EXPERIMENTAL STUDIES OF THE RADIAL DIFFUSION OF ENERGETIC ELECTRONS IN LOWER-HYBRID WAVE HEATED PLASMAS IN THE ALCATOR-C TOKAMAK

被引:10
|
作者
KNOWLTON, S [1 ]
PORKOLAB, M [1 ]
TAKASE, Y [1 ]
机构
[1] MIT, CTR PLASMA FUS, CAMBRIDGE, MA 02139 USA
关键词
D O I
10.1063/1.870748
中图分类号
O35 [流体力学]; O53 [等离子体物理学];
学科分类号
070204 ; 080103 ; 080704 ;
摘要
An upper limit for the cross-field spatial diffusion coefficient of energetic electrons in moderate density tokamak discharges has been measured, The energetic electrons were generated by square wave-modulated lower-hybrid (LH) wave injection. The decay of the fast electron population for electron energies epsilon(d) greater-than-or-equal-to 100 keV following LH radio-frequency (RF) power shutoff was inferred from the time dependence of the radial profiles of the hard x-ray bremsstrahlung emission. The experimental results were fitted to a diffusive model that includes collisional losses and electric field acceleration. The fast electron diffusion coefficient consistent with the data is D(f) less-than-or-equal-to 0.2 M2/s, at least in the inner half of the plasma. The corresponding global confinement time of the energetic electrons is estimated to be at least a factor of 2 greater than the energy confinement time of the bulk plasma in discharges of density n(e)BAR = 8 X 10(19) m-3.
引用
收藏
页码:891 / 900
页数:10
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共 28 条
  • [1] ENERGY CONFINEMENT STUDIES OF LOWER HYBRID CURRENT DRIVEN PLASMAS IN THE ALCATOR-C TOKAMAK
    TAKASE, Y
    BONOLI, PT
    KNOWLTON, S
    PORKOLAB, M
    TEXTER, S
    FIORE, C
    MCCOOL, S
    MCDERMOTT, S
    TERRY, J
    [J]. NUCLEAR FUSION, 1987, 27 (01) : 53 - 64
  • [2] OBSERVATION OF LOWER-HYBRID CURRENT DRIVE AT HIGH-DENSITIES IN THE ALCATOR-C TOKAMAK
    PORKOLAB, M
    SCHUSS, JJ
    LLOYD, B
    TAKASE, Y
    TEXTER, S
    BONOLI, P
    FIORE, C
    GANDY, R
    GWINN, D
    LIPSCHULTZ, B
    MARMAR, E
    PAPPAS, D
    PARKER, R
    PRIBYL, P
    [J]. PHYSICAL REVIEW LETTERS, 1984, 53 (05) : 450 - 453
  • [3] THEORETICAL-STUDIES OF LOWER HYBRID CURRENT DRIVE IN THE ALCATOR-C TOKAMAK
    BONOLI, PT
    PORKOLAB, M
    ENGLADE, R
    [J]. AIP CONFERENCE PROCEEDINGS, 1985, (129) : 139 - 141
  • [4] STABILIZATION OF SAWTEETH BY LOWER HYBRID WAVES IN THE ALCATOR-C TOKAMAK
    KNOWLTON, S
    PORKOLAB, M
    TAKASE, Y
    [J]. NUCLEAR FUSION, 1988, 28 (01) : 99 - 106
  • [5] ENERGY CONFINEMENT STUDIES OF LOWER HYBRID CURRENT DRIVEN DISCHARGES IN THE ALCATOR-C TOKAMAK
    KNOWLTON, S
    BONOLI, P
    FIORE, C
    MCCOOL, S
    MCDERMOTT, S
    PORKOLAB, M
    TAKASE, Y
    TEXTER, S
    [J]. AIP CONFERENCE PROCEEDINGS, 1985, (129) : 122 - 130
  • [6] ENGINEERING ASPECTS OF LOWER HYBRID MICROWAVE INJECTION INTO THE ALCATOR-C TOKAMAK
    SCHUSS, JJ
    PORKOLAB, M
    GRIFFIN, D
    BARILOVITS, S
    BESEN, M
    BREDIN, C
    CHIHOSKI, G
    ISRAEL, H
    PIERCE, N
    REISER, D
    RICE, K
    [J]. NUCLEAR TECHNOLOGY-FUSION, 1983, 4 (02): : 1413 - 1417
  • [7] LOWER-HYBRID RF HEATING OF MIT VERSATOR-II AND ALCATOR-C TOKAMAKS
    PORKOLAB, M
    BEKEFI, G
    PARKER, R
    BERNABEI, S
    MOTLEY, R
    HOOKE, WM
    [J]. BULLETIN OF THE AMERICAN PHYSICAL SOCIETY, 1978, 23 (05): : 679 - 680
  • [8] RADIAL FLUXES DUE TO RESONANT ELECTRONS IN LOWER-HYBRID CURRENT DRIVE TOKAMAK
    XIA, MF
    WU, WM
    [J]. PLASMA PHYSICS AND CONTROLLED FUSION, 1987, 29 (05) : 621 - 637
  • [9] ENERGY CONFINEMENT OF THE HIGH-ENERGY TAIL ELECTRONS DURING LOWER HYBRID CURRENT DRIVE EXPERIMENTS ON THE ALCATOR-C TOKAMAK
    TEXTER, S
    PORKOLAB, M
    BONOLI, PT
    KNOWLTON, S
    TAKASE, Y
    [J]. PHYSICS LETTERS A, 1993, 175 (06) : 428 - 432
  • [10] NUMERICAL MODELING OF LOWER HYBRID RF HEATING AND CURRENT DRIVE EXPERIMENTS IN THE ALCATOR-C TOKAMAK
    BONOLI, PT
    PORKOLAB, M
    TAKASE, Y
    KNOWLTON, SF
    [J]. NUCLEAR FUSION, 1988, 28 (06) : 991 - 1012