The multichannel motional Stark effect diagnostic on TFTR

Technical Report · Wed Jul 01 04:00:00 EDT 1992

DOI:https://doi.org/10.2172/10165998· OSTI ID:10165998

Levinton, F M

Although the 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 p} = tan{sup {minus}1} (B{sub T})/(B{sup p})) at ten radial locations. The doppler shifted 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 f/2 optics system results in an uncertainty for {gamma}{sub p} of {approximately}0.1{degrees}--0.2{degrees} with a time resolution of {approximately}5--10 ms. Initial pinch angle profiles from TFTR have been obtained. The MSE data is consistent with the estimated magnetic axis position from external magnetic measurements and the q=1 radius is in good agreement with the inversion radius from the electron cyclotron emission temperature measurements.

• Research Organization: Princeton Univ., NJ (United States). Plasma Physics Lab.
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: AC02-76CH03073
• OSTI ID: 10165998
• Report Number(s): PPPL--2853; ON: DE92018435
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700320
BEAM INJECTION HEATING
CURRENT DENSITY
INCLINATION
MAGNETIC FIELD CONFIGURATIONS
PLASMA DIAGNOSTIC TECHNIQUES AND INSTRUMENTATION
PLASMA DIAGNOSTICS
POLARIMETERS
SPATIAL RESOLUTION
STARK EFFECT
TEMPERATURE MEASUREMENT
TFTR TOKAMAK