ISSN:
1089-7623
Source:
AIP Digital Archive
Topics:
Physics
,
Electrical Engineering, Measurement and Control Technology
Notes:
A broadband reflectometric system in O-mode operation has been developed for the density profile determination, MHD and turbulent fluctuation measurement, and evaluation of the particle diffusion coefficient in the JT-60 tokamak. For the profile determination, full Ka-Q band frequencies of BWOs have been swept in 750 μs, in order to minimize the effect of doppler shift due to the fluctuation of reflection layers. The heterodyne fixed-frequency reflectometer has unveiled its effectiveness to probe MHD activities, diagnosing the m=1 tearing mode oscillations. It has also enabled the observation of the dramatic suppression of edge plasma density fluctuations at the L- to H-mode transition in the LHCD limiter plasma. Furthermore, the propagation delay of density pulses has been observed by different fixed-frequency channels during a series of sawteeth, from which the particle diffusion coefficient was evaluated, with a newly proposed method applicable to fully diffusive plasmas.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.1141562
