Application of A 10 μg tin microcalorimeter in the field of low-energy X-ray metrology

LNHB (Laboratoire National Henri Becquerel) is responsible for the French radioactivity standards and the updating of the radionuclide table containing all available atomic and nuclear data. This implies decay scheme studies which require high-energy resolution spectrometry and also activity measurements using low threshold and high detection efficiency detectors. To explore the capabilities of cryogenic detectors for low-energy X-ray metrology, there has been a collaboration with the Institut dʹAstrophysique Spatiale in order to develop a fast microcalorimeter with a tin absorber which guarantees a detection efficiency greater than 99.9% in the 1–6 keV energy range. A feasability study of a decay scheme analysis was carried out on this microcalorimeter with a 139Ce source; preliminary results on relative intensities are presented.