Ion implantation of the electron-capture nuclide Fe for measurements by means of metallic microcalorimeters.

Precise measurements of fundamental decay data such as energies and transition probabilities of radioactive isotopes are important for the development of corresponding nuclear modelling, activity determination and various applications in science and technology. The EMPIR project PrimA-LTD -"Towards new Primary Activity standardisation methods based on Low-Temperature Detectors" - aims to measure the electron-capture decay of Fe very precisely using Metallic Microcalorimeters (MMCs) with outstandingly high energy resolution. Using a high-statistics measurement, electron-capture probabilities shall be precisely determined and higher-order effects such as electron shake-up and shake-off shall be examined with unprecedented precision.

Smooth trends in fermium charge radii and the impact of shell effects.

The quantum-mechanical nuclear-shell structure determines the stability and limits of the existence of the heaviest nuclides with large proton numbers Z ≳ 100 (refs. ). Shell effects also affect the sizes and shapes of atomic nuclei, as shown by laser spectroscopy studies in lighter nuclides.