UKAEA Journals

Showing 31 - 36 of 36 Journals Results
2013

Disruptions are of significant concern to future devices, due to the large amount of energy released during the rapid quenching of the plasma. Disruption mitigation has been performed on MAST, to study the effect on heat loads and disruption time scales in a spherical tokamak. Massive gas injection is performed using a disruption mitigation valve c…

Published
2012

The application of resonant magnetic perturbations (RMPs) with a toroidal mode number of n=4 or n=6 to lower single null plasmas in the MAST tokamak produces up to a factor of 5 increase in Edge Localized Mode (ELM) frequency and reduction in plasma energy loss associated with type-I ELMs. A threshold current for ELM mitigation is observed above wh…

Published
2012

The distortion of the plasma boundary when three-dimensional resonant magnetic perturbations are applied has been measured in MAST H-mode plasmas. When the n = 3 resonant magnetic perturbations are applied to control edge localised modes, the plasma experiences a strong toroidal corrugation. The displacement of the plasma boundary is measured at va…

Published
1990

This paper presents the results of experimental studies on a number of different ' current carrying wire' type first grid electron suppressors: or ' inserts', as they shall be called throughout this paper. Extracted negative ion currents are compared for the different inserts over a range of field strengths. Currents are also compared to those extr…

Published
1990

Experiments performed in a volume production negative ion source show that the use of a tent or supercusp magnetic filter leads to a more uniform plasma at the normal extraction plane than that obtained with a dipole filter. For the tent filter geometry the extracted negative ion current density, increased as the accelerator was moved into the sour…

Published
1989

When a suitable accelerating voltage is applied to extract negative ions from a volume production source, electrons are also extracted. If no means of suppression is utilized, the electron current in a hydrogen plasma would typically be of the order of 80-100 times the negative-ion current. In the accelerator designs in use at Culham Laboratory, el…

Published