Characteristics of the high density plasma production by <i>m</i>=0 helicon wave

Abstract

The characteristics of the high density plasma production by the m = 0 azimuthal mode helicon wave is investigated. By varying the power of the applied radio frequency Prf two discharge modes exist; one is the low density mode (plasma density np&amp;lt;1012 cm−3), at which the discharge is sustained not by a helicon wave but by the antenna induction field at low Prf; the other is the high density mode (np≳1013 cm−3), in which helicon wave is excited at high Prf; in between the two modes, np jumps more than an order of magnitude. The threshold Prf for the density jump is higher for the m = 0 mode than that of the m = +1 and −1 modes excited by the helical antenna.