skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Initial Studies of Core and Edge Transport of NSTX Plasmas

Abstract

Rapidly developing diagnostic, operational, and analysis capability is enabling the first detailed local physics studies to begin in high-beta plasmas of the National Spherical Torus Experiment (NSTX). These studies are motivated in part by energy confinement times in neutral-beam-heated discharges that are favorable with respect to predictions from the ITER-89P scaling expression. Analysis of heat fluxes based on profile measurements with neutral-beam injection (NBI) suggest that the ion thermal transport may be exceptionally low, and that electron thermal transport is the dominant loss channel. This analysis motivates studies of possible sources of ion heating not presently accounted for by classical collisional processes. Gyrokinetic microstability studies indicate that long wavelength turbulence with k(subscript ''theta'') rho(subscript ''i'') {approx} 0.1-1 may be suppressed in these plasmas, while modes with k(subscript ''theta'') rho(subscript ''i'') {approx} 50 may be robust. High-harmonic fast-wave (HHFW) heating efficiently heats electrons on NSTX, and studies have begun using it to assess transport in the electron channel. Regarding edge transport, H-mode [high-confinement mode] transitions occur with either NBI or HHFW heating. The power required for low-confinement mode (L-mode) to H-mode transitions far exceeds that expected from empirical edge-localized-mode-free H-mode scaling laws derived from moderate aspect ratio devices. Finally, initial fluctuationmore » measurements made with two techniques are permitting the first characterizations of edge turbulence.« less

Authors:
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; more »; ; ; ; ; ; ; ; ;  [1]; ; « less
  1. (a), C.H. Skinner
Publication Date:
Research Org.:
Princeton Plasma Physics Lab., NJ (US)
Sponsoring Org.:
USDOE Office of Science (US)
OSTI Identifier:
788262
Report Number(s):
PPPL-3611
TRN: US0110858
DOE Contract Number:  
AC02-76CH03073
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: 19 Sep 2001
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; NSTX DEVICE; ASPECT RATIO; CONFINEMENT TIME; BEAM INJECTION HEATING; HIGH-BETA PLASMA; SCALING LAWS; TURBULENCE; ELECTRON TEMPERATURE; H-MODE PLASMA CONFINEMENT; EDGE LOCALIZED MODES; L-MODE PLASMA CONFINEMENT; PHASE TRANSFORMATIONS

Citation Formats

E.J. Synakowski, M.G. Bell, R.E. Bell, C.E. Bush, C. Bourdelle, D. Darrow, W. Dorland, A. Ejiri, E.D. Fredrickson, D.A. Gates, S.M. Kaye, S. Kubota, H.W. Kugel, B.P. LeBlanc, R. Maingi, R.J. Maqueda, J.E. Menard, D. Mueller, A. Rosenberg, S.A. Sabbagh, D. Stutman, G. Taylor, D.W. Johnson, R. Kaita, M. Ono, F. Paoletti, W. Peebles, Y-K.M. Peng, A.L. Roquemore, V.A. Soukhanovskii, and and the NSTX Research Team. Initial Studies of Core and Edge Transport of NSTX Plasmas. United States: N. p., 2001. Web. doi:10.2172/788262.
E.J. Synakowski, M.G. Bell, R.E. Bell, C.E. Bush, C. Bourdelle, D. Darrow, W. Dorland, A. Ejiri, E.D. Fredrickson, D.A. Gates, S.M. Kaye, S. Kubota, H.W. Kugel, B.P. LeBlanc, R. Maingi, R.J. Maqueda, J.E. Menard, D. Mueller, A. Rosenberg, S.A. Sabbagh, D. Stutman, G. Taylor, D.W. Johnson, R. Kaita, M. Ono, F. Paoletti, W. Peebles, Y-K.M. Peng, A.L. Roquemore, V.A. Soukhanovskii, & and the NSTX Research Team. Initial Studies of Core and Edge Transport of NSTX Plasmas. United States. doi:10.2172/788262.
E.J. Synakowski, M.G. Bell, R.E. Bell, C.E. Bush, C. Bourdelle, D. Darrow, W. Dorland, A. Ejiri, E.D. Fredrickson, D.A. Gates, S.M. Kaye, S. Kubota, H.W. Kugel, B.P. LeBlanc, R. Maingi, R.J. Maqueda, J.E. Menard, D. Mueller, A. Rosenberg, S.A. Sabbagh, D. Stutman, G. Taylor, D.W. Johnson, R. Kaita, M. Ono, F. Paoletti, W. Peebles, Y-K.M. Peng, A.L. Roquemore, V.A. Soukhanovskii, and and the NSTX Research Team. Wed . "Initial Studies of Core and Edge Transport of NSTX Plasmas". United States. doi:10.2172/788262. https://www.osti.gov/servlets/purl/788262.
@article{osti_788262,
title = {Initial Studies of Core and Edge Transport of NSTX Plasmas},
author = {E.J. Synakowski and M.G. Bell and R.E. Bell and C.E. Bush and C. Bourdelle and D. Darrow and W. Dorland and A. Ejiri and E.D. Fredrickson and D.A. Gates and S.M. Kaye and S. Kubota and H.W. Kugel and B.P. LeBlanc and R. Maingi and R.J. Maqueda and J.E. Menard and D. Mueller and A. Rosenberg and S.A. Sabbagh and D. Stutman and G. Taylor and D.W. Johnson and R. Kaita and M. Ono and F. Paoletti and W. Peebles and Y-K.M. Peng and A.L. Roquemore and V.A. Soukhanovskii and and the NSTX Research Team},
abstractNote = {Rapidly developing diagnostic, operational, and analysis capability is enabling the first detailed local physics studies to begin in high-beta plasmas of the National Spherical Torus Experiment (NSTX). These studies are motivated in part by energy confinement times in neutral-beam-heated discharges that are favorable with respect to predictions from the ITER-89P scaling expression. Analysis of heat fluxes based on profile measurements with neutral-beam injection (NBI) suggest that the ion thermal transport may be exceptionally low, and that electron thermal transport is the dominant loss channel. This analysis motivates studies of possible sources of ion heating not presently accounted for by classical collisional processes. Gyrokinetic microstability studies indicate that long wavelength turbulence with k(subscript ''theta'') rho(subscript ''i'') {approx} 0.1-1 may be suppressed in these plasmas, while modes with k(subscript ''theta'') rho(subscript ''i'') {approx} 50 may be robust. High-harmonic fast-wave (HHFW) heating efficiently heats electrons on NSTX, and studies have begun using it to assess transport in the electron channel. Regarding edge transport, H-mode [high-confinement mode] transitions occur with either NBI or HHFW heating. The power required for low-confinement mode (L-mode) to H-mode transitions far exceeds that expected from empirical edge-localized-mode-free H-mode scaling laws derived from moderate aspect ratio devices. Finally, initial fluctuation measurements made with two techniques are permitting the first characterizations of edge turbulence.},
doi = {10.2172/788262},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Wed Sep 19 00:00:00 EDT 2001},
month = {Wed Sep 19 00:00:00 EDT 2001}
}

Technical Report:

Save / Share: