Laboratory Modeling of the Nonstationary Electron Beam Interaction with Magnetized Plasma

We present the results of experimental study of the mechanisms of interaction of nonstationary electron beams with magnetized plasma under conditions where typical durations τ of electon bunches satisfy the relation fLH ≪ 1/τ < fc < fp, where fLH is the lower-hybrid frequency, fc is the electron-cyclotron frequency, and fp is the plasma frequency. It is demonstrated that the electromagnetic responses occurring in the magnetized plasma due to the intrusion of such beams are transported by whistler-mode waves. It is shown that these responses are of different nature. Namely, the transition radiation occurring in the vicinity of the point of injection of the pulsed beam into the plasma is a packet of quasi-longitudinal whistler-mode waves, while the electromagnetic response excited in a rarefied plasma is due to the Čerenkov resonance with the pulsed beam.