Characteristics of the First H-mode Discharges in NSTX

Maingi, R. ; Bell, M.G. ; Bell, R.E. ; Bush, C.E. ; Fredrickson, E.D. ; Gates, D.A. ; Kaye, S.M. ; Kugel, H.W. ; LeBlanc, B.P. ; Menard, J.E. ; Mueller, D. ; Sabbagh, S.A. ; Stutman, D. ; Taylor, G. ; Johnson, D.W. ; Kaita, R. ; Maqueda, R.J. ; Ono, M. ; Paoletti, F. ; Peng, Y-K.M. ; Roquemore, A.L. ; Skinner, C.H. ; Soukhanovskii, V.A. ; and Synakowski, E.J.

Princeton University. Plasma Physics Laboratory.

关键词: Nstx Device;    70 Plasma Physics And Fusion Technology;    Aspect Ratio;    Confinement Time;    H-Mode Plasma Confinement;   

DOI  :  10.2172/784549
RP-ID  :  PPPL-3563
RP-ID  :  AC02-76CH03073
RP-ID  :  784549

美国|英语

来源: UNT Digital Library

【 摘 要 】

We report observations of the first low-to-high (L-H) confinement mode transitions in the National Spherical Torus Experiment (NSTX). The H-mode energy confinement time increased over reference L-mode discharges transiently by 100-300%, as high as {approximately}150 ms. This confinement time is {approximately}1.8-2.3 times higher than predicted by a multi-machine ELM-free H-mode scaling. This achievement extends the H-mode window of fusion devices down to a record low aspect ratio (R/a) {approximately} 1.3, challenging both confinement and L-H power thresholds scalings based on conventional aspect ratio tokamaks.