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Title: NSTX: Facility/Research Highlights and Near Term Facility Plans

Abstract

The National Spherical Torus Experiment (NSTX) is a collaborative mega-ampere-class spherical torus research facility with high power heating and current drive systems and the state-of-the-art comprehensive diagnostics. For the 2008 experimental campaign, the high harmonic fast wave (HHFW) heating efficiency in deuterium improved significantly with lithium evaporation and produced a record central Te of 5 keV. The HHFW heating of NBI-heated discharges was also demonstrated for the first time with lithium application. The EBW emission in H-mode was also improved dramatically with lithium which was shown to be attributable to reduced edge collisional absorption. Newly installed FIDA energetic particle diagnostic measured significant transport of energetic ions associated with TAE avalanche as well as n=1 kink activities. A full 75 channel poloidal CHERS system is now operational yielding tantalizing initial results. In the near term, major upgrade activities include a liquid-lithium divertor target to achieve lower collisionality regime, the HHFW antenna upgrades to double its power handling capability in H-mode, and a beam-emission spectroscopy diagnostic to extend the localized turbulence measurements toward the ion gyro-radius scale from the present concentration on the electron gyro-radius scale. For the longer term, a new center stack to significantly expand the plasma operating parameters ismore » planned along with a second NBI system to double the NBI heating and CD power and provide current profile control. These upgrades will enable NSTX to explore fully non-inductive operations over a much expanded plasma parameter space in terms of higher plasma temperature and lower collisionality, thereby significantly reducing the physics parameter gap between the present NSTX and the projected next-step ST experiments.« less

Authors:
Publication Date:
Research Org.:
Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
941507
Report Number(s):
PPPL-4367
TRN: US0807440
DOE Contract Number:  
DE-ACO2-76CHO3073
Resource Type:
Conference
Resource Relation:
Conference: Invited Paper to: Fourth IAEA Technical Meeting on Spherical Tori and Fourteenth International Workshop on Sphgerical Torus, 7-10 October 2008 ENEA Frascati, Roma, Italy
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ABSORPTION; ANTENNAS; DEUTERIUM; DIVERTORS; EFFICIENCY; ELECTRON TEMPERATURE; ELECTRONS; EVAPORATION; HARMONICS; HEATING; IAEA; ION TEMPERATURE; LITHIUM; PHYSICS; SPECTROSCOPY; TAIL IONS; TARGETS; TURBULENCE; NSTX

Citation Formats

Ono, M. NSTX: Facility/Research Highlights and Near Term Facility Plans. United States: N. p., 2008. Web.
Ono, M. NSTX: Facility/Research Highlights and Near Term Facility Plans. United States.
Ono, M. Wed . "NSTX: Facility/Research Highlights and Near Term Facility Plans". United States. https://www.osti.gov/servlets/purl/941507.
@article{osti_941507,
title = {NSTX: Facility/Research Highlights and Near Term Facility Plans},
author = {Ono, M},
abstractNote = {The National Spherical Torus Experiment (NSTX) is a collaborative mega-ampere-class spherical torus research facility with high power heating and current drive systems and the state-of-the-art comprehensive diagnostics. For the 2008 experimental campaign, the high harmonic fast wave (HHFW) heating efficiency in deuterium improved significantly with lithium evaporation and produced a record central Te of 5 keV. The HHFW heating of NBI-heated discharges was also demonstrated for the first time with lithium application. The EBW emission in H-mode was also improved dramatically with lithium which was shown to be attributable to reduced edge collisional absorption. Newly installed FIDA energetic particle diagnostic measured significant transport of energetic ions associated with TAE avalanche as well as n=1 kink activities. A full 75 channel poloidal CHERS system is now operational yielding tantalizing initial results. In the near term, major upgrade activities include a liquid-lithium divertor target to achieve lower collisionality regime, the HHFW antenna upgrades to double its power handling capability in H-mode, and a beam-emission spectroscopy diagnostic to extend the localized turbulence measurements toward the ion gyro-radius scale from the present concentration on the electron gyro-radius scale. For the longer term, a new center stack to significantly expand the plasma operating parameters is planned along with a second NBI system to double the NBI heating and CD power and provide current profile control. These upgrades will enable NSTX to explore fully non-inductive operations over a much expanded plasma parameter space in terms of higher plasma temperature and lower collisionality, thereby significantly reducing the physics parameter gap between the present NSTX and the projected next-step ST experiments.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2008},
month = {11}
}

Conference:
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