59 citations · 109 across the 9 of their papers we have counts for
9 papers
Second stability region for gyrokinetics and the L-H transition
R. J. J. Mackenbach, A. Zocco, P. Helander
Using a simple circular tokamak geometry, we show the well-known `second stability region' of MHD-ballooning modes exists for linear gyrokinetics too -- whether electrostatic or el…
SVD-NO: Learning PDE Solution Operators with SVD Integral Kernels
Noam Koren, Ralf J. J. Mackenbach, Ruud J. G. van Sloun +2
Neural operators have emerged as a promising paradigm for learning solution operators of partial differential equa- tions (PDEs) directly from data. Existing methods, such as those…
Available energy of plasmas with small fluctuations
P. Helander, R. J. J. Mackenbach
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…
On the effect of flux-surface shaping on trapped-electron modes in quasi-helically symmetric stellarators
M. J. Gerard, M. J. Pueschel, B. Geiger +5
Using a novel optimization procedure it has been shown that the Helically Symmetric eXperiment (HSX) stellarator can be optimized for reduced trapped-electron-mode (TEM) instabilit…
Trapped-particle precession and modes in quasi-symmetric stellarators and tokamaks: a near-axis perspective
E. Rodriguez, R. J. J. Mackenbach
This paper presents the calculation of the bounce-averaged drift of trapped particles in a near-axis framework for axisymmetric and quasisymmetric magnetic fields that possess up-d…
Available energy of trapped electrons in Miller tokamak equilibria
R. J. J. Mackenbach, J. H. E. Proll, G. Snoep +1
Available energy (Æ), 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 f…
Bounce-averaged drifts: Equivalent definitions, numerical implementations, and example cases
R. J. J. Mackenbach, J. M. Duff, M. J. Gerard +3
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, an…
Constructing precisely quasi-isodynamic magnetic fields
Alan Goodman, Katia Camacho Mata, Sophia A Henneberg +6
We present a novel method for numerically finding quasi-isodynamic stellarator magnetic fields with excellent fast-particle confinement and extremely small neoclassical transport.…
The available energy of trapped electrons and its relation to turbulent transport
R. J. J. Mackenbach, J. H. E. Proll, P. Helander
A collisionless plasma possesses a certain amount of "available energy", which is that part of the thermal energy that can be converted into field energy. Here, a calculation is pr…