Diagnostics for investigation of magnetic reconnection in sawtooth crash on TFTR

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

DOI:https://doi.org/10.1063/1.1143637· OSTI ID:7009121

Yamada, M; Nagayama, Y; Davis, W; Fredrickson, E; Janos, A ^[1]; Levinton, F ^[2]

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1. Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States)
2. Fusion Physics and Technology, Torrence, California 90503 (United States)

Magnetic reconnection phenomena are documented by a set of noninvasive fast diagnostics during the crash phase of sawtooth oscillations. The electron cyclotron emission diagnostic system provides the highest resolution for measuring time evolution of electron temperature profile during a typical Tokamak Fusion Test Reactor fast sawtooth crash. The x-ray tomography also contains fast time scale information of the electron temperature profile and additionally the impurity concentration. Just before the crash, a shrinking circular hot peak and growing crescent-shaped flat island appear in the inside of the inversion radius on a bird's-eye view of the electron temperature profile. The electron temperature gradient inside the inversion radius diminishes to nearly zero after the crash. Concomitantly, {ital q}({ital r}) profile ({ital q}({ital r})=local safety factor) is measured by the motional stark effect (MSE) diagnostics to verify a magnetic field line reconnection during the sawtooth oscillation. Initial MSE data indicate that central {ital q} values increases by 5%--10% during the sawtooth crash phase even when the pressure gradient diminishes inside the {ital q}=1 region.

• DOE Contract Number: AC02-76CH03073
• OSTI ID: 7009121
• 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-)
ACCELERATORS
CHEMICAL ANALYSIS
CLOSED PLASMA DEVICES
CYCLIC ACCELERATORS
CYCLOTRONS
ELECTROMAGNETIC RADIATION
ELECTRON EMISSION
ELECTRON TEMPERATURE
EMISSION
HEAT FLOW
IONIZING RADIATIONS
MAGNETIC RECONNECTION
NBI CYCLOTRON
NONDESTRUCTIVE ANALYSIS
PLASMA DIAGNOSTICS
RADIATIONS
SOFT X RADIATION
STARK EFFECT
TFTR TOKAMAK
THERMONUCLEAR DEVICES
TOKAMAK DEVICES
X RADIATION
X-RAY EMISSION ANALYSIS