Results 81 to 90 of about 1,247 (174)

Near-edge beta induced Alfven eigenmode in DIII-D high bootstrap current fraction plasmas

Nuclear Fusion
In DIII-D high bootstrap current fraction plasmas heated solely by neutral beam injection, a fast ion-driven Beta-Induced Alfven Eigenmode (BAE) is frequently observed.
X. Jian, C. Holland, V. Chan, Z. Qiu, E. Bass, S. Ding, X. Du, Y. Zou, A. Garofalo, G. Yu, J. McClenaghan   +10 more
doaj   +1 more source

Geodesic acoustic modes in a fluid model of tokamak plasma : the effects of finite beta and collisionality

, 2015
Starting from the Braginskii equations, relevant for the tokamak edge region, a complete set of nonlinear equations for the geodesic acoustic modes (GAM) has been derived which includes collisionality, plasma beta and external sources of particle ...
Gurcan, Ozgur D, Hennequin, Pascale, Morel, Pierre, Singh, Raghvendra, Singh, Rameswar, Storelli, A, Vermare, L   +6 more
core   +3 more sources

Understanding turbulence suppression in JET D–T plasma with highly energetic fast ions via global gyrokinetic GENE simulations

Nuclear Fusion
This study focuses on understanding how turbulence is suppressed in particularly heated JET plasma discharges showing enhanced confinement, namely $99896$ , which uses a nearly 50–50 deuterium–tritium mixture, showing signs of enhanced plasma confinement.
A. Di Siena, J. Garcia, G. Merlo, A. Bañón Navarro, F. Sheffield, E. Poli, A. Ishizawa, Ye.O. Kazakov, J. Varela, T. Görler, F. Jenko, JET Contributors, the EUROfusion Tokamak Exploitation Team   +12 more
doaj   +1 more source

Gyrokinetics from variational averaging: existence and error bounds

, 2017
The gyrokinetic paradigm in the long wavelength regime is reviewed from the perspective of variational averaging (VA). The VA-method represents a third pillar for averaging kinetic equations with highly-oscillatory characteristics, besides classical ...
Possanner, Stefan
core   +1 more source

Enhancing predictive capabilities in fusion burning plasmas through surrogate-based optimization in core transport solvers

Nuclear Fusion
This work presents the PORTALS framework (Rodriguez-Fernandez et al 2022 Nucl. Fusion 62 076036), which leverages surrogate modeling and optimization techniques to enable the prediction of core plasma profiles and performance with nonlinear gyrokinetic ...
P. Rodriguez-Fernandez, N.T. Howard, A. Saltzman, S. Kantamneni, J. Candy, C. Holland, M. Balandat, S. Ament, A.E. White   +8 more
doaj   +1 more source

Current Sheets and Collisionless Damping in Kinetic Plasma Turbulence

, 2013
We present the first study of the formation and dissipation of current sheets at electron scales in a wave-driven, weakly collisional, 3D kinetic turbulence simulation.
Howes, G. G., TenBarge, J. M.
core   +1 more source

Viriato: a Fourier-Hermite spectral code for strongly magnetised fluid-kinetic plasma dynamics

, 2015
We report on the algorithms and numerical methods used in Viriato, a novel fluid-kinetic code that solves two distinct sets of equations: (i) the Kinetic Reduced Electron Heating Model (KREHM) equations [Zocco & Schekochihin, Phys.
Dorland, W., Fazendeiro, L., Kanekar, A., Loureiro, N. F., Mallet, A., Vilelas, M. S., Zocco, A.   +6 more
core   +1 more source

Kinetic-ballooning-limited pedestals in spherical tokamak plasmas

Nuclear Fusion
A theoretical model is presented that for the first time matches experimental measurements of the pedestal width-height Diallo scaling in the low-aspect-ratio high- β tokamak NSTX.
J.F. Parisi, W. Guttenfelder, A.O. Nelson, R. Gaur, A. Kleiner, M. Lampert, G. Avdeeva, J.W. Berkery, C. Clauser, M. Curie, A. Diallo, W. Dorland, S.M. Kaye, J. McClenaghan, F.I. Parra   +14 more
doaj   +1 more source

Destabilization of geodesic acoustic-like mode in the presence of poloidally inhomogeneous heat sources in tokamak plasmas

Nuclear Fusion
The effects of poloidally inhomogeneous heat sources are investigated through a gyrokinetic formula in collisionless toroidal plasmas. A gyrokinetic dispersion relation is newly derived under the assumption that equilibrium parallel heat flows are ...
Young-Hoon Lee, Jungpyo Lee
doaj   +1 more source

Energetic Consistency and Momentum Conservation in the Gyrokinetic Description of Tokamak Plasmas

, 2010
Gyrokinetic field theory is addressed in the context of a general Hamiltonian. The background magnetic geometry is static and axisymmetric, and all dependence of the Lagrangian upon dynamical variables is in the Hamiltonian or in free field terms ...
B. Scott, Catto P. J., Gelfand I. M., J. Smirnov   +3 more
core   +1 more source