Author/Authors :
Mansfield، نويسنده , , D.K. and Kugel، نويسنده , , H.W. and Maingi، نويسنده , , R. and Bell، نويسنده , , M.G. and Bell، نويسنده , , R. and Kaita، نويسنده , , R. and Kallman، نويسنده , , J. A. Kaye، نويسنده , , S. and LeBlanc، نويسنده , , B. and Mueller، نويسنده , , D. and Paul، نويسنده , , S. Sundar Raman، نويسنده , , R. and Roquemore، نويسنده , , L. and Sabbagh، نويسنده , , S. and Schneider، نويسنده , , and H. G. Skinner ، نويسنده , , C.H. and Soukhanovskii، نويسنده , , V. and Timberlake، نويسنده , , J. and Wilgen، نويسنده , , J. and Zakharov، نويسنده , , L.، نويسنده ,
Abstract :
Lithium evaporated onto plasma facing components in the NSTX lower divertor has made dramatic improvements in discharge performance. As lithium accumulated, plasmas previously exhibiting robust Type 1 ELMs gradually transformed into discharges with intermittent ELMs and finally into continuously evolving ELM-free discharges. During this sequence, other discharge parameters changed in a complicated manner. As the ELMs disappeared, energy confinement improved and remarkable changes in edge and scrape-off layer plasma properties were observed. These results demonstrate that active modification of plasma surface interactions can preempt large ELMs.
