Time dependence measurement of plasma parameters by neutral beam modulation in TEXTOR
The modulation of a neutral beam has been performed in order to study the behaviour of the plasma concerning time constants of power deposition, power transfer and power losses. The modulation of heating plasmas has been used on different tokamaks and stellarators. By studying the variation of the phase relations and amplitudes between the input power and plasma parameters at different frequencies, information concerning the different characteristic times associated with diffusion confinement or with the power transfer between particles can be obtained. This paper presents a modulation of the neutral beam power. A significant modulation of the beam current has to be achieved without modulation of the beam voltage in order to simplify the interpretation of the results. The excellent feedback system of the neutral beam injectors of TEXTOR, associated with the quality of the power supply, made this modulation possible. The set-up of the power supplies for beam modulation, first results of modulated beams into TEXTOR and preliminary interpretations of the results are presented.
Bibliographic Reference: Article: Fusion Technology 1990, Vol. 2 (1991) pp. 1151-1155
Record Number: 199111196 / Last updated on: 1994-12-02
Original language: en
Available languages: en