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Title: Electron Energy Confinement for HHFW Heating and Current Drive Phasing on NSTX

Abstract

Thomson scattering laser pulses are synchronized relative to modulated HHFW power to permit evaluation of the electron energy confinement time during and following HHFW pulses for both heating and current drive antenna phasing. Profile changes resulting from instabilities require that the total electron stored energy, evaluated by integrating the midplane electron pressure P(sub)e(R) over the magnetic surfaces prescribed by EFIT analysis, be used to derive the electron energy confinement time. Core confinement is reduced during a sawtooth instability but, although the electron energy is distributed outward by the sawtooth, the bulk electron energy confinement time is essentially unaffected. The radial deposition of energy into the electrons is noticeably more peaked for current drive phasing (longer wavelength excitation) relative to that for heating phasing (shorter wavelength excitation) as is expected theoretically. However, the power delivered to the core plasma is reduced consider ably for the current drive phasing, indicating that surface/peripheral damping processes play a more important role for this case.

Authors:
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Publication Date:
Research Org.:
Princeton Plasma Physics Lab., Princeton, NJ (US)
Sponsoring Org.:
USDOE Office of Science (SC) (US)
OSTI Identifier:
839537
Report Number(s):
PPPL-4070
TRN: US0501749
DOE Contract Number:  
AC02-76CH03073
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: 3 May 2005
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ANTENNAS; CONFINEMENT; CONFINEMENT TIME; DAMPING; DEPOSITION; ELECTRONS; EXCITATION; HEATING; INSTABILITY; LASERS; MAGNETIC SURFACES; STORED ENERGY; THOMSON SCATTERING; WAVELENGTHS; HEATING, ICRF; SPHERICAL TORUS

Citation Formats

Hosea, J C, Bernabei, S, Biewer, T, LeBlanc, B, Phillips, C K, Wilson, J R, Stutman, D, Ryan, P, and Swain, D W. Electron Energy Confinement for HHFW Heating and Current Drive Phasing on NSTX. United States: N. p., 2005. Web. doi:10.2172/839537.
Hosea, J C, Bernabei, S, Biewer, T, LeBlanc, B, Phillips, C K, Wilson, J R, Stutman, D, Ryan, P, & Swain, D W. Electron Energy Confinement for HHFW Heating and Current Drive Phasing on NSTX. United States. doi:10.2172/839537.
Hosea, J C, Bernabei, S, Biewer, T, LeBlanc, B, Phillips, C K, Wilson, J R, Stutman, D, Ryan, P, and Swain, D W. Tue . "Electron Energy Confinement for HHFW Heating and Current Drive Phasing on NSTX". United States. doi:10.2172/839537. https://www.osti.gov/servlets/purl/839537.
@article{osti_839537,
title = {Electron Energy Confinement for HHFW Heating and Current Drive Phasing on NSTX},
author = {Hosea, J C and Bernabei, S and Biewer, T and LeBlanc, B and Phillips, C K and Wilson, J R and Stutman, D and Ryan, P and Swain, D W},
abstractNote = {Thomson scattering laser pulses are synchronized relative to modulated HHFW power to permit evaluation of the electron energy confinement time during and following HHFW pulses for both heating and current drive antenna phasing. Profile changes resulting from instabilities require that the total electron stored energy, evaluated by integrating the midplane electron pressure P(sub)e(R) over the magnetic surfaces prescribed by EFIT analysis, be used to derive the electron energy confinement time. Core confinement is reduced during a sawtooth instability but, although the electron energy is distributed outward by the sawtooth, the bulk electron energy confinement time is essentially unaffected. The radial deposition of energy into the electrons is noticeably more peaked for current drive phasing (longer wavelength excitation) relative to that for heating phasing (shorter wavelength excitation) as is expected theoretically. However, the power delivered to the core plasma is reduced consider ably for the current drive phasing, indicating that surface/peripheral damping processes play a more important role for this case.},
doi = {10.2172/839537},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2005},
month = {5}
}