Community Research and Development Information Service - CORDIS


In the lower hybrid current drive (LHCD) system, the power reflection at the grill mouth of the launcher depends sensitively on the local plasma density. The launcher position relative to the plasma can be adjusted during the plasma pulse with a tolerance of better than 1 mm using a water hydraulic positional servo control system. The launcher has a moving mass of 11 tonnes and is typically 6 m long x 2 m diameter. The system must be resistant to a neutron flux of 5 x 1.0 E20 n/m2 (1 MGy), transient magnetic fields to 0.2 T and be remote handling compatible. Typical performance achieved is positional accuracy of 1 mm, maximum velocity of 0.3 m/s, acceleration of 2 m/s2, a frequency response of 4 Hz, giving a rest to rest response time of 0.2 s to a 5 mm step. The system has been on line to position the launcher during JET pulses.

Additional information

Authors: JET TEAM, JET Joint Undertaking, Abingdon, Oxon. (GB)
Bibliographic Reference: Report: JET-P(92)72 EN (1992) 189 pp.
Availability: Available from the Publications Officer, JET Joint Undertaking, Abingdon, Oxon. OX14 3EA (GB)
Record Number: 199211254 / Last updated on: 1994-11-29
Original language: en
Available languages: en