UKAEA Journals

Showing 1 - 10 of 20 Journals Results
2020
UKAEA-CCFE-PR(20)77

Anisotropy and some limiting toroidal flow effects on the stability of non resonant ideal magnetohydrodynamic modes in hybrid shaped tokamak plasmas are investigated within the ideal MHD infernal mode framework. Such effects are found to alter the plasma magnetic well/hill, which can be interpreted as imparing the average curvature, and the stre…

Preprint Published
2019
UKAEA-CCFE-PR(19)75

The evolution of the JET high performance hybrid scenario, including central accumulation of the tungsten (W) impurity, is reproduced with predictive multi-channel integrated modelling over multiple confinement times using first-principle based models. 8 transport channels are modelled predictively, with self-consistent sources, radiation and magne…

Preprint Purchase
The published version of this paper is currently under embargo and will be available on 21/05/2021
2019
UKAEA-CCFE-PR(19)21

The JET exploitation plan foresees D-T operations in 2020 (DTE2). With respect to the first D-T campaign in 1997 (DTE1), when JET was equipped with a carbon wall, the experiments will be conducted in presence of a beryllium-tungsten ITER-like wall (ILW) and will benefit from an extended and improved set of diagnostics and higher additional heating …

Preprint Published
2018
UKAEA-CCFE-PR(18)65

During the 2015-2016 JET campaigns many efforts have been devoted to the exploration of high-performance plasma scenarios envisaged for DT operation in JET. In this paper we review various key recent hybrid discharges and model the combined ICRF+NBI heating. These deuterium discharges with deuterium beams had the ICRF antenna frequency tuned to mat…

Preprint Published
2018
UKAEA-CCFE-PR(18)81

Fast ion synergistic effects were studied by predictive modelling of JET best performing pulses for various levels of Neutral Beam (NB) and Radio Frequency (RF) power. Calculated DD neutron yields were analysed with the intention of separating the impact of sheer synergistic effects due to changes in fast ion (FI) distribution function (DF) from su…

Preprint Published
2017
CCFE-PR(17)76

During development of a high-performance hybrid scenario for future deuterium–tritium experiments on the Joint European Torus, an increased level of fast ion losses in the MeV energy range was observed during the instability of high-frequency n = 1 fishbones. The fishbones are excited during deuterium neutral beam injection combined with…

Preprint Published
2014

A non-perturbative magnetohydrodynamic-kinetic hybrid formulation is developed and implemented into the MARS-K code [Liu et al., Phys. Plasmas 15, 112503 (2008)] that takes into account the anisotropy and asymmetry [Graves et al., Nature Commun. 3, 624 (2012)] of the equilibrium distribution of energetic particles (EPs) in particle pitch angle spac…

Published
2013

13MW of electron cyclotron current drive (ECCD) power deposited inside the q = 1 surface is likely to reduce the sawtooth period in ITER baseline scenario below the level empirically predicted to trigger neo-classical tearing modes (NTMs). However, since the ECCD control scheme is solely predicated upon changing the local magnetic shear, it is prud…

Published
2011

Sheared toroidal rotation is found to increase the ideal external kink stability limit, thought to be the ultimate performance limit in fusion tokamaks. However, at rotation speeds approaching a significant fraction of the Alfv´en speed, the toroidal rotation shear drives a Kelvin-Helmholtzlike global plasma instability. Optimising the rotation pr…

Published
2011

Numerical modelling of the effects of ion cyclotron resonance heating (ICRH) on the stability of the internal kink mode suggests that ICRH should be considered as an essential sawtooth control tool in ITER. Sawtooth control using ICRH is achieved by directly affecting the energy of the internal kink mode rather than through modification of the magn…

Published