UKAEA Journals

Showing 1 - 10 of 10 Journals Results
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
2015
CCFE-PR(17)35

The JET tokamak is unique amongst present fusion devices in its capability to operate at high plasma current, providing the closest plasma parameters to ITER. The physics benefits of high current operation have to be balanced against the risks to the integrity of the machine due to high force disruptions. The installation of the ITER-Like Wall (ILW…

Preprint Published
2015
CCFE-PR(15)31

New experiments in 2013-2014 have investigated the physics responsible for the decrease in H-mode pedestal confinement observed in the initial phase of JET-ILW operation (2012 Experimental Campaigns). The effects of plasma triangularity, global beta and neutrals on pedestal confinement and stability have been investigated systematically. The stabil…

Preprint Published
2015
CCFE-PR(15)09

The replacement of the JET carbon wall (C-wall) by a Be/W ITER-like wall (ILW) has affected the plasma energy confinement. To investigate this, experiments have been performed with both the C-wall and ILW to vary the heating power over a wide range for plasmas with different shapes. It was found that the power degradation of thermal energy confinem…

Preprint Published
2015
CCFE-PR(15)76

Ion cyclotron resonance frequency (ICRF) heating has been an essential component in the development of high power H-mode scenarios in JET-ILW. The steps that were taken for the successful use of ICRF heating in terms of enhancing the power capabilities and optimizing the heating performance in view of core impurity mitigation in these experiments w…

Preprint Published
2014

In order to preserve the integrity of large tokamaks such as ITER, the number of disruptions has to be limited. JET has operated previously with a low frequency of disruptions (i.e., disruption rate) of 3.4% [P. C. de Vries et al., Nucl. Fusion 51, 053018 (2011)]. The start of operations with the new full-metal ITER-like wall at JET showed a marked…

Published
2014

The ITER-like wall (ILW) at JET is a unique opportunity to study the combination of material (beryllium and tungsten) that will be used for the plasma facing components (PFC) in ITER. Both the limiters (Be) and divertor (CFC W coated and bulk W) have been designed to maximise their power handling capability. During the last experimental campaign (O…

Published
2013

The aim of the JET ITER-like Wall Project was to provide JET with the plasma facing material combination now selected for the DT phase of ITER (bulk beryllium main chamber limiters and a full tungsten divertor) and, in conjunction with the upgraded neutral beam heating system, to achieve ITER relevant conditions. The design of the bulk Be plasma fa…

Published
2009

Experiments on the Alcator C-Mod and JET tokamaks with identical values of nondimensional variables at the pedestal top are expected to have the same local plasma transport for a ratio > 4 in absolute size and thus can help to clarify other effects in pedestal formation. At the high and low fields (7.9 T, 1.4 T respectively) involved, natural-densi…

Published
2006

We present a study performed in ASDEX Upgrade H mode regime based on results from the broadband FM-CW reflectometry diagnostic, equipped with the unique capability of measuring the plasma density profile both at the low and high field sides of the tokamak. The plasma edge dynamics due to fast events such as the Edge Localized Modes (ELMs) is analyz…

Published