EPJ D Highlight - Machine learning hunts for the right mix of hydrogen isotopes for future nuclear fusion power plants
- Published on 31 August 2023
New research is an initial step in the use of deep learning to help determine the right mix of hydrogen isotopes to use in fusion power plants of the future
The process that powers the stars, nuclear fusion, is proposed as a future power source for humanity and could provide clean and renewable energy free of the radioactive waste associated with current nuclear fission plants.
Just like the fusion process that sends energy spilling out from the Sun, future nuclear fusion facilities will slam together isotopes of the universe’s lightest element, hydrogen, in an ultra-hot gas or “plasma” contained by a powerful magnetic field to create helium with the difference in mass harvested as energy.
One thing that scientists must know before the true advent of fusion power here on Earth is what mix of hydrogen isotopes to use— primarily “standard” hydrogen, with one proton in its atomic nucleus, deuterium with one proton and one neutron in its nucleus, and tritium with a nucleus of one proton and two neutrons. This is currently done with spectroscopy for prototype fusion devices called tokamaks, but this analysis can be time-consuming.
In a new paper in EPJ D, author Mohammed Koubiti, Associate Professor at the Aix-Marseille Universite, France, assesses the use of machine learning in connection with plasma spectroscopy to determine the ratios of hydrogen isotopes for nuclear fusion plasma performance.
EPJ Plus Focus Point Issue: Focus Point on Environmental and Multiplicity Effects on Planet Formation
- Published on 30 August 2023
Guest Editors: Giuseppe Lodato and Carlo Felice Manara
Star formation does not take place in isolation, and young stars are subject to different kind of interactions with their natal environment. Dynamical encounters with other young stars and photoevaporation of the protostellar disc due to the intense UV field of neighbouring stars are just a couple of examples of how the environment affects star formation. Since planets are born during the star formation process, such effects may naturally affect also planet formation itself. The aim of this focus point is to define the state of the art of our knowledge in this particular field and to provide a few highlights of interesting new research avenues to pursue.
- Published on 30 August 2023
Guest Editors: Jose L. Lopez, Michael Brunger, and Holger Kersten
The special Topical Issue of the European Physics Journal D (EPJ D) on “Electron-Driven Processes from Single Collisions to High-Pressure Plasmas” is published to honor Kurt H. Becker, who served as Editor-in-Chief for the journal from 2010 to 2016, on his 70th birthday. Electron-driven processes from single collisions to high-pressure plasmas definitely occupy a central position in atomic and plasma physics. Considering this, the Guest Editors compilated a broad range of original manuscripts that encompass the area of electron-atom and electron-molecular collisions, respectively, low-temperature plasma research and aligning with Kurt Becker’s emphasis on science innovation and entrepreneurship. Hence, the papers focus on various recent scientific and technological advances in this given area of physics, chemistry and technology of non-thermal plasmas.
- Published on 17 August 2023
The physical properties of a quantum many-body system can, in principle, be determined by diagonalizing the respective Hamiltonian, but the dimensions of its matrix representation scale exponentially with the number of degrees of freedom. Hence, only small systems that are described through simple models can be tackled via exact diagonalization. To overcome this limitation, numerical methods based on the renormalization group paradigm have been put forth, that restrict the quantum many-body problem to a manageable subspace of the exponentially large full Hilbert space. A striking example is the density-matrix renormalization group (DMRG), which has become the reference numerical method to obtain the low-energy properties of one-dimensional quantum systems with short-range interactions.
- Published on 09 August 2023
Through a new survey, researchers show how mathematical representations named ‘tensor trains’ can help to capture and simulate the dynamics of evolving quantum systems across a range of different scenarios.
Many quantum systems are heavily influenced by their surrounding environments, making them incredibly challenging to describe theoretically. To capture the dynamics and evolution of these systems, researchers often use mathematical representations named ‘tensor trains’. Through new research published in EPJ ST, a team of researchers from four different institutions in France show how tensor trains can be implemented to describe and simulate quantum systems.
