2004/10/20 by Genta Sato, Sato, Genta, W. Oohara +4
Engineering · Physics and Astronomy · #Magnetic confinement fusion research #Particle accelerators and beam dynamics #Plasma Diagnostics and Applications #physics.plasm-ph
paper · pdf · doi:10.48550/arxiv.physics/0410164
12th International Congress on Plasma Physics, 25-29 October 2004, Nice (France)
arxiv created 2004/10/20 · arxiv updated 2009/12/01
Radio-frequency discharges are performed in low magnetic fields (0-10 mT) using three types of helicon-wave exciting antennas with the azimuthal mode number of |m| = 1. The most pronounced peak of plasma density is generated in the case of phased helical antenna at only a few mT, where the helicon wave with |m| = 1 is purely excited and propagates. An analysis based on the dispersion relation well explains the density-peak phenomenon in terms of the correspondence between the antenna one-wavelength and the helicon wavelength. The m=+1 helicon wave propagates even in high magnetic fields where the density peaks are not observed, but the m=-1 helicon wave disappers. It is expected theoretically that the m=-1 helicon wave shows cutoff behavior in a low density region, [M. Kramer, Phys. Plasmas 6, 1052 (1999)], and the cutoff of m=-1 helicon wave experimentally observed coincides with the calculated one.