ECR Heating in a Helicon Device

Abstract

Abstract. This paper presents a microwave electron cyclotron resonance heating system for the linear magnetized VINETA helicon device. Thereby, a relatively cold helicon wave generated plasma is heated by resonant electron cyclotron waves. The magnetic field configuration is adjusted such that resonant energy transfer occurs locally to heat the plasma electrons. Electron temperatures of 12 eV are obtained for an Argon plasma at a pressure of 0.02 Pa. The absorption of the microwave across the resonance layer is measured with capacitive probes. Plasma parameters are characterized using compensated Langmuir probes. Additionally, a 160 GHz microwave interferometer is used to measure the line integrated plasma density. The evolution of these quantities for different microwave powers is compared to power balance computations, which indicate that the applied microwave power is dissipated by the ionization collisions; after saturation of ionization processes the power is transferred into electron kinetic energy.