-
CCFE-PR(17)282015
The JET flywheel generator converters have operated since 1983 and for over 85,000 pulses. Problems with this plant are discussed, including corrosion, unbalanced flow and arcing within the liquid resistors; starting difficulties on both machines; and failure of the plug-braking transformers at energisiation. In 2012/13 two sets of thrust bearing p…
-
CCFE-PR(15)052015
The aim of the Exhaust Detritiation System (EDS) of the JET Active Gas Handling System (AGHS) is to convert all Q-based species (Q2, Q-hydrocarbons) into Q2O (Q being indifferently H, D or T) which is then trapped on molecular sieve beds (MSB). Regenerating the saturated MSBs leads to the production of tritiated water which is stored in Briggs drum…
-
CCFE-PR(15)1272015
Prolonged operation of the Joint European Torus (JET) in a set-up involving all ITER partners will be beneficial for ITER. Experiments at JET with its ITER-like wall and using a D–T plasma mixture will help to mitigate risks in the ITER research plan. Training of the ITER operators, technicians and engineers at JET will safe valuable time when IT…
-
CCFE-PR(15)462015
A consistent deterioration of global confinement in H-mode experiments has been observed in JET [1] following the replacement of all carbon Plasma Facing Components (PFCs) with an all metal (‘ITER-like’) wall (ILW). This has been correlated to the observed degradation of the pedestal confinement, as lower electron temperature (T e ) values are …
-
CCFE-PR(15)442015
The effects of poloidal asymmetries and heated minority species are shown to be necessary to accurately describe heavy impurity transport in present experiments in JET and ASDEX Upgrade. Plasma rotation, or any small background electrostatic field in the plasma, such as that generated by anisotropic external heating can generate strong poloidal den…
-
CCFE-PR(15)322015
Results of the first dust survey in JET with the ITER - Like Wall (JET - ILW) are presented. The sampling was performed using adhesive stickers from the divertor tiles where the greatest material deposition was detected after the first JET - ILW campaign in 2011 - 2012. The emphasis was especially on metal particles (Be and W) with the aim to deter…
-
CCFE-PR(15)312015
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…
-
CCFE-PR(15)302015
Asymmetrical disruptions may occur during ITER operation and they may be accompanied by large sideways forces and rotation of the asymmetry. This is of particular concern because resonance of the rotating asymmetry with the natural frequencies of the vacuum vessel (and other in-vessel components) could lead to large dynamic amplification of the for…
-
CCFE-PR(15)512015
Drift-reduced plasma fluid models are commonly used in plasma physics for analytic studies and simulations, so the validity of such models must be verified for the regions of parameter space in which tokamak plasmas exist. By deriving and comparing the linear dispersion relations for the drift-wave instability for both a drift-reduced model and a f…
-
CCFE-PR(15)1112015
Recent studies dedicated to the characterisation of in-vessel dust in JET with the new ITER-like wall (ILW) show that dust levels are orders of magnitude lower compared with the latter stages of the carbon-wall (CW) period and are decreasing with operational time. Less than 1 g of dust was recovered in a recent inspection, compared with more than 2…
Showing 151 - 160 of 229 UKAEA Paper Results