Temporal evolution of HF-enhanced plasma lines

Abstract

A theoretical investigation is conducted of the temporal evolution of HF-enhanced plasma lines (HFPLs). An extended theoretical model is presented which was originally intended to explain the intensity overshoot of the high frequency enhanced plasma line (HFPL). The extension takes into consideration the fact that nonresistant heating of plasma electrons by the parametrically excited Langmuir waves can yield an apparent increment in electron temperature. It is pointed out that the HFPLs refer to the radar echoes at frequencies near the sum and difference of the radar frequency and the HF heater wave frequency. It is suggested that backscatter of radar signals from plasma waves having a wavenumber of 18/m cause the enhanced spectral lines.