Electron cyclotron resonance heating experiments in the GAMMA 10 tandem mirror

Two aspects of ECRH experiments in the GAMMA 10 tandem mirror are described. One is hot electron production in a minimum-B anchor cell by second harmonic ECRH. When a resonance region is located at the centre of the anchor cell, hot electrons are piled up near the centre region and the β-value attains more than 20%. For off-centre resonance, hot electrons have a spatial profile like a baseball seam. This profile is explained by a drift orbit of an electron in a minimum-B field. The other topic is observation of an intense axial electron flow with energy from hundreds of eV to a few keV generated by fundamental ECRH in the end cells. The force due to the fundamental ECRH driving heated electrons into the mirror loss cone is particularly strong. A bounce averaged Fokker-Planck code with a quasi-linear diffusion operator reproduces the electron flow with the same energies. The electron flow is a predominant ingredient for generation of the electrostatic potential in the GAMMA 10.