Core magnetic islands and plasma confinement in the H-1NF heliac

Kumar, Santhosh T. A.; Blackwell, Boyd D.; Howard, John; Harris, Jeffrey H.
August 2010
Physics of Plasmas;Aug2010, Vol. 17 Issue 8, p082503
Academic Journal
Plasma confinement in the vicinity of vacuum magnetic islands near the magnetic axis in the H-1NF heliac [S. M. Hamberger et al., Fusion Technol. 17, 123 (1990)] has been experimentally studied in a low temperature argon plasma. Experimental results indicate that, under favorable conditions, these low order (m=2) islands near the core of the plasma serve as “pockets” of higher electron density. This results in significant profile modifications including enhancement of the core radial electric field to a large positive value, possibly through an electron-root ambipolar condition. The characteristics of islands are found to be dependent on the plasma collisionality and island width.


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