Access count of this item: 75
|Title:||Highly time-resolved evaluation technique of instantaneous amplitude and phase difference using analytic signals for multi-channel diagnosticsa)|
Lee, H. Y.
|Author's alias:||大島, 慎介|
|Journal title:||Review of Scientific Instruments|
|Abstract:||A fluctuation analysis technique using analytic signals is proposed. Analytic signals are suitable to characterize a single mode with time-dependent amplitude and frequency, such as an MHD mode observed in fusion plasmas since the technique can evaluate amplitude and frequency at a specific moment without limitations of temporal and frequency resolutions, which is problematic in Fourier-based analyses. Moreover, a concept of instantaneous phase difference is newly introduced, and error of the evaluated phase difference and its error reduction techniques using conditional/ensemble averaging are discussed. These techniques are applied to experimental data of the beam emission spectroscopic measurement in the Heliotron J device, which demonstrates that the technique can describe nonlinear evolution of MHD instabilities. This technique is widely applicable to other diagnostics having necessity to evaluate phase difference.|
|Rights:||© 2014 AIP Publishing LLC|
|Appears in Collections:||Journal Articles|
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