EPJ D Highlight - Improving tuneability in optical differentiation
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- Published on 23 August 2024
By considering waves which propagate through sample surfaces as light interacts with them, a new technique could make it easier for researchers to create real-time images of microscopic samples.
Optical differentiation is a useful technique for analysing images of microscopic samples in real time. Currently, however, it lacks the ability to fine-tune the resolution in the images it produces.
Through new research published in EPJ D, a team led by Jian Wu at the National University of Defence Technology in Changsha, China, propose a new approach, which enabled them to tune the wavelengths reflected from crystal samples. Their technique could allow researchers to extract far more detailed images of their samples, and would be especially useful for analysing systems of cells and large molecules.
EPJ D Highlight - Investigating the link between N₂O ionization and ozone depletion
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- Published on 02 August 2024
Detailed measurements of the electron-impact ionization cross-section of nitrous oxide shed new light on how Earth’s ozone layer could be depleted by future manmade emissions.
Man-made emissions of nitrous oxide (N2O) are rapidly increasing globally and are predicted to pose a growing threat to Earth’s ozone layer. In the 1970s, it was discovered that N2O in the upper atmosphere can trigger ozone-depleting reactions through its interaction with low-energy electrons. However, the full impact of this process on the ozone layer remains poorly understood.
New research published in EPJ D, led by Mareike Dinger at the national metrology institute of Germany (PTB) in Braunschweig, Germany, provides extensive experimental data on the interaction between N2O and these low-energy electrons. Their measurements could offer deeper insights into the influence of man-made N2O emissions on the future state of Earth’s ozone layer.
EPJ D Highlight - Identifying useful emission lines in the sun’s outer atmosphere
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- Published on 02 August 2024
Experiments reveal deeper insights into the emission lines created by two key ions in the sun’s outer atmosphere
When studying the solar spectrum, researchers often search for specific emission lines: prominent wavelengths emitted by ions as their electrons transition from higher to lower energy levels. Emission spectra of two iron ions, Fe IX and Fe X, are particularly useful for studying the sun’s outer atmosphere. However, both of these spectra contain emission lines that can’t yet be matched with known electron transitions, limiting the information which can be gathered from them.
EPJ D Highlight - Determining Refractive Index at Relativistic Speeds
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- Published on 24 June 2024
Ideas first posed by seventeenth-century physicists have been extended in determining the mechanical refractive index of particles travelling at speeds close to that of light.
If you studied advanced physics at high school, there’s a good chance that you remember Snell’s law, which states how a ray of light bends when it crosses a boundary between two media. According to this law, the ratio of the sines of the incident and refracted angles is a non-universal constant, later understood as the relative refractive index of the refracting medium with respect to the incident one.
EPJ D Highlight - Electron-impact ionization calculations match with experiments
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- Published on 24 June 2024
Through a new calculation approach, researchers have made far more accurate predictions of how atoms are ionized when impacted by high-energy electrons.
During electron-impact ionization (EII), high-energy electrons collide with atoms, knocking away one or more of their outer electrons. To calculate the probability that ionization will occur during these impacts, researchers use a quantity named the ionization ‘cross-section’. EII is among the main processes affecting the balance of charges in hot plasma, but so far, its cross-section has proven incredibly difficult to study through theoretical calculations.
Through new research published in EPJ D, Stefan Schippers and colleagues at Justus-Liebig University of Giessen, Germany, present new calculations for the EII cross-section, which closely match with their experimental results. Their discoveries could provide useful new insights in many fields of research where hot plasma is studied: including astrophysics and controlled nuclear fusion.
EPJ D Topical Issue - Atomic and Molecular Data and Their Applications: ICAMDATA 2022
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- Published on 21 June 2024
Guest Editors: Annarita Laricchiuta, Iouli E. Gordon, Christian Hill, Gianpiero Colonna and Sylwia Ptasinska
Atomic and Molecular Data and Their Applications: the generation, collection and diffusion of accurate and consistent atomic and molecular (AM) data is crucial in various fields of science and technology, requiring the cross-disciplinary cooperation of AM data producers and users and the coordination of AM data activities and databases.
