Development of the excitation system of Alfvén waves in TCABR .

Author(s)

Edson Moriyoshi Ozono

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto de Física (IF/SBI)
• Defense date: 2000-08-28

Examining board members

Ricardo Magnus Osorio Galvao; Homero Santiago Maciel; Jiro Takahashi; Mario Ueda; Alvaro Vannucci

• Advisor: Ricardo Magnus Osorio Galvao

Abstract

The design, construction, instalation, and testing of the system for excitation of Alfvén waves in the TCABR tokamak is described. The antenna system is based upon poloidal circular rings around the plasma column in order to guarantee the excitation of a wave spectrum highly peaked around the poloidal wavenumber M = l. The antenna system is fed by a four-phase oscillator, capable of delivering lMW pulses in the frequency range from 3 to 6MHz. The oscillator has four outputs with fixed phases 0, /2, e 3 /2, so that the phase shift between different antenna elements can be conveniently varied. This feature allows exciting a rather pure spectrum of travelling waves with toroidal wavenumber N = ±2, ±4 and ± 6. A module of the antenna system was constructed, installed, and tested in the TCABR tokamak. The results of the first discharges with Alfvén wave heating obtained with the module are presented and analysed. (AU)