TECHNICAL ASPECTS OF THE NEW JET DEVELOPMENT PLAN
Recent results from JET and other large tokamaks point to the need for JET to introduce new modes of operation and additional equipment to enhance performance, and as a result gain the full benefit of deuterium-tritium (D-T) operation. The principal new additions to the JET development plan concern: operation up to plasma currents of 7MA, magnetic limiter operation, disruption control, density control and current profile control. The new additions to the JET programme entail only minor changes to the basic design of the machine itself. The ohmic heating coil stack will be reconstructed with 10 sub-coils instead of 8 sub-coils. This modification is important for magnetic limiter operation and is also desirable to achieve long flat-tops at plasma currents of 7 MA. For the magnetic limiter mode of operation, dump plates are foreseen inside the vessel in the vicinity of the X-points. The vacuum vessel supports will be reinforced to cope with the transient loads resulting from vertical instabilities. Disruption control requires new saddle coils inside the vacuum vessel. Density control includes the use of pump limiters, the study of transient wall pumping, and deep fuelling by means of pellet injectors. Current profile control will probably involve a combination of lower hybrid frequency and neutral beam current drive techniques. At the same time, the machine and all systems will be prepared for D-T operation. The various steps of the new JET programme are planned for implementation during major shutdowns scheduled until 1991. D-T operation is now planned to start by the end of 1991.
Bibliographic Reference: 14TH SOFT CONFERENCE, AVIGNON (FRANCE), SEPT. 8-12, 1986 VOL. 1, PP. 253-262 1895 P., 1986, VOL. 1 AND VOL. 2, ISBN 0 08 034935 8 WRITE TO PERGAMON PRESS, HEADINGTON HILL HALL, OXFORD, OX3 0BW (UK), PRICE: UKL 220 (FOR BOTH VOLS.)
Record Number: 1989126045601 / Last updated on: 1989-01-01
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