Magnetic confinement fusion has the potential to provide a substantial proportion of the world’s energy needs in the 21st century in a safe and environmentally friendly way. Its realisation is, however, hampered by the complex behavior of hot collisionless plasmas (ion gases) in strong magnetic fields. Such plasmas are subject to temperature and density gradient driven microturbulence which leads to particle and heat losses and tends to keep the plasma from reaching a "burning" state.
Simulations are necessary if we are to understand and control plasma microturbulence. However, because fusion plasmas are virtually collisionless, a three-dimensional (i.e., in space) fluid description must, in principle, be abandoned, in favor of a six-dimensional (i.e., in phase space) kinetic one.
Fortunately, several processes on very small spatio-temporal scales – such as the gyrating motion of the particles around magnetic field lines – can be removed, analytically, from the basic equations, thus making the problem five-dimensional. This reduces the computational requirements by many orders of magnitude, without sacrificing accuracy. This approach is called gyrokinetics, which gave the present project its name.
The GYROKINETICS project was carried out in 2006 and 2007 by researchers from the Max Planck Institute for Plasma Physics at Garching, Germany, and the Ecole Polytechnique Fédérale of Lausanne, in Switzerland using DEISA’s resources under the DECI and the JRA3 frameworks.
As a result, the research group were able to show that certain small-scale turbulent processes can make substantial contributions to the overall heat transport carried by the plasma electrons. It turned out, in particular, that there often tends to be a scale separation between ion and electron thermal transport. While the former is usually carried more or less exclusively by long wavelength fluctuations, a substantial proportion of the latter can be carried by much smaller scales.
These findings represent an important new insight into the physics of turbulent transport in magnetized plasmas, and will have important implications for future full-torus simulations of large fusion devices, such as the International Thermonuclear Experimental Reactor ITER.
Kirsti Turtiainen | alfa
When fluid flows almost as fast as light -- with quantum rotation
22.06.2018 | The Henryk Niewodniczanski Institute of Nuclear Physics Polish Academy of Sciences
Thermal Radiation from Tiny Particles
22.06.2018 | Universität Greifswald
In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.
Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...
Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...
Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.
Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...
The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.
Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.
An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.
Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...
13.06.2018 | Event News
08.06.2018 | Event News
05.06.2018 | Event News
22.06.2018 | Materials Sciences
22.06.2018 | Earth Sciences
22.06.2018 | Life Sciences