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Title: Electrostatic fluctuations and related transport in the edge and core plasma of the Keda Tokamak-5C

Abstract

Using the swept double probe and triple probe technique, temperature, density and potential fluctuations have been measured in both the plasma edge and core of the Keda Tokamak-5C (KT-5C) [{ital World Survey of Activities in Controlled Fusion Research}, Nuclear Fusion Special Supplement (International Atomic Energy Agency, Vienna, 1991), p. 190]. The fluctuation-driven particle and energy fluxes were also estimated from the correlations of {l_angle}{tilde {ital n}}{sub {ital e{tilde E}}}{sub {theta}}{r_angle} and {l_angle}{tilde {ital T}}{sub {ital e{tilde E}}}{sub {theta}}{r_angle}. Evidence has been found that there exist substantial electron temperature fluctuations of {tilde {ital T}}{sub {ital e}}/{ital T}{sub {ital e}}{approx_equal}0.4{tilde {ital n}}{sub {ital e}}/{ital n}{sub {ital e}} in both regions. At the edge of KT-5C, many of the fluctuation features, such as the velocity shear stabilization of turbulence, the non-Boltzmann relation and the role of fluctuations in the edge confinement, are very similar to those obtained from other tokamaks. In the plasma interior, the fluctuations do obey the simple Boltzmann relationship and the profiles of the normalized fluctuating levels {tilde {ital n}}{sub {ital e}}/{ital n}{sub {ital e}} and {tilde {phi}}{sub {ital p}}/{ital T}{sub {ital e}} vary roughly as {tilde {ital n}}{sub {ital e}}/{ital n}{sub {ital e}}{proportional_to}{ital n}{sub {ital e}}{sup {minus}3/2} and {tildemore » {phi}}{sub {ital p}}/{ital T}{sub {ital e}}{proportional_to}{ital n}{sub {ital e}}{sup {minus}1/2}{ital T}{sub {ital e}}{sup {minus}1}, respectively. In addition, a spiky, radially intermittent structure in the particle and energy fluxes with large levels at the low-{ital q} resonances and lower levels in between was found. The experimental results provide some new evidence, particularly in the plasma core, for a better understanding of the basic mechanism of turbulence. {copyright} {ital 1996 American Institute of Physics.}« less

Authors:
; ; ; ; ;  [1]
  1. Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui, 230026, Peoples Republic of (China)
Publication Date:
OSTI Identifier:
282801
Resource Type:
Journal Article
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 3; Journal Issue: 3; Other Information: PBD: Mar 1996
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION; TOKAMAK DEVICES; TURBULENCE; PLASMA DIAGNOSTICS; FLUCTUATIONS; TEMPERATURE MEASUREMENT

Citation Formats

Xu, Y, Wang, G, Zhai, K, Wang, C, Liu, W, and Yu, C. Electrostatic fluctuations and related transport in the edge and core plasma of the Keda Tokamak-5C. United States: N. p., 1996. Web. doi:10.1063/1.871757.
Xu, Y, Wang, G, Zhai, K, Wang, C, Liu, W, & Yu, C. Electrostatic fluctuations and related transport in the edge and core plasma of the Keda Tokamak-5C. United States. doi:10.1063/1.871757.
Xu, Y, Wang, G, Zhai, K, Wang, C, Liu, W, and Yu, C. Fri . "Electrostatic fluctuations and related transport in the edge and core plasma of the Keda Tokamak-5C". United States. doi:10.1063/1.871757.
@article{osti_282801,
title = {Electrostatic fluctuations and related transport in the edge and core plasma of the Keda Tokamak-5C},
author = {Xu, Y and Wang, G and Zhai, K and Wang, C and Liu, W and Yu, C},
abstractNote = {Using the swept double probe and triple probe technique, temperature, density and potential fluctuations have been measured in both the plasma edge and core of the Keda Tokamak-5C (KT-5C) [{ital World Survey of Activities in Controlled Fusion Research}, Nuclear Fusion Special Supplement (International Atomic Energy Agency, Vienna, 1991), p. 190]. The fluctuation-driven particle and energy fluxes were also estimated from the correlations of {l_angle}{tilde {ital n}}{sub {ital e{tilde E}}}{sub {theta}}{r_angle} and {l_angle}{tilde {ital T}}{sub {ital e{tilde E}}}{sub {theta}}{r_angle}. Evidence has been found that there exist substantial electron temperature fluctuations of {tilde {ital T}}{sub {ital e}}/{ital T}{sub {ital e}}{approx_equal}0.4{tilde {ital n}}{sub {ital e}}/{ital n}{sub {ital e}} in both regions. At the edge of KT-5C, many of the fluctuation features, such as the velocity shear stabilization of turbulence, the non-Boltzmann relation and the role of fluctuations in the edge confinement, are very similar to those obtained from other tokamaks. In the plasma interior, the fluctuations do obey the simple Boltzmann relationship and the profiles of the normalized fluctuating levels {tilde {ital n}}{sub {ital e}}/{ital n}{sub {ital e}} and {tilde {phi}}{sub {ital p}}/{ital T}{sub {ital e}} vary roughly as {tilde {ital n}}{sub {ital e}}/{ital n}{sub {ital e}}{proportional_to}{ital n}{sub {ital e}}{sup {minus}3/2} and {tilde {phi}}{sub {ital p}}/{ital T}{sub {ital e}}{proportional_to}{ital n}{sub {ital e}}{sup {minus}1/2}{ital T}{sub {ital e}}{sup {minus}1}, respectively. In addition, a spiky, radially intermittent structure in the particle and energy fluxes with large levels at the low-{ital q} resonances and lower levels in between was found. The experimental results provide some new evidence, particularly in the plasma core, for a better understanding of the basic mechanism of turbulence. {copyright} {ital 1996 American Institute of Physics.}},
doi = {10.1063/1.871757},
journal = {Physics of Plasmas},
number = 3,
volume = 3,
place = {United States},
year = {1996},
month = {3}
}