Observation of whistler wave resonances in laboratory plasma

Standing whistler wave have been investigated in the NRL Space Physics Simulation Chamber. Partial reflection of antenna-launched whistler waves from the chamber end boundaries creates a combination of standing and traveling waves. By controlling the axial magnetic field profile, cyclotron absorption of whistlers can occur before reflection, leaving only the forward propagating waves. By comparing standing wave amplitudes to the forward propagating, cavity Q's in excess of 30 have been observed. Under uniform axial magnetic field conditions, the addition of planar conducting grids near the ends of the plasma column improves reflection and increases the value of Q.