Publication Type
Conference Paper
Journal Name
Journal of Nuclear Materials
Publication Date
Page Numbers
764 to 767
Volume
390-91
Conference Name
18th International Conference on Plasma-Surface Interactions in Controlled Fusion Devices
Conference Location
Toldeo, Spain
Conference Date
-
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. (C) 2009 Elsevier B.V. All rights reserved.