- Published on 04 August 2023
The Editors-in-Chief of EPJ Photovoltaics, Pere Roca i Cabarrocas and Jean-Louis Lazzari, are pleased to highlight an important paper published recently in the Special Issue on ‘WCPEC-8: State of the Art and Developments in Photovoltaics’.
The article “How cool is floating PV? A state-of-the-art review of floating PV's potential gain and computational fluid dynamics modeling to find its root cause” is the result of the joint efforts of Gofran Chowdhury (imec, EnergyVille and University of Leuven), Mohamed Haggag (imec and University of Leuven), and Jef Poortmans (imec, EnergyVille, University of Hasselt and University of Leuven).
- Published on 02 August 2023
First-principles calculations show how to manipulate some transition metal oxides’ optical and electronic properties for use in thin-film devices.
Liquid crystal displays, touchscreens, and many solar cells rely on thin-film crystalline materials that are both electrically conductive and optically transparent. But the material most widely used in these applications, indium tin oxide (ITO), is brittle and susceptible to cracking. Researchers seeking alternatives have set their sights on strontium vanadate (SrVO3), a material that ticks all the boxes for a transparent conductor. In a study published in EPJ B, Debolina Misra, of the Indian Institute of Information Technology, Design and Manufacturing, Kancheepuram, India, and her colleagues now calculate how SrVO3‘s optical and electron transport properties vary in response to strain. Their simulations provide a detailed mechanism for tuning these properties to optimize the material’s utility in different devices and applications.
- Published on 01 August 2023
Thermal field theory seeks to explain many-body dynamics at non-zero temperatures not considered in conventional quantum field theory.
Quantum field theory is a framework used by physicists to describe a wide range of phenomena in particle physics and is an effective tool to deal with complicated many-body problems or interacting systems.
Conventional quantum field theory describes systems and interactions at zero temperature and zero chemical potential, and interactions in the real world certainly do occur at non-zero temperatures. That means scientists are keen to discover what effects may arise as a result of non-zero temperature and what new phenomena could arise due to a thermal background. In order to understand this, physicists turn to a recipe for quantum field theory in a thermal background — thermal field theory.
In a new paper in EPJ ST, Munshi G. Mustafa, Senior Professor at the Saha Institute of Nuclear Physics, Kolkata, India, introduces a thermal field theory in a simple way weaving together the details of its mathematical framework and its application.
EPJ Plus Focus Point Issue: Advances in Cryogenic Detectors for Dark Matter, Neutrino Physics, and Astrophysics
- Published on 28 July 2023
Guest Editor: Luca Pattavina
The papers included in this Focus Point collection offer a glimpse of the very broad range of applications of low-temperature detectors. This class of detectors has seen in recent years a boost in its performance and in the achieved background levels. Nowadays, cryogenic detectors are considered a leading technology in the investigation of the fundamental properties of the most abundant particles in the Universe: neutrinos and Dark Matter, and their applications reach out to nuclear, particle, and astroparticle physics. The papers included in the collection cover the most recent technological progress of low-temperature detectors, from different perspectives (e.g. computational approach, material development). The research groups that contributed to this collection show the range of methods available to tackle the latest experimental challenges of the community.
- Published on 27 July 2023
Researchers have explored the evolution of systems of interacting spins, as they transition from random to orderly alignments. Through new simulations, they show that this evolution can be investigated by measuring the changing strength of the system’s magnetism.
The Ising model describes systems of interacting atomic spins relaxing from a ‘paramagnetic’ state – whose spins point in random directions, to a ‘ferromagnetic’ state – whose spins spontaneously align with each other. So far, the nonequilibrium dynamics of this transition has been studied by measuring the growth of regions, or ‘domains’ of aligned spins. In new research published in EPJ ST, researchers led by Wolfhard Janke at the University of Leipzig, Germany, show how this can be done far more easily by measuring the strength of the system’s magnetisation. The team’s discovery could help researchers to better understand the atomic-scale interactions underlying many different phenomena in nature: from electrostatic forces, to neuroscience and economics.