Observation of a current‐driven plasma instability at the outer zone‐plasma sheet boundary

摘要: Several spacecraft experimenters have reported on the detection of large temporal variations in trapped electron fluxes near L ≃ 5–6 at midlatitudes night hemisphere. In this report we describe detail particle, wave, and field changes measured when Ogo 5 traversed an outer-zone trapping boundary type September 7, 1968. It is shown that thermal proton concentrations E > 50-kev abruptly decreased electrons with (1–4) kev mean energy were detected. also currents flowed along average geomagnetic direction plasma boundaries these accompanied by intense VLF electrostatic waves. proposed turbulent resistivity produced current-driven instabilities allows parallel dc electric fields to develop boundary. Some local temperature are discussed terms resistive heating, but it noted charging phenomena might partially account for observed shifts.