News
EPJ Plus Focus Point Issue: Laser-driven neutron sources and their applications
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- Published on 23 June 2025
Guest Editors: S. Charisopoulos, M. Roth
Recent advances in high-power laser technology have led to the development of lasers producing extremely short light pulses in the femtosecond range with very high intensities exceeding 1021 Watt/cm2. By guiding these pulses onto a solid foil, intense sources of photons, ions and neutrons can be generated, which can subsequently be used for a wide spectrum of applications, such as non-destructive testing methods in aerospace; radiographic imaging of large objects; in-operando diagnostics of lithium-ion batteries; radiation processing to fabricate smart, functional materials; and active interrogation of sensitive nuclear materials, including nuclear waste characterization. Due to these features, Laser-Driven Neutron and X-ray sources may have a large potential for contributing to socio-economic development.
The present Focus Point on Laser-Driven Neutron Sources and Their Applications is a collection of papers addressing some of the potential applications of laser driven neutron sources as well as some R&D work aiming at optimizing setups and procedures for the production of high-flux neutrons using state-of-the art laser systems.
All articles are available here and are freely accessible until 16 August 2025. For further information, read the Editorial.
EPJ A Topical Collection: Quantum Computing in Low-Energy Nuclear Theory
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- Published on 23 June 2025
Guest Editors: Thomas Ayral, Thomas Duguet, Denis Lacroix, Vittorio Somà
Quantum computing has rapidly evolved from a theoretical concept to an active field of research with real-world prototypes. Major companies and startups are racing to build increasingly powerful quantum devices, and first demonstrations of so-called “quantum advantage” have already taken place. While these machines remain limited by noise and the number of qubits, the emergence of the NISQ (noisy intermediate-scale quantum) era, and the first indications of a transition towards Fault-Tolerant machines are fueling innovations across many disciplines. Nuclear physics, with its complex many-body problems, is one of the most promising areas to benefit from these advances.
This topical collection explores the growing intersection between quantum computing/quantum information and low-energy nuclear physics/related areas. It brings together a set of articles aimed at both introducing scientists to this evolving field and highlighting recent breakthroughs. The focus is on how quantum devices—despite their current limitations—can be used to simulate highly correlated quantum systems such as atomic nuclei. These simulations may in the future eventually tackle problems that are currently beyond the reach of even the most powerful classical supercomputers.
EPJ Plus Highlight - Exploring the experimental potential of electron-hole pair production in graphene
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- Published on 16 June 2025
Electron-hole pair production in graphene can mimic many of the key quantum signatures of electron-positron pair production in a vacuum – but with key differences depending on the polarisations of the electric fields applied
Graphene provides a promising platform for exploring exotic quantum phenomena. For example, when an electron in graphene is excited to a higher energy level by an electric field, it leaves behind a positively charged ‘hole – a quasiparticle that essentially behaves like a particle of antimatter. This process is analogous to the production of electron-positron pairs in a vacuum when exposed to strong electromagnetic fields.
Through new research published in EPJ Plus, Zi-Liang Li and colleagues at China University of Mining and Technology provided new insights into how electron-hole pairs form in graphene, when subjected to two polarised electric fields separated by a time delay. Their results show that under the right conditions, graphene can provide a useful platform for precise, controllable, and easily implementable experiments for simulating pair production – offering opportunities to explore quantum effects which would otherwise be extremely difficult to access.
EPJ A Topical Collection: Short-Range Correlations and the EMC Effect
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- Published on 10 June 2025
Guest Editors: Or Hen, Douglas Higinbotham, Eliezer Piasetzky, Patrizia Rossi, Axel Schmidt
Short-range correlations (SRCs) between nucleons are to be a universal feature of nuclear structure, seen across the nuclear chart. Correlated nucleons in very close proximity are believed to interact much more strongly with each other than with the rest of the nucleus, leading to a separation of scales. In momentum space, correlated pairs of nucleons have very large relative momenta - larger than the typical nuclear Fermi momentum - while also having a small center-of-mass momentum, i.e., the momentum is balanced within the pair. Because nucleons in SRCs experience a high local nuclear density and tend to have high virtuality, they are an exciting laboratory for learning about dense nuclear matter, the isospin structure of the short-distance nucleon-nucleon interaction, and the role of non-nucleonic degrees of freedom in nuclear structure
EPJ Plus Highlight - A gentle introduction to black hole thermodynamics
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- Published on 23 May 2025
Notes provide a useful introduction to the extensive and deeply complex topic of black hole thermodynamics, offering a valuable starting point for more in-depth research.
