Design of a third-harmonic electron cyclotron emission diagnostic for ballooning mode fluctuations in PBX-M

Journal Article · Mon Oct 01 04:00:00 EDT 1990 · Review of Scientific Instruments; (USA)

DOI:https://doi.org/10.1063/1.1141758· OSTI ID:6351885

Woskov, P P; Kesner, J; Lane, B; Luckhardt, S; Machuzak, J S; Rhee, D Y; Cohn, D R ^[1]

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1. MIT Plasma Fusion Center, Cambridge, MA (USA)

A third-harmonic electron cyclotron emission diagnostic using ultrawide bandwidth ({approx}40 GHz) heterodyne receivers centered on 120 GHz with 14 channels per radial view is described for localized, long wavelength (5{approx lt}{lambda}{approx lt}50 cm), fast time response ({approx}1 {mu}s) fluctuation studies in the PBX-M tokamak. The optically gray emission signal will have a {gamma}{ital {tilde n}}{sub {ital e}}/{ital n}{sub {ital e}}+(3/{beta}){ital {tilde T}}{sub {ital e}}/{ital T}{sub {ital e}} dependence on temperature and density fluctuations where {gamma}{le}1 and 1{le}{beta}{le}3 depending on local optical depth. Electron temperature fluctuation sensitivity is estimated to be 0.2%{le}{ital {tilde T}}{sub {ital e}}/{ital T}{sub {ital e}} {le}2.9% depending on local optical depth and fluctuation frequency in the 0.1--1 MHz range. Spatial resolution of approximately 3 cm radially and 5 cm vertically are estimated for 2 keV plasmas with low suprathermal electron emission.

• OSTI ID: 6351885
• Journal Information: Review of Scientific Instruments; (USA), Journal Name: Review of Scientific Instruments; (USA) Vol. 61:10; ISSN RSINA; ISSN 0034-6748
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700102* -- Fusion Energy-- Plasma Research-- Diagnostics
BALLOONING INSTABILITY
CLOSED PLASMA DEVICES
CYCLOTRON RESONANCE
ELECTRON CYCLOTRON-RESONANCE
ELECTRON DENSITY
ELECTRON TEMPERATURE
HARMONICS
INSTABILITY
OPACITY
OPTICAL PROPERTIES
OSCILLATIONS
PBX DEVICES
PHYSICAL PROPERTIES
PLASMA DIAGNOSTICS
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
RESOLUTION
RESONANCE
SPATIAL RESOLUTION
THERMONUCLEAR DEVICES
TOKAMAK DEVICES