Role of Flute Modes in the GAMMA10 Tandem Mirror

Abstract

The steady state in the GAMMA10 tandem mirror, in which radial transport due to flute mode turbulence is balanced by plasma heating and production, is investigated. The basic equations used here exclude the Alfvén and acoustic modes, which are unnecessary for transport due to the flute modes. The basic equations can be applied to the magnetic divertor if the system is assumed to be axisymmetric. High-pressure effects in non-axisymmetric magnetic fields in GAMMA10 are taken into the magnetic specific volume. Numerical calculation is performed to investigate the transport process due to flute mode fluctuations. Mild plasma heating with production leads the system to a steady state, whereas strong heating with production leads the system into sawtooth-like oscillation due to strong flute mode turbulence.