Alpha source, especially polonium source, used outside laboratories for particle induced X-ray emission analysis e.g. of archeological or historical specimens

摘要

An alpha source comprises a trans-uranium element-containing metallic film (16) deposited on a support (18) and covered with an organic polymer layer. Preferred Features: The source includes one or more organic membranes (20, 22), which are resistant to alpha radiation, and a grating (10) of material having a low atomic number (Z is less than or equal to 8). The organic polymer layer is less than 1 (especially less than 0.5) mu m thick. The metallic layer is a less than 0.2 mu m thick layer of silver containing polonium-210 or of platinum, stainless steel or gold containing a trans-uranium element and has a surface area less than the maximum emissive surface area (17) of the support (18). A collimator (24), of copper, organic polymer or carbon, is provided at the center of the support, the support being in the form of a disc or ring preferably having a frustoconical shape.