Conceptual Design of Fundamental Harmonic Electron Cyclotron Plasma Heating System in the GOL-NB Facility

The results of modeling optimal scenario for electron cyclotron resonance (ECR) plasma heating in the GOL-NB multiple-mirror trap are presented. These results can serve as a basis for designing a system for auxiliary ECR plasma heating. Plasma heating by the extraordinary wave at the fundamental cyclotron harmonic of 70 GHz using microwave beam launched obliquely into the plasma from the high magnetic field side is demonstrated. A launching scheme is proposed that minimizes the influence of parasitic ECR in the vacuum chamber. For the basic magnetic configurations, the proposed scheme ensures ECR plasma heating with an absorption efficiency exceeding 90% in the range of on-axis plasma densities of $$(0.1{-} 4.5) \times {10^{19}}\;{{\text{m}}^{ - {\text{3}}}}$$ and an electron temperature of 20 eV. If performing special optimization, the density limit can be increased up to $$5.6 \times {10^{19}}$$ m–3.