Zobrazeno 1 - 10
of 2 698
pro vyhledávání: '"Helander, P"'
Autor:
Ek, Kaisa, Avela, Aleksi, Haaki, Willehard, Helander, Sami, Lumme, Ville, Mutikainen, Terho, Pere, Jaakko, Vesselinova, Natalia, Viitasaari, Lauri, Ilmonen, Pauliina
The recent COVID-19 pandemic has highlighted the need of studying extreme, life-threatening phenomena in advance. In this article, a zombie epidemic in Uusimaa region in Finland is modeled. A stochastic agent based simulation model is proposed and ex
Externí odkaz:
http://arxiv.org/abs/2410.12502
Autor:
Goodman, Alan G., Xanthopoulos, Pavlos, Plunk, Gabriel G., Smith, Håkan, Nührenberg, Carolin, Beidler, Craig D., Henneberg, Sophia A., Roberg-Clark, Gareth, Drevlak, Michael, Helander, Per
The stellarator is a type of fusion energy device that - if properly designed - could provide clean, safe, and abundant energy to the grid. To generate this energy, a stellarator must keep a hot mixture of charged particles (known as a plasma) suffic
Externí odkaz:
http://arxiv.org/abs/2405.19860
Autor:
Helander, P., Mackenbach, R. J. J.
The available energy of a plasma is defined as the maximum amount by which the plasma energy can be lowered by volume-preserving rearrangements in phase space, a so-called Gardner re-stacking. A general expression is derived for the available energy
Externí odkaz:
http://arxiv.org/abs/2405.12599
We draw attention to an interesting possibility in the design and operation of stellarator fusion reactors, which has hitherto been considered unrealistic under burning-plasma conditions. Thanks to recent advances in stellarator optimisation theory,
Externí odkaz:
http://arxiv.org/abs/2405.07085
Some stellarators tend to benefit from favourable average magnetic curvature for trapped particles when the plasma pressure is sufficiently high. This so-called maximum-$J$-property has several positive implications such as good fast-particle confine
Externí odkaz:
http://arxiv.org/abs/2311.14439
Autor:
Podavini, L., Zocco, A., García-Regaña, J. M., Barnes, M., Parra, F. I., Mishchenko, A., Helander, P.
Electrostatic gyrokinetic instabilities and turbulence in the Wendelstein 7-X stellarator are studied. Particular attention is paid to the ion-temperature-gradient (ITG) instability and its character close to marginal stability [Floquet-type turbulen
Externí odkaz:
http://arxiv.org/abs/2311.04342
Autor:
Plunk, G. G., Helander, P.
Publikováno v:
Journal of Plasma Physics , Volume 90 , Issue 2 , April 2024 , 905900205
The gyrokinetic theory of the residual flow, in the electrostatic limit, is revisited, with optimized stellarators in mind. We consider general initial conditions for the problem, and identify cases that lead to a non-zonal residual electrostatic pot
Externí odkaz:
http://arxiv.org/abs/2310.14218
Available energy (\AE{}), which quantifies the maximum amount of thermal energy that may be liberated and converted into instabilities and turbulence, has shown to be a useful metric for predicting saturated energy fluxes in trapped-electron-mode-dri
Externí odkaz:
http://arxiv.org/abs/2307.02304
Autor:
Mackenbach, R. J. J., Duff, J. M., Gerard, M. J., Proll, J. H. E., Helander, P., Hegna, C. C.
In this article we provide various analytical and numerical methods for calculating the average drift of magnetically trapped particles across field lines in complex geometries, and we compare these methods against each other. To evaluate bounce-inte
Externí odkaz:
http://arxiv.org/abs/2305.01225
Publikováno v:
Environmental Sciences Europe, Vol 36, Iss 1, Pp 1-16 (2024)
Abstract Background The herbicide glyphosate is the most widely used active ingredient in pesticides globally. Residues have been found in people, livestock, food and animal feed, and in the environment, but little is known about glyphosate residue i
Externí odkaz:
https://doaj.org/article/a51880f6786c41aab95c6006541c41c5
