Enhanced Plasma Uniformity in RF Plasma With Side Multihole
Capacitively coupled plasma source with side multihole is studied. Due to the hollow cathode effect at the multihole, edge plasma density is strongly increased and thus, plasma uniformity is significantly enhanced.
Experimental observation of the skin effect on plasma uniformity in inductively coupled plasmas with a radio frequency bias
Electromagnetic effects such as the skin effect, standing wave effect, and edge effect have been mainly studied in large-area, high-frequency gas discharges. In this study, we show that the skin effect can be a major factor of plasma uniformity in a high-density plasma, even if the discharge regime is in a small electrode area and under moderate excitation frequency. When a radio frequency (RF) bias power was applied to an inductively coupled plasma (ICP), the plasma density near the radial edge was largely increased and the plasma uniformity was significantly enhanced in the high-density plasma regime. This change could be understood by considering the enhanced electric field in the radial edge, the so-called skin effect. The time-dependent behavior of the plasma density and electron temperature by the bias power was also studied. When the RF bias power was applied to the ICP, the electron temperature abruptly increased due to electron heating, while variations of plasma density depending on the radial position were observed with the RF bias power in the high-density plasma of the ICP.
Pioneer 10 Observations of the Ultraviolet Glow in the Vicinity of Jupiter
A two-channel ultraviolet photometer aboard Pioneer 10 has made several observations of the ultraviolet glow in the wavelength range from 170 to 1400 angstroms in the vicinity of Jupiter. Preliminary results indicate a Jovian hydrogen (1216 angstrom) glow with a brightness of about 1000 rayleighs and a helium (584 angstrom) glow with a brightness of about 10 to 20 rayleighs. In addition, Jupiter appears to have an extensive hydrogen torus surrounding it in the orbital plane of Io. The mean diameter of the torus is about equal to the diameter of the orbit of Io. Several observations of the Galilean satellites have also occurred but only a rather striking Io observation has been analyzed to date. If the observed Io glow is predominantly that of Lyman-α, the surface brightness is about 10,000 rayleighs.