The Topical Issue collects 20 papers, giving a snapshot of the efforts of the community in the field of data production and curation. The majority of the papers are focused on the theoretical derivation of structural properties of atoms and molecules and of dynamical data (cross sections and rate coefficients) for electron scattering and heavy-particle collision processes, with different approaches. Some papers presenting experimental activity are also included in the collection. Published results contribute to the construction of new knowledge and aim at giving answer to data needs in different fields of application, ranging from astrophysics and fusion plasmas to low-temperature plasmas for technological discharges and aerothermodynamics. Another relevant topic is the data collection and dissemination through the existing web infrastructures, establishing criteria and indicators for the critical and systematic analysis and formulating new paradigms and best practices.
This Topical Issue stems from the 12th International Conference on Atomic and Molecular Data and Their Applications (ICAMDATA), held in Mola di Bari (Italy) in September 2022.
All articles are available here and are freely accessible until 18 August 2024. For further information read the Editorial.
EPJ D Highlight - A new simple scheme for atom interferometry
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- Published on 13 May 2024
New scheme proposes a simpler method for investigating matter waves with an ease of use that could make it ideal for commercial applications
Atom interferometers are devices that use the wave characteristics of matter to measure the phase between atomic matter waves to separate paths to make high-precision measurements of elements of physics, such as gravitational and magnetic fields. Atom interferometers have also found their way into industry and are used in geological surveys, mineral exploration, environmental monitoring, and for the development of precision atomic clocks.
Atom interferometers usually control matter waves and particularly particle velocity using lasers. Thus, the growth of atom interferometer application has been strongly tied to the development of advanced laser systems, with many current models based on the construction of gratings fashioned from laser beams. That means that an issue with these systems is the fact that they depend on the efficient operation of intricate laser systems. Additionally, while this method has achieved commendable precision, it fails slightly when considering shorter wavelengths.
EPJ D Highlight - Probing neptunium’s atomic structure with laser spectroscopy
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- Published on 08 May 2024
A new technique developed by researchers in Germany can measure ionisation states of this element more precisely than before, with implications for its detection and remediation in radioactive waste.
The radioactive element neptunium is one of the principal components of nuclear waste. Mass spectrometry can be used to probe its complex atomic structure, which is of value both for its intrinsic interest and for determining the isotope composition of neptunium waste. Magdalena Kaja at Johannes Gutenberg University, Mainz, Germany and her co-workers have now demonstrated a novel method of laser spectroscopy that can analyse the ionisation potential of neptunium more precisely than earlier methods. This work is now published in the journal EPJ D.
EPJ D Highlight – Estimating uncertainty in atomic spectroscopy
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- Published on 17 April 2024
A numerical toolbox offers a robust way to evaluate uncertainty in atomic wavelength measurements.
If you repeat a measurement with the same or different instruments, you’ll get slightly different numbers each time. Estimating the uncertainties associated with these numbers turns them into an informative result. In a study published in EPJ D, Alexander Kramida, of the National Institute of Standards and Technology in Maryland, USA, now explains a new statistical approach for estimating the uncertainty associated with atomic spectroscopy measurements. He discusses how this approach can be applied both to measurements of spectral line wavelengths, and to other atomic properties that are indirectly determined from them.
EPJ D Topical Issue: Dynamics and Photodynamics: From Isolated Molecules to the Condensed Phase
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- Published on 17 January 2024
Guest Editors: Luis Bañares, Ramón Hernández-Lamoneda, Pascal Larregaray, Germán Rojas-Lorenzo and Jesús Rubayo-Soneira
Dynamics and photodynamics: from isolated molecules to the condensed phase is a highly interdisciplinary topical issue with numerous connections between traditional branches of physics and chemistry.
The issue provides a snapshot of current research in different areas of molecular systems science. It consists of 12 contributions representing both experimental and theoretical studies, ranging from fundamental mechanisms to more applied levels, which are essential in numerous applications of nanotechnology and material science. The contributions featured in this issue encompass a wide range of areas, including spectroscopy, photodissociation, dynamics of reactions involving neutral and charged cluster systems, carbon nanotubes and various other subjects.
This topical issue is celebrating the 20th anniversary of the Photodynamics Conference, held in Havana in November 2022.
All articles are available here and are freely accessible until 15 March 2024. For further information read the Editorial.
