Influence of magnetic configuration and heating methods on distribution of diverted plasmas in Heliotron E

A study on the distribution of the amount of diverted plasma along torus in Heliotron E was performed for NBI and ECH plasmas under different experimental conditions. A strong up-down asymmetry of the diverted plasma flux was observed contrary to what should be expected from the vacuum magnetic configuration. The degree of this asymmetry depends on the discharge conditions. This result indicates that the knowledge of only vacuum held traces in a divertor region is not enough to predict how much ratio of the total diverted plasma comes to a concerning divertor section in the heliotron/torsatron devices. (C) 1999 Elsevier Science B.V. All rights reserved.