TITLE

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

AUTHOR(S)
Hillesheim, J. C.; Peebles, W. A.; Rhodes, T. L.; Schmitz, L.; White, A. E.; Carter, T. A.
PUB. DATE
October 2010
SOURCE
Review of Scientific Instruments;Oct2010, Vol. 81 Issue 10, p10D907
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
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.
ACCESSION #
54858195

 

Related Articles

  • Plasma mechanisms of resonant terahertz detection in a two-dimensional electron channel with split gates. Ryzhii, V.; Satou, A.; Otsuji, T.; Shur, M. S. // Journal of Applied Physics;Jan2008, Vol. 103 Issue 1, p014504 

    We analyze the operation of a resonant detector of terahertz (THz) radiation based on a two-dimensional electron gas (2DEG) channel with split gates. The side gates are used for the excitation of plasma oscillations by incoming THz radiation and control of the resonant plasma frequencies. The...

  • Spectral analysis of Hall-effect thruster plasma oscillations based on the empirical mode decomposition. Kurzyna, J.; Mazouffre, S.; Lazurenko, A.; Albarède, L.; Bonhomme, G.; Makowski, K.; Dudeck, M.; Peradzyński, Z. // Physics of Plasmas;Dec2005, Vol. 12 Issue 12, p123506 

    Hall-effect thruster plasma oscillations recorded by means of probes located at the channel exit are analyzed using the empirical mode decomposition (EMD) method. This self-adaptive technique permits to decompose a nonstationary signal into a set of intrinsic modes, and acts as a very efficient...

  • Plasma oscillations in a slot diode structure with a two-dimensional electron channel. Ryzhii, V.; Satou, A.; Khmyrova, I.; Chaplik, A.; Shur, M. S. // Journal of Applied Physics;12/15/2004, Vol. 96 Issue 12, p7625 

    We calculate the spectrum of plasma oscillations in a diode structure with a two-dimensional electron channel in a slot between strip-like short circuited contacts. Hydrodynamic electron transport equations coupled with a two-dimensional Poissons equation for the self-consistent electric...

  • Investigation of statistical characterization of radial turbulence in the edge of HuanLiuqi-2A plasma with visible spectroscopy diagnostic. Zhong, W. L.; Duan, X. R.; Yu, D. L.; Han, X. Y.; Cheng, J.; Ding, X. T.; Liu, Yi.; Yan, L. W.; Yang, Q. W. // Physics of Plasmas;Nov2010, Vol. 17 Issue 11, p112307 

    The radial motion and structure of edge turbulence in the HuanLiuqi-2A tokamak [Y. Liu et al., Nucl. Fusion 45, S239 (2005)] was measured with visible spectroscopy diagnostic system; the radial turbulence propagation velocity and correlation length were evaluated by time-delay correlation...

  • Effects of turbulent fluctuations on density measurements with microwave reflectometry in... Mazzucato, E.; Nazikian, R. // Review of Scientific Instruments;Jan1995, Vol. 66 Issue 1, p855 

    Examines the impact of short-scale turbulence of tokamak plasmas on the measurement of plasma density with microwave reflectometry. Large amplitude and phase modulations attributed to density fluctuations.

  • Reflectometer measurements of density fluctuations in tokamak plasmas (invited). Nazikian, R.; Mazzucato, E. // Review of Scientific Instruments;Jan1995, Vol. 66 Issue 1, p392 

    Observes anomalous features in reflectometer measurements of turbulent fluctuations in tokamak plasmas. Loss of coherent reflection; Large amplitude fluctuations; Large angular divergence of reflected waves.

  • Study of Plasma Fluctuations in the TUMAN-3M Tokamak during Various Types of L�H Transitions. Askinazi, L. G.; Bulanin, V. V.; D�yachenko, V. V.; Lebedev, S. V.; Levin, L. S.; Roitershtein, V. S.; Shcherbinin, O. N. // Plasma Physics Reports;Feb2002, Vol. 28 Issue 2, p103 

    The reflectometer method is used to comparatively study plasma fluctuations in the edge plasma of the TUMAN-3M tokamak during L�H transitions initiated by different methods. It is shown that the width of the spectrum of backscattered microwave radiation is the most representative parameter...

  • Low-frequency density fluctuations in a tokamak plasma. Watterson, R. L.; Slusher, R. E.; Surko, C. M. // Physics of Fluids (00319171);Sep85, Vol. 28 Issue 9, p2857 

    CO2 laser scattering and correlation techniques are used to study low-frequency density fluctuations in plasmas in the Alcator C tokamak. Using crossed-beam correlation techniques, these fluctuations are found to have largest amplitudes near the plasma edge. In discharges with mean plasma...

  • The dynamo effect in fusion plasmas. Strauss, H. R. // Physics of Fluids (00319171);Sep85, Vol. 28 Issue 9, p2786 

    A set of reduced magnetohydrodynamic equations for mean and fluctuating fields is derived and applied to the dynamo effect in reversed field pinch (RFP) and tokamak plasmas. There are two dynamo effects, the first arising from mean field equilibrium, and the second from the fluctuations. The...

Share

Read the Article

Courtesy of THE LIBRARY OF VIRGINIA

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics