UKAEA Journals

Showing 1 - 10 of 19 Journals Results
2019
UKAEA-CCFE-PR(19)73

The here presented work studies the dynamics of filaments using 3D full-f fluid simulations in the presence of detached background profiles. It was found that evolving the neutrals on the time-scale of the filament did not have a significant impact on the dynamics of the filament. In general a decreasing filament velocity with increasing plasma den…

Preprint
2019
UKAEA-CCFE-PR(19)50

A model for a beam-driven plasma neutraliser for a 1MeV, 40A beam of D- ions is presented and is based on the dimensions of the ITER gas neutraliser. For the beam-driven plasma neutraliser there is no need for an external power source for producing and sustaining the plasma. Instead the use of high magnetic fields is employed for plasma confinement…

Preprint Published
2019
UKAEA-CCFE-PR(19)11

Increased neutralisation and hence injected neutral beam power can be achieved by increasing the neutraliser target. This has the potential to increase the loading on the ion source backplate due to backstreaming electrons. Measurements of the backplate power loading due to backstreaming electrons are presented for the JET EP2 neutral beam injector…

Preprint Published
2018
UKAEA-CCFE-PR(19)48

A 1D model of an RF driven ion source is presented and is based on the ionisation of thermal electrons. The RF source differs from traditional filament and arc ion sources because there are no primary electrons present, and is simply composed of an antenna region (driver) and a main plasma discharge region. However the model does still make use …

Preprint Published
2018
UKAEA-CCFE-PR(18)35

Nuclear analysis supporting the design and licensing of ITER is traditionally performed using MCNP and the reference model ‘C-Model’, however the complexity of C-Model has resulted in the geometry creation and integration process becoming increasingly time-consuming. Serpent 2 is still a beta code, however recent enhancements mean that it could…

Preprint Published
2018
UKAEA-CCFE-PR(18)21

This paper presents the effect of self-consistent plasma backgrounds including plasma-neutral interactions, on the dynamics of filament propagation. The principle focus is on the influence of the neutrals on the filament through both direct interactions and through their influence on the plasma background. Both direct and indirect interactions infl…

Preprint Published
2016
CCFE-PR(16)46

A summary of negative ion development work being presently undertaken at the Culham Centre for Fusion Energy (CCFE) is given. The Small Negative Ion Facility (SNIF) has an RF driven volume ion source with beam extraction at energies up to 30keV. The extracted beam of Hions has an associated co-extracted electron beam with an electron to ion ratio o…

Preprint Published
2015
CCFE-PR(17)39

In normal operation the JET neutral beam injectors have the operating gas supplied to the ion source and the neutraliser. For tritium operation the gas is supplied to both the ion source and neutraliser at a point close to the earth grid (“grid gas”) due to the difficulty in producing a gas line with a secondary containment and a ceramic break fo…

Preprint Published
2015
CCFE-PR(17)24

Extensive neutronics and 3-D activation simulations were carried out to assess the levels of radiation throughout the ITER tokamak complex. The simulated radiation sources included D–T fusion neutrons exiting the cryostat and gamma rays arising from the activation of cooling water, activated pipe chases and cask transfers. Resultant biological dos…

Preprint Published
2015
CCFE-PR(17)26

For the initial phase of MAST-U operation the two existing neutral beam injection systems will be used, but must be substantially upgraded to fulfil expected operational requirements. The major elements are the design, manufacture and installation of a bespoke bending magnet and Residual Ion Dump (RID) system. The MAST-design full energy dump is b…

Preprint Published