EPJ D Highlight - Towards better neutral beam measurements for fusion reactors
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- Published on 17 October 2025
New experiments show how a force probe can accurately track neutral particle beams, helping to improve fusion plasma stability
Neutral beam injection (NBI) is a valuable method for heating plasma inside a nuclear fusion reactor, and could be key to the success of upcoming projects including ITER. For the technique to work, however, the energy imparted by particle beams must be measured as accurately as possible. While ion beams can be tracked directly by their electric currents, chargeless neutral particles require more elaborate approaches – such as calorimetric profiling, spectroscopy, ionization-based methods.
In a new study published in EPJ D, researchers led by Thomas Trottenberg at Christian-Albrechts-University of Kiel, Germany, present a method to measure neutral beams using a device called a ‘force probe’, which directly measures the momentum transferred to a target. With initial measurements closely matching theoretical predictions, the demonstration could be an important step toward realizing nuclear fusion’s potential.
EPJD Topical Issue - Precision Physics of Simple Atomic Systems – 2024
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- Published on 02 September 2025
Topical Issue (TI), “Precision Physics of Simple Atomic Systems”, edited by Paolo Crivelli, Daniel Kienzler, Fabian Schmid, Savely Karshenboim and Vladimir Shabaev.
We are happy to present through this collection, a valuable snapshot of current trends in the precision physics of simple atomic systems and will serve as a reference for researchers exploring fundamental interactions, antimatter, and quantum structure at the highest level of precision.
EPJ D Highlight - Improving simulations of the PIII process
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- Published on 22 August 2025
New simulation approach can better account for ion dynamics in the thin outer layer of plasma – offering a better understanding of the Plasma Immersion Ion Implantation process
Plasma Immersion Ion Implantation (PIII) is a surface treatment technique where a material is immersed in plasma, then subjected to high-voltage pulses. This accelerates ions from the plasma into the material surface, altering its properties and composition in a highly controlled way. PIII is now widely used to enhance the mechanical, physical, and electrical properties of materials ranging from semiconductors to biocompatible substances. So far, however, researchers have rarely considered how its performance can be affected by the evolving dynamics of ions in the plasma ‘sheath’: the thin layer near the plasma boundary, where electrons escape more readily than ions.
Through new research published in EPJ D, Mohammadreza Sattari and Jalal Ghasemi at the University of Zanjan, Iran, present an improved approach to simulating ion dynamics within the sheath.
EPJ D Highlight - Describing resonance in multi-layered spherical particles
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- Published on 19 August 2025
New mathematical expressions make it far easier to model the resonant frequencies of multi-layer spherical particles
Multi-layered spherical particles feature an intricate relationship between their physical structure and resonant frequency. Named the ‘morphology-dependent resonance’ (MDR), this relationship is highly sensitive to a variety of properties, making it especially useful in measurement.
However, since these relationships are so complex, most existing models of MDRs will only focus on the outermost layers of these particles, severely limiting their accuracy.
Through new research published in EPJ D, Lufang Guo and colleagues at the University of Shanghai for Science and Technology have created new mathematical expressions for the MDRs of multi-layered particles, which make the relationship far easier to model.
EPJ D Roadmap - Roadmap on carbon molecular nanostructures in space
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- Published on 05 August 2025
A new Roadmap is published in EPJD
The roadmap on carbon molecular nanostructures in space contains forty contributions from leading scientists in observational astronomy, laboratory astrophysics/chemistry, spectroscopy, theoretical chemistry, astrobiology, molecular reaction dynamics, graph theory and materials science. It highlights a rapidly developing, interdisciplinary field of research that is benefiting from recent technical advances in both observational astronomy and laboratory infrastructure combined with new powerful machine learning approaches to data analysis and modelling. The rapidly expanding inventory of carbon molecular nanostructures found in space is opening up many fundamental questions concerning their origin, astrochemical relevance and significance for the origin of life. The roadmap documents the state-of-the-art in observational and laboratory studies along with the current theoretical and experimental challenges to be overcome in order to achieve a greater understanding of the physics and chemistry of cosmic carbon molecular nanostructures. New insights are being made into the properties and resilience of these fascinating molecular species that are not only of fundamental importance for understanding the chemistry of space but have wider terrestrial relevance and impact in nanotechnology and catalysis.
