Coarse-grained gyrokinetics for the critical ion temperature gradient in stellarators
Physical Review Research, 2022 We present a modified gyrokinetic theory to predict the critical gradient that determines the linear onset of the ion temperature gradient (ITG) mode in stellarator plasmas.
G. T. Roberg-Clark +2 more
doaj +1 more source
On L to H-mode transitions of the tokamak and entropy reduction [PDF]
Nuclear Technology and Radiation Protection, 2006 In an ideal case, it is assumed that the models for tokamak and stellarator plasma behaviour lead to the theory of invariant manifolds by Rastović [Chaos, Solitons & Fractals, 2007]. But, at the present state of knowledge a more realistic concept for
Rastović Danilo
doaj +1 more source
Prevention of core particle depletion in stellarators by turbulence
Physical Review Research, 2023 In reactor-relevant plasmas, neoclassical transport drives an outward particle flux in the core of large stellarators and predicts strongly hollow density profiles. However, this theoretical prediction is contradicted by experiments.
H. Thienpondt +12 more
doaj +1 more source
Multi-Hop Index Modulation-Aided OFDM With Decode-and-Forward Relaying
IEEE Access, 2018 In this paper, we propose a multi-hop index modulation-aided orthogonal frequency-division multiplexing (IM-aided OFDM) system, which employs decode-and-forward (DF) relaying techniques to enable the transmission of information from source to destination
Zhongli Wang +2 more
doaj +1 more source
Perturbing an axisymmetric magnetic equilibrium to obtain a quasi-axisymmetric stellarator
, 2020 It is demonstrated that finite-pressure, approximately quasi-axisymmetric stellarator equilibria can be directly constructed (without numerical optimization) via perturbations of given axisymmetric equilibria.
Plunk, G. G.
core +1 more source
Distinct turbulence saturation regimes in stellarators [PDF]
, 2017 In the complex 3D magnetic fields of stellarators, ion-temperature-gradient turbulence is shown to have two distinct saturation regimes, as revealed by petascale numerical simulations, and explained by a simple turbulence theory.
Helander, P. +2 more
core +3 more sources
Identification of important error fields in stellarators using Hessian matrix method [PDF]
, 2019 Error fields are predominantly attributed to inevitable coil imperfections. Controlling error fields during coil fabrication and assembly is crucial for stellarators.
127313 +13 more
core +3 more sources
Impurity transport in a mixed-collisionality stellarator plasma [PDF]
, 2017 A potential threat to the performance of magnetically confined fusion plasmas is the problem of impurity accumulation, which causes the concentration of highly charged impurity ions to rise uncontrollably in the center of the plasma and spoil the energy ...
Helander, Per +3 more
core +2 more sources
Optimization of flux-surface density variation in stellarator plasmas with respect to the transport of collisional impurities [PDF]
, 2019 Avoiding impurity accumulation is a requirement for steady-state stellarator operation. The accumulation of impurities can be heavily affected by variations in their density on the flux-surface.
Buller, Stefan +4 more
core +2 more sources
Ideal MHD theory of low-frequency Alfven waves in the H-1 Heliac [PDF]
, 2012 A part analytical, part numerical ideal MHD analysis of low-frequency Alfven wave physics in the H-1 stellarator is given. The three-dimensional, compressible ideal spectrum for H-1 is presented and it is found that despite the low beta (approx.
B D Blackwell +11 more
core +1 more source