Objectives and design of the echo 6 electron beam experiment: large ionospheric perturbations and energetic particle patterns

This paper reports on several features of the ECHO 6 sounding rocket, launched 30 March 1983 from Poker Flat Research Range in Alaska. The electron beam interactions with the ionospheric plasma were studied using the two separately controllable electron guns and orthogonal pairs of electric probes mounted on a plasma diagnostic payload. The gun pulses produced a myriad of large electric probe signals covering the entire frequency range between dc and the system Nyquist frequency of 1250 Hz. In particular a signal driven at the 1 kHz gun frequency and a naturally occurring resonance at 840 Hz near the 799 Hz proton gyro frequency were studied. The 840 Hz and 1 kHz signals were superposed on large amplitude fluctuations and were extracted using power spectral analysis. The data contain a large variety of ion gyro range frequencies which are under study. The paper discusses the interpretation of the electric probe responses and large turbulent payload floating potential effects produced by the hot plasma generated by the beams