UKAEA Journals

Showing 1 - 10 of 44 Journals Results
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
2021
UKAEA-CCFE-PR(21)11

The SOLPS-ITER simulations of European DEMO reactor, with 450 MW of power to be exhausted, show an increased operational space compared to the conventional single-null configuration. Using a reduced model with fluid neutrals and bundled impurities, we assessed the existence and the boundaries of operational space for DEMO with the conventional sing…

Preprint Published
2021
UKAEA-CCFE-PR(21)07

A study of a dataset of JET plasma with the Be/W ITER-like wall (JET-ILW) shows that reaching the edge MHD ballooning limit leads to confinement degradation. However, unlike JET plasma with a carbon wall (JET-C), the JET-ILW plasma stays in a marginal dithering phase for a relatively long period, associated with a higher a ( 20%) H-mode density lim…

Preprint Purchase
The published version of this paper is currently under embargo and will be available on 28/04/2022
2020
UKAEA-CCFE-PR(20)65

A novel approach using Bayesian inference has been implemented to interpret the filamentary dynamics measured by a Langmuir probe fixed to a reciprocating assembly on MAST. The model describes the system as a superposition of time-displaced filaments and a fixed background component. Each filament is parameterised in terms of a characteristic rise …

Preprint Purchase
The published version of this paper is currently under embargo and will be available on 20/10/2021
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)78

A new inversion technique is presented for the identification of plasma filaments in wide-angle visible camera data. Direct inversion of camera data onto a field aligned basis is a poorly conditioned problem which is overcome by breaking the analysis into a `psuedo-inversion’ step followed by a `point spread function correction’ step. Camera …

Preprint Published
2019
UKAEA-CCFE-PR(19)73

The here presented work studies the dynamics of filaments using 3D full-f fluid simulations in the presence of detached background profiles. It was found that evolving the neutrals on the time-scale of the filament did not have a significant impact on the dynamics of the filament. In general a decreasing filament velocity with increasing plasma den…

Preprint
2019
UKAEA-CCFE-PR(19)23

We have modelled self-consistently the most efficient ways to fuel ITER Hydrogen (H), Helium (He) and Deuterium-Tritium (DT) plasmas with gas and/or pellet injection with the integrated core and 2D SOL/divertor suite of codes JINTRAC. As far as we are aware, for ITER this is the first time modelling of the entire plasma has been carried out to foll…

Preprint
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)58

Using a kinetic model for the ions and adiabatic electrons, we solve a steady state, electron-repelling magnetic presheath in which a uniform magnetic field makes a small angle α

Preprint Published