R. 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 PublishedJ.D. King E.J. Strait N.M. Ferraro J.M. Hanson S.R. Haskey M.J. Lanctot Y.Q. Liu N.Logan C. Paz-Soldan D. Shiraki A.D. Turnbull
Detailed measurements of the plasmas response to applied magnetic perturbations provide experimental evidence that the form of three-dimensional (3D) tokamak equilibria, with toroidal mode number n = 1, is determined by multiple stable kink modes at high-pressure. For pressures greater than the ideal magnetohydrodynamic (MHD) stability limit, as …
Preprint PublishedS. Zheng D. B. King L. Garzotti E. Surrey T. N. Todd
It has long been recognised that the shortage of external tritium sources for fusion reactors using D-T, the most promising fusion fuel, requires all such fusion power plants (FPP) to breed their own tritium. It is also recognised that the initial start-up of a fusion reactor will require several kilograms of tritium within a scenario in which radi…
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 PublishedA.D. Ash T.T.C. Jones E. Surrey D. Ciric S.I. Hall D. Young M. Afzal L. Hackett I.E. Day R. King JET EFDA Contributors
The JET Neutral Beam Injection (NBI) system is the most powerful neutral beam plasma heating system currently operating. Optical Interlocks were installed on the beam lines in 2011 for the JET Enhancement Project 2 (EP2), when the heating power was increased from 23 MW to 34 MW. JET NBI has two beam lines. Each has eight positive ion injectors oper…
Preprint PublishedC.D. Challis J. Garcia M. Beurskens P. Buratti E. Delabie P. Drewelow L. Frassinetti C. Giroud N. Hawkes J. Hobirk E. Joffrin D. Keeling D.B. King C.F. Maggi J. Mailloux C. Marchetto D. McDonald I. Nunes G. Pucella S. Saarelma J. Simps
The replacement of the JET carbon wall (C-wall) by a Be/W ITER-like wall (ILW) has affected the plasma energy confinement. To investigate this, experiments have been performed with both the C-wall and ILW to vary the heating power over a wide range for plasmas with different shapes. It was found that the power degradation of thermal energy confinem…
Preprint PublishedWayne Arter Member Ieee Elizabeth Surrey Damian.B. King
There is an increasing need to model plasma inter- action with complex engineered surfaces, notably to verify that power deposition rates are acceptable. The SMARDDA algorithm has been developed to meet this requirement, with particular reference to the neutral beam ducts that feed into the vacuum vessels of tokamaks. Application to limiters and di…
PublishedM-L. Mayoral V. Bobkov A. Czarnecka I. Day A. Ekedahl P. Jacquet M. Goniche R. King K. Kirov E. Lerche J. Mailloux D. Van Eester O. Asunta C. Challis D. Ciric J.W. Coenen L. Colas C. Giroud M. Graham I. Jenkins E. Joffrin T. Jones D.
The major aspects linked to the use of the JET auxiliary heating systems: NBI, ICRF and LHCD, in the new JET ITER-like wall (JET-ILW) are presented. We show that although there were issues related to the operation of each system, efficient and safe plasma heating was obtained with room for higher power. For the NBI up to 25.7MW was safely injected;…
PublishedD. A. Homfray K. Deakin S. Khilar R. King D. Payne M. R. Simmonds C. Tame B. Whitehead
Improving the reliability and reducing the maintenance time to give increased availability is a key feature of developing control & instrumentation (C&I) systems relevant to future fusion devices such as DEMO and to fusion power plants. Standardising access to the multiple platforms comprising C&I systems on working plant including software tha…
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