SPIDER experiment includes an RF inductively coupled plasma source working at 0.3Pa of gas pressure (H/D) where plasma is generated and heated by 8 RF drivers, fed by 4 RF circuits. A single RF circuit is composed of 2 driver connected in series, attached to a capacitive matching network, fed by 200 kW 1 MHz RF oscillator through a coaxial transmission line. The knowledge of driver impedance in different experimental conditions is a valuable window for knowing the characteristics of generated plasma. To provide this opportunity in SPIDER is a difficult task since the experiment is not compatible with a direct measurement of driver impedance in plasma operation and needs to rely on suitable electrical model of the RF circuit using as input measurements at the generator. The paper reports on the progress of the development of a detailed model of the RF circuit and provides a preliminary set of results of driver impedance for various operating conditions such as RF power, gas pressure etc.
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|This work has been carried out within the framework of the EUROfusion consortium and has received funding from the Euratom research and training programme 2014-2018 and 2019-2020 under grant agreement No 633053. The views and opinions expressed herein do not necessarily reflect those of the European Commission. The views and opinions expressed herein do not necessarily reflect those of the ITER Organization.