Plasma Physics Seminar ( Phys 769)

Bill Amatucci, NRL Experimental Investigation of Whistler and Lower Hybrid Wave Characteristics Whistler waves and lower hybrid waves are commonly found in many geophysical plasmas. The spectrum of waves is generated at frequencies from the lower-hybrid resonance up to the smaller of the electron plasma frequency or electron cyclotron frequency. There have been many interesting in situ and laboratory observations associated with whistler/lower hybrid turbulence, including artificially stimulated emissions triggered by whistler modes launched from VLF transmitters, in situ observations of lower hybrid solitary structures (LHSS), and self-ducting of large-amplitude whistler waves in the laboratory. Observations such as these have prompted an NRL Space Physics Simulation Chamber investigation of whistler/lower hybrid wave dynamics. The goals of the experiments are to reproduce spacecraft interferometric measurements of LHSS electric fields in the electrostatic regime, to investigate associated ion energization, and to study the nature of the electrostatic to electromagnetic transition of LHSS. Focus is also placed on understanding and quantifying nonlinear properties of whistler waves such as ducting, self-focusing, amplification, and wave-particle interactions. *Work supported by the Office of Naval Research and NASA.