The multichannel motional Stark effect diagnostic on TFTR

Journal Article · Thu Oct 01 04:00:00 EDT 1992 · Review of Scientific Instruments; (United States)

DOI:https://doi.org/10.1063/1.1143466· OSTI ID:7250568

Levinton, F M ^[1]

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1. Fusion Physics Technology, Inc., 3547 Voyager Street, Torrance, California 90503 (United States)

Although the {ital q} profile plays a key role in theories of instabilities and plasma equilibrium, it has been quite difficult to measure until the recent development of the motional Stark effect (MSE) diagnostic. A multichannel motional Stark effect polarimeter system has recently been installed on the Tokamak Fusion Test Reactor (TFTR). The diagnostic can measure the magnetic field pitch angle ({gamma}{sub {ital p}}=tan{sup {minus}1}({ital B}{sub {ital p}}/{ital B}{sub {ital T}})) at ten radial locations. The doppler shifted {ital D}{sub {alpha}} radiation from a TFTR heating beam is viewed near tangential to the toroidal magnetic field via a re-entrant front surface reflecting mirror. The field of view covers from inboard of the magnetic axis to near the outboard edge of the plasma with a radial spatial resolution of 3--5 cm. A high throughput {ital f}/2 optics system results in an uncertainty for {gamma}{sub {ital p}} of {similar to}0.1{degree}--0.2{degree} with a time resolution of {similar to}5--10 ms. Initial pitch angle profiles from TFTR have been obtained. The MSE data is consistent with the estimated magnetic axis position from external magnetic measurements and the {ital q}=1 radius is in good agreement with the inversion radius from the electron cyclotron emission temperature measurements.

• DOE Contract Number: AC02-76CH03073
• OSTI ID: 7250568
• Journal Information: Review of Scientific Instruments; (United States), Journal Name: Review of Scientific Instruments; (United States) Vol. 63:10; ISSN RSINA; ISSN 0034-6748
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700320* -- Plasma Diagnostic Techniques & Instrumentation-- (1992-)
BEAM INJECTION
CLOSED PLASMA DEVICES
DOPPLER EFFECT
NEUTRAL ATOM BEAM INJECTION
PLASMA DIAGNOSTICS
POLARIMETERS
RESOLUTION
SPATIAL RESOLUTION
STARK EFFECT
TFTR TOKAMAK
THERMONUCLEAR DEVICES
TOKAMAK DEVICES