An evaluation is made of the convective thresholds for the onset of parametric instabilities in the electron cyclotron heated Doublet III plasmas when the operating radiofrequency is 60 GHz. For heating at the fundamental frequency, the convection losses are quite strong so that threshold powers much in excess of present-day power inputs are required. At the second harmonic, the process of resonant decay into two short-wavelength electron Bernstein waves offers the minimum threshold power, which is, however, still somewhat higher than the 650 kW being currently applied.
動作高周波数が60 GHzの場合の電子サイクロトロン加熱されたDoublet IIIプラズマにおけるパラメトリック不安定性の発生のための対流閾値の評価を行う。基本周波数での加熱では、対流損失がかなり強いため、現在の投入パワーをはるかに超える閾値パワーが必要となる。第二高調波では、2つの短波長電子バーンスタイン波への共鳴崩壊のプロセスが最小の閾値パワーを与えるが、それでも現在印加されている650 kWよりはやや高い。