Dependence of Edge Stability on Plasma Shape and Local Pressure Gradients in the DIII-D and JT-60U Tokamaks
By:
Lao, L. L.; Kamada, Y.; Oikawa, T.; Baylor, Larry R; Burrell, K. H.; Chan, V. S.; Chance, M.; Chu, M. S.; Ferron, J. R.; Fukuda, T.; Hatae, T.; Isayama, A.; Jackson, G. J.; Leonard, A. W.; Makowski, M. A.; Manickam, J.; Okabayashi, M.; Osborne, T. H.; Snyder, P. B.; Strait, E. J.; Takeji, S.; Takizuka, T.; Taylor, T. S.; Turnbull, A. D.; Tsuchiya, K.; Wade, Mickey R
Page Number:
151-300
Volume:
41
Issue Number:
3
Book Title:
CD: IAEA 18TH Conference Proceedings
Publication Date:
September 22, 2006
Conference Name:
18th IAEA Fusion Energy Conference
Conference Location:
Sorrento, Italy
Conference Sponsor:
International Atomic Energy Agency (IAEA)
Abstract
The dependence of edge stability on plasma shape and local pressure gradients, P, in the DIII-D and JT-60U tokamaks is studied. The stronger plasma shaping in DIII-D allows the edge region of DIII-D discharges with Type I ("giant") ELMs to have access to the second region of stability for ideal ballooning modes and larger edge P′than JT-60U Type I ELM discharges. These JT-60U discharges are near the ballooning mode first regime stability limit. DIII-D results support an ideal stability based working model of Type I ELMs as low to intermediate toroidal mode number, n, MHD modes. Results from stability analysis of JT-60U Type I ELM discharges indicate that predictions from this model are also consistent with JT-60U edge stability observations.
