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Title: Recent Progress on the National Spherical Torus Experiment (NSTX)

Abstract

Recent upgrades to the NSTX facility have led to improved plasma performance. Using 5MW of neutral beam injection, plasmas with toroidal {beta}{sub T} (= 2{micro}{sub 0}<p>/B{sub T}{sup 2} where B{sub T} is the vacuum toroidal field at the plasma geometric center) > 30% have been achieved with normalized {beta}{sub N} (= {beta}{sub T}aB{sub I}/I{sub p}) {approx} 6% {center_dot} m {center_dot} T/MA.. The highest {beta} discharge exceeded the calculated no-wall {beta} limit for several wall times. The stored energy has reached 390kJ at higher toroidal field (0.55T) corresponding to {beta}{sub T} {approx} 20% and {beta}{sub N} = 5.4. Long pulse ({approx}1s) high {beta}{sub p} ({approx}1.5) discharges have also been obtained at higher {beta}{sub {phi}} (0.5T) with up to 6MW NBI power. The highest energy confinement times, up to 120ms, were observed during H-mode operation which is now routine. Confinement times of {approx}1.5 times ITER98pby2 for several {tau}{sub E} are observed during both H-Mode and non-H-Mode discharges. Calculations indicate that many NSTX discharges have very good ion confinement, approaching neoclassical levels. High Harmonic Fast Wave current drive has been demonstrated by comparing discharges with waves launched parallel and anti-parallel to the plasma current.

Authors:
; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Princeton Plasma Physics Lab. (US)
Sponsoring Org.:
USDOE Office of Science (US)
OSTI Identifier:
803991
Report Number(s):
PPPL-3716
TRN: US0300595
DOE Contract Number:  
AC02-76CH03073
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: 2 Jul 2002
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; BEAM INJECTION; CONFINEMENT; CONFINEMENT TIME; HARMONICS; PERFORMANCE; PLASMA; STORED ENERGY

Citation Formats

D.A. Gates, M.G. Bell, R.E. Bell, J. Bialek, T. Bigelow, M. Bitter, P. Bonoli, D. Darrow, P. Efthimion, and et al. Recent Progress on the National Spherical Torus Experiment (NSTX). United States: N. p., 2002. Web. doi:10.2172/803991.
D.A. Gates, M.G. Bell, R.E. Bell, J. Bialek, T. Bigelow, M. Bitter, P. Bonoli, D. Darrow, P. Efthimion, & et al. Recent Progress on the National Spherical Torus Experiment (NSTX). United States. doi:10.2172/803991.
D.A. Gates, M.G. Bell, R.E. Bell, J. Bialek, T. Bigelow, M. Bitter, P. Bonoli, D. Darrow, P. Efthimion, and et al. Tue . "Recent Progress on the National Spherical Torus Experiment (NSTX)". United States. doi:10.2172/803991. https://www.osti.gov/servlets/purl/803991.
@article{osti_803991,
title = {Recent Progress on the National Spherical Torus Experiment (NSTX)},
author = {D.A. Gates and M.G. Bell and R.E. Bell and J. Bialek and T. Bigelow and M. Bitter and P. Bonoli and D. Darrow and P. Efthimion and et al.},
abstractNote = {Recent upgrades to the NSTX facility have led to improved plasma performance. Using 5MW of neutral beam injection, plasmas with toroidal {beta}{sub T} (= 2{micro}{sub 0}<p>/B{sub T}{sup 2} where B{sub T} is the vacuum toroidal field at the plasma geometric center) > 30% have been achieved with normalized {beta}{sub N} (= {beta}{sub T}aB{sub I}/I{sub p}) {approx} 6% {center_dot} m {center_dot} T/MA.. The highest {beta} discharge exceeded the calculated no-wall {beta} limit for several wall times. The stored energy has reached 390kJ at higher toroidal field (0.55T) corresponding to {beta}{sub T} {approx} 20% and {beta}{sub N} = 5.4. Long pulse ({approx}1s) high {beta}{sub p} ({approx}1.5) discharges have also been obtained at higher {beta}{sub {phi}} (0.5T) with up to 6MW NBI power. The highest energy confinement times, up to 120ms, were observed during H-mode operation which is now routine. Confinement times of {approx}1.5 times ITER98pby2 for several {tau}{sub E} are observed during both H-Mode and non-H-Mode discharges. Calculations indicate that many NSTX discharges have very good ion confinement, approaching neoclassical levels. High Harmonic Fast Wave current drive has been demonstrated by comparing discharges with waves launched parallel and anti-parallel to the plasma current.},
doi = {10.2172/803991},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue Jul 02 00:00:00 EDT 2002},
month = {Tue Jul 02 00:00:00 EDT 2002}
}

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