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UKAEA-CCFE-CP(23)272021
Disruptions pose a serious challenge for future tokamak power plants; at the large stored thermal and magnetic energies of ITER and DEMO plasmas, the heat loads and electromagnetic forces during disruptions must be mitigated. With this objective, JET experiments employing impurity shattered pellet injection (SPI) have recently been undertaken. W…
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UKAEA-CCFE-CP(23)192021
Control of plasma H:D isotope mix using solely shallow pellets (in H or D) was demonstrated in recent experiments, attaining ~50%:50% ratio. The isotope mix propagates from the edge to the core on the confinement timescale. Isotope dependence of energy confinement is within error bar to scaling laws. A dataset is collected for different pellet s…
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UKAEA-CCFE-CP(23)132021
JET has investigated one the key issues for the baseline scenario in ITER, the integration of a radiative divertor for heat load control with the use of neon and nitrogen as seed impurity. A characterization of the choice of the impurity seed on plasma confinement, neutrons, pedestal MHD stability, pedestal instabilities, core transport is given…
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UKAEA-CCFE-CP(21)122021
This contribution outlines a strategy for assessing tritium (T) inventory in plasma facing components (PFC) during JET T operations. It is based on retention as a fraction of fuel injected in-vessel, currently reported as 0.24% for 2011-2012 operating period, in conjunction with the planned T pulse schedule providing fueling of 4 g T injected per d…
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UKAEA-CCFE-CP(21)082021
The pedestal plays an important role in determining the confinement in tokamak H-mode plasmas. However, the steep pressure gradients in this transport barrier also lead to edge localized modes (ELMs) [1]. There is good understanding of the pedestal in type I ELM regimes [2], however, type I ELMs are known to damage plasma facing components and f…
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UKAEA-CCFE-PR(21)672021
Using the PION ICRH modelling code on JET tokamak pulses, the effect of including pitch angle dependence within the RF diffusion operator is investigated. This is found to be of greatest importance to the particle distribution function in cases of higher harmonic heating and lower heating ion mass, resulting in faster drop-off of the distribution 
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UKAEA-CCFE-PR(21)362021
The interaction of Alfvén Eigenmodes (AEs) and energetic particles will determine the success of future tokamaks. In JET, eight in-vessel antennas were installed to actively probe stable AEs with frequencies ranging 25 – 250 kHz and toroidal mode numbers abs(n)< 20. During the 2019-2020 deuterium campaign, almost 7500 resonances and …
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UKAEA-CCFE-PR(21)302021
Recent JET Deuterium experiments with an advanced internal transport barrier (ITB) scenario have been performed to clearly observe destabilised toroidicity-induced Alfvén eigenmodes (TAEs) by fast ions; interestingly, these also exhibit unstable electromagnetic (EM) perturbations in the sub-TAE frequency range. We identify such EM perturbations to…
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UKAEA-CCFE-PR(21)262021
The first divertor was installed in the JET machine between 1992 and 1994 and was operated with carbon tiles and then beryllium tiles in 1994-5. Post-mortem studies after these first experiments demonstrated that most of the impurities deposited in the divertor originate in the main chamber, and that asymmetric deposition patterns generally favouri…
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UKAEA-CCFE-PR(21)072021
A study of a dataset of JET plasma with the Be/W ITER-like wall (JET-ILW) shows that reaching the edge MHD ballooning limit leads to confinement degradation. However, unlike JET plasma with a carbon wall (JET-C), the JET-ILW plasma stays in a marginal dithering phase for a relatively long period, associated with a higher a ( 20%) H-mode density lim…
Showing 51 - 60 of 229 UKAEA Paper Results