Overview of JET results using a beryllium first wall
This paper summarises results from the initial operation (in June 1989) of the JET tokamak with an evaporated Be coating on the walls and graphite limiters. In August the graphite limiter tiles were replaced with Be tiles, and a three week experimental campaign was conducted in September/October. In the first phase oxygen was reduced to a negligible level and the carbon flux halved. In the second phase, for limiter mode operation, carbon was reduced by another factor of five and Be became the dominant impurity. High power, long pulse additionally heated limiter mode discharges with Z(eff)<1.5 were achieved and density limits were increased by a factor of up to two. ICRF produced H-modes were obtained in X-point operation (double null). The combination of Be gettering with new operational procedures to delay the strong influx of carbon from the X-point tiles enabled the achievement of record fusion parameters in H-mode discharges including a transient n(d)T(i)tau(E) value of 9 x 1.0 E20 m(-3)keVs, corresponding to a Q(DT) equivalent of about 0.8.
Bibliographic Reference: Report: JET-P(89)83 EN (1989) 28 pp.
Availability: Available from the Publications Officer, JET Joint Undertaking, Abingdon, Oxon. OX14 3EA (GB)
Record Number: 199011038 / Last updated on: 1994-12-01
Original language: en
Available languages: en