High-Precision Laser Spectroscopy of He-like C4+ Ions
Prof. Dr. Wilfried Nörtershäuser (TU Darmstadt Institut für Kernphysik)

Nuclear charge radii of radioactive isotopes are typically referenced to a stable nucleus in the isotopic chain through an atomic isotope shift measurement. In some cases, this can limit the uncertainty of the obtained charge radii of radioactive nuclei to the uncertainty of the reference measurements from elastic electron scattering or muonic atom spectroscopy. To overcome this limit in light mass nuclei like 10,11B, an all-optical approach for the charge radius determination purely from laser spectroscopy measurements and non-relativistic QED calculations was tested with the well-known nucleus of 12C through laser excitation of helium-like 12C4+ from the metastable 2 3S1 state with a lifetime of 21 ms to the 2 3P𝐽 states. The high-precision collinear laser spectroscopy of 12C4+ has been performed at the Collinear Apparatus for Laser Spectroscopy and Applied Physics (COALA) at at TU Darmstadt in the Institute of Nuclear Physics and meanwhile extended to 13C4+.

I will give an overview of the project and present the results including the extracted all-optical nuclear charge radius of 12C. An outlook on planned measurements at COALA and a potential application on short-lived isotopes at ISOLDE will be provided.

This project is supported by DFG (Project-ID 279384907 - SFB 1245).