Conference Papers

Showing 1 - 5 of 5 Conference Paper Results
2020
UKAEA-CCFE-CP(20)99
27th IAEA Fusion Energy Conference, Ahmedabad, India, 22-27 October 2018

Unraveling the conditions that permit access to H-mode continues to be an unresolved physics issue for tokamaks, and accurate extrapolations are important for planning ITER operations and DEMO design constraints. Experiments have been performed in JET, with the ITER-like W/Be wall, to increase the confidence of predictions for the L-H transition po…

Preprint Published
2020
UKAEA-CCFE-CP(20)71
27th IAEA Fusion Energy Conference, Ahmedabad, India, 22-27 October 2018

The fast-ion transport has been investigated in low-collisionality discharges at ASDEX Upgrade and TCV using offaxis neutral beams. In both devices Alfven eigenmode activity was observed which does, however, not strongly affect the global fast-ion confinement. In contrast, charge exchange losses have been identified to have a strong effect. At TCV …

Preprint
2019
UKAEA-CCFE-CP(19)28
27th IAEA Fusion Energy Conference, Ahmedabad, India, 22-27 October 2018

A detailed cross-device investigation on the role of filamentary dynamics in high density regimes has been performed within the EUROfusion framework comparing ASDEX-Upgrade (AUG) and TCV tokamaks. Both devices have run density ramp experiments at different levels of plasma current, keeping toroidal field or q95 constant in order to disentangle the …

Preprint Published
2019
UKAEA-CCFE-CP(19)11
22nd Topical Conference on High Temperature Plasma Diagnostics (HTPD), San Diego, USA, 16-19 April 2018

Ion cyclotron emission (ICE) is a commonly observed feature of magnetized toroidal plasmas in the presence of fast ions. It is generally agreed that this emission is caused by a strongly inverted (in the velocity space) population of confined fast ions originating from either neutral beam injection (NBI), fusion reactions, or acceleration by waves …

Preprint Published
2018
UKAEA-CCFE-CP(18)04
27th IAEA Fusion Energy Conference, Ahmedabad, India, 22-27 October 2018

An edge resonant transport layer has been found to explain many aspects of fast-ion confinement under symmetry breaking 3D edge perturbations, such as edge localized modes (ELMs) and externally applied magnetic perturbations (MPs). Experimental measurements in the ASDEX Upgrade (AUG) tokamak show that fast-ion losses in the presence of symmetry bre…

Preprint Published