UKAEA Journals

Showing 1 - 8 of 8 Journals Results
2019
UKAEA-CCFE-PR(20)18

It is demonstrated that tokamak plasma can be fuelled by pellets while simultaneously maintaining ELM suppression by external resonant magnetic perturbations (RMPs). Pellets are injected from vertical high field site and deposited at outer part of plasma cross section. Each pellet triggers benign MHD event followed by short lived ELM free phase. Th…

Preprint Published
2017
CCFE-PR(17)48

The ITER tokamak needs to sustain a plasma in a regime of high energy confinement (H-mode) to exceed fusion breakeven where power output exceeds input. H-mode plasmas are typically unstable to edge localised modes (ELMs), in which plasma escapes and strikes the plasma facing components. Scaled up to ITER, the energy released by ELMs can cause criti…

Preprint
2016
CCFE-PR(16)19

ELM control may be essential to develop ITER scenarios with a reasonable lifetime of divertor components, whilst ELM pacing may be essential to develop stationary ITER scenarios with a tungsten divertor. Resonant magnetic perturbations (RMPs) have mitigated ELMs in high collisionality plasmas in JET. The efficacy of RMPs in mitigating the ELMs is f…

Preprint Published
2016
CCFE-PR(16)09

The complete refuelling of the plasma density loss (pump-out) caused by mitigation of Edge Localised Modes (ELMs) is demonstrated on the ASDEX Upgrade tokamak. The plasma is refuelled by injection of frozen deuterium pellets and ELMs are mitigated by external resonant magnetic perturbations (RMPs). In this experiment relevant dimensionless paramete…

Preprint Published
2016
CCFE-PR(16)82

We focus on JET plasmas in which ELMs are triggered by pellets in the presence of ELMs which occur naturally. We perform direct time domain analysis of signals from fast radial field coils and toroidal full flux azimuthal loops. These toroidally integrating signals provide simultaneous high time resolution measurements of global plasma dynamics and…

Preprint Published
2007

The structural changes during the phase change between the amorphous and crystalline phase in Ge 2 Sb 2 Te 5 have been the subject of intense study due to the importance of Ge 2 Sb 2 Te 5 in phase change memory devices. In our study, the energetics of the transition between the crystalline and the amorphous phase of Ge 2 Sb 2 Te 5 is explored using…

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
2005

Atomistic simulations combining a Monte Carlo algorithm and molecular static relaxations were carried out to predict the alloying profile in pyramid and dome shaped Ge(Si)/Si(001) islands. The results show that the composition profile is dominated by the surface segregation of Ge and segregation of Si to the substrate island interface. Within the i…

Published