New Mode Conversion Process and Overdense Plasma Heating in the Electron Cyclotron Range of Frequencies

摘要

Through a particle-simulation investigation, a new mode conversion process, through which an incident fast extraordinary mode (fast X mode) is converted into an electron Bernstein mode (B mode) via a slow extraordinary mode (slow X mode), is discovered in plasmas whose maximum density exceeds the cutoff density of the slow X mode. The converted B mode is found to heat the electrons efficiently in an overdense-plasma region, when a plasma has the optimum density gradient at the plasma surface.