Phenomenology of intense electron cyclotron emission bursts during high power neutral beam heating on TFTR (abstract)

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

DOI:https://doi.org/10.1063/1.1143636· OSTI ID:7009122

Taylor, G ^[1]; Bush, C E ^[2]; Fredrickson, E; Park, H K; Ramsey, A T ^[1]

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1. Princeton University, Princeton, New Jersey 08543 (United States)
2. Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830 (United States)

A 20-channel grating polychromator has been used to study intense bursts of electron cyclotron emission (ECE) from TFTR deuterium plasmas predominantly heated by 90--110-keV neutral beams ({ital P}{sub inj}/{ital P}{sub oh}{gt}30). The ECE bursts have a duration of 20--150 {mu}s and are usually seen 300--500 ms after the start of neutral beam injection, when the stored energy and neutron production are collapsing or rolling over. In most cases the ECE bursts have {Delta}{ital f}/{ital f}{similar to}0.2--0.5, if this frequency spread is due entirely to relativistic broadening it implies an electron energy of 10--100 keV (Core electron temperatures in these plasmas are typically 7--12 keV). The ECE bursts are often correlated with ELM activity during limiter H modes and appear to occur at the beginning of the rise in the {ital D}{sub {alpha}} signal. In some instances the spectral width of the ECE burst is narrow enough ({Delta}{ital f}/{ital f}{similar to}0.1) to allow identification of the origin of the emission, in these cases the source appears to be within 0.2 m of the plasma edge and the ECE burst exhibits a delay characteristic of an outwardly directed velocity of 2--3{times}10{sup 3} m/s. This work is supported by U.S. Department of Energy Contract No. DE-AC02-76-CHO-3073.

• DOE Contract Number: AC02-76CH03073
• OSTI ID: 7009122
• 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 HEATING
BREMSSTRAHLUNG
CLOSED PLASMA DEVICES
CYCLOTRON RADIATION
DEUTERIUM
ELECTROMAGNETIC RADIATION
HEATING
HYDROGEN ISOTOPES
ISOTOPES
LIGHT NUCLEI
LINE WIDTHS
NUCLEI
ODD-ODD NUCLEI
PLASMA HEATING
RADIATIONS
STABLE ISOTOPES
TFTR TOKAMAK
THERMONUCLEAR DEVICES
TOKAMAK DEVICES