Identifying the Structure of Whistler Wave Excitation in a Laboratory Plasma

Tuesday, 15 December 2015
Poster Hall (Moscone South)
Xin An1, Bart Van Compernolle1, Jacob Bortnik1, Richard M Thorne1 and Lunjin Chen2, (1)University of California Los Angeles, Los Angeles, CA, United States, (2)University of Texas at Dallas, Richardson, TX, United States
The excitation of whistler waves is studied with a gyrating electron beam injected into a cold plasma in a controlled laboratory environment. The mode structure of whistler wave excitation is identified using a phase-correlation technique. It is shown that whistler waves are excited through Landau resonance, cyclotron resonance and anomalous cyclotron resonance. The dominant wave mode excited through cyclotron resonance is nearly parallel-propagating, whereas wave modes excited through Landau resonance and anomalous cyclotron resonance can propagate close to the resonance cone. Linear analysis on wave growth rate captures the major resonance modes in the experiment. The results have implications for the generation process of whistler waves in the Earth's inner magnetosphere.