Perpendicular ion heating by velocity‐shear‐driven waves

Abstract

Perpendicular ion heating resulting from velocity‐shear‐driven ion‐cyclotron waves has been measured for the first time. The experiment was performed in the Naval Research Laboratory's Space Physics Simulation Chamber (SPSC) under plasma conditions approaching those in the natural space environment. Sheared cross‐field flow is induced by a controllable, inhomogeneous, transverse, DC electric field ( L E ∼ (1–2)ρ i ) created without drawing significant levels of magnetic‐field aligned current. Mode frequency data suggest that the most efficient heating occurs when the Doppler shifted frequency in the ion frame is located near a harmonic of the ion‐cyclotron frequency.