73 citations
Counting papers with at most 25 authors, so collaboration author lists do not stand in for the people here.
- Seoul National UniversityKR11 papers
- Pohang University of Science and TechnologyKR8 papers
- Korea Advanced Institute of Science and TechnologyKR7 papers
- University of California San DiegoUS6 papers
- Commissariat à l'Énergie Atomique et aux Énergies AlternativesFR5 papers
- Princeton Plasma Physics LaboratoryUS5 papers
- Ulsan National Institute of Science and TechnologyKR5 papers
- CEA CadaracheFR4 papers
- General Atomics (United States)US4 papers
- Princeton UniversityUS4 papers
- Southwestern Institute of PhysicsCN4 papers
- Columbia UniversityUS3 papers
39 papers · 1 filter
Gyrokinetic simulations on zonal flow-turbulence spreading coupling
Min Ki Jung, Sumin Yi, Taik Soo Hahm +1
Zonal flows and turbulence spreading play important roles in magnetic fusion plasma confinement, yet their coupling mechanisms remain elusive. Using global nonlinear gyrokinetic si…
Friction-induced scale-selection in the extended Cahn-Hilliard model for zonal staircase
M. Leconte, T. S. Hahm
In this work, we describe a possible mechanism to set the radial scale of zonal flows, which may be applicable to the staircase found in the global full-f simulations…
Inhomogeneous mixing: From microscopic dynamics to mesoscopic staircases
T. Long, M. J. Choi, P. H. Diamond
Inhomogeneous mixing and the consequent mesoscopic layered structure have been observed in many physical systems, including magnetically confined fusion plasmas. Especially, in pla…
Control of pedestal-top electron density using RMP and gas puff at KSTAR
Minseok Kim, S. K. Kim, A. Rothstein +20
We report the experimental results of controlling the pedestal-top electron density by applying resonant magnetic perturbation with the in-vessel control coils and the main gas puf…
TorbeamNN: Machine learning based steering of ECH mirrors on KSTAR
Andrew Rothstein, Minseok Kim, Minho Woo +12
We have developed TorbeamNN: a machine learning surrogate model for the TORBEAM ray tracing code to predict electron cyclotron heating and current drive locations in tokamak plasma…
Gyrokinetic simulations of the effects of magnetic islands on microturbulence in KSTAR
Xishuo Wei, Javier H Nicolau, Gyungjin Choi +8
Gyrokinetic simulations are utilized to study effects of magnetic islands on the ion temperature gradient (ITG) turbulence in the KSTAR tokamak with resonant magnetic perturbations…
Leveraging turbulence data from fusion experiments
Minjun J. Choi
Various methods for leveraging turbulent fluctuation measurements from fusion plasma experiments are introduced, along with selected application examples. These can be categorized…
Exploring relaxation dynamics in warm dense plasmas by tailoring non-thermal electron distributions with a free electron laser
Yuanfeng Shi, Shenyuan Ren, Hyun-kyung Chung +2
Knowing the characteristic relaxation time of free electrons in a dense plasma is crucial to our understanding of plasma equilibration and transport. However, experimental investig…
Operational Space and Plasma Performance with an RMP-ELM Suppressed Edge
C. Paz-Soldan, S. Gu, N. Leuthold +14
The operational space and global performance of plasmas with edge-localized modes (ELMs) suppressed by resonant magnetic perturbations (RMPs) are surveyed by comparing AUG, DIII-D,…
Effect of temperature anisotropy on the dynamics of geodesic acoustic modes
J. N. Sama, A. Biancalani, A. Bottino +7
In this work, we revisit the linear gyro-kinetic theory of geodesic acoustic modes (GAMs) and derive a general dispersion relation for an arbitrary equilibrium distribution functio…
The constraint of plasma power balance on runaway avoidance
Christopher J. McDevitt, Xian-Zhu Tang, Christopher J. Fontes +2
In a post-thermal-quench plasma, mitigated or unmitigated, the plasma power balance is mostly between collisional or Ohmic heating and plasma radiative cooling. In a plasma of atom…
