Minimization of the edge modes and near fields of a Travelling Wave Array antenna for WEST

TL;DR

This paper evaluates the compatibility of a Travelling Wave Array antenna with the tungsten environment of the WEST tokamak, focusing on power spectrum and near fields, and demonstrates its resilience to variations for potential fusion reactor applications.

Contribution

It introduces an assessment of TWA antenna performance in WEST, analyzing sensitivity to load and capacitor variations, and compares it to existing antennas for fusion reactors.

Findings

TWA shows high resilience to load and capacitor variations.

Power spectrum sensitivity to frequency variations is manageable.

TWA parameters are comparable or superior to WEST Q2 antenna.

Abstract

The Travelling Wave Array (TWA) antenna was proposed as a promising alternative for Ion Cyclotron Resonant Heating (ICRH) in future fusion reactors. In this study, the possibility to make a TWA compatible with a tungsten environment like the WEST tokamak is assessed. For this purpose, two aspects of the antenna are investigated: the power spectrum and the near fields excited by the antenna. The sensitivity of these parameters to load and capacitor layout variations is taken into account while satisfying a proper antenna frequency response. The sensitivity of the power spectrum to frequency variation is also investigated to allow the possibility of fast feedback of the power deposition into the core plasma of WEST. The high resilience of the TWA to these variations is demonstrated and the main parameters of the TWA expected in WEST are compared to the WEST Q2 antenna for the same loading. Possible optimizations of the TWA antenna are discussed. The present study is fully transferable to a fusion reactor like DEMO or ARC.