UKAEA Journals

Showing 1 - 10 of 33 Journals Results
2021
UKAEA-CCFE-PR(21)24

Small Angle Neutron Scattering (SANS) is performed to analyse the microstructural state of reference CuCrZr material with carefully controlled heat treatments, small-scale manufacturing mock-ups of assemblies and high-heat-flux exposed mock-ups. The information derived from the SANS data corresponds well to existing literature data based on microsc…

Preprint Published
2020
UKAEA-CCFE-PR(20)114

Achieving high neutron yields in today’s fusion research relies on high power auxiliary heating in order to attain required core temperatures. This is usually achieved by means of high Neutral Beam (NB) and Radio Frequency (RF) power. Application of NB power is accompanied by production of fast beam ions and associated Beam-Target (BT) reactio…

Preprint Published
2019
UKAEA-CCFE-PR(20)19

A study of mixed hydrogen-deuterium H-mode plasmas has been carried out in JET-ILW to strengthen the physics basis for extrapolations to JET D-T operation and to support the development of strategies for isotope ratio control in future experiments. Variations of input power, gas fuelling and isotopic mixture were performed in H-mode plasmas of the…

Preprint Published
2018
UKAEA-CCFE-PR(20)124

NBI-heated L-mode plasmas have been obtained in JET with the Be/W ITER-like wall (JET-ILW) in H and D, with matched profiles of the dimensionless plasma parameters in the plasma core confinement region and same Ti/Te and Zeff. The achieved isotope identity indicates that the confinement scale invariance principle is satisfied in the core confine…

Preprint Published
2019
UKAEA-CCFE-PR(20)08

The initial current ramp phase of JET hybrid plasmas is used to optimise the target q-profile for main heating to allow access to high beta and avoid MHD instabilities. Mixed protium-deuterium experiments, carried out at JET since the installation of the beryllium-tungsten wall, have shown that the q-profile evolution during this Ohmic phase varies…

Preprint Published
2019
UKAEA-CCFE-PR(19)62

The pedestal structure, ELM losses and linear MHD stability are analysed in a series of JET-ILW H and D type I ELMy H-mode plasmas. The pedestal pressure (pPED) is typically higher in D than in H at the same input power, with the difference mainly due to lower density in H than in D. At the same input power, the pedestal electron pres…

Preprint Purchase
The published version of this paper is currently under embargo and will be available on 09/03/2022
2019
UKAEA-CCFE-PR(19)11

Increased neutralisation and hence injected neutral beam power can be achieved by increasing the neutraliser target. This has the potential to increase the loading on the ion source backplate due to backstreaming electrons. Measurements of the backplate power loading due to backstreaming electrons are presented for the JET EP2 neutral beam injector…

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)28

Fishbones are ubiquitous in high-performance JET plasmas and are typically considered to be unimportant for scenario design. However, during recent high-performance hybrid experiments, sporadic and explosive fishbones have been observed which correlate with a reduction in performance and main chamber hotspots. Clear evidence has been obtained of fu…

Preprint Published