VELOCITY-SHEAR-DRIVEN ION-CYCLOTRON WAVES AND ASSOCIATED TRANSVERSE ION HEATING

Recent sounding rocket experiments, such as SCIFER, AMICIST, and ARCS- 4, and satellite data from FAST, Freja, DE-2, and HILAT, provide compe lling evidence of a correlation between small-scale spatial plasma inh omogeneities, broadband low-frequency waves, and transversely heated i ons. These naturally arising, localized inhomogeneities can lead to sh eared cross-magnetic-field plasma flows, a situation that has been sho wn to have potential for instability growth. Experiments performed in the Naval Research Laboratory's Space Physics Simulation Chamber demon strate that broadband waves in the ion-cyclotron frequency range can b e driven solely by a transverse, localized electric field, without the dissipation of a field-aligned current. Significant perpendicular ion energization resulting from these waves has been measured. Detailed c omparisons with both theoretical predictions and space observations of electrostatic waves found in the presence of sheared cross-magnetic-f ield plasma flow are made.