High-density hydrogen-plasma production in a simple torus using helicon waves

High-density hydrogen-plasma production in a simple torus using the m=+1 azimuthal mode of helicon waves is investigated. The measured dispersion relation of helicon waves in the high-density region shows deviation from that of the m=+1 mode derived using a uniform-plasma dispersion relation. The dispersion relation is calculated for the parabolic, modified-parabolic density profiles, and for a uniform plasma with a vacuum region.