Nuclear Sciences & Technologies


EPJ E News - One year of Tips & Tricks


It is the tricks that often form the commonality between researchers working in different fields. A little over a year ago the European Physical Journal E published the first papers in a new section called Tips and Tricks (T&T). The goal of this new section was simple: to provide a venue to publish a novel numerical recipe, sample preparation method, or experimental design.

Such details are often only briefly described in the scientific literature, passed only from student to student, or simply shared as a ‘personal communication’ between research groups. Sometimes such enabling techniques are not passed on at all. In all such cases, the scientific community as a whole is not able to use this knowledge to move forward. Moreover, while the research of some team may not be directly relevant to another, a computational method, experimental procedure, or sample cell design has the potential to be broadly transformative. We have found during our careers that various sample cell configurations, experimental designs, or sample preparation techniques were shared amongst our colleagues. In some cases the science became secondary to a particular technique, and more emails were shared describing a trick than citations earned on a paper where only a brief description was provided. The first year of EPJE's T&T has been exciting, with 13 papers that span many different tools and methods, from vesicles-on-a-chip to a three-body potential for molecular dynamics. You will find them all listed below with their respective links.


EPJ A Highlight - Wavy energy potential patterns from scattering nuclei reveal hidden information

A feynman diagram of proton-neutron scattering mediated by a neutral pion.

New approach to analysing anomalies in collisions between atomic nuclei promises a new perspective on how they interact

Anomalies always catch the eye. They stand out from an otherwise well-understood order. Anomalies also occur at sub-atomic scale, as nuclei collide and scatter off into each other—an approach used to explore the properties of atomic nuclei. The most basic kind of scattering is called ‘elastic scattering,’ in which interacting particles emerge in the same state after they collide. Although we have the most precise experimental data about this type of scattering, Raymond Mackintosh from the Open University, UK, contends in a paper published in EPJ A that a new approach to analysing such data harbours potential new interpretations of fundamental information about atomic nuclei.


EPJ D Colloquium: From nuclear to meso systems: how small is simple and how large is complex?

How small is simple and how large is complex? This is the question asked in a new Colloquium article by Jean-Patrick Connerade of Imperial College, published as part of the Topical Issue of EPJ D on Dynamics of Systems at the Nanoscale.


EPJ Plus Highlight - Proving Einstein right using the most sensitive Earth rotation sensors ever made

Physicists have now found a way to measure Earth's rotation in an extremely accurate way. (Photo Fotolia, ID #60274978 by Denis Tabler)

A new study use the most precise inertial sensor available to date to measure whether Earth partially drags inertial frames along with its rotation

Einstein’s theory of gravity, also referred to as General Relativity, predicts that a rotating body such as the Earth partially drags inertial frames along with its rotation. In a study recently published in EPJ Plus, a group of scientists based in Italy suggests a novel approach to measuring what is referred to as frame dragging. Angela Di Virgilio of the National Institute of Nuclear Physics, INFN, in Pisa, Italy, and her colleagues propose using the most sensitive type of inertial sensors, which incorporate ring lasers as gyroscopes, to measure the absolute rotation rate of the Earth.


EPJ E Highlight - Speed-dependent attraction governs what goes on at the heart of midge swarms

Trajectories of individual midges within a swarm recorded using high-speed cameras.

New study reveals swarm cohesion stems from an adaptive behaviour, where the faster individual midges fly, the stronger the gravitational-like force they experience

Ever wondered what makes the collective behaviour in insect swarms possible? Andy Reynolds from Rothamsted Research, UK, and colleagues at Stanford University, California, USA, modelled the effect of the attraction force, which resembles Newton’s gravity force, acting towards the centre of a midge swarm to give cohesion to their group movement. In a recent study published in EPJ E, their model reveals that the gravity-like attraction towards the heart of the swarm increases with an individual’s flight speed. The authors confirmed the existence of such an attractive force with experimental data.


EPJ B Highlight - Potential new applications stem from controlling particles’ spin configurations

credit: Creativity103.

Physicists prove important constraints for fermion gases with spin population imbalance

Fermions are ubiquitous elementary particles. They span from electrons in metals, to protons and neutrons in nuclei and to quarks at the sub-nuclear level. Further, they possess an intrinsic degree of freedom called spin with only two possible configurations, either up or down. In a new study published in EPJ B, theoretical physicists explore the possibility of separately controlling the up and down spin populations of a group of interacting fermions. Their detailed theory describing the spin population imbalance could be relevant, for instance, to the field of spintronics, which exploits polarised spin populations.


EPJ D Highlight - Reading between the lines of highly turbulent plasmas

A short sequence of solitons.

Study shows how to identify highly turbulent plasma signatures in the broadening of the shapes of lines emitted by ions and atoms within

Plasma, the ionised state of matter found in stars, is still not fully understood, largely due to its instability. Astrophysicists have long-since sought to develop models that can account for the turbulent motions inside plasma, based on observing line shapes emitted by atoms and ions in the plasma. Turbulences are typically detected through the observation of broadened lines due to the Doppler effect, similar to the principle behind radar. In a new study published in EPJ D, Roland Stamm from the CNRS and Aix-Marseille University, France, and colleagues develop an iterative simulation model that accurately predicts, for the first time, the changes to the line shape in the presence of strong plasma turbulence. Ultimately, the authors aim to provide a system for assessing plasma turbulence that is valid for both a stellar atmosphere and the ITER tokamak designed to generate fusion energy. Line shapes are extensively employed as a powerful diagnostic tool for detecting turbulences in stable gases and plasmas. For many years now, astrophysicists have developed and employed models that gauge the effect of turbulent motions in the broadening of line shapes due to the Doppler effect. Such models are now also being employed to understand the role of turbulences in plasmas created to harvest energy from fusion.


EPJ Plus Highlight - Does the universe have a rest frame?

A simplified diagram showing the basic idea of the experimental design.

Experiment aims at resolving divergence between special relativity and standard model of cosmology

Physics is sometimes closer to philosophy when it comes to understanding the universe. Donald Chang from Hong Kong University of Science and Technology, China, attempts to elucidate whether the universe has a resting frame. The results have recently been published in EPJ Plus.


EPJB Colloquium: The continuous-time random walk, fifty years on

This Colloquium paper published in EPJ B by R. Kutner and J. Masoliver revisits the most significant achievements and future possibilities for continuous-time random walk (CTRW), a versatile and widely applied formalism.


EPJ E Highlight - Molecular scale transporter with a twist, powered by liquid crystal defects

Twisting effect, called chirogyral, dictated by the handedness of the fibre in a vertical magnetic field.

Delivery of biochemical substances is now possible using a novel application of liquid crystal defects, forming a loop enclosing the substance travelling alongside twisted fibres

Defects that break the symmetry of otherwise orderly material are called topological defects. In solid crystals, they are called dislocations because they interrupt the regularly structured atom lattice. In contrast, topological defects called disclinations take the form of loops in liquid crystal of the nematic variety, whose elongated molecules look like a shoal of fish. New experiments supported by a theoretical model show how defects forming loops around twisted plastic fibres dipped in liquid crystal could be used for the transport of biochemical substances, when controlled by electric and magnetic fields. Published in EPJ E, these findings - achieved by Mallory Dazza from the Ecole normale supérieure Cachan, France, and colleagues - have potential applications in electro-optical micromechanical and microfluidic systems.


G. Moutiers and A. Nicolas
ISSN: 2491-9292 (Electronic Edition)

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