40 citations · 91 across the 15 of their papers we have counts for
16 papers · 1 filter
Destabilization of temperature-gradient-driven plasma turbulence by equilibrium flow shear
Haomin Sun, Plamen G. Ivanov, Justin Ball +2
A novel physical mechanism whereby sheared equilibrium flow enables temperature-gradient-driven turbulence is identified. Gyrokinetic simulations of ion-scale plasma turbulence sho…
On the transition to large fluxes and access to second stability in gyrokinetic simulations of electromagnetic turbulence in STEP
Daniel Kennedy, Yujia Zhang, Toby Adkins +6
This work investigates the nonlinear transition to large heat fluxes observed in local gyrokinetic simulations of electromagnetic turbulence in STEP. Using the stress-balance frame…
Zonal-flow generation and saturation of electromagnetic ion-scale turbulence in tokamaks
Y. Zhang, T. Adkins, M. Barnes +5
Local flux-tube gyrokinetic simulations of ion-scale turbulence in tokamak plasmas at finite plasma beta are conducted to investigate the generation of zonal flows via turbulent st…
High-beta runaway transitions in a fluid model of electromagnetic ion-temperature-gradient turbulence
Y. Zhang, M. Barnes, A. A. Schekochihin +2
Gyrokinetic simulations of tokamak turbulence indicate that fluctuation levels increase abruptly and dramatically when the plasma beta exceeds a certain critical value. This increa…
Scaling laws for the cutoff wavenumber of the short-wavelength ion-temperature-gradient mode in a Z-pinch
O. Gupta, M. Barnes, F. I. Parra +4
We use a heuristic fluid model to predict the dependence of the cutoff wave number for the short-wavelength ion temperature gradient (SWITG) mode on ion density gradient, ion tempe…
Asymptotic scaling theory of electrostatic turbulent transport in magnetised fusion plasmas
T. Adkins, I. G. Abel, M. Barnes +8
Turbulent transport remains one of the principal obstacles to achieving efficient magnetic confinement in fusion devices. Two of the dominant drivers of the turbulence are microsca…
The gyrokinetic field invariant and electromagnetic temperature-gradient instabilities in `good-curvature' plasmas
P. G. Ivanov, P. Luhadiya, T. Adkins +1
Curvature-driven instabilities are ubiquitous in magnetised fusion plasmas. By analysing the conservation laws of the gyrokinetic system of equations, we demonstrate that the well-…
Suppression of temperature-gradient-driven turbulence by sheared flows in fusion plasmas
P. G. Ivanov, T. Adkins, D. Kennedy +3
Starting from the assumption that saturation of plasma turbulence driven by temperature-gradient instabilities in fusion plasmas is achieved by a local energy cascade between a lon…
On the importance of parallel magnetic-field fluctuations for electromagnetic instabilities in STEP
D. Kennedy, C. M. Roach, M. Giacomin +8
[ABRIDGED] This paper discusses the importance of parallel perturbations of the magnetic-field in gyrokinetic simulations of electromagnetic instabilities and turbulence at mid-rad…
Intermittency of density fluctuations and zonal-flow generation in MAST edge plasmas
A. Sladkomedova, I. Cziegler, A. R. Field +5
The properties of the edge ion-scale turbulence are studied using the beam emission spectroscopy (BES) diagnostic on MAST. Evidence of the formation of large-scale high-amplitude c…
Scale invariance and critical balance in electrostatic drift-kinetic turbulence
T. Adkins, P. G. Ivanov, A. A. Schekochihin
The equations of electrostatic drift kinetics are observed to possess a symmetry associated with their intrinsic scale invariance. Under the assumptions of spatial periodicity, sta…
An analytical form of the dispersion function for local linear gyrokinetics in a curved magnetic field
P. G. Ivanov, T. Adkins
Starting from the equations of collisionless linear gyrokinetics for magnetised plasmas with an imposed inhomogeneous magnetic field, we present the first known analytical, closed-…
Dimits transition in three-dimensional ion-temperature-gradient turbulence
Plamen G. Ivanov, Alexander A. Schekochihin, William Dorland
We extend our previous work on the 2D Dimits transition in ion-scale turbulence (Ivanov et al. 2020) to include variations along the magnetic field. We consider a three-field fluid…
Electromagnetic instabilities and plasma turbulence driven by electron-temperature gradient
T. Adkins, A. A. Schekochihin, P. G. Ivanov +1
Electromagnetic (EM) instabilities and turbulence driven by the electron-temperature gradient are considered in a local slab model of a tokamak-like plasma. The model describes per…
Toroidal and slab ETG instability dominance in the linear spectrum of JET-ILW pedestals
Jason F. Parisi, Felix I. Parra, Colin M. Roach +9
Local linear gyrokinetic simulations show that electron temperature gradient (ETG) instabilities are the fastest growing modes for in the steep gradient regio…
Zonally dominated dynamics and Dimits threshold in curvature-driven ITG turbulence
P. G. Ivanov, A. A. Schekochihin, W. Dorland +2
The saturated state of turbulence driven by the ion-temperature-gradient instability is investigated using a two-dimensional long-wavelength fluid model that describes the perturbe…