Alfvenic behavior of alpha particle driven ion cyclotron emission in TFTR

Technical Report · Sat Jul 01 04:00:00 EDT 1995

DOI:https://doi.org/10.2172/93736· OSTI ID:93736

Cauffman, S; Majeski, R ^[1]; McClements, K G ^[2]

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1. Princeton Plasma Physics Lab., NJ (United States)
2. UKAEA Government Division, Oxfordshire (United Kingdom). Euratom/UKAEA Fusion Association; and others

Ion cyclotron emission (ICE) has been observed during D-T discharges in the Tokamak Fusion Test Reactor (TFTR), using rf probes located near the top and bottom of the vacuum vessel. Harmonics of the alpha cyclotron frequency ({Omega}{sub {alpha}}) evaluated at the outer midplane plasma edge are observed at the onset of the beam injection phase of TFTR supershots, and persist for approximately 100-250 ms. These results are in contrast with observations of ICE in JET, in which harmonics of {Omega}{sub {alpha}} evolve with the alpha population in the plasma edge. Such differences are believed to be due to the fact that newly-born fusion alpha particles are super-Alfvenic near the edge of JET plasmas, while they are sub-Alfvenic near the edge of TFTR supershot plasmas. In TFTR discharges with edge densities such that newly-born alpha particles are super-Alfvenic, alpha cyclotron harmonics are observed to persist. These results are in qualitative agreement with numerical calculations of growth rates due to the magnetoacoustic cyclotron instability.

• Research Organization: Princeton Univ., NJ (United States). Plasma Physics Lab.
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: AC02-76CH03073
• OSTI ID: 93736
• Report Number(s): PPPL--3119; ON: DE95016254
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ALFVEN WAVES
CYCLOTRON INSTABILITY
INSTABILITY GROWTH RATES
MAGNETOACOUSTIC WAVES
PULSED D-T REACTORS
TFTR TOKAMAK