Laboratory study on ion cyclotron waves and their relation to auroral arcs

The response of a collisionless, fully ionized and magnetized plasma to an electron drift is investigated. A barium Q-machine plasma in which the temperature is less than the electron temperature is used. The ion response, that is, density and energy, is determined optically electron energy is determined with an analyzer, and potential fluctuation with a capacitive probe. The electron drift destabilizes ion cyclotron waves, which heat the ions and depress the density. The plasma potential is changed drastically, both in space and time. It is found that electrons are accelerated on the time scale of the wave period as well as on a steady state basis. A comparison is made between the results and measurements in the polar magnetosphere above auroral arcs