EPJ D Highlight - Bound and virtual states in low-energy electron and positron scattering
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- Published on 27 June 2025
New mathematical approach confirms that low-energy charged particles can briefly bind to atoms or molecules
So far, it has remained an open question whether moving charged particles can briefly form bound states with neutral atoms and molecules. In previous experiments, researchers observed enhanced positron annihilation at energies corresponding to specific vibrational modes in neutral molecules, which they interpreted as evidence that the positrons were briefly bound. Until now, however, this interpretation has not yet been corroborated through other scattering observables.
Through new research published in EPJ D, Kamil Fedus and Grzegorz Karwasz at Nicolaus Copernicus University, Poland, present a new method for estimating the energies of both bound and virtual states of low-energy charged particles from elastic scattering cross-sections. Their approach confirms previous theoretical predictions about the formation of bound and virtual states during the scattering of these particles—helping physicists better understand how the scattering process unfolds.
EPJ D: Holger Kersten appointed Editor-in-Chief
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- Published on 04 April 2025
The European Physical Journal D (EPJ D) is glad to announce that Prof. Holger Kersten (Kiel University, Germany) has been appointed as one of the Editors-in-Chief for the journal starting on January 1st, 2025.
Prof. Kersten’s experience and standing in the field will be invaluable to lead and develop the journal together with the other two Editors-in-Chief Prof. Almut Beige and Prof. Sylwia Ptasinska.
The publishers - EDP Sciences, Springer Nature, and the Italian Physical Society - wish to thank Prof. Joachim Burgdörfer for the great work and effort he demonstrated in leading the journal over the past years.
EPJ D Topical Issue - Electron and positron interactions and their applications: a tribute to Professor Michael Brunger
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- Published on 21 March 2025
Guest editors: Márcio Henrique Franco Bettega, Stephen Buckman, Dragana Maric, Sylwia Ptasinska, Ron White
The Topical issue "Electron and Positron Interactions and Their Applications" is a collection of 27 scientific contributions that honor the exceptional scientific career of our colleague, friend, and collaborator the late Professor Michael James Brunger. The contributions that have been published in this volume are related to the recent state-of-art experimental and theoretical developments and applications in the field of Atomic and Molecular Physics, which include electron, positron, positronium, and photon interactions with atoms, molecules, and crystals. This topical issue received contributions from more than eighty authors and co-authors from sixteen different countries and/or affiliated institutions. Professor Michael J. Brunger was co-author in two of these contributions. Processes such as elastic and electronic inelastic collisions, ionization, and dissociative electron attachment were investigated by different experiments and theoretical methods covering applications in biology, plasma physics, and atmospheric science.
All articles are available here and are freely accessible until 18 May 2025. For further information read the Editorial.
EPJ D Topical Issue - Atomic Spectra and Oscillator Strengths (ASOS14)
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- Published on 27 January 2025
Guest Editors: Paul Indelicato, Stefan Schippers, Alexander Kramida, Glenn Wahlgren, Lydia Tchang-Brillet
The Topical Issue (TI), “Atomic spectra and oscillator strengths”, summarises the basic and primary atomic data needed in modelling a large variety of plasmas, covering radiative properties of atoms and atomic ions in different wavelength ranges going from X-ray to infrared (IR). These data find important applications in solar or stellar atmospheres and other astrophysical plasmas, and also in laboratory plasmas, such as fusion plasmas and laser-produced plasmas, among others.
EPJ D Highlight - Discovering new details in atomic hyperfine structures
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- Published on 20 September 2024
A new approach to analysing infrared spectra reveal 20 new energy levels in the hyperfine structure of Protactinium
Since the late 1960s, the Laboratoire Aimé Cotton (LAC) in Orsay, France, has made significant progress in the classification of complex atomic spectra. These advances have been driven both by the development of Fourier transform spectroscopy, and through novel theoretical interpretations of atomic spectra.
In new research published in EPJ D, Sophie Kröger from the Berlin University of Technology and Economics carried out detailed analysis of Protactinium's infrared (IR) spectrum, revealing 20 new energy levels that were previously undetectable with earlier methods employed by the LAC. The study showcases important progress in the precision of atomic spectrum measurements, which could soon offer deeper insights into atomic structures and interactions.
