New plasma measurements with a multichannel millimeter-wave fluctuation diagnostic system in the DIII-D tokamak (invited)

Journal Article · Fri Oct 15 00:00:00 EDT 2010 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/1.3466900· OSTI ID:22055815

Hillesheim, J C; Peebles, W A; Rhodes, T L; Schmitz, L; Carter, T A ^[1]; White, A E ^[2]

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1. Department of Physics and Astronomy, University of California, Los Angeles, Los Angeles, California 90095-1547 (United States)
2. Massachusetts Institute of Technology, Cambridge, Massachusetts 02139-4307 (United States)

A novel multichannel, tunable Doppler backscattering (DBS)/reflectometry system has recently been developed and applied to a variety of DIII-D plasmas. Either DBS or reflectometry can be easily configured for use in a wide range of plasma conditions using a flexible quasi-optical antenna system. The multiple closely spaced channels, when combined with other fluctuation diagnostic systems, have opened up new measurements of plasma properties. For example, the toroidal and fine-scale radial structure of coherent plasma oscillations, such as geodesic acoustic modes, have been probed simultaneously in the core of high temperature plasmas by applying correlation analysis between two toroidally separated DBS systems, as well as within the multichannel array. When configured as a reflectometer, cross-correlation with electron cyclotron emission radiometry has uncovered detailed information regarding the crossphase relationship between density and temperature fluctuations. The density-temperature crossphase measurement yields insight into the physics of tokamak turbulence at a fundamental level that can be directly compared with predictions from nonlinear gyrokinetic simulations.

• OSTI ID: 22055815
• Journal Information: Review of Scientific Instruments, Vol. 81, Issue 10; Other Information: (c) 2010 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0034-6748
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
ANTENNAS
BACKSCATTERING
CYCLOTRONS
DOPPLER EFFECT
DOUBLET-3 DEVICE
ELECTRON EMISSION
FLUCTUATIONS
HOT PLASMA
MEASURING METHODS
NONLINEAR PROBLEMS
OSCILLATIONS
PLASMA DIAGNOSTICS
PLASMA WAVES
SIMULATION