Muonic x-ray spectroscopy uses muons to obtain information about the structure of the atom and the nucleus. In muonic atoms, the energy levels of atomic orbitals are significantly more sensitive to the finite size correction. By probing these orbitals using x-ray spectroscopy, the nuclear size correction can be extracted, providing valuable input for laser spectroscopy in the form of absolute charge radii with a relative precision better than 10−3. Continuing on developments that allowed measurements on target quantities of about 5 μg, we showed the feasibility of using implanted targets. In the future, this will allow the measurement of absolute charge radii of long-lived radioactive isotopes that are not available in sufficient enrichment or large quantities. In this contribution, we shall report on the target preparation, involving high-fluence implantation, and on the preliminary results of the muX experimental campaign.

Producing novel medical radionuclides in the quantities necessary for pre-clinical and clinical use requires an ion source able to handle high ion throughputs, operated efficiently, to deliver high specific activity samples. This is only possible with the understanding of how different parameters affect the ion source performance. Offline mass separators are needed to run systematic studies that would help us to derive the laws governing those ion sources. At KU Leuven, we are refurbishing the Leuven Isotope Separator, a mass separator previously used for implantations of radioisotopes in solid-state samples and Mössbauer spectroscopy. In the past couple of years, the machine has undergone significant updates and has been adapted to integrate the target ion source units used at CERN-ISOLDE. This paper discusses the modifications to the Leuven Isotope Separator, as well as its potential as a test bench for the study of radioactive ion beams in the future.

Copper is the conventional, broadly applied anode current collector in lithium-ion batteries, because Li does not form intermetallic alloys with Cu at room temperature. Fast diffusion and trapping of lithium in copper were, however, suggested in the past, and the involved diffusion mechanisms are still not clarified. By using three complementary methods, we determine grain boundary and lattice diffusion of lithium in copper. We show that indiffusion into copper is possible not only from metallic lithium deposits at the surface but also from a Lit-containing electrolyte. Lattice diffusion (D-0= 3.9 x 10(-9) cm(2)/s; E-a = 0.68 eV) and grain boundary diffusion (D-0 = 1.5 x 10(-11) cm(2)/s; E-a = 0.36 eV) are found to be 13 orders of magnitude lower than previously published. Furthermore, for practical Li-ion battery considerations, lithium trapping in copper current collectors, which relies heavily on operating temperature and morphology, is discussed.