The LHC will undergo a luminosity upgrade by nearly a factor ten during the 2024-2016 shutdown. For this, the ATLAS detector will undergo substantial upgrades. Most important is the replacement of the complete inner tracker for a new silicon based system. The Niels Bohr Institute contributes to this in three areas: a) In a consortium between NBI and the universities in Lund, Oslo, and Uppsala,...
A plasma is useful for industrial and material processing due to high treatment effects and environmental compatibility. Surface modification for adhesion improvement is among the most promising applications for plasmas. Practically it is realized by introducing electrical energy to a gas to generate a plasma as a reactive gas, in which a material surface is exposed. During plasma
surface...
In experimental studies of aging, the temperature T is externally controlled and
identified as the phonon “bath” temperature measured on a thermometer.
Aging is a non-linear phenomenon. Thus the response of the system to a small
perturbation is not linear and it depends on both sign and magnitude of input.
For instance, consider small up temperature and down temperature jump to the
same...
The existence of cool starspots on sun-like stars has been known for more than five decades based on photometric observations. The development of observing and analysis techniques that has occurred during the past three decades has also enabled us to map in detail the starspot configurations on other stars than the Sun. Here, we will present detailed stellar surface maps of the cool giant star...
Nano electro-optomechanical (NEMO) systems consisting in high-quality mechanical resonators interacting with electrical and optical fields are widely used in sensing and photonics applications. We investigate such a NEMO formed by a pair of suspended, ultrathin silicon nitride membranes. By piezoelectrically controlling the membranes' tensile stress we demonstrate tuning of their vibrational...
Physics is an empirical science. Therefore, learning physics must include learning how to design and conduct experiments, analyze and interpret data, and revise models and apparatus. Physics lab courses at the introductory and upper-division levels are one of only a few opportunities for students to engage in these authentic physics practices. For many students, instructional labs are the only...
Entanglement is a key resource for quantum information processing, and generating and maintaining entanglement is therefore a central challenge in quantum information science.
Entangled states are fragile and generally degrade under unavoidable interactions of a system with its environment. Surprisingly, it has nevertheless been realised that dissipation may in some cases aid the generation...
The realisation of magnetically confined fusion power plants offers a safe, clean and inexhaustible source of energy. So far the most promising device for realising such a power plant is the so-called tokamak, a doughnut shaped torus consisting of high field magnets to encase the fusion plasma.
Conventional tokamaks, such as JET in the UK, have a large column in the centre of the doughnut...
In the last two decades, the astrophysical community discovered a multitude of planets orbiting other stars. The variety of planetary environments that these exoplanets may harbour is still unknown. Most importantly it propels the fundamental scientific and philosophical quest of searching for the first detection of life beyond our own planet. As more observational data become available,...
The strong nuclear force is the residual interaction between hadrons, which are bound states of quarks and gluons. These fundamental particles interact via Quantum Chromodynamics (QCD), a strongly-coupled non-abelian gauge theory, which must be simulated on a discrete space-time lattice using high-performance computing resources. Such simulations are necessarily performed in `imaginary' time,...
For a few years it has been know, that for liquids which exhibits a strong correlation between the potential energy and the virial in some subsets of their phase diagram (called R-simple liquids), contains isomorph lines, along which properties such as structure are invariant. In this work, the hydrodynamics near the hydrodynamic limit is explored for a simple Lennard-Jones system. In...
The vision of LIFE (acronym of Learning, Inspiration, Fascination & Engagement) is to create a world class learning laboratory and contribute decisively to enhancing scientific learning and education in the Danish society. Specifically, modern physical sciences cover a variety of topics, such as Atomic, molecular, and optical (AMO) physics and solid state physics, highly relevant for the...
The region of neutron-rich light nuclei has seen a great rise in attention over the last few decades. 11Li is a famous example of a so-called "nuclear halo", where loosely bound neutrons extends to large distances. However, to understand and aid the theoretical description we require better experimental information on both 11Li itself, but also 10Li and 9Li.
I will present our current...
Terrestrial gamma-ray flashes (TGFs), the only known natural events on Earth with energies of several tens of MeV, are produced by energetic electrons accelerated in thunderclouds in the vicinity of conducting lightning channels. But what is the real production mechanism of energetic electron and photon beams?
Launched on April, 2nd, 2018, the Atmosphere-Space Interactions Monitor (ASIM) is a...
The recently detected gravitational wave signals of the merger events of pairs of black holes and neutron stars have revolutionized astrophysics by revealing new sources of fundamental importance for exploring the Universe. In this talk, I will demonstrate the exotic nature and awesome physical processes related to these binary compact objects. I will show examples of our recent theoretical...
