-
UKAEA-CCFE-CP(19)422019
Plasma detachment needs to be achieved in ITER [1] and future devices such as DEMO to dissipate most of the power in the Scrape-Off-Layer (SOL) and reduce the particle flux reaching the divertor targets. In order to enhance our capability to improve current, and design future tokamaks, we must improve our understanding of the relative effect on det…
-
UKAEA-CCFE-CP(19)282019
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 …
-
UKAEA-CCFE-CP(19)202019
Reducing the plasma power exhaust impacting on plasma facing components during steady state operation is one of the major design issues in future tokamaks such as ITER. Impurity seeding, e.g. with N, is one method of achieving this and has been used for a long time in tokamak research [1]. In this work we exploit a recently developed spectroscopic …
-
UKAEA-CCFE-PR(19)552019
In ITER and DEMO, achieving detachment at lower densities would allow to reduce the amount of impurity seeded and to improve confinement by running at lower separatrix densities. Analytic models predict that a increase of total flux expansion would allow such a reduction in upstream density at detachment. However, both experiments and modelling …
-
UKAEA-CCFE-PR(19)072018
Ray-tracing techniques are applied to divertor filtered imaging, a diagnostic that has long been plagued by polluting reflected light features in metal walled fusion machines. A physically realistic surface reflection model is developed from a Cook-Torrence microfacet BRDF model. Camera calibration images of in-vessel point lights at JET are use…
-
UKAEA-CCFE-PR(18)822018
Recent experiments on TCV have made significant progress toward partial detachment of the outer divertor in neutral beam heated H-mode plasmas. The heating power required to enter H-mode was measured in a range of divertor configurations, finding that, in the vicinity of the PL-H/ne curve, the threshold power is largely independent of the poloidal …
-
UKAEA-CCFE-PR(19)032018
A new 1D divertor plasma code, SD1D, has been used to examine the role of recombination, radiation, and momentum exchange in detachment. Neither momentum or power losses by themselves are found to be sufficient to produce target ion flux rollover in detachment; radiative power losses are required to a) limit and reduce the ionization source and …
-
UKAEA-CCFE-PR(18)362018
This paper further analyses the EDGE2D-EIRENE simulations presented by [Chankin et al (2017 Nucl. Mater. Energy 12 273], of L-mode JET plasmas in vertical-vertical (VV) and vertical-horizontal (VH) divertor configurations. As expected, the simulated outer divertor ionisation source peaks near the separatrix in VV …
-
UKAEA-CCFE-PR(18)232018
Ray-tracing techniques are applied to bolometry, a diagnostic particularly sensitive to machine geometry due to the effect of volume sampling. Sightlines from the ASDEX-Upgrade bolometer foils were ray-traced with a path tracing algorithm, where the optical path is represented by a statistical bundle of ray paths connecting the foil surface with th…
-
CCFE-PR(17)752017
This paper presents the use of a novel modelling technique based around intermittent transport due to filament motion, to interpret experimental profile and fluctuation data in the scrape-off layer (SOL) of JET during the onset and evolution of a density profile shoulder. Three cases are studied at different points in a density ramp experiment wher…
Showing 21 - 30 of 38 UKAEA Paper Results