Community Research and Development Information Service - CORDIS


Several neutral beam injection (NBI) systems are now capable of injection of powers greater than 20 MW, some for pulse lengths in excess of 5 sec. These high power NBI systems have demonstrated the flexibility and utility of neutral beam heating, coupling easily to many plasma configurations, providing heating, fuelling and current drive capability and allowing access to new, improved plasma confinement regimes. The current status of NBI systems is reviewed and successful solutions to the technological problems encountered in design of high power beams, ranging from high heat transfer elements to large area cryopumps, are discussed. The interface to tokamak operations such as the drift duct, stray field cancellation and fast interlock mechanisms are presented. The upgrading of NBI systems for tritium injection on JET and TFTR is reviewed. The possible parameters for a 'Next Step' injector are presented, showing the choice of negative ion beams as an attractive option, the main areas of uncertainty being in the source and accelerator stack designs. The beamlines themselves should be able to take advantage of the properties of negative ions to lead to some marked simplifications.

Additional information

Authors: STORK D, JET Joint Undertaking, Abingdon, Oxon. (GB)
Bibliographic Reference: Report: JET-P(90)63 EN (1990)
Availability: Available from the Publications Officer, JET Joint Undertaking, Abingdon, Oxon. OX14 3EA (GB)
Record Number: 199110557 / Last updated on: 1994-12-02
Original language: en
Available languages: en