TOKAMAK PLASMA INTERACTION WITH LIMITERS.

摘要

The importance of plasma purity is first discussed in terms of the general requirements of controlled thermonuclear fusion. The tokamak approach to fusion and its inherent problem of plasma contamination are introduced. A main source of impurities is due to the bombardment of the limiter by energetic particles and thus the three main aspects of the plasma-limiter interaction are reviewed, boundary plasma conditions, fuelling/recycling and impurity production. The experimental program carried out on the DITE tokamak at Culham Laboratory, UK is described. The experiments investigated these three topics and the results are compared with predicted behaviour; new physical phenomena are presented in all three areas.;Simple one-dimensional fluid equations are found to adequately describe the SOL plasma, except in regard to the pre-sheath electric field and ambipolarity; in the latter, local flow conditions are generally non-ambipolar. Recycling of fuel particles from the limiter is observed to be near unity at all times. The break-up behaviour of recycled and gas puffed D