theoretical and experimental, especially in the infrared and visible photon energy regimes. Laser systems capable of producing high intensities also at photon energies in the (soft) X-ray regime open access [...] Penning trap setup is designed in a portable fashion, such that it can be attached to existing laser systems easily. Initial measurements have been performed at the FLASH laser facility at DESY, Hamburg. Picture [...] K.C. Ballentin, Thomas Stöhlker and Manuel Vogel, Physics Reports 13, 22669 (2023) - "Resistive cooling of ions’ center-of-momentum energy in a Penning trap on milli-second time scales" , Markus Kiffer