Ohmic Flux Consumption During Initial Operation of the NSTX Spherical Torus

Menard, J. ; LeBlanc, B. ; Sabbagh, S.A. ; Bell, M. ; Bell, R. ; Fredrickson, E. ; Gates, D. ; Jardin, S. ; Kaye, S. ; Kugel, H. ; Maingi, R. ; Maqueda, R. ; Mueller, D. ; Ono, M. ; S.Paul ; Skinner, C.H. ; Stutman, D. ; Team., and the NSTX Research

Princeton University. Plasma Physics Laboratory.

关键词: 70 Plasma Physics And Fusion Technology;    Operation;    Aspect Ratio;    Nstx Device;    Performance;   

DOI  :  10.2172/764943
RP-ID  :  PPPL-3490
RP-ID  :  AC02-76CH03073
RP-ID  :  764943

美国|英语

来源: UNT Digital Library

【 摘 要 】

The spherical tokamak (ST), because of its slender central column, has very limited volt-second capability relative to a standard aspect ratio tokamak of similar plasma cross-section. Recent experiments on the National Spherical Torus Experiment (NSTX) have begun to quantify and optimize the ohmic current drive efficiency in a MA-class ST device. Sustainable ramp-rates in excess of 5MA/sec during the current rise phase have been achieved on NSTX, while faster ramps generate significant MHD activity. Discharges with Ip exceeding 1MA have been achieved in NSTX with nominal parameters: aspect ratio A=1.3--1.4, elongation k=2--2.2, triangularity d=0.4, internal inductance li=0.6, and Ejima coefficient CE=0.35. Flux consumption efficiency results, performance improvements associated with first boronization, and comparisons to neoclassical resistivity are described.