The Ground-State Lamb Shift in the Heaviest Hydrogen-like Ion (U91+): High-Resolution X-ray Spectroscopy at the CRYRING Electon CoolerONLINE ONLY

I will report on the preparation of the experiment E138 "The Ground State Lamb Shift in the Heaviest Hydrogen-like Ion (U91+): High Resolution X-ray Spectroscopy at the CRYRING Electron Cooler". This experiment aims at a spectroscopic precision of better than 1 eV, which is necessary to probe 2nd order QED contributions to the 1s Lamb shift in Highest-Z systems. To reach this goal we will employ novel low-temperature detectors, namely the maXs micro calorimeter developed within the SPARC Collaboration. The presentation will give a status update on the preparation of the experimental setup. Special emphasis will be given to aspects related to the special type of detector, ranging from correcting signal drifts due to temperature instabilities to the integration with the standard MBS data acquisition system of GSI. Moreover, I will present conclusions drawn from the first commissioning run with heavy ions at the x-ray spectroscopy setup at the electron cooler of CRYRING@ESR.