UKAEA Papers

Showing 11 - 20 of 236 UKAEA Paper Results
2022
UKAEA-CCFE-PR(22)06

Intermittent fluctuations in the boundary of magnetically confined plasmas are investigated by numerical turbulence simulations of a reduced fluid model describing the evolution of the plasma density and electric drift vorticity in the two-dimensional plane perpendicular to the magnetic field. Two different cases are considered, one describing resi…

Preprint Published
2022
UKAEA-CCFE-PR(22)05

The analysis of quiescent discharges exhibiting edge harmonic magnetoydrodynamic activity in the JET-Carbon wall machine is presented. It is observed that the quiescent phase with multiple-n harmonic oscillations is sustained until a threshold in pedestal electron density and collisionality is crossed. The macroscopic pedestal parameters associated…

Preprint Published
2022
UKAEA-CCFE-PR(22)03

This paper reports on the development of reduced models for electron temperature gradient (ETG) driven transport in the pedestal. Model development is enabled by a set of 61 nonlinear gyrokinetic simulations with input parameters taken from the pedestals in a broad range of experimental scenarios. The simulation data has been consolidated in a new …

Preprint
2022
UKAEA-CCFE-PR(22)01

Electromagnetic instabilities and turbulence driven by the electron-temperature gradient are considered in a local slab model of a tokamak-like plasma, with constant equilibrium gradients (including magnetic drifts but no magnetic shear). The model describes perturbations at scales both larger and smaller than the electron inertial scale de

Preprint
2022
UKAEA-CCFE-CP(22)01

Plenary talk for EPS. First paragraph of abstract: Fusion reactors need to achieve many things simultaneously – this is integration. Embracing it is part of the transition the fusion community is now making, and it brings opportunities as well as challenges: a better solution or more margin in one technical or operation area could enable/be en…

Preprint Published
2019
UKAEA-CCFE-PR(19)79

The exhaust (loss) power components due to ELMs, radiation and heat transport across the edge transport barrier (ETB) between ELMs are quantifed for H-mode plasmas in JET-C and JET-ILW to provide data for comparison with simulations of pedestal heat transport. In low-current, JET-ILW pulses with a low rate of gas fuelling, the pedestal heat tran…

Preprint Published
2021
UKAEA-CCFE-PR(21)82

The benefits of an optimised Super-X divertor configuration in mitigating the steady-state power and particle fluxes to the surfaces of the MAST Upgrade divertor have been quantified by performing a detailed comparison with a conventional divertor for the first time.  In otherwise identical plasmas with conventional and Super-X divertor configu…

Preprint
2021
UKAEA-CCFE-PR(21)81

The impact of plasma shaping through magnetic well modifications on the stability of resistive ballooning modes in tokamaks is analysed, also including finite diamagnetic flows. Various limiting cases of the dispersion relation, obtained by matching the averaged ballooning equation across the ideal and resistive layers, are analysed. It is found th…

Preprint
2021
UKAEA-CCFE-PR(21)80

This article reports the first observation of the high-field side high density (HFSHD) in the limiter devices. In the J-TEXT high density discharges, the high-density front at the HFS scrape-off layer (SOL) region edge has been clearly identified by the far-infrared laser polarimeter-interferometer. The HFSHD forms at the HFS SOL, and then expan…

Preprint Purchase
The published version of this paper is currently under embargo and will be available on 27/10/2022