A. Shepherd B. Pouradier Duteil T. Patton A. Rigoni G. Serianni E. Sartori. A. Pimazzoni
SPIDER (Source for the Production of Ions of Deuterium Extracted from a Radio frequency plasma) is the full scale prototype for the ITER Heating Neutral Beam (HNB) source. Driven by four driver coil pairs powered by oscillators the SPIDER source plasma exhibits fluctuations in a range of frequencies that have been observed by Langmuir probes and So…
PreprintA. Shepherd R. Akers A. Barth I.E. Day G. Fishpool R. McAdams R. Tivey R. Verhoeven
Neutral beam injection is one of the primary auxiliary heating systems for tokamak plasmas. Once the neutral beam leaves the neutraliser collisions with background neutral particles in the beamline and tokamak vessel re-ionises part of the neutral beam. These particles can be deflected by the tokamak magnetic field, potentially damaging unshielded …
Preprint PublishedI. 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 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 Published