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Title: Initial high beta operation of the HBT-EP tokamak

Abstract

HBT-EP is a new research tokamak designed and built to investigate passive and active feedback techniques to control MHD instabilities. In particular, HBT-EP will be able to test techniques to control fast MHD instabilities occurring at high Troyon-normalized beta, [beta][sub N] [equivalent to] [beta]Ba/I[sub p][Tm/MA], since it is equipped with a thick, close-fitting, and adjustable conducting shell. The major goals of the initial operation of HBT-EP have been the achievement of high beta operation ([beta][sub N] [approximately]3) using only ohmic heating and the observation of MHD instabilities. By using a unique fast start-up technique, the authors have successfully achieved these goals. A variety of MHD phenomena were observed during the high beta operation of HBT-EP. At modest beta ([beta][sub N] [le] 2), discharges have been maintained for more than 10 msec, and these discharges exhibit saturated resistive instabilities. When [beta][sub N] approaches 3, major disruptions occur preceded by oscillating, growing precursors. During start-up, one or more minor disruptions are usually observed. A 1-D transport code has been used to simulate the evolution of the current profile, and these early minor instabilities are predicted to be double tearing modes. The simulation also reproduces the observed high beta operation when saturated neo-Alcatormore » energy confinement scaling is assumed.« less

Authors:
; ; ; ; ; ; ; ; ; ;  [1]
  1. Columbia Univ., New York, NY (United States)
Publication Date:
OSTI Identifier:
5118263
DOE Contract Number:  
FG02-86ER53222
Resource Type:
Journal Article
Journal Name:
Journal of Fusion Energy; (United States)
Additional Journal Information:
Journal Volume: 12:3; Journal ID: ISSN 0164-0313
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; COLUMBIA HIGH-BETA TOKAMAK; OPERATION; PLASMA INSTABILITY; CLOSED PLASMA DEVICES; INSTABILITY; THERMONUCLEAR DEVICES; TOKAMAK DEVICES; 700340* - Plasma Waves, Oscillations, & Instabilities- (1992-)

Citation Formats

Sankar, M K.V., Eisner, E, Garofalo, A, Gates, D, Ivers, T H, Kombargi, R, Mauel, M E, Maurer, D, Nadle, D, Navratil, G A, and Xiao, Q. Initial high beta operation of the HBT-EP tokamak. United States: N. p., 1993. Web. doi:10.1007/BF01079674.
Sankar, M K.V., Eisner, E, Garofalo, A, Gates, D, Ivers, T H, Kombargi, R, Mauel, M E, Maurer, D, Nadle, D, Navratil, G A, & Xiao, Q. Initial high beta operation of the HBT-EP tokamak. United States. https://doi.org/10.1007/BF01079674
Sankar, M K.V., Eisner, E, Garofalo, A, Gates, D, Ivers, T H, Kombargi, R, Mauel, M E, Maurer, D, Nadle, D, Navratil, G A, and Xiao, Q. Wed . "Initial high beta operation of the HBT-EP tokamak". United States. https://doi.org/10.1007/BF01079674.
@article{osti_5118263,
title = {Initial high beta operation of the HBT-EP tokamak},
author = {Sankar, M K.V. and Eisner, E and Garofalo, A and Gates, D and Ivers, T H and Kombargi, R and Mauel, M E and Maurer, D and Nadle, D and Navratil, G A and Xiao, Q},
abstractNote = {HBT-EP is a new research tokamak designed and built to investigate passive and active feedback techniques to control MHD instabilities. In particular, HBT-EP will be able to test techniques to control fast MHD instabilities occurring at high Troyon-normalized beta, [beta][sub N] [equivalent to] [beta]Ba/I[sub p][Tm/MA], since it is equipped with a thick, close-fitting, and adjustable conducting shell. The major goals of the initial operation of HBT-EP have been the achievement of high beta operation ([beta][sub N] [approximately]3) using only ohmic heating and the observation of MHD instabilities. By using a unique fast start-up technique, the authors have successfully achieved these goals. A variety of MHD phenomena were observed during the high beta operation of HBT-EP. At modest beta ([beta][sub N] [le] 2), discharges have been maintained for more than 10 msec, and these discharges exhibit saturated resistive instabilities. When [beta][sub N] approaches 3, major disruptions occur preceded by oscillating, growing precursors. During start-up, one or more minor disruptions are usually observed. A 1-D transport code has been used to simulate the evolution of the current profile, and these early minor instabilities are predicted to be double tearing modes. The simulation also reproduces the observed high beta operation when saturated neo-Alcator energy confinement scaling is assumed.},
doi = {10.1007/BF01079674},
url = {https://www.osti.gov/biblio/5118263}, journal = {Journal of Fusion Energy; (United States)},
issn = {0164-0313},
number = ,
volume = 12:3,
place = {United States},
year = {1993},
month = {9}
}