Particle and energy transport properties deduced from the dynamical response of the plasma
The dynamical response of the electron density and the electron temperature to the injection of pellets in Tore Supra is used to investigate the particle and energy transport. On the basis of the time evolution of these parameters, the transfer function of the system is estimated with an appropriate system identification method. The form of these transfer functions is such that it leads directly, and without any a priori knowledge of the system, to a representation of the transport in terms of poles (eigenvalues) and eigenmode profiles. The advantage of this procedure is that eigenvalues and eigenvectors are deduced without any restriction on the underlying processes and directly from the raw data, avoiding delicate profile treatment. The properties of these poles and eigenmodes are then used to build a model for the transport processes. The poles are common to both the density and the temperature transfer functions and each eigenmode shares two poles. This clearly demonstrates the presence of coupling between particle and heat flow. In addition, it is possible to identify those mechanisms playing a significant role and to quantify the corresponding transport coefficients.
Bibliographic Reference: Paper presented: 18th European Conference of the EPS-Plasma Physics Division, Berlin (DE), June 3-7, 1991
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Record Number: 199110381 / Last updated on: 1994-12-02
Original language: en
Available languages: en