Results 71 to 80 of about 4,926 (209)

Instabilities and turbulence in stellarators from the perspective of global codes

Nuclear Fusion, 2023
In this work, a comparison of the global gyrokinetic codes EUTERPE and GENE-3D in stellarator configurations of the Large Helical Device (LHD) and the Wendelstein 7-X (W7-X) is carried out.
E. Sánchez, A. Bañón Navarro, F. Wilms, M. Borchardt, R. Kleiber, F. Jenko   +5 more
doaj   +1 more source

Stellar populations

, 2013
This is a summary of my lectures during the 2011 IAC Winter School in Puerto de la Cruz. I give an introduction to the field of stellar populations in galaxies, and highlight some new results. Since the title of the Winter School was {\it Secular Evolution of Galaxies} I mostly concentrate on nearby galaxies, which are best suited to study this theme ...
openaire   +3 more sources

Stellar Prominences [PDF]

Symposium - International Astronomical Union, 1996
I review recent observational and theoretical progress in the study of condensations of cool material trapped in the coronae of rapidly rotating stars. Such condensations were discovered over a decade ago, producing transient moving absorption features in the optical Balmerseries lines.
openaire   +2 more sources

Stellar Oscillons

Annals of the New York Academy of Sciences, 1998
ABSTRACT: We study the weakly nonlinear evolution of acoustic instability of a plane‐parallel polytrope with thermal dissipation in the form of Newton's law of cooling. The most unstable horizontal wavenumbers form a band around zero and this permits the development of a nonlinear pattern theory leading to a complex Ginzburg‐Landau equation (CGLE ...
Umurhan, O. M., Tao, L., Spiegel, E. A.
openaire   +3 more sources

Model for second harmonic ECRH plasma start-up in stellarators

Nuclear Fusion
Plasma ionisation avalanche under constant electric field is well described by classical theory. It is the standard tokamak start-up method. In this work, we investigate an analogous avalanche process driven by electron cyclotron resonance (ECR). This is
C. Albert Johansson, Pavel Aleynikov, Alvaro Cappa, the W7-X Team   +3 more
doaj   +1 more source

Stellar atmospheres

This is a pre-print of a chapter for the Encyclopedia of Astrophysics (edited by I. Mandel, section editor F.R.N.
Puls, Joachim, Herrero, Artemio, Prieto, Carlos Allende   +2 more
openaire   +2 more sources

Extension and its characteristics of ECRH plasma in the LHD

, 2004
One of the main objectives of the LHD is to extend the plasma confinement database for helical systems and to demonstrate such extended plasma confinement properties to be sustained in steady state.
A Komori, A Sagara, Alejaldre C, B J Peterson, Bornatici M, H Funaba, H Idei, H Nakanishi, H Yamada, I Yamada, Iiyoshi A, J Miyazawa, K Ida, K Ikeda, K Itoh, K Kawahata, K Khlopenkov, K Nagaoka, K Narihara, K Nishimura, K Ohkubo, K Saito, K Tanaka, K Toi, K Tsumori, K Watanabe, K Yamazaki, Kubo S, Kubo S, M Emoto, M Goto, M Isobe, M Nishiura, M Osakabe, M Shoji, M Yokoyama, M Yoshinuma, Maassberg H, N Ashikawa, N Noda, N Ohyabu, N Takeuchi, N Tamura, Notake T, O Kaneko, O Motojima, R Kumazawa, R Sakamoto, S Inagaki, S Kubo, S Masuzaki, S Morita, S Murakami, S Muto, S Ohdachi, S Sakakibara, S Sudo, Shimozuma T, Shimozuma T, T Ido, T Kobuchi, T Minami, T Morisaki, T Mutoh, T Notake, T Ozaki, T Seki, T Shimozuma, T Tokuzawa, T Watanabe, T Watari, Y Hamada, Y Nagayama, Y Nakamura, Y Narushima, Y Oka, Y Takeiri, Y Yoshimura, Yokoyama M   +78 more
core   +1 more source

Multiscale turbulence in stellarators

Nuclear Fusion
We present the first gyrokinetic simulations of multiscale turbulence in a stellarator, using the magnetic geometry of Wendelstein 7-X (W7-X) and experimentally relevant parameters. A broad range of scenarios is explored, including regimes where electron-
G. Merlo, A. Bañón Navarro, T. Görler, F. Jenko, F. Wilms   +4 more
doaj   +1 more source

The level of non-thermal velocity fluctuations deduced from Doppler spectroscopy and its role on TJ-II confinement

, 2009
The goal of this investigation is to study, in the line of previous works, the level of velocity fluctuations in different scenarios of the TJ-II stellarator.
Baciero, Dinklage, Landi, McCarthy, Rapisarda, Rapisarda, Zurro   +6 more
core   +1 more source

Global linear drift-wave eigenmode structures on flux surfaces in stellarators: ion temperature gradient mode

Nuclear Fusion
Turbulent transport greatly impacts the performance of stellarator magnetic confinement devices. While significant progress has been made on the numerical front, theoretical understanding of turbulence in stellarators is still lacking. In particular, due
Hongxuan Zhu, H. Chen, Z. Lin, A. Bhattacharjee   +3 more
doaj   +1 more source