Abstract
Energy is the white gold of our era; it is precious and essential for a broad range of basic activities like cooking, heating, communications, food production, and transports. A sustainable energy source, i.e. at the same time reliable, clean, safe, and affordable, would then be the ideal solution to meet the needs of the global population in harmony with a farsighted preservation of...
The mismatch between neutrino mass and flavor states, combined with the mass difference between these states, produces the interference phenomena known as neutrino oscillation. However, any coupling between the neutrino and the environment in which it propagates degrades the coherence between neutrinos, resulting in the damping of neutrino oscillations probability over distance. Such an...
The primary goal of the ultra-relativistic heavy-ion collision program at the Large Hadron Collider (LHC) is to study the properties of the Quark-Gluon Plasma (QGP), a novel state of strongly interacting matter which exists in the early universe. Anisotropic flow, which quantifies the anisotropy of the momentum distribution of final state particles, is sensitive to the initial conditions and...
I will report on a reform of the laboratory teaching at the department of physics and astronomy, Aarhus University. Instead of having the lab teaching be an integrated part of courses on mechanics, electrodynamics, and modern physics, we have now separated all lab teaching from theoretical courses and created a programme of three experimental phuysics courses with separate learning objectives...
I will talk about how to use astrophysical transients to address fundamental questions about the Universe we live in. Astrophysical transients, such as massive stars exploding as supernovae, are the spotlights of the Universe, which is filled with small solid particles, ‘cosmic dust’, of unknown origin. Some question which shall be addressed are: Are supernovae the long sought production...
A promising bottom-up method for fabricating novel devices and structures is by magnetically guided self-assembly. To this end, precise models of magnetic particle interaction, in particular dipole-induced clustering and the properties of the aggregate structures, are necessary. We present a model of magnetic nanoparticle (MNP) interactions, implemented with a molecular dynamics algorithm,...
The combination of the two monomers benzothiadiazole (BT) and thiophene (T), acting as a light-absorbing unit, is an interesting research area of polymer photovoltaics. Understanding the unit BT-1T could potentially reveal a fundamental insight in the ultrafast dynamics during a photoinduced process. By combining quantum mechanical and molecular dynamics (MD) computer simulations we can...
The semiconducting material CZTS is considered as a promising absorber for a thin-film solar cell. In contrast to the other existing, commercially available thin-film cells of CdTe and (GICS) CuInGaSe. CZTS consists exclusively of non-toxic, environmentally available and inexpensive elements. All thin-film cells have an absorbing layer of a thickness of about 1 µm, while silicon absorbers...
With small-angle scattering, we may study the structure of (soft) matter, e.g. polymer melts, on length scales of ~1-100 nm. If there is alignment in the system on these length scales, the small-angle scattering pattern will be anisotropic.
The anisotropy of the scattering patterns can be quantified by expansion in spherical harmonics which separates contributions based on their symmetries....
English:
Leading measurements of neutrino oscillations using the IceCube detector at the South Pole rely on atmospheric neutrinos as the signal flux. Presently, signal simulation is done using Monte Carlo techniques. In the future the inclusive neutrino flux can be found with analytical solutions of the cascade equation, giving a much more physical and flexible treatment of the flux. The...
It was recently shown that the exponentially repulsive EXP pair potential defines a system of particles in terms of which simple liquids’ quasiuniversality may be explained$ ^{\text{a,b}}$. The quasiuniversality was illustrated by showing that the structure of the Lennard-Jones system at four state points is well approximated by those of EXP pair-potential systems with the same reduced...
Developing new coatings and bringing them out of the R&D phase into actual applications is not an easy task. The presentation illustrates how we have developed new coatings based on reactive sputtering processes utilizing different plasma techniques, HiPIMS, pulsed DC and DC magnetron sputtering. The HiPIMS platform was used to develop a very hard TiB2 coating characterized by a low residual...
Current standard model physics require atoms and antiatoms to have the same energy spectra, but it was only in 2012 that the ALPHA collaboration as the first managed to test this prediction, by measuring a transition in trapped antihydrogen. ALPHA has made great progress since then and published measurements of several line shapes. The challenge with antimatter is of course that it is...
This contribution will give an overview of sources of energetic ions in fusion plasmas and discuss their dynamics. Specifically, we will discuss the importance of fusion born alpha particles and their role in making fusion energy a sustainable energy source for the future.
The front-end signal processing for small and medium scale experiments mostly rely on off the
shelf modular electronics, which is often housed in VME crates. In addition to the constraints
imposed by hardware, the achievable acquisition rates of such modules depend heavily on the
readout software. In this talk, I will introduce an asynchronous readout scheme that
significantly improves the...
