AMPTE observations and simulation results

Abstract One of the main experiments of the Active Magnetospheric Particle Explorers (AMPTE) satellite experiments was the release of neutral atoms which ionized by photoionization, creating artificial expanding plasmas in the solar wind. In the experiments carried out diamagnetic cavities were produced which interrupted the solar wind flow. In this paper we examine how the newly created expanding plasma couples to the solar wind by means of electromagnetic instabilities driven by unstable velocity space ion distributions. In particular we show how lower-hybrid waves are generated from the unstable ion distributions and how these waves can produce high energy electron tails. The development of the diamagnetic cavity and the barium cloud was also analysed using a 2-D hybrid code. The experimental results will be compared with theory and a computer simulation of the electron acceleration and heating in the microturbulence.