1. Quantum Electrodynamics in Strong Electromagnetic Fields: Substate Resolved K$\alpha$ Transition Energies in Helium-like Uranium
- Author
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Pfäfflein, Philip, Weber, Günter, Allgeier, Steffen, Andelkovic, Zoran, Bernitt, Sonja, Bondarev, Andrey I., Borovik, Alexander, Duval, Louis, Fleischmann, Andreas, Forstner, Oliver, Friedrich, Marvin, Glorius, Jan, Gumberidze, Alexandre, Hahn, Christoph, Hengstler, Daniel, Herdrich, Marc Oliver, Herfurth, Frank, Hillenbrand, Pierre-Michel, Kalinin, Anton, Kiffer, Markus, Kröger, Felix Martin, Kubullek, Maximilian, Kuntz, Patricia, Lestinsky, Michael, Litvinov, Yuri A., Löher, Bastian, Menz, Esther Babette, Over, Tobias, Petridis, Nikolaos, Ringleb, Stefan, Sighu, Ragandeep Singh, Spillmann, Uwe, Trotsenko, Sergiy, Warczak, Andrzej, Zhu, Binghui, Enss, Christian, and Stöhlker, Thomas
- Subjects
Physics - Atomic Physics - Abstract
Using novel metallic magnetic calorimeter detectors at the CRYRING@ESR, we recorded X-ray spectra of stored and electron cooled helium-like uranium (U$^{90+}$) with an unmatched spectral resolution of close to 90 eV. This allowed for an accurate determination of the energies of all four components of the K$\alpha$ transitions in U$^{90+}$. We find good agreement with state-of-the-art bound-state QED calculations for the strong-field regime. Our results do not support any systematic deviation between experiment and theory in helium-like systems, the presence of which was subject of intense debates in recent years.
- Published
- 2024