Mesoscopic transport in KSTAR plasmas: avalanches and the staircase
Minjun J. Choi, Jae-Min Kwon, Lei Qi +18
The self-organization is one of the most interesting phenomena in the non-equilibrium complex system, generating ordered structures of different sizes and durations. In tokamak pla…
Gyrokinetic modelling of anisotropic energetic particle driven instabilities in tokamak plasmas
Brando Rettino, Thomas Hayward-Schneider, Alessandro Biancalani +5
Energetic particles produced by neutral beams are observed to excite energetic-particle-driven geodesic acoustic modes (EGAMs) in tokamaks. We study the effects of anisotropy of di…
Zonal profile corrugations and staircase formation: Role of the transport crossphase
M. Leconte, T. Kobayashi
Recently, quasi-stationary structures called staircases were observed in gyrokinetic simulations, in all transport channels [Dif-Pradalier et al. Phys. Rev. Lett. 114,…
Limit Cycle Oscillations, response time and the time-dependent solution to the Lotka-Volterra Predator-Prey model
M. Leconte, P. Masson, Lei Qi
In this work, the time-dependent solution for the Lotka-Volterra Predator-Prey model is derived with the help of the Lambert W function. This allows an exact analytical expression…
Stochastic fluctuation and transport of tokamak edge plasmas with the resonant magnetic perturbation field
Minjun J. Choi, Jae-Min Kwon, Juhyung Kim +17
We present that a statistical method known as the Complexity-Entropy analysis is useful to characterize a state of plasma turbulence and flux in the resonant magnetic perturbation…
Phase-mixing v.s. phase synchronization in the dynamics of flow-shear induced edge transport barrier
M. Leconte
Nonlinear relaxation oscillations of flow-shear induced transport barriers can be qualitatively reproduced using a phenomenological critical-gradient model [M. Leconte, Y.M. Jeon a…
Deep neural network Grad-Shafranov solver constrained with measured magnetic signals
Semin Joung, Jaewook Kim, Sehyun Kwak +7
A neural network solving Grad-Shafranov equation constrained with measured magnetic signals to reconstruct magnetic equilibria in real time is developed. Database created to optimi…
Effects of zonal flows on transport crossphase in dissipative trapped-electron mode turbulence in edge plasmas
M. Leconte, R. Singh
For H-mode, standard decorrelation theory predicts that it is the turbulence intensity that is mainly affected via flow-induced shearing of turbulent eddies. However, for…
Effects of plasma turbulence on the nonlinear evolution of magnetic island in tokamak
Minjun J. Choi, Laszlo Bardoczi, Jae-Min Kwon +7
Magnetic islands (MIs), resulting from a magnetic field reconnection, are ubiquitous structures in magnetized plasmas. In tokamak plasmas, recent researches suggested that the inte…
Impact of free electron degeneracy on collisional rates in plasmas
Gareth O. Williams, H. -K. Chung, S. Künzel +19
Degenerate plasmas, in which quantum effects dictate the behavior of free electrons, are ubiquitous on earth and throughout space. Transitions between bound and free electron state…
Observation of non-local effects in ion transport channel in J-TEXT plasmas
Yuejiang Shi
In cold pulse experiments in J-TEXT, the ion transport shows similar non-local response as the electron transport channel. Very fast ion temperatures decreases are observed in the…
Bayesian with Gaussian process based missing input imputation scheme for reconstructing magnetic equilibria in real time
Semin Joung, Jaewook Kim, Sehyun Kwak +7
A Bayesian with GP(Gaussian Process)-based numerical method to impute a few missing magnetic signals caused by impaired magnetic probes during tokamak operations is developed such…
Distinct stages of radio frequency emission at the onset of pedestal collapse in KSTAR H-mode plasmas
Minho Kim, Shekar G. Thatipamula, Jieun Lee +4
Using a high-speed and broadband radio frequency (RF) (0.1-1 GHz) spectrum analyzer developed on the KSTAR tokamak, it is found that several distinct stages of RF emission appear a…