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Title: Operational Regimes of the National Spherical Torus Experiment

Abstract

The National Spherical Torus Experiment (NSTX) is a proof-of-principle experiment designed to study the physics of Spherical Tori (ST), i.e., low-aspect-ratio toroidal plasmas. Important issues for ST research are whether the high-eta stability and reduced transport theoretically predicted for this configuration can be realized experimentally. In NSTX, the commissioning of a digital real-time plasma control system, the provision of flexible heating systems, and the application of wall conditioning techniques were instrumental in achieving routine operation with good confinement. NSTX has produced plasmas with R/a {approx} 0.85 m/0.68 m, A {approx} 1.25, Ip * 1.1 MA, BT = 0.3-0.45 T, k * 2.2, d * 0.5, with auxiliary heating by up to 4 MW of High Harmonic Fast Waves, and 5 MW of 80 keV D0 Neutral Beam Injection (NBI). The energy confinement time in plasmas heated by NBI has exceeded 100 ms and a toroidal beta (bT = 2m0<p>/BT02, where BT0 is the central vacuum toroidal magnetic field) up to 22% has be en achieved. HHFW power of 2.3 MW has increased the electron temperature from an initial 0.4 keV to 0.9 keV both with and without producing a significant density rise in the plasma. The early application of bothmore » NBI and HHFW heating has slowed the penetration of the inductively produced plasma current, modifying the current profile and, thereby, the observed MHD stability.« less

Authors:
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; more »; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; « less
Publication Date:
Research Org.:
Princeton Plasma Physics Lab., NJ (US)
Sponsoring Org.:
USDOE Office of Science (US)
OSTI Identifier:
798187
Report Number(s):
PPPL-3700.pdf
TRN: US0202147
DOE Contract Number:  
AC02-76CH03073
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: 3 Jun 2002
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; AUXILIARY HEATING; BEAM INJECTION; COMMISSIONING; CONFIGURATION; CONFINEMENT; CONFINEMENT TIME; CONTROL SYSTEMS; ELECTRON TEMPERATURE; HARMONICS; HEATING; MAGNETIC FIELDS; PHYSICS; STABILITY; TRANSPORT

Citation Formats

D. Mueller, M.G. Bell, R.E. Bell, M. Bitter, T. Bigelow, P. Bonoli, M. Carter, J. Ferron, E. Fredrickson, D. Gates, L. Grisham, J.C. Hosea, D. Johnson, R. Kaita, S.M. Kaye, H. Kugel, B.P. LeBlanc, R. Maingi, R. Majeski, R. Maqueda, J. Menard, M. Ono, F. Paoletti, S. Paul, C.K. Phillips, R. Pinsker, R. Raman, S.A. Sabbagh, C.H. Skinner, V.A. Soukhanovskii, D. Stutman, D. Swain, Y. Takase, J. Wilgen, J.R. Wilson, G.A. Wurden, and S. Zweben. Operational Regimes of the National Spherical Torus Experiment. United States: N. p., 2002. Web. doi:10.2172/798187.
D. Mueller, M.G. Bell, R.E. Bell, M. Bitter, T. Bigelow, P. Bonoli, M. Carter, J. Ferron, E. Fredrickson, D. Gates, L. Grisham, J.C. Hosea, D. Johnson, R. Kaita, S.M. Kaye, H. Kugel, B.P. LeBlanc, R. Maingi, R. Majeski, R. Maqueda, J. Menard, M. Ono, F. Paoletti, S. Paul, C.K. Phillips, R. Pinsker, R. Raman, S.A. Sabbagh, C.H. Skinner, V.A. Soukhanovskii, D. Stutman, D. Swain, Y. Takase, J. Wilgen, J.R. Wilson, G.A. Wurden, & S. Zweben. Operational Regimes of the National Spherical Torus Experiment. United States. doi:10.2172/798187.
D. Mueller, M.G. Bell, R.E. Bell, M. Bitter, T. Bigelow, P. Bonoli, M. Carter, J. Ferron, E. Fredrickson, D. Gates, L. Grisham, J.C. Hosea, D. Johnson, R. Kaita, S.M. Kaye, H. Kugel, B.P. LeBlanc, R. Maingi, R. Majeski, R. Maqueda, J. Menard, M. Ono, F. Paoletti, S. Paul, C.K. Phillips, R. Pinsker, R. Raman, S.A. Sabbagh, C.H. Skinner, V.A. Soukhanovskii, D. Stutman, D. Swain, Y. Takase, J. Wilgen, J.R. Wilson, G.A. Wurden, and S. Zweben. Mon . "Operational Regimes of the National Spherical Torus Experiment". United States. doi:10.2172/798187. https://www.osti.gov/servlets/purl/798187.
@article{osti_798187,
title = {Operational Regimes of the National Spherical Torus Experiment},
author = {D. Mueller and M.G. Bell and R.E. Bell and M. Bitter and T. Bigelow and P. Bonoli and M. Carter and J. Ferron and E. Fredrickson and D. Gates and L. Grisham and J.C. Hosea and D. Johnson and R. Kaita and S.M. Kaye and H. Kugel and B.P. LeBlanc and R. Maingi and R. Majeski and R. Maqueda and J. Menard and M. Ono and F. Paoletti and S. Paul and C.K. Phillips and R. Pinsker and R. Raman and S.A. Sabbagh and C.H. Skinner and V.A. Soukhanovskii and D. Stutman and D. Swain and Y. Takase and J. Wilgen and J.R. Wilson and G.A. Wurden and S. Zweben},
abstractNote = {The National Spherical Torus Experiment (NSTX) is a proof-of-principle experiment designed to study the physics of Spherical Tori (ST), i.e., low-aspect-ratio toroidal plasmas. Important issues for ST research are whether the high-eta stability and reduced transport theoretically predicted for this configuration can be realized experimentally. In NSTX, the commissioning of a digital real-time plasma control system, the provision of flexible heating systems, and the application of wall conditioning techniques were instrumental in achieving routine operation with good confinement. NSTX has produced plasmas with R/a {approx} 0.85 m/0.68 m, A {approx} 1.25, Ip * 1.1 MA, BT = 0.3-0.45 T, k * 2.2, d * 0.5, with auxiliary heating by up to 4 MW of High Harmonic Fast Waves, and 5 MW of 80 keV D0 Neutral Beam Injection (NBI). The energy confinement time in plasmas heated by NBI has exceeded 100 ms and a toroidal beta (bT = 2m0<p>/BT02, where BT0 is the central vacuum toroidal magnetic field) up to 22% has be en achieved. HHFW power of 2.3 MW has increased the electron temperature from an initial 0.4 keV to 0.9 keV both with and without producing a significant density rise in the plasma. The early application of both NBI and HHFW heating has slowed the penetration of the inductively produced plasma current, modifying the current profile and, thereby, the observed MHD stability.},
doi = {10.2172/798187},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2002},
month = {6}
}