomenon is used to consolidate damaged objects (wood, stone) after impregnating them throughout their structure with a liquid resin.
Consolidation by gamma irradiation gives good results for objects that have spent a long time underwater and that cannot easily withstand removal from this environment. Some objects recovered from around the wreck of the Titanic have thus been preserved.
Gamma radiation, similar to X-rays, is even more penetrating. Its action affects the entire interior of the irradiated object. No hidden area escapes it. It does not produce any residual radioactivity.
Gamma radiography
In 1997, the national museums and the National Museum of Asian Arts (Guimet Museum) entrusted three precious statues of Khmer deities to the CEA department for applications of ionizing radiation at Saclay. The more penetrating gamma rays from cobalt-60, compared with X-rays, reveal the internal consolidations of one of these statuettes.
© CEA/Saclay (Department of Applications and Metrology of Ionizing Radiation)
Radiographs of statues using X-rays and gamma rays are also carried out (at much lower doses). Gamma rays offer the advantage of revealing the interior of thick and absorbing objects and of determining, for example, whether a statue has undergone restoration work.