Study of radioactive materials with synchrotron radiation

Synchrotron radiation brings 3 major improvements compared to other X-ray sources usually used in laboratories. Its high brilliance permits the study of size-reduced samples, the low divergency of the beam gives the possibility to increase the angular resolution of the diffractometer and the spectrum of the X-photons which is continuous, allows the experimenter to chose a particular wavelength. Synchrotron radiation is becoming an important tool to investigate radioactive materials particularly burnt nuclear fuels. Zircon is the corrosion product that appears on fuel clad during irradiation, the use of synchrotron radiation with the right wavelength and a discerning incidence angle has clearly shown a crystallographic change of the zircon induced by heavy ion irradiation. X-ray fluorescence induced by synchrotron radiation can give information on fission products which were till then undetected because of the lack of sensibility of previous methods. (A.C.)