Discharge regimes and density jumps in a helicon plasma source

Conference · Thu Jul 01 04:00:00 EDT 1999

OSTI ID:20050637

Shinohara, S; Yonekura, K

A high density plasma source using a helicon wave is becoming very attractive in plasma processing and confinement devices. In the previous work, the characteristics of this wave and plasma performance with diameters of 5 and 45 cm have been studied, and the helicon wave was only observed after the density jump. Recently, density jumps from the low to high electron densities with a level of 10{sup 13} cm{sup {minus}3} were investigated by changing the antenna wavenumber spectrum, and the obtained results were compared with the inductively coupled plasma (ICP). However, the mechanisms of density jumps and plasma production are still open questions to be answered. Here, the authors try to investigate the discharge regimes and density jumps in a helicon plasma source, by changing the antenna wavenumber spectrum. For he case of the parallel current directions in the antenna, where the low wavenumber spectrum part is large, the density jump was observed with the low RF input power of P{sub in} < 300 W regardless of the magnetic field. On the other hand, for the case of the opposite directions, where the low wavenumber spectrum part is small, the threshold power to obtain the jump became high with the increase in the magnetic field. This can be understood from the dispersion relation of the helicon wave. The wave structures and the dispersion relations in the discharge modes will be also shown.

• Research Organization: Kyushu Univ., Fukuoka (JP)
• OSTI ID: 20050637
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
DISPERSION RELATIONS
HELICON WAVES
MANUFACTURING
PLASMA DENSITY
PLASMA PRODUCTION
THERMONUCLEAR DEVICES