UKAEA Journals

Showing 1 - 10 of 16 Journals Results
2021
UKAEA-CCFE-PR(21)62

Drift-reduced MHD models are widely used to study magnetised plasma phenomena, in particular for magnetically con ned fusion applications, as well as in solar and astrophysical research. This letter discusses the choice of Ohm’s law in these models, the resulting dispersion relations for the dynamics parallel to the magnetic field, and the impli…

Preprint
2021
UKAEA-CCFE-PR(21)45

Transport processes around the magnetic X-point of tokamaks, such as turbulence and mean-field drifts, are scarcely understood and difficult to investigate in experiments. In this paper, we explore the dynamics in a newly developed X-point scenario on the basic toroidal plasma device TORPEX and use it to validate plasma edge turbulence codes. In-si…

Preprint
2019
UKAEA-CCFE-PR(21)62

We present the rst parallel electron transport results obtained using the newly developed 1D transport code SOL-KiT. In order to properly predict divertor heat loads it is of key importance to develop a thorough understanding of discrepancies between diff erent parallel transport modelling approaches. With the capability to self-consistently s…

Preprint Published
2018
UKAEA-CCFE-PR(20)110

The role of magnetic perturbations generated by filaments in the scrape-off layer is investigated by performing simulations of 3D seeded filaments with an electromagnetic numerical code which includes sheath boundary conditions. Depending on the plasma , three smoothly connecting regimes were identified: an electrostatic regime where the magnet…

Preprint Published
2019
UKAEA-CCFE-PR(19)16

The STORM module of BOUT++ [L. Easy et al., Phys. Plasmas 21, 122515 (2014)] is generalized to simulate plasma turbulence at the periphery of tokamak devices in diverted configuration and it is used to carry out three-dimensional nonlinear flux-driven simulations in double null configuration with realistic experimental par…

Preprint Published
2018
UKAEA-CCFE-PR(18)19

A statistical framework was introduced in textit{Militello et al., Nucl. Fusion 56, 104004 (2016)} to correlate the dynamics and statistics of L-mode and inter-ELM plasma filaments with the radial profiles of thermodynamic quantities they generate in the Scrape Off Layer. This paper extends the framework to cases in which the filaments are emitted …

Preprint Published
2016
CCFE-PR(16)63

In tokamak transport barriers, the radial scale of profile variations can be comparable to a typical ion orbit width, which makes the coupling of the distribution function across flux surfaces important in the collisional dynamics. We use the radially global steady-state neoclassical f code Perfect to calculate poloidal and toroidal flows, and radi…

Preprint Published
2016
CCFE-PR(16)56

Neutral atoms can strongly influence the intrinsic rotation and radial electric field at the tokamak edge. Here, we present a framework to investigate these effects when the neutrals dominate the momentum transport. We explore the parameter space numerically, using highly flexible model geometries and a state of the art kinetic solver. We find that…

Preprint Published
2016
CCFE-PR(16)44

A theoretical framework is developed to clarify the relation between the profiles of density and temperature in the Scrape Off Layer (SOL) with the fluctuations (filaments) that generate them. The framework is based on the dynamics of independent filaments and on their statistical behaviour and can be used to rigorously understand the mechanisms th…

Preprint Published
2016
CCFE-PR(16)38

Simulations have been carried out to establish how electron thermal physics, introduced in the form of a dynamic electron temperature, affects isolated filament motion and dynamics in 3D. It is found that thermal effects impact filament motion in two major ways when the filament has a significant temperature perturbation compared to its density per…

Preprint Published