Upper Limit to Landau Damping in Helicon Discharges
نویسندگان
چکیده
The uncommonly high rf absorption efficiency of helicon discharges has been thought to be caused by Landau damping of helicon waves and the concomitant acceleration of primary electrons. By constructing an energy analyzer that accounts for rf fluctuations in plasma potential, it is shown that Landau-accelerated electrons are too sparse to explain the ionization efficiency. Instead, rf absorption and ionization are found to be consistent with the mechanism of mode coupling to Trivelpiece-Gould modes at the plasma boundary. [S0031-9007(99)08827-4]
منابع مشابه
Evidence for Trivelpiece-Gould modes in a helicon discharge.
The high ionization efficiency of helicon discharges has been attributed to Landau damping and mode coupling to Trivelpiece-Gould (TG) modes. Though theory predicts the importance of TG modes, they have rarely been seen. Here they were detected directly by measuring their radiofrequency current with a J-dot probe, thus supporting the contention that TG modes play a role in these enigmatic plasm...
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