News / Highlights / Colloquium
- Published on 29 June 2016
New study could help unveil negative effect of radiation on biological tissues due to better understanding of low energy electron-induced reactions
High energy radiation affects biological tissues, leading to short-term reactions. These generate, as a secondary product, electrons with low energy, referred to as LEEs, which are ultimately involved in radiation damage. In a new study, scientists study the effect of LEEs on a material called trifluoroacetamide (TFAA). This material was selected because it is suitable for electron scavenging using a process known as dissociative electron attachment (DEA). These findings were recently published in EPJ D by Janina Kopyra of Siedlce University, Poland, and colleagues in Germany, as part of a topical issue on Advances in Positron and Electron Scattering.
- Published on 15 June 2016
Great potential for a new, more accurate, tool for using electron collisions to probe matter
There are several ways to change a molecule, chemically or physically. One way is to heat it; another is to bombard it with light particles, or photons. A lesser known method relies on electron collision, or e-beam technology, which is becoming increasingly popular in industry. In a review outlining new research avenues based on electron scattering, Michael Allan from the University of Fribourg, Switzerland and colleagues explain the subtle intricacies of the extremely brief electron-molecule encounter, in particular with gentle, i.e., very low energy electrons. In this paper, which was recently published in EPJ D, the authors describe how the use of very low energy electrons and a number of other performance criteria, make the approach with the so-called Fribourg instrument a more appealing candidate than previously available tools used to study electron collisions.
- Published on 07 June 2016
The role of statistics in quantum scale observation explains microscale behaviour
There is a gap in the theory explaining what is happening at the macroscopic scale, in the realm of our everyday lives, and at the quantum level, at microscopic scale. In this paper published in EPJ D, Holger Hofmann from the Graduate School of Advanced Sciences of Matter at Hiroshima University, Japan, reveals that the assumption that quantum particles move because they follow a precise trajectory over time has to be called into question. Instead, he claims that the notion of trajectory is a dogmatic bias inherited from our interpretation of everyday experience at the macroscopic scale. The paper shows that trajectories only emerge at the macroscopic limit, as we can neglect the complex statistics of quantum correlations in cases of low precision.
- Published on 18 May 2016
New study blames temperature increase on locally reoccurring discharges in microelectronic devices
In microelectronics, devices made up of two electrodes separated by an insulating barrier are subject to multiple of microdischarges—referred to as microfilaments—at the same spot. These stem from residual excited atoms and ions from within the material, the surface charge deposited on the insulating part of the device, and local temperature build-up. These reoccurences can lead to the creation of pin-holes in the material of the microelectronic devices where they occur, and are due to local reductions in the electric field. Now, Jozef Ráhel and colleagues from Masaryk University in the Czech Republic have elucidated the mechanism of microdischarge reoccurrence, by attributing it to the temperature increase in a single microdischarge. These results were recently published in EPJ D.
- Published on 17 May 2016
New model for controlling hot molecules reactions, which are relevant to fusion, space exploration and planetary science
Hot molecules, which are found in extreme environments such as the edges of fusion reactors, are much more reactive than those used to understand reaction studies at ambient temperature. Detailed knowledge of their reactions is not only relevant to modelling nuclear fusion devices; it is also crucial in simulating the reaction that takes place on a spacecraft’s heat shield at the moment when it re-enters Earth’s atmosphere. Further, it can help us understand the physics and chemistry of planetary atmospheres. In a novel and comprehensive study just published in EPJ D, Masamitsu Hoshino from Sophia University, Tokyo, Japan, and colleagues reveal a method for controlling the likelihood that these reactions between electrons and hot molecules occur, by altering the degree of bending the linear molecules, modulated by reaching precisely defined temperatures.
- Published on 02 February 2016
The field of microplasmas gained recognition as a well-defined area of research and applications within the larger field of plasma science and technology about 20 years ago. Since then, the level of activity in microplasma research and applications has continuously increased.
A new review article published in EPJ D provides a snapshot of the current state of microplasma research and applications. Given the rapid proliferation of microplasma-based applications, the authors focus primarily on the status of microplasma science and on current understanding of the physical principles that govern the formation and behaviour of microplasmas. They also address microplasma applications, limiting such discussion to examples where the application is closely tied to the plasma science. The article includes some key references to recent reviews, describing some of the diverse range of current and emerging applications.
- Published on 18 January 2016
Numerical model takes us one step closer to understanding anti-hydrogen formation, to explain the prevalence of matter and antimatter in the universe
Antihydrogen is a particular kind of atom, made up of the antiparticle of an electron - a Positron - and the antiparticle of a Proton - an antiproton. Scientists hope that studying the formation of anti hydrogen will ultimately help explain why there is more matter than antimatter in the universe. In a new study published in EPJ D, Igor Bray and colleagues from Curtin University, Perth, Australia, demonstrate that the two different numerical calculation approaches they developed specifically to study collisions are in accordance. As such, their numerical approach could therefore be used to explain antihydrogen formation.
- Published on 15 December 2015
Creation of ephemeral muonium atoms could help measure proton size
A true-muonium only lives for two microseconds. These atoms are made up one positively and one negatively charged elementary particle, also known as muons. Although they have yet to be observed experimentally, a Japanese theoretical physicist has come up with new ways of creating them, in principle, via particle collisions. The first method involves colliding a negatively charged muon and a muonium atom made up of a positive muon and an electron. The second involves colliding a positively charged muon and a muonic hydrogen atom made up of a proton and a negative muon. The author found that the second option offers the most promising advances for muonium detection. These findings have been published in EPJ D by Kazuhiro Sakimoto from the Japan Aerospace Exploration Agency in Kanagawa.
- Published on 02 December 2015
High-precision and high-accuracy magnetic field measurement to support quest for missing antimatter in the universe
Every measurement is potentially prone to systematic error. The more sensitive the measurement method, the more important it is to make sure it is also accurate. This is key for example in measuring magnetic fields in state-of-the-art fundamental physics experiments. Now, an international team of physicists has developed an extremely high-precision method for the determination of magnetic fields. The resulting device, they found, has an intrinsic sensitivity that makes it ideal for fundamental physics and cosmology experiments attempting to explain the missing antimatter of the universe. The findings by Hans-Christian Koch from the University of Fribourg, Switzerland, and colleagues have just been published in EPJ D.
- Published on 17 November 2015
Study investigates how best to stabilise the output of quantum dot LEDs
Noise is an issue in optical telecommunications. And findings means of controlling noise is key to physicists investigating light-emitting diodes or lasers. Now, an Italo-Iraqi team has worked on a particular type of light source, called the quantum dot light-emitting diode (QDLED). In a study published in EPJ D, Kais Al Namee from the National Institute of Optics, in Florence, Italy and colleagues, demonstrate that modulating bias current of the QDLED could lead to countering the noise. This, in turn, leads to stabilising such light sources, making them better suited for optical telecommunications.