314 citations · 2.4k across the 62 of their papers we have counts for
50 papers · 1 filter
X-ray and extreme-ultraviolet spectra from collisions of Ar and O ions with neutrals
Stepan Dobrodey, Chintan Shah, Sonja Bernitt +4
We present measurements of K-shell x-ray emission following charge exchange of fully ionized argon with various neutral gaseous targets at small collision energies inside an electr…
Enhanced One-Color-Two-Photon Resonant Ionization in Highly Charged Ions by Fine-Structure Effects
Moto Togawa, Chunhai Lyu, Chintan Shah +25
Ultraintense pulses from X-ray free-electron lasers can drive, within femtoseconds, multiple processes in the inner shells of atoms and molecules in all phases of matter. The ensui…
A cryogenic Paul trap for probing the nuclear isomeric excited state Th
Daniel Moritz, Kevin Scharl, Markus Wiesinger +16
While laser excitation of the nuclear isomeric transition in Th has been recently achieved for thorium atoms embedded in large-bandgap crystals, laser excitation and charac…
Testing inter-electronic interaction in lithium-like tin
Jonathan Morgner, Vladimir A. Yerokhin, Charlotte M. Konig +9
Magnetic moments of bound-electron systems are a sensitive tool for testing fundamental interactions. factors of lithium-like ions have been rigorously studied in recent years,…
Comprehensive Laboratory Benchmark of K-shell Dielectronic Satellites of Fe XXV-XXI Ions
Chintan Shah, Pedro Amaro, Filipe Grilo +7
We report on comprehensive laboratory studies of the K-shell dielectronic recombination (DR) resonances of Fe XXV - XXI ions that prominently contribute to the hard X-ray spectrum…
Excited-state magnetic properties of carbon-like
Lukas J. Spieß, Shuying Chen, Alexander Wilzewski +13
We measured the -factor of the excited state in ion to be with a relative uncertainty of . The magnetic field…
Hanle Effect for Lifetime Analysis: Li-like Ions
Jan Richter, Moto Togawa, José R. Crespo López-Urrutia +1
Accurate lifetime measurements of excited states of highly charged ions (HCIs) are essential for advancing diagnostics in both laboratory and astrophysical plasmas, especially in t…
Hanle effect for lifetime determinations in the soft X-ray regime
Moto Togawa, Jan Richter, Chintan Shah +16
By exciting a series of transitions in helium-like nitrogen ions with linearly polarized mono…
High-accuracy Measurements of Core-excited Transitions in Light Li-like Ions
Moto Togawa, Steffen Kühn, Chintan Shah +11
The transition energies of the two -core-excited soft X-ray lines (dubbed q and r) from to the respective upper levels an…
Measurement of differential collisional excitation cross sections for the K emission of He-like oxygen
Filipe Grilo, Chintan Shah, José Marques +3
We measure the energy-differential cross sections for collisional excitation of the soft X-ray electric-dipole K () emission from He-like oxygen (O VII), using an electro…
Natural-linewidth measurements of the 3C and 3D soft-x-ray transitions in Ni XIX
Chintan Shah, Steffen Kühn, Sonja Bernitt +15
We used the monochromatic soft-x-ray beamline P04 at the synchrotron-radiation facility PETRA III to resonantly excite the strongest transitions in neon-like Ni XIX ions, $…
Laboratory Benchmark of Dielectronic Recombination Satellites of Fe XVII
Gabriel J. Grell, Maurice A. Leutenegger, Pedro Amaro +2
We calculated cross sections for the dielectronic recombination (DR) satellite lines of Fe XVII and benchmarked our predictions with experimental cross sections of Fe XVII resonanc…
High-Precision Transition Energy Measurements of Neon-like Fe XVII Ions
Chintan Shah, Moto Togawa, Marc Botz +15
We improve by a factor of 4-20 the energy accuracy of the strongest soft X-ray transitions of Fe XVII ions by resonantly exciting them in an electron beam ion trap with a monochrom…
Narrow and ultra-narrow transitions in highly charged Xe ions as probes of fifth forces
Nils-Holger Rehbehn, Michael K. Rosner, Julian C. Berengut +4
Optical frequency metrology in atoms and ions can probe hypothetical fifth-forces between electrons and neutrons by sensing minute perturbations of the electronic wave function ind…
Stringent test of QED with hydrogenlike tin
J. Morgner, B. Tu, C. M. König +11
Inner-shell electrons naturally sense the electric field close to the nucleus, which can reach extreme values beyond for the innermost electrons. Espe…
Cold highly charged ions in a radio-frequency trap with superconducting magnetic shielding
Elwin A. Dijck, Christian Warnecke, Malte Wehrheim +12
We implement sympathetic cooling of highly charged ions (HCI) by fully enclosing a linear Paul trap within a superconducting radio-frequency resonator. A quantization magnetic fiel…
An Optical Atomic Clock Based on a Highly Charged Ion
Steven A. King, Lukas J. Spieß, Peter Micke +9
Optical atomic clocks are the most accurate measurement devices ever constructed and have found many applications in fundamental science and technology. The use of highly charged i…
New Measurement Resolves Key Astrophysical Fe XVII Oscillator Strength Problem
Steffen Kühn, Charles Cheung, Natalia S. Oreshkina +19
One of the most enduring and intensively studied problems of X-ray astronomy is the disagreement of state-of-the art theory and observations for the intensity ratio of two Fe XVII…
Comprehensive Laboratory Measurements Resolving the LMM Dielectronic Recombination Satellite Lines in Ne-like Fe XVII Ions
Filipe Grilo, Chintan Shah, Steffen K"uhn +7
We investigated experimentally and theoretically dielectronic recombination (DR) populating doubly excited configurations (LMM) in Fe XVII, the strongest channel for soft X…
Sensitivity to New Physics of Isotope Shift Studies using the Coronal Lines of Highly Charged Calcium Ions
Nils-Holger Rehbehn, Michael K. Rosner, Hendrik Bekker +8
Promising searches for new physics beyond the current Standard Model (SM) of particle physics are feasible through isotope-shift spectroscopy, which is sensitive to a hypothetical…
Algorithmic Ground-state Cooling of Weakly-Coupled Oscillators using Quantum Logic
Steven A. King, Lukas J. Spieß, Peter Micke +4
Most ions lack the fast, cycling transitions that are necessary for direct laser cooling. In most cases, they can still be cooled sympathetically through their Coulomb interaction…
An ultralow-noise superconducting radio-frequency ion trap for frequency metrology with highly charged ions
J. Stark, C. Warnecke, S. Bogen +17
We present a novel ultrastable superconducting radio-frequency (RF) ion trap realized as a combination of an RF cavity and a linear Paul trap. Its RF quadrupole mode at 34.52 MHz r…
The Heidelberg compact electron beam ion traps
P. Micke, S. Kühn, L. Buchauer +16
Electron beam ion traps (EBIT) are ideal tools for both production and study of highly charged ions (HCI). In order to reduce their construction, maintenance, and operation costs w…
Coherent laser spectroscopy of highly charged ions using quantum logic
P. Micke, T. Leopold, S. A. King +6
Precision spectroscopy of atomic systems is an invaluable tool for the advancement of our understanding of fundamental interactions and symmetries. Recently, highly charged ions (H…