Beyond a black hole’s event horizon, the gravitational pull becomes so strong that not even light can escape. As a result, the process of any object being captured by a black hole is `irreversible’. The basic idea of black hole thermodynamics, as developed originally by Bekenstein and Hawking half a century ago, is that this irreversibility is of the same nature as the thermodynamic irreversibility that is familiar in everyday life.
EPJ Plus Highlight - Quantum refrigerators explored with a new theoretical framework
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- Published on 23 May 2025
New research takes the Carnot cycle to the realm of quantum physics to explore an ideal refrigeration system
A Carnot refrigerator is a theoretical ideal model of a cooling system that operates in the most efficient way possible. Based on the principles of thermodynamics and the Carnot cycle first theorised by French physicist Sadi Carnot in 1824, Carnot refrigeration has enthralled scientists for over 200 years, even when not directly implemented, providing inspiration for “real-life” cooling systems like fridges and air-conditioners.
A new paper published in the journal the EPJ Plus by Bolu Abant Izzet Baysal University physicist Ferdi Altintas offers a framework for designing quantum refrigerators, relevant for cooling in quantum technologies like quantum computing.
EPJ Plus Highlight - Understanding explosive transitions in propagating flames
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- Published on 19 May 2025
Mathematical analysis sheds new light on the mechanisms which unfold as propagating flames transition from one type of combustion to another
As a flame propagates through a mixture of air and flammable fuel, it can suddenly transition from one type of combustion to another. While it initially spreads at subsonic speeds through a process named ‘deflagration’, the flame will suddenly switch to a supersonic motion, driving a shockwave which compresses and ignites the fuel directly in front of it: a process named ‘detonation’. To date, however, some details of the mechanisms which unfold as this transition takes place are still being investigated.
EPJ A Topical Collection: Radiative corrections: from medium to high energy experiments
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- Published on 16 May 2025
Guest Editors: Andrei Afanasev, Jan C. Bernauer, Ethan W. Cline, Ronald Gilman, André Peshier, Hubert Spiesberger
Modern lepton-scattering experiments at medium to high energy achieve a precision that requires an accurate understanding of radiative corrections, including the re- sulting uncertainties of relevant observables in the given experimental setting. The development of associated tools is a subject of active research. It is a showcase for a fruitful interplay between theoretical and experimental efforts, and of particular importance with regard to the ongoing experimental program at Jefferson Lab and to the future Electron-Ion Collider at the Brookhaven National Lab.
This Topical Collection focuses on spin-polarized and unpolarized fixed target ex- periments with electrons, e+e− collisions, meson decays, and elastic e±p and μ±p scattering, from both experimental and theoretical perspectives.
The articles included in the Topical Collection are available here and are freely accessible until 16 July 2025. For further information read the Editorial.
EPJ A Topical Collection: Heavy and Super-Heavy Nuclei and Elements: Production and Properties
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- Published on 12 May 2025
Guest Editors: Nicolas Alamanos, Maria José Garcia Borge, Sigurd Hofmann, Peter Möller, Andrey G. Popeko
Interest in the possible existence of elements (SuperHeavy Elements, SHE) at the next doubly-magic numbers beyond 20882Pb126, sufficiently stable to allow experimental studies of their properties, has been around since at least the 1950ies. In analogy with the magic neutron number 126 it was assumed that the next magic proton number would be Z = 126. However in the mid sixties it was realized that already available, calculated single-particle diagrams showed that Z = 114 would be a more plausible next magic proton number. This realization, the advent of the Strutinsky method, and improving experimental facilities led to many theoretical studies of SHE properties and to experimental efforts to form those. However in the next 15 years or so only a very few new elements (up to Z = 106) were discovered, none near the postulated island of stability. In a Nature article in 1979 Hermann reviewed the status and presented a somewhat bleak view of future prospects. Others had even remarked that the earlier Nobel symposium 27 in 1974 seemed to be the funeral services for SHE.
EPJ QT Highlight - Progress in terrestrial very long baseline atom interferometry
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- Published on 12 May 2025
The second of a series of workshops, held in London in April 2024, saw over 250 experts make progress towards a blueprint for a kilometre-long atom interferometer.
Interferometry is a technique that extracts information from the interference patterns of superimposed waves, most typically electromagnetic waves. However, atom interferometry, as its name implies, instead uses atoms that are treated as waves through wave-particle duality. Atom interferometers can make exceptionally precise measurements, for example to test foundational physical principles or detect gravitational waves. This decade, international experts in terrestrial very long baseline atom interferometry (TVLBAI) have met for two workshops; progress reported at the second of these, held in London in April 2024, has recently been published in EPJ Quantum Technology.
