213 citations · 246 across the 10 of their papers we have counts for
10 papers
SPECTRE: A robust solver for 3D equilibria with arbitrary topology
E. Balkovic, J. Loizu, E. Lanti +6
We present SPECTRE, a new equilibrium code based on the Multi-Region relaxed MHD model for robustly calculating 3D equilibria with general magnetic topology, allowing for flux surf…
Flux pumping and bifurcated relaxations of helical core in 3D magnetohydrodynamic modelling of ASDEX Upgrade plasmas
H. Zhang, M. Hoelzl, I. Krebs +12
Flux pumping was achieved in recent hybrid scenario experiments in the ASDEX Upgrade (AUG) tokamak, which is characterized by a sawtooth-free helical quiescent state and the anomal…
A comparison of low-n Mercier unstable Wendelstein stellarators and quasi-interchange modes in tokamaks
Rohan Ramasamy, Haowei Zhang, Joachim Geiger +5
Mercier's criterion is typically enforced as a hard operational limit in stellarator design. At the same time, past experimental and numerical studies have shown that this limit ma…
Quantitative Magnetohydrodynamic Modelling of Flux Pumping in ASDEX Upgrade
Haowei Zhang, Matthias Hölzl, Isabel Krebs +9
The sawtooth-free hybrid scenario has been achieved recently in ASDEX Upgrade (AUG) with applied non-inductive current sources and auxiliary heating [A. Burckhart et al 2023 Nucl.…
Nonlinear MHD modeling of soft limits in W7-AS
Rohan Ramasamy, Ksenia Aleynikova, Nikita Nikulsin +5
An important question for the outlook of stellarator reactors is their robustness against pressure driven modes, and the underlying mechanism behind experimentally observed soft $β…
How well can VMEC predict the initial saturation of external kink modes in near circular tokamaks and stellarators?
Rohan Ramasamy, Matthias Hoelzl, Sophia Henneberg +3
The equilibrium code, VMEC, is used to study external kinks in low tokamaks and stellarators. The applicability of the code when modelling nonlinear MHD effects is explor…
Modelling of saturated external MHD instabilities in tokamaks: a comparison of 3D free boundary equilibria and nonlinear stability calculations
Rohan Ramasamy, Guillermo Bustos Ramirez, Matthias Hoelzl +5
3D free boundary equilibrium computations have recently been used to model external kinks and edge harmonic oscillations (EHOs), comparing with linear MHD stability codes, and nonl…
JOREK3D: An extension of the JOREK nonlinear MHD code to stellarators
Nikita Nikulsin, Rohan Ramasamy, Matthias Hoelzl +4
Although the basic concept of a stellarator was known since the early days of fusion research, advances in computational technology have enabled the modelling of increasingly compl…
Nonlinear MHD simulations of external kinks in quasi-axisymmetric stellarators using an axisymmetric external rotational transform approximation
Rohan Ramasamy, Matthias Hoelzl, Erika Strumberger +2
Reduced magnetohydrodynamic (MHD) equations are used to study the nonlinear dynamics of external kinks in a quasi-axisymmetric (QA) stellarator with varying fractions of external r…
The JOREK non-linear extended MHD code and applications to large-scale instabilities and their control in magnetically confined fusion plasmas
M Hoelzl, GTA Huijsmans, SJP Pamela +50
JOREK is a massively parallel fully implicit non-linear extended MHD code for realistic tokamak X-point plasmas. It has become a widely used versatile code for studying large-scale…