I. Turner R. McAdams W. Arter A. Ash M. Barnard D. Ciric I. Day D. Keeling D. King C. Lane M. Nicassio T. Robinson A. Shepherd J. Zacks
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 PublishedI Turner A J T Holmes J Zacks R McAdams
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 PublishedR. McAdams A. J. T. Holmes D. B. King E. Surrey I. Turner J. Zacks
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 PublishedR. McAdams A. Sparkes A. Ash I. Day D. King M. Kovari A. Shepherd I. Turner J. Zacks D. Ciric JET EFDA Contributors
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 PublishedJ. Zacks I. Turner I. Day K. Flinders B. Crowley R. McAdams
The Small Negative Ion Facility (SNIF) at CCFE has been undergoing continuous development and enhancement to both improve operational reliability and increase diagnostic capability. SNIF uses a CW 13.56MHz, 5kW RF driven volume source with a 30kV triode accelerator. Improvement and characterisation work includes: • Installation of a new “L” t…
Preprint Published